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Background: Brachiaria humidicola (Bh) has the ability to produce biological nitrification inhibitors (NIs) and release NIs from the root to the soil. Aims: To compare the effects of growing Bh with Brachiaria ruziziensis (Br, which is not able to produceNIs) on soil nitrogen (N) dynamics,Ngases and carbon dioxide (CO2) emissions and nitrifiers and denitrifiers following sheep urine application, a laboratory incubation was conducted in a He/O2 continuous flow denitrification system (DENIS). This incubation was conducted in the absence of light. Hence themeasured effects of Bh and Br on N cycling were the residual effect of biological NIs released into the soil prior to the incubation and released via root death. Methods: The treatmentswere: (1) Bhwith water application (Bh+W); (2) Bh with sheep urine (Bh + U); (3) Br with water application (Br + W); (4) Br with sheep urine (Br + U). Results: Results showed that soil NO3– concentration increased significantly in the soil with sheep urine application after the incubation. Soil nitrous oxide (N2O) and nitric oxide (NO) emissions increased immediately after the sheep urine application and peaked twice during the incubation. Cumulative emissions for the first peak were significantly lower from the Bh + U treatment (0.054 kg N ha–1) compared with the Br + U treatment (0.111 kg N ha–1), but no significant differences were observed in the total cumulative N2O and NO emissions between the Bh + U and Br + U treatment at the end of the incubation. Sheep urine addition did not affect the AOA, nirS and nosZ gene copies, but significantly increased the AOB gene copies after the incubation. Conclusions: We conclude that the residual effect of Bh to mitigate N2O emissions in a highly nitrifying soil is short-lived.

Mix pasture contains more complete nutrition for animal feed. This study aims to determine the effect of giving sheep feces compost with different fertilization doses and intervals on the productivity of mixed pastures (Clitoria ternatea and Brachiaria ruziziensis). This research was conducted in Kotangan Village, Kec. Galang, Kab. Deli Serdang North Sumatra from September to November 2020. The experimental design was used a split-plot design with two treatment factors and three replications. Factor I is the main plot, namely the fertilization interval: N1 = once every four weeks and N2 = once every two weeks. Factor II as a subplot which were doses of compost : P0 = control (without compost), P1 = compost 1 kg/plot (10 t/h), P 2 = compost 2 kg/plot (20 t/h) and P3 = compost 3 kg/plot (30t/h).The variables observed were plant height, number of leaves, number of tillers, number of branches, fresh production, dry matter, crude protein, and crude fiber. The results showed that sheep feces compost doses and different time intervals for fertilization had a significant effect (P0,05) on plant height, the number of leaves and number of branches of Clitoria ternatea, the height of Brachiaria ruziziensisas, and fresh and dry mixed pasture production. The appropriate fertilization interval was once every two weeks, and the best fertilizer dose was 3 kg/plot (30 t/h).

The control of sourgrass (Digitaria insularis (L.) Fedde) is a challenge in soybean culture, and pre-emergent herbicides appear as a management option. The objective of this work was to evaluate the control of sourgrass using pre-emergent herbicides positioned in different water regimes and amounts of straw. The experiment was carried out in a greenhouse with a completely randomized design in a 6 x 3 factorial scheme, in the first factor the water regimes were allocated and in the second the pre-emergent herbicides (diclosulam (29.4 gia ha-1); flumioxazin + imazethapyr (50 + 106 gia ha-1) and diuron + sulfentrazone (420 + 210 gia ha-1)) these factors were isolated for the amounts of corn straw + Brachiaria ruziziensis (0 and 3 t ha-1). When applied directly to the soil and on straw, diclosulam showed the lowest percentages of control in all water regimes with the first rain of 5 mm and the second of 20 mm. Diuron + sulfentrazone and flumioxazin + imazethapyr did not present significant differences in water regimes, adequately controlling the sourgrass. The effectiveness of diclosulam was influenced by drought intervals after application, diuron + sulfentrazone and flumioxazin + imazethapyr showed an efficient control of sourgrass in all treatments. O controle do capim-amargoso (Digitaria insularis (L.) Fedde) é um desafio na cultura da soja, e os herbicidas pré-emergentes surgem como opção de manejo. O objetivo desse trabalho foi avaliar o controle do capim-amargoso através de herbicidas pré-emergentes posicionados em diferentes regimes hídricos e quantidades de palha. O experimento foi realizado em casa de vegetação com delineamento experimental inteiramente casualizado em esquema fatorial 6 x 3, no primeiro fator alocou-se os regimes hídricos e no segundo os herbicidas pré-emergentes (diclosulam (29,4 g.i.a ha-1); flumioxazin + imazethapyr (50 + 106 g.i.a ha-1) e diuron + sulfentrazone (420 + 210 g.i.a ha-1)) esses fatores foram isolados para as quantidades de palha de milho + Brachiaria ruziziensis (0 e 3 t ha-1). Na aplicação diretamente no solo e sobre palha, o diclosulam apresentou as menores porcentagens de controle em todos os regimes hídricos com primeira chuva de 5 mm e segunda de 20mm. Já diuron + sulfentrazone e flumioxazin + imazethapyr não apresentaram diferenças significativas nos regimes hídricos controlando adequadamente o capim-amargoso. A eficácia do diclosulam sofreu influência dos intervalos de seca após a aplicação, diuron + sulfentrazone e flumioxazin + imazethapyr apresentaram um controle eficiente do capim-amargoso em todos os tratamentos.

Made available in DSpace on 2021-06-25T10:58:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 BACKGROUND: Corn intercropped with ruzigrass is common in Brazil, and it can improve the physicochemical features of soils, increase water retention, and suppress the emergence of resistant weeds and soil nematodes. As both corn and ruzigrass are hosts to Spodoptera frugiperda (the main corn pest in South America), the cultivation of both these plants in the same place at one time motivates investigation into the pest population dynamics. We hypothesize that the intercropping system influences S. frugiperda pressure and leaf injury in corn. Considering that if corn hybrids with high dose toxin expression are used, ruzigrass may be a potential host to susceptible S. frugiperda larvae, consequently an alternative refuge and be included as a tool for the resistant management of Bt corn. To test these hypotheses about the use of ruzigrass as an alternative host of S. frugiperda in an intercropping system with corn, we conducted field trials in three seasons to verify S. frugiperda population dynamics and leaf injury to crop systems. In addition to phenotypic evaluation, we also characterized molecularly S. frugiperda strains collected in corn and ruzigrass to identify strain differences. RESULTS: The insects collected in both corn and ruzigrass were identified as corn strains. Ruzigrass was used as a S. frugiperda host during all crop cycles. The intercropped system did not increase the S. frugiperda population or leaf injury on Bt corn. CONCLUSION: The results suggest that the intercropped system is not prejudicial to Bt corn cultivation since high dose concept applies to all larvae instars. The results also suggest that ruzigrass may be used as a promising alternative refuge in Bt corn agroecosystems, if compliance with management strategies is followed. Department of Entomology Federal University of Grande Dourados (UFGD) Department of Biostatistics Institute of Biosciences–IBB São Paulo State University (UNESP) Department of Biostatistics Institute of Biosciences–IBB São Paulo State University (UNESP)

This study compared the feed intake and performance of Yankasa sheep fed Congo grass (Brachiaria ruziziensis) basal diet with different protein supplements of Cotton Seed Cake (CSC), PalmKernel Cake (PKC), Brewer'sDriedGrain (BDG) and sole B. ruziziensis grass (control). Sixteen (16) Yankasa sheep weighing between 21.63 and 22.23kg and aged about 12 months were randomly allotted to treatment diets. The total dry matter and crude protein intake were highest (P

Rising inorganic fertilizer prices have led to return to the use of organic nutrient sources to reduce cost and improve pasture productivity. The present study determined the response of Brachiaria ruziziensis and Brachiaria mulato II to swine manure application rates: effect on biomass yield, nutritive quality and acceptability by WAD sheep. The experiment was a 3 × 2 factorial arrangement laid out as a split-plot design with three swine manure application -1rates (0, 5, 10 t ha ) as the main plot and two Brachiaria species (B. ruziziensis and B. mulato II) as the sub-plot replicated three times. Growth parameters were determined at 2, 4, 6 and 8 weeks after sowing, while dry matter yield was determined at 8 weeks after sowing. Chemical composition and in vitro gas production of the harvested grass samples were conducted and the acceptability of the forage material by WAD sheep was also determined. Results showed that B. ruziziensis was morphologically taller than B. mulato II at all weeks of growth. The heights of the plants significantly (P < 0.05) increased with increasing manure application rate at all weeks of growth. A significantly (P < 0.05) higher dry matter yield was recorded for -1B. ruziziensis than in B. mulato (6.24 vs. 4.16 t ha ). Dry matter yield of the plants increased as the rate of manure application increased. The crude protein content of both grasses increased significantly (P

This study was carried out to determine rumen dry matter degradability of Brachiaria ruziziensis (Congo grass) by cannulated Yankasa rams fed different supplements (maize offal, wheat offal, groundnut hay). The research was carried out at Polycon Research farm, Federal Polytechnic Bauchi. Four (4) cannulated Yankasa rams were used for the study, each animal was replicated three times. In-sacco method involving small nylon bags containing experimental diets were inserted into the rumen of the cannulated rams at 0 hour, with inspection at 6, 12, 18 and 24 hours. Three (3) nylon bags marked with different colours containing different treatment diets were inserted into the cannula of the rumen to test for degradability, the small nylon bags were removed at different hours (6, 12, 18 and 24 hours, respectively) to test their degradability. The supplementary treatment diets were wheat offal (WO), Maize Offal (MO) and Groundnut Hay (GH) while Brachiaria ruziziensis was fed as basal diet. The rumen degradability showed significant difference (P

En zone soudano-sahélienne, la productivité des cultures est limitée par les effets néfastes du changement climatique et la pauvreté des sols. L’insertion des plantes de couverture dans les systèmes de production pourrait être une alternative d’amélioration des rendements et de la biomasse. Pour atteindre cet objectif, la pratique conventionnelle de la culture du maïs a été comparée pendant cinq années (2014-2018), à quatre systèmes de culture associant des plantes de couverture. Le dispositif expérimental utilisé a été un bloc de Fisher avec 6 traitements en 4 répétitions. Les résultats ont montré que l’insertion du Cajanus cajan, du Stylosanthes hamata, du Brachiaria ruziziensis et Mucuna cochinchinensis dans un système de culture à base du maïs permet d’améliorer la production de biomasse fourragère sans négativement affecter son rendement. Utilisée dans la supplémentation des animaux, la biomasse produite peut nourrir pendant 90 jours 7 unités de bétail tropical (UBT) en culture pure du maïs et 8 à 13 unités de bétail tropical (UBT) en fonction du type de plantes de couverture. Dans le cadre de la production fumure organique, les mêmes tendances de variations ont été obtenues en fonction des systèmes de culture. L’insertion des plantes de couverture est un élément intégrateur agriculture-élevage.Mots clés : Changement climatique, maïs, légumineuse, biomasse fourragère, zone Soudano-sahélienne, Mali English Title: Cover crop insertion effect on productivity of maize-based cropping system in the context of crop-livestock integrationIn Sudano-Sahelian zone, crop productivity is limited by climate change effect and poor soils. Inserting cover crops into production systems could be an alternative to improve yields and biomass. To achieve this goal, conventional practice of maize cultivation was compared over a five-year period (2014-2018) with four cropping systems using cover crops. The experimental design used was a Fisher block with 6 treatments in 4 replicates. The results showed that the insertion of Cajanus cajan, Stylosanthes hamata, Brachiaria ruziziensis and Mucuna cochinchinensis in a maize-based cropping system improves biomass production without negatively affecting its yield. Used in animal supplementation, the biomass produced can feed 7 Tropical Livestock Units (UBT) of pure maize crop and 8 to 13 UBT for 90 days, depending on the type of cover crop. In the case of organic manure production, the same variations were obtained depending on cropping systems. The insertion of cover crops in cropping system is an integrating agriculture-livestock component.Keywords: Climate change, maize, legumes, fodder biomass, fodder biomass, Sudano-Sahelian zone, Mali.

Weeds can occur in cultivated areas, competing with crops and causing considerable losses. Herbicides are the basis of weed control; however, they are questionable due to their possible negative impacts on human health and the environment. An alternative for controlling weeds is using cover plants. This study aimed to determine the floristic composition of weeds in an Amazonian agrosystem with cover plants and to evaluate the production of biomass, the soil cover rate and the weed suppression potential of cover plants. The experimental design was in randomized blocks, in a 4 x 2 factorial scheme. The factors under study were the cover species ( Brachiaria ruziziensis , Canavalia ensiformis , Mucuna deeringiana ) and the control group that consisted of weeds, evaluated during two agricultural years (2017 and 2018), with four replicates. Digitaria horizontalis was the most important weed species and was completely suppressed by B. ruziziensis . This cover type had a large production of biomass, greater coverage of the soil and high suppression of weeds in the Amazonian agrosystem.

The aim of this study was to evaluate the use of mining co-products from the Irati (rhythmite and bituminous shale) and Corumbatai Formations (clayey siltstone) as sources of multi-nutrients for the cultivation of Brachiaria ruziziensis. The treatments were arranged within the double factorial scheme (7 × 2), completely randomized with 10 replications and placed into pots inside a greenhouse. Two factors were evaluated: the type of co-product and the soil class (Arenosol and Ferralsol). The mining co-products were applied in their isolated form and in composite (blended) form. At 60 and 140 days after the application of treatments, the ions available in the soil were determined. After that, four Brachiaria ruziziensis plants were cultivated per pot. After 40 days of cultivation, the aerial part of the plants was cut. Afterward, the macronutrients, as well as the production of shoot dry mass of the plants, were determined. The application of co-products, in general, increased the pH and the contents of ions available: K+ (Mehlich-1), Mg2+, Ca2+, P, SO42− and Si. As a highlight, at 140 days, rhythmite was the most efficient co-product in increasing pH, Ca2+ and Mg2+, with increases of 23%, 241% and 722% in Arenosol, respectively. Also at 140 days, bituminous shale increased the contents of SO42− by 72% and 427% in Ferralsol and Arenosol, respectively. Moreover, the accumulation of K, Ca, Mg and S, as well as the production of shoot dry mass of Brachiaria improved with the application of the co-products. In conclusion, the application of mining co-products alters the chemical attributes of both the soil and the plant, and this favors the production of shoot dry mass of Brachiaria, which demonstrates the potential to be a clean environmental solution to soil fertilization.

The objective of this research is to evaluate the impact of soil management and localized irrigation techniques on water use efficiency in the cultivation of cauliflower. The treatments consisted of 4 different types of soil management: Direct seeding using crotalaria and brachiaria cover crops, a treatment used both in conjunction, and another that employed a conventional system. Two different irrigation techniques were used: Surface and subsurface. The experimental design was completely random in a factorial arrangement (4x2) with four repetitions. Each experimental unit was composed of 20 cauliflower plants, with a density of 1.8 m between rows and 0.5 m between plants. The experiment was carried out in two stages; the first stage consisted of the establishment of the cover crops and the second stage of the planting of cauliflower cv. Avenger in the different treatments. The cover species were cut at ground level 108 days after they had been sown. The cauliflower seedlings were grown in a protected environment and transplanted after 21 days. Irrigation was managed through the use of tensiometry. Water use efficiency was the variable that was analyzed; the Tukey Test at 5% level of probability was applied to the data that was obtained. A combined use of crotalaria/brachiaria cover crops with subsurface drip irrigation is recommended; this was the combination that most efficiently saved water. Key words: Brassica oleracea cv. botrytis, Crotalaria ochroleuca, Brachiaria ruziziensis, soil management, irrigation.

O manejo cultural nas estrelinhas do cafeeiro pode influenciar diretamente na produtividade da cultura. Objetivou-se com este trabalho avaliar o crescimento inicial de clones de cafeeiro robusta, irrigados por gotejamento, submetidos a diferentes manejos culturais nas entrelinhas. A área de pesquisa foi conduzida em uma lavoura cafeeira com 30 dias de transplantada até aproximadamente 12 meses, adotando-se delineamento experimental em blocos casualizados, com cinco repetições. Os tratamentos foram constituídos por cinco cultivos distintos nas entrelinhas do cafeeiro: vegetação espontânea (plantas daninhas), milho e feijão em sucessão, estilosantes campo grande, Brachiaria ruziziensis e ausência de vegetação (limpo). Avaliaram-se as características biométricas do cafeeiro: altura de planta, diâmetro da copa, diâmetro do caule, e número de ramos plagiotrópicos do cafeeiro; a densidade, umidade e porosidade do solo até os 0,40 m de profundidade; índice de Clorofila Falker e trocas gasosas entre as 7h-18h. O manejo com vegetação espontânea e B. ruziziensis interferiram negativamente no diâmetro da copa e nos índices de clorofila do cafeeiro. Maiores valores de transpiração (2,67 mmol m-2 s-1) foram observados na ausência de cobertura, e os menores valores (2,19 mmol m-2 s-1) no cultivo com milho e feijão em sucessão. As trocas gasosas não são influenciadas pela presença do consórcio cultural nas entrelinhas e, são mais efetivas no início da manhã e final da tarde. Pode-se adotar manejos com estilosantes; milho e feijão em sucessão; e ausência de vegetação nas entrelinhas do cafeeiro em fase de formação.

Aim: A study was conducted at the Research and Experimental Farm (REF) of the University of Dschang between March 2015 and December 2016, and then at the Animal Nutrition Laboratory of the Faculty of Agronomy and Agricultural Sciences. The objective of this study was to evaluate the direct and residual effects of fertilization with hen droppings on the protein content of Brachiaria ruziziensis at different phenological stages. Methodology: A factorial design comprising five levels of fertilization in terms of nitrogen in the form of hen droppings (0, 25, 50, 75 and 100 kg N/ha), and three phenological stages of cutting (bolting, flowering and after seed set) on 6 m2 plots (3 m x 2 m) in four replicates, i.e. a total of 60 experimental plots was used. Fertilization with hen droppings was done one month after the stump chips were grown in the first year of cultivation (direct effects). In the second year of cultivation (residual effects), no fertilization was applied. The total nitrogen content of the plant samples was determined by the Kjeldhal method and the crude protein contents were obtained by multiplying the nitrogen contents by the forage-specific coefficient of 6.25. Results: This study showed that protein contents obtained under the direct effect were significantly higher than those obtained under the residual effect of fertilization. Fertilization at 100 kg N/ha resulted in the highest protein contents under direct and residual fertilization. Conclusion: In view of the results obtained, fertilization with hen droppings at a dose of 100 kg N/ha would be recommended for the cultivation of B. ruziziensis in order to limit mineral fertilizer inputs and improve its protein content.

Soybean [Glycine max (L.) Merrill] is a major grain-legume used in rotation with cereal crops throughout the world. However, little is known about the soybean-based crop rotations effects on potassium (K) efficiency and its cycling capacity in soil. Therefore, a field study was carried out over 2 years to assess K cycling and which soil depth contributes to K uptake in first soybean crop as well as in the following crop rotation within the same rainfed growing season. Four rotations were evaluated, including (1) soybean-fallow, (2) soybean-ruzigrass (Brachiaria ruziziensis), (3) soybean-corn (Zea mays L.), and (iv) soybean-intercrop (corn and ruzigrass). Rubidium (Rb) was used as a K tracer and applied at the depths of 0, 0.3, and 0.6 m. For soybean, 60% of the K was taken up from the shallow soil layer, whereas the depths of 0.3 and 0.6 m accounted for 25 and 15%, respectively. In the second crop, ruzigrass monoculture and intercrop enhanced K uptake (41–302 kg ha−1) relative to the corn monoculture, and most of the K originated from a soil depth of 0.3–0.6 m, with average values of 40 and 34%, respectively. The K cycled from soybean residue contributed between 1 and 13% of the total nutrient cycling. In the soybean crop, most of the K was taken up from the upper soil layer. The soybean-intercrop rotation was the best pathway for allying the benefits of high K-cycling grass with the production of a cash crop.

Aim: A study was conducted at the Research and Experimental Farm (REF) of the University of Dschang with the aim of evaluating the direct and residual effects of fertilization with hen droppings on the growth and biomass yield of Brachiaria ruziziensis at flowering. Methodology: A factorial design with five levels of fertilization in terms of nitrogen in hen droppings (0, 25, 50, 75 and 100 kg N/ha) on 6 m2 (3 m x 2 m) plots in four replicates, i.e. a total of 20 experimental plots was used. Fertilization with hen droppings was done one month after the placement of the stump chips, during the first year of cultivation (direct effects). In the second year of cultivation (residual effects), no fertilization was done. Measurements of plant heights and diameters were made on 40 plants per level of fertilization. Leaf, stem and whole-plant biomass assessments were made on all plots in relation to their fertilization levels. Results: This study shows that the direct effect of fertilization in the form of hen droppings resulted in heights and diameters significantly greater than those obtained under the residual effect of fertilization. Biomasses of whole plants and their different compartments obtained under the residual effect of fertilization were significantly higher than those obtained under the direct effect of fertilization. Under the direct and residual effect of fertilization, the heights, diameters and biomasses of the fertilized plots were greater than those of the control plots. The level of fertilization corresponding to the dose of 100 kg N/ha gave the best results. Conclusion: Fertilization with hen droppings at a dose of 100 kg N/ha would be recommended for the cultivation of B. ruziziensis over a two-year period, in order to limit the use of mineral fertilizers.

Inclusion of some plants especially spices in the diets of farm animals have been researched upon extensively for parameters like growth, blood chemistry, and feed utilization among others. In contrary, the use of turmeric as feed additive for ruminant production is so low, while its effects on reproduction (especially during pregnancy) in ruminants are not available due to little/no information on its properties, processing, and inclusion rate. Thus, a study was conducted to evaluate pre- and post-weaning performances of kids produced by three breeds of goat fed diets supplemented with graded levels of turmeric powder intensively in southwestern Nigeria. Kids produced by Kalahari Red (KR), West African Dwarf (WAD), and KalaWAD Does fed diets containing turmeric powder (TP) at different levels were monitored for pre-weaning that lasted for 12 weeks, while selected kids were observed for 4 weeks post-weaning. Each Doe breed was fed diet at 5% bodyweight during pregnancy and pre-weaning, including some selected kids during post-weaning. Dietary treatments included concentrate diet (CD) as TP-0, CD + 2 g/kg TP as TP-2g, and CD + 5 g/kg TP as TP-5 g. Brachiaria ruziziensis was used as basal diet. Data obtained were arranged in a 3 × 3 factorial layout in a completely randomized design, while analysis of variance was done using SAS 9.1. Significance level was taken at 5% probability, while means were separated using Duncan’s multiple range test of the same statistical package. Results of the study for breed effect revealed that KR kids had the best (p < 0.05) pre-weaning performance from birth (3.2 kg) till weaning (14.5 kg) and for weight gains (11.2 kg and 134.0 g/day). No mortality was recorded for WAD kids. For TP effects, the kids fed TP-2g had the highest (p < 0.05) weight gains (1.6 kg and 58.6 g/day) and reduced value for feed conversion ratio (FCR) of 6.2 for post-weaning performance. Kids fed TP-5g had the highest (p < 0.05) value for protein efficiency ratio (PER) of 1.4 at the end of post-weaning. For interaction effects of breeds and TP, KR kids fed TP-5g performed best (p < 0.05) at the pre-weaning period in terms of weights from birth (3.6 kg) till weaning (15.7 kg), while KR kids fed TP-2g had highest (p < 0.05) pre-weaning weight gains (12.5 kg and 148.9 g/day). KR kids fed TP-5g performed best (p < 0.05) at the post-weaning period in terms of weight gains (1.8 kg and 64.4 g/day). KR kids fed TP-2g and KalaWAD kids fed TP-5g had the lowest FCR (5.2) and the highest PER (1.6) respectively at the post-weaning period. It can be concluded that breeds of kid, TP inclusion, and their interaction influenced pre- and post-weaning performances of the kids.

Background Great efforts have been made to identify grasses that are resistant to spittlebugs (Hemiptera: Cercopidae). However, the time required to develop and launch new cultivars is relatively long. The employment of resistance inducers is a current strategy that may be useful for the control of insect pests. This analysis evaluates the feasibility of using the chemical inducers silicon and nitric oxide to increase spittlebug resistance based on changes in forage grass vegetative characteristics and the biological traits of Mahanarva spectabilis (Distant, 1909). Results Mahanarva spectabilis nymphs and adults can cause significant damage to forage grasses. Furthermore, silicon and nitric oxide inducers were not sufficient to lessen this damage by positively influencing the growth and development of forage grasses. These inducers did not negatively alter the biological parameters of M. spectabilis or diminish its population. However, phenolic compound concentrations increased when forage grasses were treated with silicon or attacked by adult insects, but this parameter was not useful to predict spittlebug resistance. This fact suggests that the physiological and biochemical changes caused by silicon should be further studied. Conclusion The current analysis demonstrated that application of the chemical inducers silicon and nitric oxide is currently not a viable strategy for the effective and economic management of M. spectabilis on Brachiaria ruziziensis, Pennisetum purpureum and Digitaria sp. © 2019 Society of Chemical Industry.

Appropriate methods of mutation induction are of high importance in pastures for increased genetic variability and improved performance. The objective of this research was to improve the agronomic and nutritive performance of mutant lines (M7) through induced mutagenesis to seeds of a local landrace Brachiaria ruziziensis. The seeds were irradiated with 0, 10, 20, 30 and 40Gy doses of gamma radiation from Cobalt 60 (60Co). Treatments were; KE 0Gy, KE 10Gy, KE 20Gy, KE 30Gy and KE 40Gy resulting into M1 seeds. The M1 seeds were planted in the greenhouse in germination pots for one month and the seedlings transplanted to the field. Seeds of M6 plants (M7 seeds) were used to establish field experiment in a completely randomized block design, with three replications. Parameters measured included; tillering, leaf-stem ratio, dry matter weight, and seed weight. Data collected was analyzed using the SAS package. Mutant lines exhibited better agronomic performance compared to the wild type. Performance increased with increased gamma-ray exposure with 40Gy treatment outperforming all other treatments whereas the control performed dismally. There was a significant difference (P0.05) in the dry matter with 40Gy treatment having the highest values of dry matter yields, whereas control had the lowest values. Application of nuclear technology to other grasses would lead to increased biomass and improved nutrition for increased animal productivity leading to food and nutrition security.

Background Several factors may degrade pastures, in particular, inadequate nutrient application and spittlebug attacks. Mahanarva spectabilis (Distant, 1909) (Hemiptera: Cercopidae), one of the species that occur in Brazil, is a limiting pest in forage production. This study analyzes the influence of fertilization with the macronutrients nitrogen, phosphorus and potassium (NPK) on the survival of M. spectabilis nymphs, and the effects of damage by nymphs and adults on the production, quality and regrowth capacity of the forages Brachiaria ruziziensis, Pennisetum purpureum and Digitaria sp. Results Fertilization of the forages differentially affected damage due to spittlebug herbivory. Attacks by nymphs and adults decreased chlorophyll content, plant regrowth and forage quality, and increased injury, regardless of fertilization. The availability of nutrients in the soil not only decreased fiber content, but also increased crude protein, chlorophyll content and regrowth, even when pest infested. Soil fertilization increased the capacity of forage plants to lessen, albeit not eliminate, the effects of injury by M. spectabilis. Conclusion Forages in fertilized soil are more tolerant to attacks by M. spectabilis nymphs and adults. © 2019 Society of Chemical Industry.

The edible Ruspolia differens (Orthoptera: Tettigoniidae) is a widely-consumed insect in East Africa but surprisingly little is known of its host plant use in the field. We studied host plants used by non-swarming R. differens for 15 months, in central Uganda. In particular, we assessed the use of host plant species with respect to host cover in the field and host parts used by R. differens, also recording their sex, developmental stages, and colour morph. Ruspolia differens were found on 19 grass and two sedge species and they were observed predominantly (99% of 20,915 observations) on seven grasses (namely, Panicum maximum, Brachiaria ruziziensis, Chloris gayana, Hyparrhenia rufa, Cynodon dactylon, Sporobolus pyramidalis, and Pennisetum purpureum). Ruspolia differens was most frequently observed on the most common grass of each study site but P. maximum, and S. pyramidalis were used more frequently than expected from their cover in the field. Furthermore, R. differens were observed predominantly on inflorescences (97% of feeding observations) and much less frequently on the leaves (3.0%), stems (0.1%), and inflorescence stalks (0.1%) of grasses and sedges. Host use was not independent of sex, developmental stage, or colour morph. Panicum maximum was the preferred host of the youngest nymphs of R. differens. Overall, our findings indicate that a continuous supply of diverse grass resources with inflorescences is necessary for the management and conservation of wild populations of R. differens.

The direct and residual effects of different levels of chicken manure fertilization on the growth and biomass production of B. ruziziensis at the bolting were studied in West Cameroon. The objective of this study was to evaluate the effects of different levels of chicken manure fertilization on the growth and biomass production of Brachiaria ruziziensis at the bolting. A factorial device comparing five doses of nitrogen into chicken manure (0, 25, 50, 75 and 100 kg N/ha) on plot of 6 m2 (3 × 2 m) in four replicates, (i.e. a total of 20 experimental plots) was used. Chicken manure was spread one month after planting pieces of stump during the first year. In the second year, no fertilization was brought up. 40 plants were harvested by treatment for heights and diameters measurements. The evaluation of stems biomass, leaves and whole plants was done on each plot based on the level of fertilization. The results obtained showed that chicken manure fertilization had a positive effect on the growth and biomass production of the B. ruziziensis on the direct and residual effect of fertilization. Thus, the height, diameters and biomass of whole plants in the fertilized plots were significantly larger than in the control plots. The mineralization of the organic matter contained in the chicken manure with doses of 100 kg N/ha was done on the direct and residual effect in order to assure a maximal plant growth. The level of T4 fertilization (corresponding to the dose of 100 kg N/ha) gave the best results. Referring to the result obtained, the level of T4 fertilization corresponding to 100 kg N/ha would be suitable for an optimal B. ruziziensis growth in order to avoid providing the soil with mineral fertilizer.

Soil tillage and cover crops impact spontaneous vegetation in agrosystems. Soil tillage destroys seedlings and can affect the soil seedbank. Cover crops compete with naturally occurring spontaneous species. Our aim was to gain insight into how soil tillage (here, the false seedbed technique) and cover crops impact the spontaneous vegetation in fallows preceding banana crops. In a fallowed field in Guadeloupe (French West Indies), two factors were combined in a split-plot design: the soil tillage modality before cover crop sowing (with or without the false seedbed technique) and the cover crop species (Crotalaria spectabilis, Pueraria phaseoloïdes, a 50/50 mix of Brachiaria decumbens + Brachiaria ruziziensis, a spontaneous vegetation control). On a monthly basis, in three permanent quadrats per sub-plot, all spontaneous species were identified and their numbers counted, while calculating the species richness and Shannon's diversity index. The spontaneous vegetation dynamics contrasted depending on the treatment. From 7 months post-sowing the species density, richness and Shannon index were significantly lower in treatments with B. decumbens + B. ruziziensis and P. phaseoloïdes, while in treatments with C. spectabilis, the species density and richness were significantly higher with than without the false seedbed technique. These effects were probably related to differences in the competitive ability of the cover crop used and, to a lesser extent, to the false seedbed effects on the soil seedbank. This is the first study to show that under a tropical climate, sown cover crop species combined with different soil tillage modalities have substantial impacts on the species density, richness and diversity of the spontaneous plant community over a 1-year period. These results could help farmers in their weed control strategies by providing them with a deeper understanding of the effects of practices on the spontaneous plant community.

This experiment was aimed to investigate the production characteristics and nutritive quality of Ruzi grass by varying levels of organic and inorganic fertilizer viz. cow dung (CD) and urea fertilizer (UF), respectively. The treatments were arranged into a factorial design and grouped according to a completely randomized design with three replications. Three doses of CD (0; 5; and 10 t/ha) were applied at sowing and four UF doses were applied as top dressing (0, 25, 50 and 100 kg/ha). The application of CD and UF have a positive effect on the length of leaves (p=0.00 and p=0.02) but their interactions are not significantly different (p=0.12). The effect of CD, UF and their interaction significantly increased the number of leaves (p=0.00), the number of tillers (p=0.00) and dry matter yield (p=0.00). There were no significant effect of CD and interaction on the leaf/stem ratio (p=0.17 and p=0.23, respectively) but UF slightly increased the ratio (p=0.00), CP% (p£0.00), NDF% (p£0.00) and ADF% (p£0.00). The best combination of fertilizer could be noted at 50 kg/ha UF and 10 t/ha CD to obtain better results. It might recommend that better fertilizer management can improve productivity as well as the nutritional quality of Ruzi grass.

Some species of the genus Brachiaria are cultivated worldwide in tropical and subtropical climate regions as the main feed for ruminants. Several studies report photosensitization by Brachiaria decumbens, Brachiaria brizantha, and Brachiaria humidicola, but the poisoning by Brachiaria ruziziensis have been reported only twice. Cutaneous and hepatic lesions may be caused by the steroidal saponins present in the leaves or by the mycotoxin sporidesmin produced by the saprophyte fungus Pithomyces chartarum. The present report describes the clinical and pathological changes observed in an outbreak of hepatogenic photosensitization in sheep kept in B. ruziziensis pastures. In addition, the present study will provide a better understanding of the etiology of this photosensitization through the evaluation of the saponin protodioscin and the spore count of P. chartarum. Santa Ines and Lacaune mixed-breed sheep showed signs of photosensitization after feeding B. ruziziensis. Clinical signs included jaundice, apathy, dehydration, and photosensitization characterized by facial edema and cutaneous scars, especially in the ears. Pathological examination of the liver revealed diffuse infiltrates of foamy cells, rare multinucleated cells, and mild enlargement of hepatocytes (megalocytosis). The skin showed acute epidermal and dermal necrosis with occlusive thrombi. B. ruziziensis showed low levels of protodioscin (0.020 ± 0.024% in mature leaves and 0.065 ± 0.084% in sprouts) but high P. chartarum spore counts (mean of 479,844 ± 443,951 spores/g plant). Thus, sheep grazing B. ruziziensis pastures must be closely monitored because of the risk of photosensitization.

New approaches based on image analysis can assist in phenotyping of biological characteristics, serving as support for decision-making in modern agribusiness. The aim of this study was to propose a method of high-throughput phenotyping of free access for processing of 2D X-ray images of brachiaria grass (Brachiaria ruziziensis cv. Ruziziensis) seeds, as well as correlate the parameters linked to the physiological potential of the seeds. The study was carried out by means of automated analysis of X-ray images of seeds in which a macro, called PhenoXray, was developed, responsible for digital image processing, for which a series of descriptors were obtained. After the X-ray analysis, a germination test was performed on the seeds and, from this, variables related to the physiological quality of the seeds were obtained. The use of the macro PhenoXray allowed large-scale phenotyping of seed X-rays in a simple, rapid, robust, and totally free manner. This study confirmed that the methodology is efficient for obtaining morphometric data and tissue integrity data in Brachiaria ruziziensis seeds and that parameters such as relative density, integrated density, and seed filling are closely related to the physiological attributes of seed quality.

The grain sorghum intercropped with Brachiaria provides the production of grains and dry mass in the off-season; however, there is a lack of information related to the implantation of these species. The objective of this study was to identify the best association of sorghum and Brachiaria in the production of grain and dry matter in the Brazilian Cerrado region. The experiment was conducted in Rio Verde, State of Goiás, in the experimental design of randomized blocks, in a 2×3×4+5 factorial scheme, with four replications. Two sorghum hybrids (BRS 330 and DKB 551) associated to three Brachiaria species (Brachiaria brizantha cultivar Marandu, Brachiaria decumbens and Brachiaria ruziziensis) were evaluated in four systems of Brachiaria implantation (row, interrow, row + interrow of sorghum and spread). Additional treatments referred to the two sorghum monocrops and the three Brachiaria species. The sorghum and Brachiaria consortium resulted in a reduction in grain yield, but the Brachiaria implantation systems in the row, interrow and spread were the most promising. The sorghum hybrid DKB 551 was the most sensitive to the competition with Brachiaria, although there were no grain yield differences in the intercropping. The Brachiaria intercropped in the interrow and in the row + interrow, mainly with B. ruziziensis, were the most promising for the production of dry mass and total crude protein. The cultivation of Brachiaria intercropped with sorghum provided a greater contribution of dry mass in the off-season, an important fact for the no-tillage system in the agricultural production systems of the Brazilian Cerrado. RESUMO O consórcio de sorgo granífero com braquiária proporciona a produção de grãos e massa seca na entressafra; contudo, há carência de informações relacionadas à implantação dessas espécies. Sendo assim, este trabalho teve por objetivo identificar a melhor associação de sorgo granífero e braquiária na segunda safra para produção de grãos e massa seca na região do Cerrado. O experimento foi conduzido em Rio Verde, Goiás, no delineamento experimental de blocos randomizados, em esquema fatorial 2×3×4+5, com quatro repetições. Foram avaliados dois híbridos de sorgo granífero (BRS 330 e DKB 551) associados a três espécies de Brachiaria (Brachiaria brizantha cultivar Marandu, Brachiaria decumbens e Brachiaria ruziziensis) em quatro sistemas de implantação da braquiária (linha, entrelinha, linha + entrelinha do sorgo e a lanço). Os tratamentos adicionais referiam-se aos dois monocultivos de sorgo e às três espécies de braquiária. O consórcio de sorgo com braquiária ocasionou redução no rendimento de grãos, porém os sistemas de implantação da braquiária na linha, entrelinha e a lanço foram os mais promissores. O híbrido de sorgo DKB 551 foi o mais sensível à competição com a braquiária, sem, contudo, haver diferenças de rendimento de grãos em consórcio. Os consórcios das braquiárias na entrelinha e na linha + entrelinha, principalmente com a B. ruziziensis, foram os mais promissores para produção de massa seca e proteína bruta total. O cultivo de braquiária com o sorgo proporcionou maior aporte de massa seca na entressafra, fato importante para o sistema de plantio direto nos sistemas de produção agrícola dos Cerrados.

Ipyporã grass, a Brachiaria interspecific hybrid was developed by crossing a genotype of Brachiaria ruziziensis (syn. Urochloa ruziziensis) and an access of Brachiaria brizantha (syn. Urochloa brizantha), which have different nitrogen requirements. Therefore, the objective with work was to verify the nitrogen requirement of the interspecific hybrid of Brachiaria hybrid cv. Ipyporã. Experiment was carried out in a greenhouse in a randomized block design, with twelve treatments and four replications. Treatments consisted of a 4 x 3 factorial arrangement, with four nitrogen doses (0; 100; 200 and 300 mg dm3) and three forages (Brachiaria hybrid cv. BRS Ipyporã, Brachiaria humidicola cv. Llanero and Panicum maximum cv. Zuri). Each experimental plot consisted of a 3 dm³ pot with three plants. Three evaluation harvest were done . B. hybrid had greater response to nitrogen fertilization for number of tillers and leaves than the other forages. However, for the total dry mass, B. hybrid was less responsive to nitrogen than P. maximum grass (high demand) and more responsive than B. humidicola (low demand), which shows that this hybrid has medium nitrogen requirement.

In intercropping systems, a high plant density can delay the biomass accumulation and affect the water availability to plants. This study aimed to evaluate the soil water dynamics and the crop yield performance in maize and Brachiaria ruziziensis intercropping under different sowing densities of the forage grass. The experiment was conducted in a randomized block design, with treatments associated to the sowing densities (2 kg ha-1, 4 kg ha-1, 6 kg ha-1 and 8 kg ha-1) and the single cropping for both species as controls. The maize plants were evaluated for grain yield and B. ruziziensis for number of plants per hectare and shoot fresh and dry matter. The intercropping performance was evaluated using the land-use efficiency index. The soil water dynamics was monitored in two soil depths (0-0.3 m and 0.3-0.6 m) by using the time domain reflectometry method. The evaluation of soil water storage was carried out from plots with four of the crop systems (single maize or B. ruziziensis, and intercropping with the extreme sowing densities), at four different times. The increase in the sowing density of B. ruziziensis decreased the grain yield of the intercropped maize by 30.8 %. The intercropping system using 2 kg ha-1 of the grass seeds resulted in the best land-use efficiency (23 %). In addition, the intercropping treatments promoted a higher extraction of water from the soil, mainly at the maize growth stages with higher hydric demand (e.g., flowering and grain filling). These systems stimulate the extraction of water from deeper soil layers, when compared to maize in single cropping. RESUMO Em cultivos consorciados, uma alta densidade de plantas pode retardar o acúmulo de biomassa e afetar a disponibilidade hídrica às plantas. Objetivou-se avaliar a dinâmica da água no solo e o desempenho produtivo no consórcio de milho e Brachiaria ruziziensis sob diferentes densidades de semeadura desta forrageira. O experimento foi conduzido em blocos casualizados, com tratamentos associados às densidades de semeadura (2 kg ha-1, 4 kg ha-1, 6 kg ha-1 e 8 kg ha-1) e ambas as espécies em monocultivo como testemunhas. No milho, avaliou-se a produtividade de grãos e, na braquiária, o número de plantas por hectare e as massas verde e seca da parte aérea. O desempenho do consórcio foi avaliado pelo índice de uso eficiente da terra. A dinâmica da água no solo foi monitorada em duas profundidades (0-0,3 m e 0,3-0,6 m), pela técnica de reflectometria no domínio do tempo. A avaliação do armazenamento de água no solo foi realizada a partir de parcelas com quatro dos sistemas de cultivo (milho ou braquiária em monocultivo, e consórcios com as densidades de semeadura extremas), em quatro períodos. O aumento na densidade de semeadura de B. ruziziensis diminuiu a produtividade dos grãos do milho consorciado em 30,8 %. O consórcio usando 2 kg ha-1 de sementes da forrageira proporcionou melhor eficiência no uso da terra (23 %). Ademais, os tratamentos com consórcio promoveram maior extração de água do solo, especialmente nas fases de maior exigência hídrica do milho (e.g., florescimento e enchimento de grãos). Estes sistemas simulam a extração de água em maiores profundidades, quando comparados ao milho em cultivo solteiro.

Forage plant breeders often use visual scores to assess agronomic traits because of the costs associated with in-depth phenotyping in the initial stages of breeding cycles. The aim of this study was to investigate the impact of the number of graders on the effectiveness of indirect selection of high-yielding genotypes and determine an optimal number of graders in the early-stage trials of Urochloa ruziziensis. For that purpose, five graders assessed 2.219 U. ruziziensis genotypes in an augmented block design. Biomass production and vigor scores were evaluated in two cuts and were analyzed using a linear mixed model approach. Vigor scores were analyzed considering each grader's score and the combinations of two, three, four, and five graders. Genetic variance was significant for both traits. Visual evaluation was effective in identifying productive genotypes based on the statistical criteria. The optimal number of graders for indirect selection of high-yielding U. ruziziensis genotypes is three.

Microsporogenesis studies in Brachiaria have been concentrated in the species B. ruziziensis, B. decumbens and B.brizantha and hybrids because they have great importance as forage. Besides the sexual behavior, B. ruziziensis is among a minority of Brachiaria diploid species (2n = 2 × = 18), while most are tetraploid (2n= 4 × = 36) and apomictic. Brachiaria ruziziensis is used in intra and interspecific crossbreedings. For the success of interspecific hybridization, artificial tetraploidization of B. ruziziensis is necessary. The aim of this study was to compare the microsporogenesis in diploid and synthetic tetraploid B. ruziziensis plants and their respective progenies. The slides were prepared by squash technique and stained with 1% propionic carmine for meiocyte analysis and Alexander's stain for pollen viability. Abnormalities were found in all phases of meiosis in the families of the diploid and tetraploid plants and, in general, the rate was considered low, with the percentage varying according to the genotypes. The diploid family was considered more stable. For both families, there is a tendency to reduce the total frequency of abnormalities in the progenies compared to the mother plants. This response indicates that combinations of random crosses or self-fertilization among plants with the same ploidy level were favorable. For the diploid accessions, the pollen viability index was high, reaching up to 88.3%, whereas the tetraploidized plants presented lower values, reaching a maximum of 61.1%. The results will be of interest to researchers involved in tropical forage breeding or conducting intraspecific crosses, since the occurrence of regular meiosis in progenies ensures the formation of viable pollen grains.

Repetitive DNA sequences have been widely used in cytogenetic analyses. The use of gene sequences with a low-copy-number, however, is little explored especially in plants. To date, the karyotype details in Brachiaria spp. are limited to the location of rDNA sites. The challenge lies in developing new probes based on incomplete sequencing data for the genus or complete sequencing of related species, since there are no model species with a sequenced genome in Brachiaria spp. The present study aimed at the physical location of conserved genes in chromosomes of Brachiaria ruziziensis, Brachiaria brizantha, and Brachiaria decumbens using RNAseq data, as well as sequences of Setaria italica and Sorghum bicolor through the fluorescent in situ hybridization technique. Five out of approximately 90 selected sequences generated clusters in the chromosomes of the species of Brachiaria studied. We identified genes in synteny with 5S and 45S rDNA sites, which contributed to the identification of chromosome pairs carrying these genes. In some cases, the species of Brachiaria evaluated had syntenic segments conserved across the chromosomes. The use of genomic sequencing data is essential for the enhancement of cytogenetic analyses.

Endophytic Paraconiothyrium strains associated with Brachiaria spp. and Panicum maximum were screened in vitro and in vivo for antagonism against Sclerotinia sclerotiorum and grass growth promotion. Based on multilocus phylogenetic analyses, three Paraconiothyrium estuarinum strains and two Paraconiothyrium cyclothyrioides strains were identified. In vitro, P. estuarinum strain CML 3699 was the most efficient in S. sclerotiorum mycelial growth inhibition. Volatile organic compounds (VOCs) produced by Paraconiothyrium strains reduced the sclerotia number, sclerotia weight and apothecia number in comparison to the control. The VOCs of P. cyclothyrioides strain CML 3698 promoted higher inhibitory effects on apothecium production. Paraconiothyrium estuarinum CML 3695, when inoculated into Brachiaria ruziziensis seeds, promoted increased biomass in comparison to those in non-inoculated seeds. All strains were sensitive to higher glyphosate doses, which reduced their mycelial development. However, when the mycelia of the endophytic fungi were removed and transferred to new PDA medium, the fungi recovered growth. After desiccation of Paraconiothyrium-inoculated B. ruziziensis with glyphosate, Paraconiothyrium strains recovered the ability to colonize the sclerotia of S. sclerotiorum and reduced carpogenic germination via a Trojan-horse-like mode of action. Considering that grass can be deployed by farmers as a physical barrier to S. sclerotiorum ascospore release, the growth promotion and parasitism of sclerotia exerted by Paraconiothyrium strains towards B. ruziziensis reinforce this disease control strategy.

Para melhor controle e eficiência dos cultivos agrícolas nas regiões semiáridas brasileiras, o uso de avaliações com dados provenientes de sensoriamento remoto em conjunto com sistemas de informações geográficas (SIG) estão sendo amplamente utilizados. Neste trabalho objetivou-se comparar os índices vegetativos em sistema de cultivo de milho e plantas de cobertura do solo nas condições semiáridas do Brejo da Paraíba. A pesquisa foi realizada em Areia, Paraíba, Brasil, nos anos agrícolas de 2018/2019 e 2019/2020. O delineamento foi em blocos casualizados, com quatro repetições, no esquema fatorial 3 × 6, correspondente a três genótipos de milho (cultivar Robusto, milho crioulo Pontinha e híbrido AG1051) e seis sistemas de cultivo de plantas de cobertura [(Brachiaria ruziziensis, milheto (Pennisetum glaucum), feijão guandu (Cajanus cajan), Crotalária espectabilis, Crotalária juncea e como testemunha apenas o solo descoberto)], totalizando 18 tratamentos. Foram avaliados os índices vegetais de Visible Atmospherically Resistant Index, Redness Index, Normalized green-Red Difference Index, Ground Level Image Analysis, Excess Red-Green, Excess Red Vegetative Index, Excess Green Index e o Color Index of Vegetation Extraction. De maneira geral, os resultados demonstraram que para observar diferenças entre os genótipos de milho é indicado o uso do índice Excess Red Vegetative Index. Para observar diferenças do efeito das plantas de cobertura no milho, indica-se o Normalized green-Red Difference.

Made available in DSpace on 2021-06-25T10:54:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Plant-associated microbiomes have been a target of interest for the prospection of microorganisms, which may be acting as effectors to increase agricultural productivity. For years, the search for beneficial microorganisms has been carried out from the characterization of functional traits of growth-promotion using tests with a few isolates. However, eventually, the expectations with positive results may not be realized when the evaluation is performed in association with plants. In our study, we accessed the cultivable sugarcane microbiome under two conditions of agronomic management: organic and conventional. From the use of a new customized culture medium, we recovered 944 endophytic and epiphytic bacterial communities derived from plant roots, stalks, leaves, and rhizospheric soil. This could be accomplished by using a large-scale approach, initially performing an in planta (Cynodon dactylon) screening process of inoculation to avoid early incompatibility. The inoculation was performed using the bacterial communities, considering that in this way, they could act synergistically. This process resulted in 38 candidate communities, 17 of which had higher Indole-3-acetic acid (IAA) production and phosphate solubilization activity and, were submitted to a new in planta test using Brachiaria ruziziensis and quantification of functional traits for growth-promotion and physiological tests. Enrichment analysis of selected communities has shown that they derived mainly from epiphytic populations of sugarcane stalks under conventional management. The sequencing of the V3-V4 region of the 16S rRNA gene revealed 34 genera and 24 species distributed among the phylum Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. We also observed a network of genera in these communities where the genus Chryseobacterium stands out with a greater degree of interaction, indicating a possible direct or indirect role as a keystone taxon in communities with plant-growth promotion capacities. From the results achieved, we can conclude that the approach is useful in the recovery of a set of sugarcane bacterial communities and that there is, evidence of synergistic action providing benefits to plants, and that they are compatible with plants of the same family (Poaceae). Thus, we are reporting the beneficial bacterial communities identified as suitable candidates with rated potential to be exploited as bioinoculants for crops. Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Câmpus Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane s/n Programa de Pós-Graduação em Microbiologia Agropecuária Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Câmpus Jaboticabal Via de Acesso Prof. Paulo Donato Castellane s/n Universidade Federal de Mato Grosso Instituto de Biociências, Av. Fernando Corrêa Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Câmpus Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane s/n Programa de Pós-Graduação em Microbiologia Agropecuária Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Câmpus Jaboticabal Via de Acesso Prof. Paulo Donato Castellane s/n FAPESP: 2017/09008-5

Made available in DSpace on 2018-11-26T15:47:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-02-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Nitrate leaching is a primary pathway of nitrogen loss from agricultural systems, and is affected by both tillage and cropped species. However, there is little information on conservation systems without nitrogen fertilization. Nitrate leaching was assessed in soybean (Glycine max) cropped in rotation with the following cover crops under no-till and chiseling: ruzigrass (Brachiaria ruziziensis), grain sorghum (Sorghum bicolor), pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor), Sunn hemp (Crotalaria juncea), triticale (X Triticosecale) and sunflower (Helianthus annuus). Ruzigrass and grain sorghum cropped in the fall/winter resulted in similar NO3 (-) leaching, which was greater under sunflower than under triticale, likely due to high N uptake and immobilization in plant residues. Sunn hemp as a spring crop resulted in higher NO3 (-) leaching than pearl millet at two locations and forage sorghum at one location likely due to a higher N input by biological fixation. Millet resulted in the lowest N leaching by depleting the soil solution. Chiseling/fallow resulted in higher nitrogen leaching as compared with non-fixing N cover crops. Even when N is not applied, it is important to intensify cropping systems in tropical environments using cover crops with vigorous root systems and high N demand, which prevent N leaching, as well as provides N to the following crop as the straw is mineralized. Sao Paulo State Univ, Coll Agr Sci, Botucatu, SP, Brazil Sao Paulo State Univ, Coll Agr Sci, Botucatu, SP, Brazil FAPESP: 2011/02117-7

The demand for Brachiaria ruziziensis seeds and planting material is increasing in India as it is spreading into new niche areas of silvi-pastoral systems, horti-pastoral systems, mango orchards, and coconut plantations due to its resilience to drought and low light intensities. Brachiaria ruziziensis produces low numbers of pure seeds. In this study, seeds were collected periodically after a single destructive harvest (SDH) and shade drying. Application of irrigation and fertiliser produced a 2.3 fold increase in seed yield compared to the control. However, when seeds were collected through a single destructive harvest (SDH) and shade drying, rather than sweating, the seed qualitative parameters such as seed germination and seed viability improved three and five folds, respectively. Field management techniques such as irrigation and fertiliser application influenced the quantity of seeds produced whereas harvesting methods promoted the quality of seeds produced in B. ruziziensis . Seed germination could also be improved (50%) by treating the seeds with raw cow dung which contains many beneficial microorganisms that produce cellulolytic enzymes, alleviating seed dormancy. Seed yield improved in B.ruziziensis with chemical sprays such as Brassinosteroid 10 ppm (145 kg/ha) and Tryptophan 100 ppm (147 kg/ha) compared to the control, water spray (131 kg/ha). Brassinosteroid sprays could enhance pollen fertility and yield probably through interactions with anther development and sugar metabolism, respectively. Brachiaria ruziziensis produces more vegetative growth in the second year due to its perennial growth habit. The filled seed yield from the second-year crop was 0.8 times less in the control compared to the first year, even with chemical sprays. Perennial plants, in general, maintain their longevity through a physiological trade-off between seed yield and underground growth. Hence, it is beneficial to replant B. ruziziensis every year if grown for seed purposes.

Made available in DSpace on 2018-11-26T17:40:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 Plants affect soil phosphorus (P) solubility through root exudates, but studies are lacking on species used as relay or cover crops in tropical environments. We evaluated the effect of cover crops on soil phosphorus (P) availability in an oxisol. Ruzigrass (Brachiaria ruziziensis), pearl millet (Pennisetum glaucum), peanut (Arachis hypogaea), crambe (Crambe abyssinica), and sorghum (Sorghum bicolor) were grown in pots with soil. Phosphorus uptake, soil inorganic and organic P, maximum P adsorption capacity, and plant root systems were assessed. When root length density is high, the efficiency of P uptake is low due to root competition. Crambe results in greater soil P availability, while peanut and sorghum decrease the soil maximum P adsorption capacity, probably by exuding or stimulating microbial production of organic acids and phenolic compounds. Hence, crambe, peanut, and sorghum are species that may be of interest to increase P use efficiency in cropping systems. Sao Paulo State Univ, Dept Crop Sci, Coll Agr Sci, CP 237, BR-18601370 Botucatu, SP, Brazil Sao Paulo State Univ, Dept Crop Sci, Coll Agr Sci, CP 237, BR-18601370 Botucatu, SP, Brazil

Background: Carbonaceous shale is one of the common rock types in Malaysia. The most common types of landslides in Malaysia were happened on the cut slope before the construction of highway. Brachiaria ruziziensis and Colopogonium mucunoides were used as the mix vegetation to investigate the effect of chemical amendments on plant growth and root shear strength relationship. Objective: The objective of this study: (1) To investigate the effect of compound fertilizer nitrogen, phosphorus, potassium (NPK), NPK+Ground Magnesium Limestone (GML) (NGL), NPK+GML+foliar fertilizer (Vita-Grow™) (NGF) and control (Ctrl) and (2) To determine the soil shear strength, biomass and root growth. Materials and Methods: The soil samples were analyzed for pH, Total Nitrogen (TN), Soil Organic Carbon (SOC), available phosphorus, exchangeable Al, Ca, Mg and K and trace nutrients (Fe, Mn, Cu and Zn). Results: The carbonaceous shale was low in pH, total N, soil organic carbon, extractable P, basic cations (Ca, Mg and K) and micronutrients (Fe, Cu and Zn). Both P and Ca/Mg were low indicating inherent infertility and chemical constraints for root developments. The dry matter yield, root length and root weight of Brachiaria ruziziensis and Colopogonium mucunoides were increased significantly against NGF treatment. The increased of plant top and root dry weight treated with NGF were 26 and 38%, respectively, compared to the other treatments. The significant root shear strength relationship indicates that root enhanced shear strength by reducing the cohesion and increased the angle of internal friction component. The shear strength analysis from the direct shear test method is to determine the shear strength from the plotted graph. The shear strength analysis showed that NGF treatment was having high shear strength in 5.4, 10.9 and 16.3 and normal stress in 54, 109 and 163 kN m–2. Rapid vegetation growth observed within a 5 months period demonstrated that nutrient and lime application effectively ameliorated chemical constraints to plant growth. Conclusion: The plant mix species treated with NPK+GML+foliar fertilizer (NGF) indicated higher shear strength, dry matter yield and root densities in all layers.

Fresh and conserved pangola grass (Digitaria eriantha Steud., synonym D. decumbens) were compared in terms of in vitro gas production and in vivo nutrient digestibility, metabolisable energy (ME) concentration and average daily gain (ADG) of Thai indigenous cattle. The study was designed as a completely randomised design with Ruzi grass (Brachiaria ruziziensis) as a control and pangola grass in fresh, hay and silage forms at the same age at harvest (45 days regrowth) as treatments. As intended, the dry matter (DM) intake of forages supplemented with concentrate and a protein block was not different (p > .05) among treatments. All forms of pangola ranked higher in crude protein and ME concentrations than Ruzi grass. Pangola silage, to which 5% sugarcane molasses was added at ensiling to minimise the risk of bad fermentation, produced more gas in vitro after 96 hours of incubation and had greater (p

Chiselling has been used to alleviate soil compaction but cover crops with deep, vigorous roots can improve root growth and activity of the cash crop for a longer time. The determination of root activity in addition to root mass or length may improve the understanding of plant response to compaction. The objective of this experiment was to evaluate root growth and activity as affected by the alleviation of soil compaction using mechanical and biological methods. The experiment was conducted in Botucatu, Sao Paulo, Brazil, from 2009 to 2011, on a clay, Typic Rhodudalf soil. Crop rotations including pear millet (Pennisetum glaucum), soybean (Glycine max), grain sorghum (Sorghum bicolor), maize (Zea mays), ruzi grass (Brachiaria ruziziensis) and castor bean (Ricinus communis) in plots, either chiselled or not. Root growth was assessed by core sampling and root activity was determined indirectly using rubidium injected at several depths as a marker. Root activity was instrumental in interpreting the effects of tillage and crop rotations on soil amelioration. Compared with the initial compacted condition, chiselling increased root growth and activity just for the first 18 months of the experiment, but crop rotations, mainly including ruzi grass and castor bean, increased root growth and activity in the soil profile from the second year on. Generally, root mass was poorly correlated with root activity, except in the case of ruzi grass. Introduction of ruzi grass plus castor bean into the cropping system improves not only root growth and activity in the soil profile but also soybean yield.

In Exp. 1, Brachiaria ruziziensis (11.1 % CP) was inoculated or not with two sources of monensin, resulting in three treatments: 1) no monensin inoculation (CONT), 2) 20 mg of monensin sodium-A/kg of DM (Elanco Animal Health; MON-A), and 3) 20 mg of monensin sodium-B/kg of DM (Shandong Qilu King-Phar Pharmaceutical Co. Ltd.; MON-B). Three rumen-fistulated Jersey steers were offered a cool-season forage-based diet and were used as the rumen inoculum donors. Volatile fatty acids concentrations were evaluated at 0, 6, 12, 24, 30, and 48 h after treatment inoculation. Overall, acetate and butyrate concentrations were reduced in MON-A vs. CONT (P ≤ 0.02), whereas both monensin products reduced Ac:Pr ratio vs. CONT (P ≤ 0.01); however, MON-A also (P = 0.05) reduced the Ac:Pr ratio vs. MON-B. A treatment × hour interaction was detected for rumen propionate concentration (P = 0.01), primarily because MON-A resulted in greater propionate than CONT and MON-B at 24 and 48 h (P ≤ 0.03), but no differences were observed between CONT vs. MON-B (P ≥ 0.27). In Exp. 2, 240 Nellore bulls (initial BW = 363.2 ± 40.9 kg) were ranked and blocked according to initial BW, and within blocks animals were allotted into pens (n = 10 pens/treatment). Pens were randomly assigned into one of three treatments: 1) corn-based diet with no monensin (CONT), 2) CONT plus 28 mg of MON-A/kg of DM, and 3) CONT plus 28 mg of MON-B/kg of DM. The CONT diet was composed of sugarcane bagasse, ground corn, DDGS, urea, and a mineral-vitamin mix. The experimental period lasted 106 d and was divided into a 21-d adaptation period and an 85-d finishing phase. During the adaptation phase, both monensin sources increased (P ≤ 0.01) BW change, ADG, and F:G, as well as reduced DMI variation (P = 0.02). When the entire experimental period was evaluated, no treatment effects were detected for final BW, DMI, and ADG (P ≥ 0.26). Nonetheless, DMI variation was reduced as monensin was included (P = 0.01) and only MON-A improved the efficiency by reducing F:G vs. CONT (P = 0.05) and biological efficiency vs. MON-B (P = 0.05). Additionally, carcass ADG tended (P = 0.10) to be greater for MON-A vs. MON-B, whereas no other differences in the carcass characteristics were observed (P ≥ 0.53). In summary, the source of monensin inoculated in vitro and offered to Nellore bulls during the feedlot phase significantly affected the energetic efficiency and the performance of the animals.

Livestock production in the lowlands of Eastern Oromia of Ethiopia depends mainly on natural pastures and crop residues which are of poor quality and the yield is generally low during the dry season. Therefore, there is a need to introduce alternative forages of high quality that are adapted to the region. The objective of this study was to identify and select the best Brachiaria grass accession/s for dry matter (DM) yield and nutritive quality in lowlands of Eastern Oromia. The experiment was conducted in the lowlands of Fedis and Dire-Dawa districts during 2018 to 2020. The experimental materials were brachiaria decumbens accessions 1087, 13205, 14721, 14720 and brachiaria ruziziensis accessions 13332, 14743, 14771, 14774, 14813. These grass accessions were compared with one local check, a locally cultivated brachiaria grass. Plant established successfully at both sites for the last three years. Tiller numbers, plant height, forage dry matter yield and plot covers were recorded at 16 weeks after planting. Significant (p

A supressão da forrageira e posterior dessecação da biomassa em sistema de consórcio com milho é fundamental para garantir rentabilidade das culturas. Nesse sentido, o trabalho teve como objetivo avaliar o desempenho do milho consorciado com Brachiaria ruziziensis e tempo de dessecação da biomassa sobre a cultura da soja em sucessão. Foram instalados dois experimentos idênticos na safrinha de 2016 utilizando delineamento experimental de blocos ao acaso com três sistemas de cultivo: milho, milho + braquiária e braquiária, com 16 repetições. Foram avaliados o desempenho das culturas e produção de biomassa. Em sucessão, foi semeado duas cultivares de soja com arquiteturas distintas (NA 7337 RR® com maior capacidade de engalhamento e ANTA 82 RR® sem essa característica) utilizando delineamento experimental de blocos ao acaso, com quatro repetições, em arranjo fatorial 3x4, sendo três sistemas de cultivo (milho, milho + braquiária e braquiária) e quatro épocas de dessecação (0, 7, 14 e 21 dias antes da semeadura da soja (DAS)). Nestes experimentos foram avaliados o desempenho agronômico da soja. Os resultados obtidos mostraram que a braquiária em consórcio com o milho não reduz a produtividade da cultura desde que o solo apresente adequada fertilidade. Para a cultivar Anta 82 RR®, recomenda-se efetuar o manejo da dessecação em torno de 15 DAS para o cultivo milho e milho + braquiária e 23 DAS para o sistema somente com braquiária. A cultivar NA 7337 RR® demonstrou ser mais interessante para ser cultivada em sucessão a braquiária (em consórcio ou isolada).

The autotetraploid forage Congo signal grass (Brachiaria ruziziensis) is an important component in the Brachiaria breeding programme. As with other tropical forage grass species, the association between flowering and seed yield components, the mode of inheritance and the effects of population structure on phenotypic breeding are lacking. Seventeen characteristics evaluated in 59 half-sib progeny of seven subpopulations were analysed using a mixed model methodology. According to the commonality analysis, the total seed yield (0.67) and number of days to flowering (0.22) had a greater influence on the filled-seed yield. The flowering synchrony, total number of panicles, filled-seed yield, green matter yield and dry matter yield presented statistically significant additive genetic variance between and within the subpopulations. The QST estimates ranged from 0.09 for the flowering synchrony index to 0.31 for the filled-seed yield. The effects of population structure and its use in breeding programmes are further discussed.

Sorghum is an alternative crop to produce grains in the off-season in Brazilian Cerrado and the intercropping with Brachiaria species enable to produce dry matter on the soil surface for a longer time. However, there is limited information on Brachiaria ruziziensis seed density to be applied to intercropping with sorghum without causing decreases in sorghum grain yield. The objective of the study was to evaluate the seeding density of B. ruziziensis in different intercropped systems with grain sorghum grown after soybean harvest, in off-season cultivation, to produce grains and the effects of straw on the agronomic performance of the soybean crop in succession to intercropping. This study was conducted in the field during the 2014 off-season in Rio Verde, Goias. The experimental design was complete randomized blocks in a 3×5 factorial arranged with four replications corresponded to intercropping on rows, inter-rows and broadcast sowing with the densities of 2, 4, 6, 8 and 10 viable pure seeds m-2 of B. ruziziensis. Monocultures of sorghum and these forage crop were also evaluated. The results demonstrated the absence of effects of intercropping systems and seeding density on the yield of sorghum grains and on the cultivation of soybean in succession. The intercropping was effective in producing straw on soil surface to Cerrado no-tillage system. Key words: Brachiaria species, Glycine max, straw, off-season crop, Sorghum bicolor.

The effects of tillage systems on the dynamics of web blight caused by Thanatephorus cucumeris and yield of common bean (Phaseolus vulgaris) cv. Perola were studied in three field experiments during the planting seasons of 2004/2005, 2005/2006 and 2006/2007. Congo grass (Urochloa ruziziensis) was managed in a naturally infested field to establish the following cropping systems: no-till (NT), minimum-tillage (MT) (disking with partially incorporated straw); and conventional tillage (CT) (residues burial by soil plowing). The area under disease progress curves (AUDPCs) and the disease progress rates were generally low in the NT system during the three cropping seasons, most likely due to the benefits of grass mulching. In general, AUDPC values were higher in the 2005/2006 compared to the other seasons due to more uniform rainfall distribution during the crop cycle. Bean yield was highest in CT despite a higher the high AUDPC, probably due to immobilization of nutrients in the soil after herbicide-burning of U. ruziziensis. An additional study conducted in 2006/2007 showed that distribution of 2 to 10 t. ha−1 of U. ruziziensis straw over bare soil increased average yield by 29.9 %, while disease severity was reduced by 31.1 %, in comparison to control plots with no mulch.

The objective of this study was to evaluate the effects of soil cover with sugarcane residue on weed emergence of four weeds from the genus Brachiaria. The study was conducted in an area whose soil was classified as Red Nitosol. Seven different amounts of sugarcane residue (0, 3, 6, 9, 12, 15 and 18 ton ha-1) were used as soil cover. The residue of variety SP832847 was used upon four weed species: Brachiaria decumbens, B. brizantha, B. ruziziensis, and, B. humidicola. The experimental design was a randomized block with four replications. The weeds were sown 1 cm deep and covered by the residue. The seeding rate in use was 1,200 plants m-2. The study was comprised of two phases: the first phase was an evaluation of plant emergence (more than 1 cm for shoots) at 9, 12, 19, 34 and 43 days after sowing (DAS), and in the second phase, plant emergence was evaluated after removal of the straw residue at 89, 130, 175, 196, 217 and 234 DAS. The amount of sugarcane residue used as soil cover influenced the emergence pattern of Brachiaria spp. Minor germination was noticed after residue removal. Amounts greater than 9 ton ha-1 decreased the total number of seedlings in all species, except for B. ruziziensis, whose emergence decreased at 12 ton ha-1. RESUMO O objetivo deste trabalho foi avaliar os efeitos da cobertura do solo com palha de cana-deaçúcar sobre a emergência de plantas daninhas do gênero Brachiaria spp. O estudo foi conduzido em uma área pertencente à Fazenda Experimental da UNESP, campus Botucatu/SP, em um solo classificado como Nitossolo Vermelho de textura argilosa. Foram avaliadas sete diferentes quantidades de palha de cana-de-açúcar (0, 3, 6, 9, 12, 15 e 18 t ha-1) utilizadas como coberturas do solo. Utilizou-se a palha da variedade SP832847 sobre quatro espécies de plantas daninhas: Brachiaria decumbens, B. brizantha, B. ruziziensis e B. humidicola. O delineamento experimental utilizado foi de blocos casualizados com quatro repetições. As plantas daninhas foram semeadas a 1 cm de profundidade e posteriormente cobertas pela palha. A taxa de semeadura utilizada foi 1.200 plantas m-2. O estudo foi compreendido por duas fases distintas: na primeira, foram avaliadas as plantas emersas (mais de 1 cm de parte aérea) aos 9, 12, 19, 34 e 43 dias após a semeadura (DAS) e, na segunda, a emergência das plantas após a remoção da palha aos 89, 130, 175, 196, 217 e 234 DAS. A quantidade de palha de cana-de-açúcar usada como cobertura do solo influenciou a dinâmica de germinação das diferentes espécies de Brachiaria. Após a remoção do palhiço de cana-de-açúcar utilizado como cobertura do solo, houve pouca germinação dessas espécies. Quantidades superiores a 9 t ha-1 proporcionaram redução do número total de plântulas em todas as espécies, com exceção de B. ruziziensis que apresentou redução a partir de 12 t ha-1.

Resumo: O objetivo deste trabalho foi avaliar o acúmulo de forragem e o valor nutritivo do híbrido de Urochloa 'BRS RB331 Ipyporã' (Urochloa brizantha x Urochloa ruziziensis) submetido à pastejo intermitente. Os tratamentos corresponderam às combinações entre as condições de pré-pastejo, interceptação de 95% da luz incidente e máxima interceptação de luz, e as de pós-pastejo, 10 e 15 cm de altura de resíduo, em delineamento de blocos ao acaso, em arranjo fatorial 2x2, com quatro repetições. Pastos manejados com 95% de interceptação da luz apresentaram maior taxa de acúmulo de forragem, proporção de folhas, relação folha:colmo, teor de proteína bruta e densidade populacional de perfilhos basilares (DPPb), em comparação àqueles manejados com máxima interceptação da luz. Pastos manejados com 15 cm de altura do resíduo apresentaram maior DPPb do que os manejados com 10 cm e apresentaram pequena variação de DPPb entre as estações do ano avaliadas, independentemente do tratamento. Pastos do híbrido interespecífico de Urochloa 'BRS RB331 Ipyporã' apresentam maior acúmulo de forragem e maiores teores de proteína bruta e digestibilidade in vitro da matéria orgânica e menores teores de fibra em detergente neutro na fração folha, quando manejados com 95% de IL nas condições de pré-pastejo, com 30 cm de altura do dossel, associada com 15 cm de altura de resíduo. Abstract: The objective of this work was to evaluate the forage accumulation and nutritional value of the Urochloa hybrid 'BRS RB331 Ipyporã' (Urochloa brizantha x Urochloa ruziziensis) subjected to intermittent grazing. The treatments corresponded to combinations of the pre-grazing conditions, interception of 95% of incident light and maximum light interception, and of the post-grazing heights, 10 and 15 cm, in a randomized complete block design with a 2x2 factorial arrangement and four replicates. Pastures grazed at 95% of light interception showed higher forage accumulation rate, proportion of leaves, leaf:stem ratio, crude protein content, and basal tiller population density (BTPD), in comparison with those managed at maximum light interception. Pastures managed with post-grazing heights of 15 cm showed greater BTPD than those managed at 10 cm and showed a slightly variation in BTPD among the evaluated seasons of the year, regardless of the treatment. Pastures of the interspecific hybrid of Urochloa 'BRS RB331 Ipyporã' show greater forage accumulation and higher crude protein content and in vitro organic matter digestibility, and lower content of neutral detergent fiber in the leaf fraction, when managed with 95% LI under pre-grazing conditions of 30-cm sward height, associated with a post-grazing 15-cm sward height.

Apomixis, asexual reproduction through seed, enables breeders to identify and faithfully propagate superior heterozygous genotypes by seed without the disadvantages of vegetative propagation or the expense and complexity of hybrid seed production. The availability of new tools such as genotyping by sequencing and bioinformatics pipelines for species lacking reference genomes now makes the construction of dense maps possible in apomictic species, despite complications including polyploidy, multisomic inheritance, self-incompatibility, and high levels of heterozygosity. In this study, we developed saturated linkage maps for the maternal and paternal genomes of an interspecific Brachiaria ruziziensis (R. Germ. and C. M. Evrard) × B. decumbens Stapf. F1 mapping population in order to identify markers linked to apomixis. High-resolution molecular karyotyping and comparative genomics with Setaria italica (L.) P. Beauv provided conclusive evidence for segmental allopolyploidy in B. decumbens, with strong preferential pairing of homologs across the genome and multisomic segregation relatively more common in chromosome 8. The apospory-specific genomic region (ASGR) was mapped to a region of reduced recombination on B. decumbens chromosome 5. The Pennisetum squamulatum (L.) R.Br. PsASGR-BABY BOOM-like (psASGR–BBML)-specific primer pair p779/p780 was in perfect linkage with the ASGR in the F1 mapping population and diagnostic for reproductive mode in a diversity panel of known sexual and apomict Brachiaria (Trin.) Griseb. and P. maximum Jacq. germplasm accessions and cultivars. These findings indicate that ASGR–BBML gene sequences are highly conserved across the Paniceae and add further support for the postulation of the ASGR–BBML as candidate genes for the apomictic function of parthenogenesis.

The purpose of this research was to identify the soil organic matter (SOM) fractions changes in a crop rotation system under no-till system (NTS). This research was carried out from October 2010 to February 2014 in a Rhodic Hapludox. The experiment was set up in completely randomized blocks in a factorial design with eight cover crops and three soil depths (0-5, 5-10 and 10-20 cm) with four repetitions. Cover crops: fall-winter corn, intercropping fall-winter corn with 'Brachiaria ruziziensis', intercropping fall-winter corn with 'B. brizantha' cv. Marandu, intercropping fall-winter corn with Crotalaria spectabilis, 'B. ruziziensis, B. brizantha cv.' Marandu, 'Pennisetum glaucum' L. and set-aside area. The results of SOM granulometric fractionation showed that 6.5% of the total organic carbon (TOC) stocks were in the particulate organic carbon (POC) fraction. The low values of POC observed in this research are associated with the weather condition of experimental site, which shows high temperature and moisture. In relation to the labile carbon (LC), the highest LC stock was observed in 0-5 cm depth, which differed from the 10-20 cm depth. The POC, LC and labile nitrogen (LN) were the SOM fractions that showed to be more sensitive to detect the changes promoted by the cover crops and soil depths in NTS, as well as the carbon management index (CMI). The intercropping fall-winter corn with 'B. brizantha' cv. Marandu and 'B. ruziziensis' were efficient in increasing the CMI in deeper depth (10-20 cm).