Allelopathic Effects of Bermuda grass (Cynodon dactylon) on Seed Germination, Growth and Yield of Bread Wheat (Triticum aestivum)

Because of abundance and importance of Cynodon dactylon in wheat fields a factorial experiment was conducted with three replicates to study allelopathic effects on Cynodon dactylon on wheat in 2oo7. Extract of different parts of this weed in five levels (control, leaf, shoot, root, and flower extract) and its different concentrations in 4 levels (1:5, 1:10, 1:15, and 1:20) were used to evaluate its concentration effects on seed germination, vegetative growth and seed yield of wheat. Anova showed that effect of main factor and interactions on some attributes studied were significant. All concentrations of extracts decreased germination as compared to control. But, weed root and total plant parts extracts showed highest reduction on germination. 1:5 extract concentration decreased radical and plumole length, seedling dry weight, seed and percentage of germination by 81.38, 79.37, 73.75, 97.33 and 70.31%, respectively. ANOVA in green house showed significant effect of some main factors and interactions. Increasing extract concentrations from 1:20 to 1:5 decreased significantly all attributes. Rate of reduction in plant height, spike length, leaf number, peduncle length, biomass, seed number, TKW, and yield in 1:5 concentration as compared to control were 53.88, 40.42, 52.80, 63.85, 82.84, 88.63, 76.10 and 95.84%, respectively. Base on this experiment, it can be said that Cynodon dactylon produces allelopatic chemical materials and thus decreases germination, growth and seed yield of wheat considerably.