Authors : M. Sedghi , R. Seyed Sharifi , A. Namvar , T. Khandan-e-Bejandi and P. Molaei
Abstract: In order to study the effects of plant density and weed interference on sunflower yield and its attributes and also to determine the response of grain filling period in sunflower to plant density and weed interference, a factorial experiment was carried out using randomized complete block design with 3 replicates at research site of university of Mohaghegh Ardabili. Treatment were three levels of plant density (6, 8 and 10 plant m 2 as D1, D2 and D3, respectively) and 2 levels of weed control (weedy and weed free). Results indicated that plant density had significant effects on sunflower growth characteristics. The highest grain yield obtained from D2. The highest 1000-grain weight, grain per head, stem and head diameter, dry matter, yield per plant and harvest index recorded at D1, while D3 showed the highest values of plant height and percentage of hollow grains. The levels of weed control did not affected sunflower yield and yield attributes significantly (except number of grain per head) that probably due to soil salinity, weed genus, planting row space, density and high tolerance of sunflower to weeds. The highest rate and duration of grain filling recorded at D1 in both levels of weed treatments. Furthermore, D1 showed the highest mean of final grain weight, that probably due to effects of density on light interception by canopy.
M. Sedghi , R. Seyed Sharifi , A. Namvar , T. Khandan-e-Bejandi and P. Molaei , 2008. Responses of Sunflower Yield and Grain Filling Period to Plant Density and Weed Interference. Research Journal of Biological Sciences, 3: 1048-1053.