Evaluation of certain natural materials as additives for preserving the activity of baculoviruses under exposure to the ultraviolet,uv,in the sunlight

This work was carried out at the Insect Virology Unit, Department of ýEconomic Entomology and Pesticides, Faculty of Agriculture, Cairo ýUniversity, Giza,Egypt, throughout the period extended from 2006 to ýý2010. The aim of the study was the laboratory and field evaluations of ýplant-derived material containing natural antioxidants as UV- ýprotective additives to SpliNPV against natural sun light. The study ýfocuses on testing inexpensive, local and natural products to be used as ýstandard additives to SpliNPV virus product, in order to sustain ýeffectiveness of virus bio-control agents, the tested additive materials ýwere used at the laboratory evaluation as a plant extracts at 1% ýconcentration. Twenty plant-derived products were compared in three ýsuccessive Phases, Phase _One- where materials were tested in groups ýthat could be arranged in descending order as follows: Group A: cacao, ýcarob pods, green tea, sage garden and vanilla pods. Group B: green ýcoffee, lemon grass, wheat, doum palm, and coriander leaves. Group C: ýred cabbage, green cabbage, parsley, rucola and coriander seeds. And ýGroup D: grape vine, grape seed, pomegranate, garlic, and onion. Phase ýý_Two- where the best two additives of each group (i. e., 8 additives, ýbeside green tea as a comparative additive known from literature as a ýsuperior protective material), were pooled out and further investigated, ýwith a maximum exposure test period to UV irradiation. The results ýdetermined the nine tested additives arranged in a descending following ýorder of efficiency: cacao, red cabbage, green cabbage, coffee, grape ývine, carob pods, green tea, lemon grass, and grape seeds. These ýadditives retained 58.30, 30.98, 50.34, 49.99, 28.46, 43.22, 45.35, 28.66, ýand 50.36 OAR% (l0hr), respectively and 821.44, 711.16, 686.05, 594.42, ýý590.83, 530.02, 505.45, 449.38 and 439.32 LIT50 values (min), ýrespectively (14.40 OAR% (10hr) and 222.14 LIT50 value (min) for the ývirus alone treatment). In Phase Three, the best four additives resulted ýfrom Phase Two were , further investigated under natural field sunny ýconditions, and evaluated at 5 and 10% concentrations.At 5% ýconcentration: The tested additives were in the following order of ýefficiency: cacao, red cabbage, green cabbage and green coffee; giving ýý83.34, 49.78, 53.57 and 44.96 LIT50 values (hr), respectively (7.69 LIT50 ývalue (hr) for the virus alone treatment). At 10% concentration: cacao ýwas again the best protective additive followed by green coffee, red ýcabbage and green cabbage; giving 113.11, 58.40, 59.22 and 51.91 LIT50 ývalues (hr), respectively. (7.69 LIT50 value (hr) for the virus alone ýtreatment). In conclusion, cacao gave the maximum protection rate for ýthe NPV at 1%, 5% and 10% concentrations as evident in both ýlaboratory and field evaluations. The other three top additives (green ýcoffee, red cabbage and green cabbage) were promising in the ýlaboratory but not so long in the field as cacao.ý