Luciana M. Villanueva, Jocelyn C. Perez, Floresca T. Agustin, Katherine C. Basalong, Crescinti P. Agluya, Randy R. Wan-aten, Janet L. Togay-an
ABSTRACT
Entomopathogens were isolated from different insect hosts such as diamond back moth, cabbage butterfly, mole cricket, silkworm, cabbage looper and aphids. Using their morphological characteristics, they were identified as Beauveria, Metarhizium, Nomuraea and Verticillium.
Rice grains favored the growth of Nomuraea while Beauveria and Metarhizium preferred rice bean seeds. Verticillium grew very well on potato broth. Compatibility test was also done to determine if the bacterial antagonists could be combined with Verticillium. Except for Bacillus subtilis (PCN 2011-004), all the bacterial antagonists tested were compatible with Verticillium.
Three Bacillus subtilis isolates (PCN 2011-002, PCN 2011-005, STR 2011-001) and an unidentified bacterium were highly inhibitory to the growth of Alternaria brassicae and significantly more effective than the standard fungicide, Mancozeb. B. subtilis (PCN-2011-005) significantly suppressed Colletotrichum lindemuthianum. On the other hand, all the bacterial isolates and organic-based products inhibited the egg hatching of Meloidogyne incognita except B. subtilis (ST 2011-001).
Application of entomopathogenic nematode (EPN), Oscheius tipulae at the rate of 1,200 infective juveniles (IJs) was lethal to the cabbage butterfly at lower exposure time which was comparable to B. thuringiensis. However, at lower EPN concentrations, longer exposure time is needed to significantly kill the cabbage butterfly. On the other hand, the entomopathogens were more toxic to cabbage butterfly than cutworms.
In carrots, fermented banana juice and dead EPNs significantly reduced the number of galls. However, no significant difference was observed on the yield. Likewise, the frequency of application did not significantly affect the nematode and yield parameters. In an on- station field trial the BCA-based technology significantly lowered the number of galls in carrots as compared to the conventional farming practice. Although slightly higher marketable yield was obtained from plants grown using the conventional farming method, the return on cash expense (ROCE) was higher in the BCA-based technology.
In Chinese cabbage, the BCA-based technology was comparable to the conventional farming practice in terms of efficacy against club root infection, degree of damage due to cabbage worm and flea beetle under greenhouse conditions. Likewise, on- station field trial showed comparable efficacy of the BCA –based technology and conventional farming practice, however, slightly higher ROCE was obtained in the former than in the latter farming practice. The same results were also obtained in on-farm trials in Atok and Alapang, La Trinidad. The BCA-based technology and the organic farmers’ practice were also compared in an on-farm trial at Atok, Benguet. Results obtained showed that the two practices were comparable.
In snap beans, on –station field trial showed significantly higher bean rust infection in plants grown using BCA-based technology compared to the conventional farming practice resulting in significantly lower marketable yield. However, higher ROCE was obtained from the former than the latter farming practice. On the other hand, on –farm trial in Alapang, La Trinidad, Benguet showed comparable efficacy of BCA-based technology and conventional farming practice against bean rust infection. However, significantly lower marketable yield was obtained from BCA-based technology than the conventional farming practice. Under greenhouse conditions, application of BCA-based technology significantly reduced the powdery mildew infection in tomato as compared to the conventional farming practice. On the other hand, results of the on-farm trial in Alapang, La Trinidad, Benguet showed significantly higher late blight infection in plants applied with BCA-based technology than those grown under the conventional farming practice, but had significantly lower root knot nematode infection. However, yield was significantly higher in the conventional farming practice than the BCA-based technology.Go back