Effect of extracts of some weeds on growth and yield of wheat (Triticum aestivum L.) planted at different distances and on associated weeds

The field was carried out during the winter season of 2019 in Basra Governorate. To demonstrate the allelopathy effect of Cynodon dactylon and Dichanthium annulatum extract, used six treatments are as follows; Spraying with (extract of Cynodon dactylon and Dichanthium annulatum, a full dose of the pesticide Atlantis, half the dose of the pesticide, mixing the two extracts with the full dose of the pesticide, mixing the two extracts with half of dose of the pesticide, without spraying (control). Of weeds control and growth and yield variety of wheat (22) cultivated at the end of November, with two distances (20 and 30) cm, split plots design with were used randomized complete block design with three replications. The results showed significant superiority of the experimental treatments in all the studied traits. They gave a statistical discrepancy in the control treatment results compared to the comparison treatment (control without spray). The results also showed the treatment's superiority (mixing two extracts with half of the Herbicides dose) over the rest of the treatments. Also, the results showed that the planting distance exceeded (30) cm at a distance of (20) cm in all the studied traits except for the dry weight of the weeds, as the distance was given (20) cm, the minimum dry weight was (21.65) g. m2, compared with the distance (30) cm gave, it was (31.44) g. m2. Can conclude that the use of the extracts with half the pesticide amount can provide a suitable alternative to reduce the concentration of pesticides as a step to preserve the environment, reduce its damage and control the growth of the weeds.