Natural Farming Boosts Coccinelid Abundance and Suppressing Rice Leaf Folder (Cnaphalocrosis Medinalis) in Rice in Indo-Burma Region.

Abstract

Ecological engineering cropping systems were developed for aroma (Pusa Basmati-1121, Badshah bhog, and Gandhi Biron) and non-aroma rice varieties (Tripura Chikan Dhan, Tripura Nirogi Dhan, and Tripura Sharat Dhan). 2017-18 and 2018-19 field experiments were performed at the ICAR Research Complex for NEH Region, Mizoram Centre, Kolasib, Mizoram. Ecological engineering parameters such as pest defender ratio, occurrence ratio (OR) of entomophages, preference ratio (PR) of pests, biodiversity indices (species diversity, richness, and evenness) of entomophages and pests, and cost benefit ratio (CBR) were assessed for all cropping systems. The population of Micraspis crocea (Mulsant) on rice was most affected by rice (Gomati Dhan) + Pusa Basmati-1121, followed by rice + Gandhi Biron and rice + Badsha Bhog. Rice + Tripura Nirogi Dhan, Rice + Tripura Sharat Dhan, and Rice + Tripura Chikon Dhan border systems impacted rice's moderate entomophage population more than rice alone. rice + Pusa Basmati-1121, rice + Gandhi Biron, and rice + Badsha Bhog border cropping system reduced leaf folder (Cnaphalocrosis medinalis (Guenee), population and damage on rice compared to rice alone. rice + Tripura Nirogi Dhan, rice + Tripura Sharat Dhan, and rice + Tripura Chikon Dhan border cropping system showed moderate pest population and damage. Pest defender ratio was highest on rice + Pusa Basmati-1121 (1: 6.23 and 1: 4.08), rice + Gandhi Biron (1: 5.76 and 1: 3.83) and rice + Badsha Bhog (1: 5.26 and 1: 3.35) border system compared to rice + Tripura Nirogi Dhan (1: 4.00 and 1: 2.65), rice +Tripura Sharat Dhan (1: 3.09 and 1: 2.31), and rice + Tripura Chikon Dhan (1: 2.90 and 1: 1.83) border system and rice alone (1:1.75 and 1: 1.68) border systems. Rice + Pusa Basmati-1121, rice + Gandhi Biron, and rice + Badsha Bhog border systems had the highest OR of entomophages, lowest PR of pests, highest yield, and highest CBR compared to rice + Tripura Nirogi Dhan, Tripura Sharat Dhan, and Tripura Chikon Dhan border cropping systems and rice alone.