بررسي تاثير تراكم گياهي و توزيع كود نيتروژن در مراحل مختلف رشد بر عملكرد و اجزاء عملكرد ذرت دانه اي رقم سينگل كراس 704

Effects of plant density and pattern of nitrogen fertilizer application at different growth stages on yield and yield components of corn (Zea Mays L.) cultivars 704

In order to determine the best plant density and pattern of nitrogen fertilizer application on yield and yield components of corn (CV SC-704) an experiment was conducted in the experimental field of kerman University (Iran) in 2008. The experiment was a factorial based on randomized complete block design with three replication, treatments were the combination of the levels of three plant densities including 10(D1), 8(D2) and 6(D3) plants per m2 and five patterns of nitrogen fertilizer application including:1/3 of total amount of nitrogen (326 kg ha-1) at planting, 1/3 at 4-6 leaf stage and 1/3 at 8-12 leaf stage(Nl); 1/2 at planting and Vi at 4-6 leaf stage(N2); 1/2 at planting and 1/2 at 8-12 leaf stage(N3); 1/2at 4-6 leaf stage and 1/2 8-12 leaf stage (N4) and total amount at planting (N5). Results showed that plant density significantly affected on yield and yield components of corn. Maximum yield was obtained under 10 plants per m-2 (7 ton ha-1) while minimum yield was obtained at 6 plants per m2 (2.4 ton ha-1). Plant density also showed significant effects on growth characteristics. Generally plant height, leaf number and leaf area were greater in higher plant densities. However, stem diameter was reduced at higher plant densities. Different patterns of plant densities also have significant effects on yield and yield components so that highest value was obtained at N1 (5.9 ton ha-1) and lowest at N5 (3.21 ton ha-1). Value was obtained that to obtain highest yield it is better to apply the nitrogen fertilizer at several stages of growth during crop growth. There was a significant interaction between plant density and nitrogen fertilizer only in the case of yielding, generally obtained at D1 and N1.