Search

Seed treatments have a potential to improve seed performance traits and consequently optimize crop establishment. However, there is a lack of systematic research for these techniques in lucerne, especially under field conditions. The goal of this study was to investigate the potential of various seed treatments on the improvement of lucerne germination and emergence under lab conditions and early seedling growth in the field. Compared treatments were heat treatment; seed priming with water, potassium permanganate, chitosan, vermitea, or bokashi juice; and seed coating with cinnamon, gypsum, wood ash, tannin quebracho, and cocoa powder. Among the seed priming methods, potassium permanganate and chitosan provided the best results in the improvement of seedling length or emergence dynamics, whilst coating with bentonite and gypsum could be recommended for having a positive impact on root development. Cinnamon powder significantly improved the emergence dynamics, seedling, and shoot length. The combination of priming and coating methods seems to be the most effective when assessed under the field conditions, where some positive response in root traits can be evaluated. [ABSTRACT FROM AUTHOR]

Alfalfa (Medicago sativa L., AL)‐based forage mixtures are a major constituent of ruminant rations, and optimizing their energy‐to‐protein ratio has been identified as a way to improve N use efficiency. This study aimed to determine whether the energy‐to‐protein ratio could be improved by adding red clover (Trifolium pratense L., RC) or birdsfoot trefoil (Lotus corniculatus L., BT) at different seeding proportions, and/or one grass species [timothy, Phleum pratense L., or tall fescue, Schedonorus arundinaceus (Schreb.) Dumort] to AL. Annual forage yield, species proportion in botanical composition, and nutritive value of forage were measured at three sites in Canada for 2 post‐seeding years. The addition of RC or BT did not affect the annual forage yield but it increased the concentration of forage nonfiber carbohydrates (NFCs), particularly of soluble sugars, and decreased concentrations of crude protein (CP), nonprotein nitrogen (NPN), and rapidly degradable protein (PB1) of AL‐based mixtures. The addition of one percentage unit of RC or BT to forage botanical composition improved the NFC/CP ratio by 0.005, and the NFC/(NPN + PB1) ratio by 0.024. The addition of either grass species to AL mixtures also increased the two ratios, but it was related to a CP decrease with no increase in NFC concentrations. Adding RC or BT to AL‐based mixtures is therefore a valuable strategy to increase the forage energy to protein ratio. Core Ideas: Adding red clover to alfalfa‐based mixtures reduced the protein degradability more than birdsfoot trefoil.Adding red clover or birdsfoot trefoil to alfalfa‐based mixtures improved the energy‐to‐protein ratio.Adding grass to alfalfa‐based mixtures improved the energy‐to‐protein ratio by decreasing the protein concentration. [ABSTRACT FROM AUTHOR]

Introduction: Biological control of root diseases of lucerne (Medicago sativa L.) has potential benefits for stand performance but this remains unsupported by evidence from practical field studies. Methods: In field experiments at three sites our objectives were to determine the effect of Pythium oligandrum, as spring, autumn and intensive regime treatments on (i) lucerne plant density and root traits development, and (ii) forage yield and forage traits. Lucerne stands were managed under two or three treatments: non-treated control and P. oligandrum applied at two intensities of application under four-cut utilization. Results and discussion: Under relatively dry conditions (annual mean 10°C and <500 mm precipitation) lucerne dry matter yield was significantly reduced by 6%, which could be related to mechanisms of inappropriate stimulation and disturbance of the balance between auxins and ethylene. Under annual precipitation of >500 mm, positive impacts on stand height or fine root mass were observed for the autumn and intensive treatments where positive root response was visible only in alluvial soil. However, these changes did not result in higher yield and probably more applications per year will be needed for significant forage yield improvement. This study highlights the limits of field-scale biological control in which the potential of P. oligandrum for lucerne productivity improvement was realised only under a humid environment or deep alluvial soils, where higher root disease infestation may also be expected. [ABSTRACT FROM AUTHOR]

The relationship between root morphology and productivity in lucerne (Medicago sativa L.) has been well documented, but the effect of sowing rate on root development is unclear. Results from three field experiments were analysed to address these objectives: (a) to investigate lucerne root development as a function of distance among plants, (b) to evaluate the effect of sowing rates on lucerne root traits and (c) to investigate the relationship between root traits and forage yield and yield components. A 4‐year experiment that compared spaced plants (50 × 50 cm, four plants m2) versus row seeding (12.5 cm, 700 germinated seeds m−2) revealed fast annual tap‐root diameter (TD) development in spaced plants, with about 12 mm, and three times greater TD and five times the lateral root number compared with row‐spaced plants. Three‐year field plot experiments at one site compared sowing rates of 400 versus 700 germinated seeds m−2 in less favourable soil for lucerne, and 700 versus 900 seeds m−2 in a better soil. Across experiments, higher plant density and root potential index were positively related to forage yield only when in association with better soil conditions and optimal water supply. Lower plant density offered advantages for faster root development. An effect of reduction in the sowing rate was increased stand height and increased yield in the third cut in a year with drought stress. Results show the need for investigation of effects of more precise spatial arrangement of lucerne plants to ensure optimization of root development and to enable yield benefits and drought resistance. [ABSTRACT FROM AUTHOR]

Evaluation of crop and forage yield stability is of increasing relevance in the context of current and recent environmental changes but, in contrast to other field crops, there are no published systematic analyses among forage crops in Europe. A study of stability performance was conducted with 13 Czech cultivars of lucerne at four locations over a 2‐year period with the following aims: (a) to evaluate yield stability of varieties across different environments and (b) to calculate measurable benefits of variety selection in relation to the specific environment. The cultivar Vlasta was identified as the highest yielding cultivar (annual yield 16.0 t DM/ha), whereas the lowest yielding cv. Magda, Tereza and Oslava averaged around 14.9 t DM/ha. Effect of genotype × environment interaction (G × E) was two times higher than for genotype alone. Additive main effects and the multiplicative interaction (AMMI) model showed that the highest yielding cultivars may not be stable across environments. This study demonstrated further that significant yield improvement could be detected, even among a relatively homogenous group of domestic cultivars, and this was driven mainly by site productivity: the improvement was +10% in low‐yielding sites, compared with +3% in high‐yielding sites. Results highlight that advanced agronomy should also consider stability parameters such as AMMI stability value or superiority measures for forage crops in response to the challenges associated with climate change. [ABSTRACT FROM AUTHOR]

Root diseases of lucerne (Medicago sativa L.) play a significant role in reducing the persistence and productivity of stands; however, the potential of using biological control in lucerne crops has not yet been investigated. Our objectives were to determine the effect of biological crop protection on (i) lucerne plant density and root traits development and (ii) lucerne forage yield and nutritive value in a two-year field experiment. The lucerne stand was managed under three treatments of disease control: an untreated control and spraying with either Albit (hydrolysate of microorganisms containing microelements and poly-beta-hydroxy butyric acid) or Polyversum (mycoparasitic Pythium oligandrum) under five-cut utilization. Application of Albit resulted in a negative yield response, associated with a reduction of root branching, and it also reduced crude protein and increased crude fibre and water-soluble carbohydrates in the second cut of the first year of the experiment. Polyversum increased the percentage of infected plants relative to the control in the last year of the experiment. The study highlights that biological control of lucerne under field conditions may not always be beneficial because of the complex interactions between plant, biological preparation, and environment. [ABSTRACT FROM AUTHOR]

It is a common practice to grow lucerne ( Medicago sativa L.) in mixture with grass. The development of lucerne root morphology along with concomitant forage mixture growth, however, has been rarely studied in multi-year field experiments. Our objectives were: (i) to assess the effect of a grass component on lucerne root trait development, (ii) to evaluate changes in forage yield and aboveground traits in the lucerne monocultures and lucerne-grass mixtures and (iii) to investigate the relationships between root traits and lucerne yield, total forage yield, as well as forage aboveground traits, using multivariate methods. Treatments were a factorial combination of four lucerne varieties and three lucerne sowing ratios [100% (L100), 90% (L90) and 75% (L75)] with grass hybrid Festuca pratensis × Lolium multiflorum under a three-cut harvesting regime in a 4-year experiment. Lucerne yield, total forage yield and forage aboveground traits were evaluated at each cut. Each autumn, lucerne plants were evaluated for root morphology traits and scored for root disease. The negative impact of the presence of a grass component on lucerne root morphology development was observed only in combination with the higher lucerne sowing ratio (L90), with reduced intensity of root branching and increased depth of the first lateral root. In two post-seeding years out of three, total forage yield was 4–8 % higher for lucerne-grass mixture in comparison with monoculture. From all lucerne yield components in the mixture, stem density was the best predictor for lucerne yield. Lucerne root morphology explains about 10% of forage yield and aboveground traits variability where calculated root potential index, lucerne plant density and root dry matter mostly correlated with lucerne yield in the mixture. Root potential index was an effective indicator for monitoring root development and was even effective for comparing lucerne varieties in mixture. Understanding the relationships between root morphology development and lucerne stand performance in a mixture can help in optimization of sowing ratio and stand evaluation. [ABSTRACT FROM AUTHOR]

Changes in lucerne ( Medicago sativa L.) root morphology concurrent with forage growth have been little studied in multi-year field experiments with lucerne stands though they could provide explanations for differences in performance among tested treatments. Our objectives were: (i) to compare lucerne root trait development under three- and four-cut managements over a 4-year period, and (ii) to investigate relationships among root traits, and between root traits and lucerne varieties, cutting frequencies, root sampling periods, lucerne dry matter yield and evidence of root disease incidence and plant density, using multivariate methods. Treatments were a factorial combination of 15 lucerne cultivars with managements of three and four cuts per year. Each spring and autumn, plants were evaluated for root morphology traits and scored for root disease. Root morphology traits were strongly modified by sampling period and plant density, which together explained over 40% of total variability. The development over time was positively associated with an increase in tap-root diameter (TD) and root mass accumulation, whereas root density determined changes in root branching traits. The four-cut management reduced TD and root branching in association with lower forage yield. Variety effect was significant but contributed only 2.8% of total variability. Root branching showed a positive correlation with forage yield through a large increase of TD for branch-rooted plants, but more intensive root branching was associated with a significantly higher disease score than in tap-rooted plants. For optimization of evaluation of root traits, we proposed a root potential index (RPI) integrating TD and plant density. This RPI showed a closer relation to yield than TD, plant density or root biomass alone, in the arable cultivation layer. Our results reveal that monitoring of root morphology is an effective tool to characterize the production potential of lucerne as a sown field crop, and may explain yield differences among the various experimental treatments. Understanding these relationships between root morphology and lucerne stand performance can help in breeding selection as well as effective lucerne stand evaluation. [ABSTRACT FROM AUTHOR]

Fertilization management affects both productivity and nutritive value of forage legumes. However, there are few studies about changes in lucerne non-structural carbohydrates under long-term fertilization. The aims of this study were to compare the effects of mineral fertilization and organic manure on lucerne plant parts (leaf, stem) starch and water-soluble carbohydrate (WSC) accumulation in association with canopy structure following 60 years of different fertilization management approaches. Treatments investigated were: two contrasting levels of mineral N, P2O5 and K2O application (0:0:0 and 91:71:175), each with and without farmyard manure. Changes were mainly reflected in WSC content where intensive mineral fertilization consistently reduced the stem and forage WSC in contrast to unfertilized control or manure alone. These changes could be associated with a dilution effect presented by the highest increase of maximal stem length at these treatments. Manure improved leaf and forage WSC despite the associated increase in maximal stem length and leaf weight ratio, probably as a result of improved soil environment together with the potentially increased presence of arbuscular mycorrhizal fungi. Results showed that manure fertilization has potential for improvement of lucerne WSC, despite some negative relationships between lucerne canopy traits and sugar content. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine in greenhouse experiments seed emergence of 14 lucerne varieties (mostly of the Czech origin) under different soil conditions (Luvisol, Chernozem and Cambisol). Soil conditions significantly influenced seed emergence in seven varieties. Their seed emergence was lower in Cambisol (72%) than in Chernozem (80%) and Luvisol (91%). In other varieties the soil effect was not significant. The effect of variety could not be separated from the effect of seed lot in our experiment. However, germination, occurrence of hard seeds, germinative energy and thousand-seed weight were not significantly different between the groups of varieties that could be classified as sensitive and tolerant to the examined soil conditions. The obtained results indicated that the selection of suitable lucerne variety or seed lot could be a tool for improving emergence in deteriorated soil conditions. [ABSTRACT FROM AUTHOR]

The root morphology of alfalfa is connected to many important agronomic traits but few investigations have focused on European varieties. The goal of this study was to screen the variability of root morphology among several alfalfa varieties in the seeding year. In this experiment ten varieties of alfalfa (nine Czech varieties and Europe) were analyzed for selected root morphological parameters after excluding stand density effect. Our results from seeding year show that although significant differences could be detected between the evaluated varieties these differences were small. Cluster analysis showed that the major differences between the varieties were in depth of the first branching point, lateral root number and root diameter. Experimental data indicates lateral root number is inversely correlated with the depth of the first branch point. This preliminary study is being continued to investigate more fully the main differences between varieties in the following years. [ABSTRACT FROM AUTHOR]

• Mineral fertilization reduced nutritive value under increased forage productivity. • Long-term manure fertilization improved nutritive value of leaves and stems. • Soil conditions under long-term manure fertilization reduced drought stress of lucerne plants. • Fertilization explained 38 % of variability of lucerne forage quality. • Half of fertilization effect could be contributed simply by changes in canopy structure. Fertilization management influences not only productivity but also the nutritive value of forage legumes. However, there have been few studies about these effects in long-term fertilization experiments. Our objectives were: (i) to compare the effects of mineral fertilization and organic manure on lucerne forage yield and leaf and stem nutritive value over a 2-year period following 60 years of different fertilization managements, and (ii) to investigate relationships among canopy structure traits and forage nutritive value in association with these fertilization treatments. The long-term fertilization experiment was established with four replications in the Czech Republic in 1955. Three levels of mineral N, P and K application (0:0:0, 39:24:109 and 91:31:146) were investigated, each with and without farmyard manure, resulting in six treatments. Lucerne stands were established in 2012 and 2013 in two strips. Forage yield was measured in two cuts in 2014 and 2015, respectively. Canopy structure traits and forage nutritive value (crude protein, ash, neutral detergent fibre (NDF) and NDF digestibility (NDFD) were analysed in the first cut in each year. Intensive mineral fertilization reduced lucerne nutritive value through a reduction in stem NDFD (-6%) and leaf weight ratio (-10 %) under higher forage productivity (+10 % of annual yield). Manure fertilization improved nutritive value of leaves and stems, with an associated increase in whole plant nutritive value as leaf proportion was maintained with increased yield (+8%). This positive response could be attributed to a soil environment effect: greater root development in soil that had received long-term manure fertilization probably reduced forage lignification and maintained leaf proportion in association with reduced drought stress. Long-term manure fertilization demonstrated potential for improvement of lucerne nutritive value despite the negative relationships between increased plant growth under higher nutrient supply and forage nutritive value. [ABSTRACT FROM AUTHOR]