Efeito do extrato aquoso das folhas de nim indiano (Azadirachta indica) sobre o crescimento inicial de plantas daninhas.

Abstract

Weeds pose serious problems for crops by multiple losses causing yield losses by competition for water, light, nutrients and space. Allelopathy is a biological phenomenon that occurs when a plant species releases to the environment substances that may inhibit germination and / or establishment of other plant species and has potential application in agricultural ecosystems. The aim of the study was to evaluate the occurrence of allelopathic action of Neem on weeds using experiments conducted in the Laboratory of Plant Ecology at the Center for Agricultural Sciences, Federal University of Paraíba, Campus II, Areia-PB. For the evaluation of allelopathic potential of Azadirachta indica aqueous extracts were used in different concentrations from dehydrated leaves in seeds of different weeds in germitest paper. It was observed that the most sensitive species of Neem leaves extract was jureminha to values below the other weeds studied, whereas the picão-preto proved to be even less sensitive to the extract. The more sensitive physiological variable to the extract was the growth of the aerial part of the seedling, whereas germination showed less sensitive. Can be said that the minimum concentration to be used for there to be effective in reducing the effects root, shoot, IVG and germination of all species is 50%. The Indian Neem showed promising results, since at low concentrations of this extract was detrimental effect on the target plants.