در تراكمهاي مختلف بوته SC 711 و SC ارزيابي كشت مخلوط دو هيبريد ذرت دانه اي 407

Evaluation of two corn cultivars under mix-cropping system using different plant densities

To determine the optimal planting densities and evaluate the yield possibility of corn cultivar under mix-cropping system in Dezful region, a factorial design based on Randomized Complete Blocks Design with four replications was carried out in 1999 at Dezful. Four planting densities including of 65000, 75000, 85000 and 95000 plants/ha, in different combination with the pure stands of two hybrid ( SC704 and SC711) along with three mixed cropping ratios [including of 3(SC704): 1 (SC711), 2(SC704):2(SC711) and l (SC704):3(SC711)J comprised the twenty experimental treatments. Data collected were analysed to determine the optimal cultivar mix-cropping ratio by using both agronomical and competitional indices and reciprocal yield model. Results shoewd that intercropping of corn hybrids and incresed SC711 in mix systems caused the reduction in tassel and silk appearance intervals by 5.97 days the I (SC704):3(SC71 1) mix ratio, an increase in leaf angle and horizontal arrangement of leaves in canopy. The grain yield of pure cultivation of SC704 and 3(SC704): l (SC71 1) mixed ratio were amounted to be maximum (7860 and 7842 kg/ha, respectively) and with the increasing of SC71 1 portions, grain yield decreased. A agronomical and competitional indices measured showed that 1(SC704):3(SC711) combination of hybrids with 85000 plants/ha due to obtaining of LER-1.214, 21.5% increase in relative yield total(RYT), highest competativity, least reduction in per plant yield and maximum per plant yield proved it to be the best combination. Relative competition ability(RCA) and nich differentiation index (NDʹ) estimates indicated that intracompetition of SC71 1 as compared to its inter-competition was higher than SC704 and 8% nich differentiation between hybrids showed that mixed-cropping system yielded more than their pure cultivation.