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Bioactivity of nine essential oils (EOs) was studied on Anagasta kuehniella eggs in relation to the longevity of females, parasitism and emergence rates and sex ratio in the generations parental, F1 and F2 of Trichogramma galloi in comparison to a trade formulation of Azadirachta indica. There was no F1 and F2 progeny with Zingiber officinale being the most harmful. The greatest reductions in the parasitism rates (57, 43 and 28%) in the parental generation was caused by Allium sativum, Carapa guianensis and A. indica, respectively. In addition, A. sativum reduced the longevity (4.7 days) in the parental generation and emergence (33%) of F1. Tested EOs did not affect the sex ratio in the generations F1 and F2 and emergence in the F2. Allium sativum and Z. officinale were non-selective to T. galloi; while A. indica, C. guianensis and P. nigrum oils may compromise the progeny; therefore, their use must be avoided. Citrus sinensis, Mentha piperita, Origanum vulgare, Syzygium aromaticum and Thymus vulgare were selective to T. galloi, and these EOs are promising for IPM programs.

Continuous use of glyphosate in citrus groves in the Gulf of Mexico region has selected for resistant Parthenium hysterophorus L. populations. In this study, the target-site and non-target-site resistance mechanisms were characterized in three putative glyphosate-resistant (GR) P. hysterophorus populations, collected in citrus groves from Acateno, Puebla (GR1 and GR2) and Martinez de la Torre, Veracruz (GR3), and compared with a susceptible population (GS). Based on plant mortality, the GR populations were 9.2-17.3 times more resistant to glyphosate than the GS population. The low shikimate accumulation in the GR population confirmed this resistance. Based on plant mortality and shikimate accumulation, the GR3 population showed intermediate resistance to glyphosate. The GR populations absorbed 15-28% less 14C-glyphosate than the GS population (78.7% absorbed from the applied) and retained 48.7-70.7% of 14C-glyphosate in the treated leaf, while the GS population translocated ~68% of absorbed herbicide to shoots and roots. The GR3 population showed the lowest translocation and absorption rates, but was found to be susceptible at the target site level. The 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene sequence of the GR1 and GR2 populations showed the Pro106-Ser mutation, conferring 19- and 25-times more resistance in comparison to the GS population, respectively. Reduced absorption and impaired translocation conferred glyphosate resistance on the GR3 population, and contributed partially to the resistance of the GR1 and GR2 populations. Additionally, the Pro-106-Ser mutation increased the glyphosate resistance of the last two P. hysterophorus populations.

A database on the performance of native plants under different environmental conditions can improve the selection of species most suitable for carbon offset programs. The objective of this work was to identify the potential of 25 tree species for carbon offsetting in a degraded area in the Brazilian Atlantic Forest, with a scoring system based on the survival rate (SV) and average annual carbon increment (IMAC). The diameter and height of trees were measured to estimate the annual increments to select those to be scaling by species by the non-destructive method, and to estimate the volume and carbon of each plant by species. The mean SV of trees was 47% with high variability ranging from 5 to 100%, especially for Schinus terebinthifolius (100%); Sapindus saponaria (95%); Senna multijuga (80%); Handroanthus chrysotricha (80%); Plathymenia foliolosa (75%); Cassia grandis (75%) and Colubrina glandulosa (60%), all pioneers except for H. chrysotricha and C. grandis. The lowest SV were for Caesalpinia peltophoroides (20%); Tibouchina granulosa (10%); Anadenanthera pavonina (5%); Cariniana legalis (5%); Samanea inopinata (5%) and Syzygium jambos (5%), all non-pioneering species, except for A. pavonina. The growth of non-pioneer species was generally lesser than pioneer ones, except for Ceiba speciosa. Among non-pioneers, T. granulosa, Bombacopsis glabra and C. grandis stood out for the hight growth. None of the species reached a maximum score (10 points) for the sum of the parameters considered. The highest scores (nine points) were for Schizolobium parahyba and S. multijulga, both pioneers. The lowest scores (two points) were for A., Cariniana legalis, Lecythis pisonis, Samanea Inopinata and S. jambos followed by Cedrela fissilis, Caesalpinia peltophoroides, Cytharexyllum myrianthum, Hymenaea courbaril, Psidium guineense and Tibouchina granulosa (three points) and Anadenanthera macrocarpa and Sterculia chicha (four points). The methodology adopted allowed the assessment on of the potential of plant species for carbon offsetting projects in degraded areas, specifically in the Brazilian Atlantic Forest.

The use of chemical insecticides and non-selective natural products authorized for use in organic farming may reduce the effectiveness of egg parasitoids. The side-effects of ten plant essential oils on immature stages of Trichogramma pretiosum were evaluated. Carapa guianensis, Origanum vulgare and Zingiber officinalle during the F1 generation, and Azadirachtin and Mentha piperita in the F2 generation were slightly harmful (class II: 30–79%) to the emergence of this parasitoid. All essential oils affected the longevity of females of the F1 and F2 generations. Thymus vulgaris and Z. officinalle were the oils most harmful to female longevity. Carapa guianensis proved slightly harmful (class II: 30–79%) to parasitism in the F1 generation when applied during the egg-larval and pre-pupal stages and O. vulgare in the F1 generation in the pre-pupal stage alone, of this parasitoid. The sex ratio was lower than 0.5 during the pre-pupal stage of the F1 generation with Azadirachtin, C. guianensis, O. vulgare, Piper nigrum and Syzigium aromaticum, but this parameter was not affected for the other biological stages of T. pretiosum in the F1 and F2 generations. The Azadirachtin, C. guianensis, M. piperita, O. vulgare, T. vulgaris and Z. officinalle oils revealed a mild toxic effect to the immature stages of T. pretiosum and, therefore, it should be used according to patterns of ecological selectivity. Allium sativum and Citrus sinensis essential oils were not harmful to T. pretiosum, and can be used in Integrated Pest Management.

At present, appearance of herbicide resistant weeds is not new because repeated herbicide treatments per agricultural year/cycle are usual in both perennial and annual crops worldwide. Characterizing resistance mechanisms implied in each herbicide resistant weed is the best tool and the basis to develop integrated weed management (IWM) strategies. The main resistance mechanisms which confer low sensibility to glyphosate in a previously confirmed glyphosate-resistant Chloris radiata population (ChrR), occurring in Colombian rice fields, were characterized. Pure line selection by clone plants showed high resistance levels in ChrR. Comparing with GR50 and LD50 values, ChrR was 9.6 and 10.8 times more resistant with respect to a representative susceptible population (ChrS). The nontarget site mechanisms reduced glyphosate absorption and translocation did not contribute to the glyphosate resistance of the ChrR population. However, enzyme activity assays and DNA sequencing demonstrated that at least one target-site resistance mechanism is involved in such resistance. All ten ChrR plants tested had the amino acid substitution Pro-106-Ser. The results may be crucial to decrease the resistance distribution of C. radiata in Colombia by implementing IWM programs. The change in weed control strategies in rice fields from Colombia must include herbicides with different mode of action from glyphosate and non chemical methods to preserve the useful life of glyphosate longer for weed control in the country.

Premix or tank mix of glyphosate and 2,4-D are a good alternative to control glyphosate-resistant and -tolerant weeds; however, the combination of herbicides may increase the environmental impacts, since mixtures often have higher toxicity than a single herbicide. In addition, antagonism between these herbicides has also been reported. We compared the efficacy of a premix glyphosate+2,4-D formulation with respect to the tank mix of both herbicides on glyphosate-resistant Conyza canadensis and -tolerant Epilobium ciliatum populations in laboratory and field experiments. 2,4-D suppressed the glyphosate-resistance/tolerance of both species, whose populations presented similar responses to their susceptible counterparts (LD50 ≥ 480+320 g ha−1 glyphosate + 2,4-D, respectively). Plants of both species treated with the premix formulations retained ∼100-μL more herbicide solution, accumulated 20–25% and 28–38% more shikimate and ethylene, respectively, and presented greater 14C-glyphosate absorption and translocation, depending on the species, compared to plants treated with the tank mix treatment. Although doubling the field dose (720 + 480 g ha−1) improved (5–22%) the control of these weeds in the field, split applications of both premix and tank mix provided the best control levels (≤70%), but premix treatments maintained control levels above 85% for longer (120-d). No antagonism between glyphosate and 2,4-D was found. The addition of 2,4-D controlled both broadleaf species. For all parameters evaluated on the C. canadensis and E. ciliatum populations in the laboratory and in the field, the premix treatments showed better performance than the tank mix treatments. Premix formulations could reduce the environmental impact of herbicides used to control glyphosate resistant/tolerant weeds by decreasing the herbicide amount needed to achieve an acceptable weed control level.

Brazil must restore 12 million hectares of degraded areas by 2030 to meet its goal of the Paris Global Climate Agreement (PGCA). In view of this, the development of mixed planting projects related to carbon-offset in degraded areas is increasing, which demonstrates environmental and social responsibility of corporate and governmental organizations. Despite the great potential of mixed restoration plantations to mitigate climate change, Brazil must overcome major challenges in achieving the ratified goals of the PGCA as well as the effectiveness of its carbon-offset projects. In this context, this study has focused on the evaluation of the growth and survival of tree species in a carbon-offset plantation from a degraded area in southeastern Brazil. Five-hundred-and-nine seedlings (15 forest species) were planted in a completely randomized design. Diameter at the soil level and height of individuals were measured at 40 months. Three individuals of each species were selected and was scaling by a non-destructive method. Timber volume was estimated from the sum of the volume of the sections of the individuals, obtained by the Smalian formula. The average annual carbon increment of the individuals was estimated by the equation adjusted from the Schumacher & Hall model. The potential of carbon-offset of the tested plants was evaluated from the SP and μC analysis. The REML (Restricted Maximum Likelihood)/BLUP (Best Linear Unbiased Prediction) method was used to predict μC values for species ordering with carbon -offset potential. Survival was 47.54% at 40 months. The carbon stock of the planting was 2.60 ± 6.2 Kg C individual−1, and the average annual increase in carbon (AAIC) was 0.78 Kg C individual−1year−1. The AAIC value was lower than the average value stipulated for carbon-offset projects (6.0 Kg CO2 individual−1 year−1). Pioneer species contributed more to carbon storage than non-pioneer species.

Made available in DSpace on 2020-12-10T17:38:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-15 Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) Seedlings of macauba (Acrocomia aculeata (Jacq.) Lodd. ex Mart) palm spend similar to 10 months in nursery before being taken to the field. Since there are no registered herbicides for macauba, weed control in seedling containers is done manually; however, macauba leaves have thorns that injure workers' hands. In this work, the selectivity of indaziflam, isoxaflutol, oxyfluorfen and sulfentrazone was evaluated on macauba seedlings produced in nurseries, incorporated (INC) to the substrate and/or applied before (PRE) and after (POST) transplantation, as well as its efficacy for the weed control. Seedlings were no intoxicated by the herbicides regardless of the application method. However, considering the height, leaf area and dry weight and root volume, the INC and PRE applications of indaziflam were not selective for macauba. In contrast, POST-indaziflam applications stimulated the growth of seedlings (< 100 cm), being even greater than the control (75 cm) M 10 months. Regarding weed control, the INC treatments lost effectiveness up to 40 % from 14 to 56 days after application (DAA), except indaziflam which maintained a control above 95 %. Weed control of PRE applications decreased up to 60 % for all four herbicides, while the POST applications of indaziflam, oxyfluorfen and sulfentrazone maintained control levels >= 80 % at the same period. Weed presence reduced the growth rate of macauba seedlings by similar to 40 % (32 cm high in the non-weeding control vs 55 cm in the weeding control) at 126 DAA. In addition, weeds reduced the growth of seedlings in most treatments, since the plant height was similar to the non-weeding control. Isoxaflutole, oxyfluorfen and sulfentrazone were selective for macauba seedlings, regardless of the herbicide application method. Indaziflam was selective for seedlings only in POST applications. The evaluated herbicides were efficient in controlling most weed species up to 56 DAA in PRE and POST applications. Univ Fed Vicosa, Dept Fitotecnia, BR-36570900 Vicosa, MG, Brazil Univ Fed Sao Carlos, Dept Quim, BR-13565905 Sao Carlos, Brazil Univ Estadual Paulista Julio de Mesquita Melo UN, Fac Ciencias Agr & Vet FCAV, BR-14884900 Jaboticabal, Brazil Univ Estadual Paulista Julio de Mesquita Melo UN, Fac Ciencias Agr & Vet FCAV, BR-14884900 Jaboticabal, Brazil