Allelopathic effect of pistacia khinjuk leaf extracts on chenopodium album, physalis alkekengi and amaranthus retroflexus

A weed is a term applied to any plant considered as one major problem in farm fields and gardens. Weeds cause serious damages to farmers per year, bringing about heavy losses in farm and garden yield. Thus, in order to contain the growth and spread of weeds, farmers have no way but using chemical weed killers known as herbicides. As chemical methods have had serious negative effects in recent decades, using allelopathies, combined with other species within intercropping systems, to control unwanted plants and providing a good cultivated setting has attracted great attention. To reduce using chemical herbicides in farms and garden and developing sustainable agriculture, this article studies the Allelopathic effects of Pistacia khinjuk leaf extract on seed germination of Chenopodium album, Physalis alkekengi and Amaranthus Retroflexus in Jahrom. The research indicated that the leaf extract from Pistacia khinjuk contains materials decreasing the growth parameters in Amaranthus Retroflexus. However, in Physalis Alkekengi and Chenopodium album L., any process of germination did not affected by the density of Pistacia khinjuk extract. Extract with high density reduced significantly the extent of seed germination by 95%. The results revealed that weeds have the same influence on various factors of growth, excluding weight and length of seedling. To put it another way, there is no significant difference between Physalis Alkekengi and Amaranthus Retroflexus with Chenopodium Album over some factors from germination rate to intermediate germination periods, germination speed, and length of their hypocotyls and radical roots. However, a significant difference is observed between them and Amaranthus Retroflexus L. in confident level of 95%.