RESULTS OF ENVIRONMENTAL TESTING OF SPRING RAPESEED VARIETIES OF DOMESTIC AND FOREIGN SELECTION UNDER THE NORTHERN KAZAKHSTAN CONDITIONS
The objective of research conducted in Kostanay Scientific Research Institute of Agriculture (the Republic of Kazakhstan) was to identify collective material of varieties of spring rapeseed that are flexible, high-yielding, high-oily, technologically and environmentally adaptive to adverse growing conditions of the Northern Kazakhstan. Spring rapeseed cultivars were of Kazakhstani and German selection and bred by All-Russian Research and Development & Design Rapeseed Institute, All-Russian Research Institute of oil-yielding crops, and the Siberian Research Station of All-Russian Research Institute of oil-yielding crops (the Heros cultivar was taken as a control). The experiment was laid by fallow predecessor, which was prepared as bare fallow according to climatic cropping pattern. During vegetation a series of measures to combat harmful objects in the crops (e.g. weeds, pests, and diseases) were performed. On average over the years of research the longest vegetation period was observed for the Start and Kupol cultivars (103 days). The most early-maturing were the GK-001 and Grifin cultivars (91 and 93 days, respectively). Over the research period the studied rapeseed cultivars were practically unaffected by lodging. Crop infestation monitoring revealed the presence of blue flea, cabbage moth, cabbage bug, cabbage aphid, rapeseed beetle, leaf beetle, and sawfly. Rapeseed was insignificantly affected by Alternaria blight, and powdery mildew was not observed on plants. According to the research results, the highest yield of oilseeds in 2012-2014 was registered on the variants with Kupol (26.6 c/ha) and Start (24.5 c/ha) cultivars exceeding control values by 6.5 and 4.4 c/ha, respectively. The K-39, G-2, K-4 and Granite cultivars were also consistently superior to the control variant: their average yield was 23.2-23.5 c/ha. During the research period the oil yield per 1 hectare was the highest on the variants with Kupol cultivar - 11.2 c/ha. On the variants with Start, Granite, K-39, and K-4 cultivars it was 9.3-9.9 c/ha (control value was 7.8 c/ha). In addition to high level of productivity and oil yield, such cultivars as Heros, Lipetskiy, Bulat, K-39, K-4, and G-2 are notable for optimally short vegetation period of 97-99 days.