Phytotoxic effects of perennial weeds extracts on germination and seedling development of some field crops

Abstract

The present investigation was aimed to document the allelopathic phenomena of weeds and its hazardous impacts on seed germination and seedling development of numerous field crops. Results generally indicate that crops under investigation differed in their germination sensitivity to allelochemicals liberated by weed leachates. It is possible to produce tentative ranking of allelochemicals sensitivity for the seven crops as following : high sensitive crops : rice and cotton ; moderately sensitive crops : wheat, faba bean and maize; and poorly sensitive (resistant) crops: Egyptian clover and lupine. Likewise, weeds under investigation differed among themselves in their allelopathic potentiality on the establishment of the studied crops. Data confirmed the harmful impacts of bermuda-grass and nut-sedge on rice, maize and cotton ; bindweed on rice, faba bean, wheat, cotton and lupine ; and cogongrass on rice and cotton.