Vol. 10, Special Issue 6 (2021)

Author(s):
Kushal Thakur, Abhishek Sharma and Keshav Sharma

Abstract:
Physical control is one of the main approaches to crop protection against insects, the others being chemical, biological and cultural.). From theoretical and technical points of view, all of these approaches have limits that make them more or less suitable for control of a given pest. In practice, the relative merits of each approach are also weighed against numerous factors before an actual decision is made regarding the most appropriate methods to be implemented. A majority of agricultural commodities are protected using chemical control but ideally, all components and technologies should be blended optimally and harmoniously into an integrated pest management (IPM) program. Ideally integrated pest management should rely on an array of tactics. In reality, the main technologies in use are synthetic pesticides. Because of well documented problems with reliance on synthetic pesticides, viable alternatives are sorely needed. Physical controls can be classified as passive (e.g. trenches, fences, organic mulch, particle films, inert dusts and oils), active (e.g. mechanical, polishing, pneumatic, impact and thermal) and miscellaneous (e.g. cold storage, heated air, flaming, hot water immersion). Some physical methods such as oils have been used successfully or pre-harvest treatments for decades. Another recently developed method for pre-harvest situations is particle films. As we move from production to the consumer, legal constraints restrict the number of options available. Consequently, several physical control methods are used for post-harvest situations. Two noteworthy examples re the entoleter, an impacting machine used to crush all insect stages in flour and hot water immersion of mangoes, used to kill tephritid fruit fly immature in fruit. The future of physical control methods will be influenced by socio-legal issues and by new developments in basic and applied research.