Allelopathy and chemical ecology are directly involved in problems of replanting orchards and regeneration of forests. It offers potential for orchards and forests producing and releasing allelochemicals to destroy insects, and pests harmful to trees and can develop in them resistance to other environmental stresses, as well (as drought resistance). However, its long terms effects may turn out negative especially in tropics. Allelochemicals may impact the availability of nutrients destroying symbiotic microbes, destruction and change in soils, reducing biodiversity etc. However, it is generally pointed out that for curing or developing resistance or producing more other side long-term adverse effects of allelopathy in biotic resources resource management cannot be overlooked. It should must develop new methods so that its adverse effects are overcome.