اثر تراكم و آرايش كاشت بر عملكرد ذرت دانه اي رقم سينگل كراس 700

Effects of Plant Density and Planting Pattern on Grain Yield

به منظور تعيين تراكم و آرايش كاشت مناسب ذرت رقم KSC700 آزمايشي با استفاده از طرح بلوك هاي كامل تصادفي به صورت استريپ پلات- فاكتوريل با چهار تكرار طي دو سال زراعي (3-1382) در شرايط آب و هوايي خرم آباد به اجرا درآمد. دو فاصله رديف 60 و 75 سانتي متر در كرت هاي افقي و دو تيمار الگوي كاشت يك و دو رديف روي پشته و تراكم در چهار سطح 95, 80, 65 و 120 هزار بوته در هكتار به صورت فاكتوريل در كرت هاي عمودي مورد بررسي قرار گرفتند. نتايج نشان داد كه با الگوي كاشت دو رديفه امكان افزايش تراكم وجود دارد به طوري كه آرايش كاشت دو رديفه با فاصله رديف كاشت 75 سانتي متر و تراكم 95 هزار بوته در هكتار با 12.24 تن در هكتار عملكرد دانه برتري معني داري نسبت به ساير تيمارها داشت. در آرايش كاشت يك رديفه، فاصله رديف 60 سانتي متر با تراكم 80 هزار بوته در هكتار با عملكرد 10.9 تن در هكتار در مرتبه بعدي قرار گرفت.

Maize Rough Dwarf Virus (MRDV) and Iranian Maize Mosaic Virus (IMMV) are dominant and common viral diseases in Isfahan province. Their transmission is by Laodelphax striatellus . In order to study the effects of planting date and commercial maize hybrids on infection of these viruses, an experiment was conducted in Kabutarabad Agricultural Research Station in Isfahan for two years (2000 and 2002). The experiment was in a spilt plot design that the main factor was various planting dates (5May, 24May and 10June) and sub factor was corn hybrids KSC704, KSC647, KSC604 and KSC301, with four replications. Mean Percentages of plants infected with each virus were determined by samples collected from two central rows in each treatment. Data were converted to Arcsin x/100 and were compared by Duncan’s multiple range test. Results showed that infected plants to IMMV was lower in the third planting date and was significantly different from other planting dates. Percentage of plants infected with IMMV in different hybrids were significantly different. Hybrid KSC301 had the lowest and KSC704 had the highest percentage of infected plants. Mean Percentage of plants infected with MRDV was significantly different in various planting dates. The highest and lowest infections were found in the second and third planting dates, respectively. Mean percentage of infected plants of hybrids to MRDV was significantly different in all plating dates. Hybrid KSC301 had the lowest and hybrids KSC604, KSC647 and KSC704 had the highest infected plants respectively