Pigeonpea-Lac insect interaction: Effect of lac culture on grain yield and biochemical parameters in pigeonpea

Abstract

Present experiment was conducted to know the impact of pigeonpea-lac insect interaction for the production of raw lac/scrapedlac as well as grain yield and protein quality in seeds. On the basis of broodlac and scrapedlac yield, five genotypes of pigeonpea viz., IPA 8-2, Bahar, Assam local, Acc.no. 591139 and RCMP 5 were identified promising for lac production. Rearing of lac insect on pigeonpea reduced 100 seed weight (13.03%) and grain yield per plant (12.08%) significantly but no significant reduction was observed on crude protein content in seeds (1.02%). Biochemical traits measured in mature leaves in inoculated and control plants revealed that reducing sugar (RS), chlorophyll ‘a’ and total chlorophyll decreased after lac insect inoculation but non-reducing sugar, total sugar (TS), proline and malondialdehyde increased after insect inoculation. The biotic stress rendered due to lac insect (free phenol) and abiotic stresses due to high temperature (malondialdehyde) did not significantly affect scrapedlac yield. High chlorophyll components along with high metabolites (RS and TS) supported high scrapedlac yield. Hence, farmers can cultivate lac on this host plant to get good raw lac and grain yield without losing the crude protein quality of grain. The loss in grain yield is compensated by additional income from raw lac.The profit obtained from raw lac along with grain will be much higher than sole crop for grain.