Evaluation of Organic Modules for Rapeseed (Brassica rapa var. toria L.) Production

Abstract

The main aim of the study was to develop environment-friendly organic module for rapeseed production to provide pesticide free edible oil for mankind. The field trial was laid out with four treatments having six replications in a randomized block design for five years at AAU-Zonal Research Station, Shillongani, Assam during Rabi 2017-18 to 2021-22. Treatments, T1 and T2 were the organic modules (M I and M II), T3 was with recommended package of practices (PoP) and T4 was the absolute control. The initial and the final soil nutrient status as well as soil microbial population were tested using standard procedure. It was observed that the treatments with PoP (T3) recorded the lowest disease severity and insect-pest pressure and yielded the highest. Interestingly, it was found that the two organic modules were also successful in obtaining good yield and had a significant difference over the control plot. Treatment T2 i.e., organic module II comprising seed inoculation with Trichoderma viride based biopesticide (Biogreen-5) and biofertilizer (Azotobacter & PSB) + soil application of vermicompost + rock phosphate + borax + foliar spray with Bacillus megaterium + foliar sprays of NSKE 5% (need based) + installation of bird perch and yellow sticky trap recorded yield of 10.29 q ha-1, which was statistically at par with T3(10.44 q ha-1). The higher yield under organic module II might be attributed to lower disease severity of both Alternaria leaf (21.0%) and pod blight (13.6%) and aphid population (7.48 10-1 cm terminal shoot). The field trial showed that organic module II has enough potential to lower Alternaria blight severity and aphid population of rapeseed and, also improve soil nutrient status as well as soil microbial population. Organic farming would ultimately enhance ecosystem productivity and sustainability in long term. It would also improve soil health, reduces environmental pollution leading to better human health.