On probability models for describing population dynamics of major insect pests under rice-potato-okra cropping system

In the present investigation, trends in population dynamics of major insect pests under rice-potato-okra cropping system have been studied through probability models. Among the major insect pests climbing cutworms were observed on rice, whiteflies and jassids on potato and whiteflies, aphids and jassids on okra. The data have been taken from an experiment which was conducted by the staff of department of Agronomy during kharif, Rabi and summer season 2006-07 at the Krishi Nagar farm, Adhartal JNKVV, Jabalpur, following randomized complete block design (RCBD) with varying number of treatments under each crop. The variety pusa basmati was taken for rice, kufri jawahar for potato and ladies finger for summer okra. The occurrences of the insects were grouped in the form of frequency distribution according to the number of plants. The Poisson distribution is found to be adequate for describing the pattern of climbing cutworms on rice, whiteflies and jassids on potato and aphids on okra. In addition to these, Polya-Aeppli distribution is well fitted for the number of whiteflies and jassids on okra. These distributions may be used for forecasting of the losses in these crops due to major insect pests considered here.