Effects of previous crops and different planting patterns on weed density reduction and wheat yield in Khouzestan climate conditions

This experiment was conducted in 2009-10 cropping year in order to investigate the effects of previous crops and planting pattern on weeds and wheat yield reduction at Shams-Abad village of Dezful. The experimental design was a randomized complete block with split plot arrangement with four replications. Main treatments (previous crops) consisting: mung bean (P1), clover (P2) and fallow (P3) and sub treatments (Planting pattern) consisting: two rows on 60cm spaced furrows (A1), three rows on 75cm spaced furrows (A2) and four rows on 95cm spaced furrows (A3). Results based on variance analysis showed that planting pattern treatments had significant effect on weeds dry weight in two stages of bolting and heading of wheat, grain yield, spike number in m2, grain number in spike and 1000-kernel weight traits. Also, previous crops treatments had significant effect on weeds dry weight traits in three stages of bolting, heading and physiological maturness of wheat, grain yield, spike number in m-2 and grain number in spike. Interaction of planting pattern and previous crops had significant effect on traits: weeds dry weight in heading stage of wheat, spike number in m2 and kernel number in spike. Totally, results indicated that previous crop mung bean (P1) with four rows on 95cm spaced furrows (A3) had significantly controlled weeds and increased grain yield in wheat.