Sunflower seedlings dry matter content as affected by chemical treatment and storage length.

Chemical treatment of seed is a common crop protection measure. In the case of sunflower seed, fungicides are used regularly and insecticides at an increasing rate. In some cases, sunflower hybrid seed not planted in the first year is planted in the second or even third year after production. Seed vigour decreases gradually over time, which negatively affects seed emergence and subsequent plant growth and development. Seed with high vigour is expected to germinate quickly, producing seedlings that grow fast and uniformly. The objective of this study was to assess the effects of seed chemical treatment and storage length on seedling dry matter content in different sunflower hybrids. The study included several variants with fungicide and pesticide treatments and an untreated control. In the case of the hybrid NS-H-111, highest values of the studied characteristic were recorded in the control and directly after chemical treatment. In the case of the hybrid Sremac, the lowest value was recorded in seed treatment with benomyl+metalaxyl, highest in the treatments directly after chemical treatment and in seed stored for six months. In the case of the hybrid Sumadinac, highest values were recorded in the control and in seed treatment with fludioxonil+metalaxyl, the lowest in seed treatment with fludioxonil+metalaxyl+im idacloprid. Regarding the effect of different seed storage periods, highest values of the studied characteristic were recorded shortly after chemical treatment and in seed stored for six months.