Effect of planting pattern and plant population on agronomic traits of new sunflower cultivars in Khoy.

This study is conducted to evaluate effect of two row spaces and five plant densities on seed yield and agronomic traits of two new sunflower varieties as a strip plot design with 4 replications in khoy agricultural and natural resources research station within 2 years from 2006. Combination of row space and variety treatments located in horizontal plots whereas plant densities on vertical plots. The results from combined analysis of variance showed that horizontal factor has significant effect on flower initiation, growth period, 1000 seed weight, seed number, leaf area index, oil content and oil yield. Plant densities had significant effect on all traits except flower initiation. KSC43/128 had lower growth period in both row space comparing Lakumka. Considering 1000 seed weight Lakmka was superior than KSC43/128 ( 96-98 gr) but oil content of Lakumka( 38%) was about 3% lower than KSC43/128. Seed yield of two varieties didn't differ from each other in row spaces of 60 and 75cm although the highest seed yield was achieved from row spaces of 60cm. In plant densities of 3 and 9 p/m2 growth period was 111 and 106 respectively. As plant density increased, Plant height increased from 154cm in lower density to 181cm in highest density because of competition between plants whereas as plant density increased, head and stem diameter and 1000 seed weight decreased significantly. Leaf area index in flowering period was 2.71 and 5.57 for plant densities of 3 and 9 p/m2 respectively. Effect of plant density was significant on seed and oil yield. The highest seed and oil yield was obtained from 75000 p/ha respectively 3947 and 1606 kg/ha. We could say at all: o There was no significant difference between seed yield of Lakumka and KSC43/128. o 60cm row space was better than 75cm. o The suitable plant density for sunflower in spring-irrigated of khoy and similar areas is 75000p/ha. Within row spaces for 60 and 75 cm row spaces are 22 and 18 cm respectively. o Russian cultivar Lakumka could be interesting for farmers because of seed's large size. o As plant density increase, growth period, head and stem diameter, seed number and seed weight decrease whereas plant height, harvest index and seed and oil content increase.