Appraisal of quantitative and qualitative losses in six rice genotypes caused by Trogoderma granarium (Everts) and Rhyzopertha dominica (F.)

Abstract

The present study was conducted to probe out the nutritive losses caused by Rhyzopertha dominica (F.) and Trogoderma granarium (Everts) were quantified in six rice genotypes (KSK-434, KSK-282, Irri-6, Shaheen basmati, Basmati 385 and Chenab basmati). Percent crude protein, ash and moisture content were measured for qualitative losses, while for quantitative losses, frass weight and weight loss were examined after infestation period of 90 days of. Highest weight losses (25.76%) and (15.37%) were observed in KSK-434 by infestation of R. dominica and T. granarium, respectively, compared with un-infested grains after a storage period of 90 days. Highest frass weight (8.57 g) was recorded for KSK-434 while relatively low frass weight (4.16 g) was recorded for Basmati 385 by infestation of R. dominica. Relatively low frass weights of 5.67, 4.46 and 4.01 g were recorded in KSK-434, Chenab basmati and Shaheen basmati, respectively by attack of T. granarium. Highest percentage moisture values (14.03 and 11.24%) were recorded for KSK-434 by infestations of both test insects compared to non-infested (controls). Percent crude protein was decreased (from 6.97% to the 4.92%) due to infestation of R. dominica values by strain were KSK-434 (4.54%), Shaheen basmati (4.89%) and chenab basmati (4.92%). In the case of T. granarium infestation, almost all the varieties sustained the low protein contents except KSK-434 (5.02%) and Basmiti 385 (5.17%) and Shaheen basmati, protein contents loss comparable to non-infested control (7.09%). Ash content was high in genotype KSK- 282 (0.68 %) compared to control. KSK-434 and Chenab basmati had relatively low ash percentage due to high infestation of T. granarium. R. dominica attack produced the highest percent ash content (0.66%) in KSK-282 and the least (0.44%) in KSK- 434. The tested rice genotypes were more susceptible to R. dominica than T. granarium among the different genotypes of selected cereals.