Dry matter accumulation in the varieties of wheat (Triticum aestivum L.) according to previous crop

A. Ivanova, N. Tsenov
Abstract. The constant interest in common wheat investigations is determined by the main share this crop has in agriculture and by the unique properties it possesses. This investigation was carried out under field conditions for a three-year period (2009 – 2011) in the trial field of Dobrudzha Agricultural Institute – General Toshevo (DAI). The trial was designed according to the split plot method in four replications, the size of the trial plot being 12 m2. Five common wheat genotypes developed at DAI were subjected to investigation (Iveta, Enola, Pryaspa, Bolyarka, Dragana). The trial involved four previous crops: oilseed rape, pea, sunflower and maize, and three norms of mineral fertilization depending on the type of previous crop. Fertilization with phosphorus and potassium was used as a background (Р К ), kg/ha and nitrogen was tested at the following fertilizer norms: N , N and N kg/ha after previous crops oilseed rape, 60 60 60 120 180 sunflower and maize, and N , N and N kg/ha after pea, with check variant N P K . The effect of the type of previous crop on dry matter accumulation in the 30 60 90 0 0 0 investigated common wheat varieties was analyzed. It was found that dry matter accumulation continued throughout the entire growth season, the year conditions being decisive for its amount. Dry matter accumulation during the individual stages of growth and development was specific for each investigated cultivar. The investigated cultivars accumulated higher total biomass than the standard Pryaspa. After the early previous crops (oilseed rape and pea), the amounts of dry matter formed were higher at the end of the growth period (after heading). After the late previous crops (sunflower and maize) the new wheat varieties formed higher total biomass as early as the beginning of spring growth. After predecessor pea the highest amounts of dry matter were formed.