S.H. Mahmoodi, R. Hamidi
Key words: Wheat straw, allelopathy, wild mustard, Sinapis arvensis, water and phosphorus stresses, extract concentration.
Field, greenhouse, and laboratory experiments were conducted to evaluate the impact of soil moisture and phosphorus on allelopathic potential of wheat residues, and to study the effect of wheat extract concentrations on the germination and growth of wild mustard (Sinapis arvrnsis L.). The field experimental design was split-plot with 4 replications. The main factor was three moisture levels including 100, 200, and 300 mm crop evapotranspiration and the sub factor was five phosphorus fertilizer levels of 0, 50, 100, 150, and 200 kg/ha. The results showed that under soil moisture and phosphorous stresses, the inhibitory effects of wheat residues on Sinapis arvrnsis seed germination and other growth parameters had an obvious increase. The weed seed germination peaked (62%) at extract that prepared from plants that received 100 kg P/ha (F3) and the highest amount of water (W1). A significant decrease in mustard seed germination percentage was recorded with increasing extract concentration. At all soil moisture levels the severe reduction of the weed shoot dry weight was obtained from no fertilized plots indicated the wheat plant produced the highest amounts of allelochemicals. The extract that made from wheat plant which received the lowest amounts of moisture markedly inhibited the weed plant height in a concentration-dependent manner. In all soil moisture levels, wheat plant that received 150 kg P/ha produced leachates that exerted the lowest inhibitory effects on wild mustard 1000-seeds weight. Results showed that utilizing the naturally occurring chemicals may play an important role in controlling weeds in sustainable agriculture system.
Read Full Article: Volume 2, Number 6, June 2012 – IJAAR