كليدواژه :
ذرت , تراكم بوته , كود نيتروژن , عملكرد دانه , plant density , Nitrogen , Yield , كشاورزي
چكيده لاتين :
In order to investigate the effects of plant density and nitrogen rates on yield and yield components of corn (Var. SC704) a field experiment was conducted as split-plot arranged in a randomized compelete block design with four replications in 1999 at Koushkak Agricultural Research Center of Shiraz University. The treatments composed of nitrogen at four rtes: 0, 80, 160, and 240 kg/ha as main plots and plant density at four levels: 6, 7.4, 8 and 10.2 plants/m as subplots. Results showed that increasing N rates did not significantly affect ear weight. Lowest ear weight was observed with lowest N. Increasing N rates increased 1000-grain weight, however, there was no significant difference between 160 and 240 kgN/ha. Similary, N rates of 80, 160, and 240 kg/ha showed no significant difference for harvest index, grain yield, and number of kernel per ear. Positive effect of nitrogen on number of kernel per ear increased grain yield. Harvest index was not affected by plant density. Increasing plant density decreased number of kernel per ear, 1000-grain weight and ear weight. Increasing plant density decreased grain yield per plant. Therefore, increasing grain yield was due to increasing number of plants per area which has compensated yield decrease per plant. The highest grain yield (12490 kg/ha) was obtained from the interaction between highest N (240 kg/ha) and lowest plant density(10.2 plant/m2).
