ABSTRACT
Aim: Laboratory studies were conducted to study the potential of entomopathogenic nematodes and their interaction with the commonly used insecticides viz., clothianidin, imidacloprid and chlorpyriphos against first, second and third instar grubs of H. longipennis and B. coriacea.Methodology: Two entomopathogenic nematodes viz., Heterorhabditis indica Poinar and Steinernema caprocapsae Weiser were tested against I-III instar grubs of Brahmina coriacea (Hope) and Holotrichia longipennis (Blanchard) under laboratory conditions @1600IJs per cup by soil application. The mortality data was recorded after every 24 hrs up to 5 days. For evaluating the interaction effects among different tested biocontrol agents with insecticides, each entomopathogenic nematode species and insecticides was tested alone and in combination. H. indica and S. carpocapsae were applied @ 400IJs per cup. Insecticides were applied at a lower concentrations viz. 150, 100 and 75 ppm for chlorpyriphos, imidacloprid and clothianidin, respectively and were applied on the same day of nematode application with a gap of 2 hrs. Mortality data was taken after 24 hrs. Results: Individual application of H. indica and S. carpocapsae @1600 IJs per cup had clearly lethal effect and produced mortality to the tune of 55.5-90.7 % in both the species of white grubs. H. indica revealed higher virulence as compared to S. carpocapsae against both the species. Combination of both the species with all the tested insecticides yielded synergistic interactions and H. indica+ imidacloprid combination proved to be the most promising among all the tested combinations. Interpretation: Tested entomopathogens and insecticide combination produced synergistic interactions more effectively to first, second and early third instar grubs (H. longipennis and B. coriacea).
ABSTRACT
Aim: The objective of the study was to develop and characterize the properties of sago (sabudana) from cassava based reconstituted dry starch with addition of pre-gelatinized starch and wet starch as binders.Methodology: The dry starch was soaked for 12 hrs at 30 % concentration and then sago was prepared at 40% moisture content with addition of pre-gelatinized starch and wet starch as binders in different treatment combinations. Results: The sago developed from the combination of reconstituted dry starch (75%) and wet starch (25%) had an optimal commercial size (3.36 mm) and shape (sphericity value, 76 %). The swelling power (5.98%) was high in reconstituted dry starch sago and solubility (13.42 %) was high in wet starch sago without the addition of any binders. The increase in cooking time (10.37%) and decrease in cooking loss (1.73%) were observed for sago developed with pre-gelatinized starch as binder. The lowest oil absorption index (0.45 g g-1) was noticed for sago prepared with wet starch as a binder. The storage modulus was comparatively lower for sago paste prepared using wet starch and thus the sago gel behaved like a dilute solution with increase in storage modulus and phase angle. Interpretation: The physico-functional properties of the cassava -based reconstituted dry starch sago can be improved by adding wet starch as a binder due to less retrogradation rate. Further, the addition of pre-gelatinized starch as a binder with reconstituted cassava dry starch can reduce the cooking loss in sago.