The effect of ensiling on variety rank of forage maize

The objective of the present study was to calculate an optimal harvest period for both fresh and ensiled samples of forage maize and to calculate a set of harvest dates (called a harvest window), for which the variety ranking of the fresh forage corresponds with the variety ranking at the optimal harvest period calculated from the ensiled forage. Forage maize is fed almost exclusively as silage, but official variety trials with silage maize determine quality parameters in fresh (i.e. non-preserved) forage. Eight silage maize varieties were monitored at six harvest dates (from 25 to 40% dry matter content) in Merelbeke (Belgium) in 2013-15. At each harvest date, fresh samples were taken and half of the sampled material was ensiled in micro silos for 20 weeks. An optimal harvest period was calculated based on frequently measuring starch concentration and organic matter digestibility for both fresh and ensiled forage. Eventually, harvesting the silage maize at a dry matter content of 32-35% guaranteed an optimal harvest period. Based on the results of eight varieties, reporting variety ranks without going through the ensiling process continues to be a scientifically justified practice in Belgian official variety trials. Varieties with a superior fresh quality keep their leading position after ensiling, but variety differences become smaller after ensiling

Test sorghumrassen op vier proeflocaties

De droogtetolerantie en ziekteresistentie van sorghum maken het gewas steeds geschikter voor teelt en gebruik als ruwvoer in Nederland. Het gewas is echter nog niet uitontwikkeld. Veredelaars zetten elk jaar stappen om betere sorghumrassen te ontwikkelen voor Nederland. Zo wordt momenteel gezocht naar rassen die in het Nederlandse klimaat opbrengst combineren met een redelijk zetmeelgehalte en een goede verteringscoëfficiënt

Comparison of image analysis and direct measurement of UPOV taxonomic characteristics for variety discrimination as determined over five growing seasons, using industrial chicory as a model crop

Tests for distinctness, uniformity and stability (DUS) are an essential component of variety registration and granting plant breeders' rights. This study, performed on industrial chicory (Cichorium intybus L.), included (1) an evaluation of the discriminating power of the UPOV characteristics and (2) a comparison of the root shape between the UPOV-based characteristics and characteristics determined via image analysis. Five consecutive growing periods were studied to assess the long-term stability of the parameters. Lack of discriminating power of characteristics for examining distinctness may impede breeding progress by failing to discriminate novel candidate varieties. However, a balance needs to be set so that newly introduced characteristics or new evaluation methodologies are not too powerful as to damage the protection of registered varieties. The results showed great differences in the discriminating power of the UPOV characteristics. The elimination of some of these low-discriminating characteristics would probably result in savings, but would have no consequences on the decisions taken by DUS testing authorities. Image analysis-derived characteristics could either replace currently-used parameters or provide additional characteristics with good discriminating power, determined in an objective and standardized way. Here we discuss possible implications for variety registration

Stay-green characterization in Belgian forage maize

The term stay-green' (SG) is used in studies with varieties showing delayed senescence in the field. However, delayed appearance of visual symptoms of leaf senescence does not guarantee a longer duration of photosynthesis. The question arises whether the variation in photosynthetic capacity between silage maize varieties currently on the Belgian market is large enough to define different SG types. Furthermore, physiological traits were investigated as proxies for photosynthesis, including chlorophyll concentration, nitrogen (N) concentration, SPAD readings and greenness score. Finally, the functionality of the SG trait was determined by studying dry matter (DM) and N partitioning in the plants. To address these questions, eight silage maize varieties were monitored at two sites in Belgium over 2 years (2013-2014). Two plant types were found: hereafter called ' normal ' and ' SG '. The SG varieties had higher values for photosynthetic capacity and they coincided with higher values for the proxies. Because a higher photosynthetic capacity did not provoke higher assimilate accumulation in the leaves, the SG trait was characterized as a cosmetic one. The SG trait influenced N dynamics in the plant: lower N translocation from the leaves to the ear resulted in lower ear N concentration and lower ear DM yield. No differences in whole-crop N concentration and whole-crop DM yield were found. As the SG trait mainly provokes shifts in partition of DM and N between vegetative and generative tissues, the energy source also shifts from starch (provided by the ear) to cell wall material (provided by the stover)

Screening for soybean varieties suited to Belgian growing conditions based on maturity, yield components and resistance to Sclerotinia sclerotiorum and Rhizoctonia solani anastomosis group 2-2IIIB

© 2018 Cambridge University Press. Policy makers and farmers in north-west Europe are expressing a growing interest in soybean production. However, cool and wet climatic conditions in this region pose challenges for this crop in terms of reaching maturity and producing sufficient yield and create additional disease pressure from the fungal pathogens Sclerotinia sclerotiorum and Rhizoctonia solani. To increase the chance for successful introduction of this new crop in Belgium and to determine the main issues for local soybean breeding programmes, 14 early maturing varieties were screened over a 2-year-period for their agronomic performance. Based on novel bioassays, susceptibility to S. sclerotiorum and R. solani anastomosis group (AG) 2-2IIIB was evaluated. The varieties tested were able to reach sufficient maturity (average seed moisture content of 19.0%) by the beginning of October. Significant differences were observed in most agronomic characteristics, with seed yield and protein content ranging from 2002 to 2916 kg dry matter/ha and 35.5-43.3%, respectively. Taller varieties ripened later but reached higher protein levels compared with shorter varieties. Tolerance to lodging was correlated with seed and protein yield but was not correlated with plant height. Large seeds corresponded with a high protein content. Susceptibility to S. sclerotiorum reflected significant differences between varieties. In contrast, levels of susceptibility to R. solani AG 2-2IIIB were similar between most varieties, with only the variety Primus showing significantly less disease. The results of the current study hold promise for a successful introduction of soybean cultivation in north-west Europe and areas for further crop improvement have been identified.status: publishe