Development of the pest management products and systems for organic vegetable production in Southern Luzon [Philippines]

The insecticidal activities of 27 plant species were evaluated against representative insect pest of pechay, stringbeans, eggplant and ampalaya(common cutworm, Spodoptera litura; cabbage worm, Crocidolomia pavonana, black bean aphids, Aphis craccivora; pechay aphids, Lipaphis erysimi; and flea beetle, Phyllotera sp.); and for fungicidal activity against five fungal isolates namely: Rhizoctonia solani, Sclerotium rolfsii, Phomopsis vexans, Ralstonia solanacearum and Fusarium sp. The possible active component from each plant species were extracted with water, vinegar from kaong and wine from coconut. Percent recovery of the juice from the promising botanical insecticides ranged from 32 to 94%. Among the plant extracts evaluated, langkauas (Alpinia pyramidata) seemed to be the most promising even as water extract since it provided the highest control of eggplant flea beetle (100% mortality), cutworm (73%) and black bean aphids (60%) and exhibited the highest growth inhibition effect. Oregano (Coleus amboinicus) crude water extract was effective against black bean aphids of stringbeans. Other promising botanical insecticides include the makabuhai (Tinospora rumphii), marigold (Targetes erecta), lantana (Lantana camara) and luyang dilaw (Curcuma longa). The crude water extract from leaves of oregano and lantana, luyang dilaw and langkauas rhizomes exhibited contact toxicity, anti-feedant and growth inhibitory effects. The promising crude extracts were evaluated in researcher-managed field under organic production methods and was compared with the conventional practice of growing stringbeans. Based on methomyl in reducing beanfly, aphid and pod borer population, and as effective as mancozeb in reducing the incidence of root and stem or rot disease. The best crude plant extracts which is the combination of oregano and luyang dilaw extracts was further evaluated in organic farms. Biological control agents like the predatory earwig, Euborellia annulata and the sink bug, Eocanthecona furcellata were found promising especially against cutworm larvae. Likewise, Snellenius manilae was shown effective in parasitizing the first and second instar larvae of cutworm. Moreover, the performance of Telenomus sp., an egg parasitoid of cutworm was verified in the laboratory. Screening of pure plant and wine extracts using the filter paper disc method showed that none of the extracts using their filter possess inhibitory activity against Fusarium spp., R. solani, S. rolfsii, Ralstonia solanacearum and P. vexans affecting eggplant, pechay and stringbeans. The vinegar extracts from almost all plants as well as pure vinegar showed inhibitory activity against Fusarium spp. Moreover, the vinegar extract from holy basil, lantana and pandan, showed inhibitory activities against R. Solani and S. rolfsii. However, no inhibitory activity was observed against Rastonia solanacearum. On the other hand, acapulco and garlic vine extracted using vinegar exhibited fungicidal activity however, vinegar alone showed inhibitory activity against the test pathogens. Out of the 15 biological control agents evaluated against the test pathogens, three isolates were found to have potential based on dual culture method. The plant extracts from langkauas, luyang dilaw, marigold, and oregano fungicidal activity against sp. as shown by the formation of zone of inhibition. Three plant extracts [3 wettable powders (50WP) and 3 emulsifiable concentrates (95EC) from the most effective plant extracts (langkauas, oregano and luyang dilaw) were formulated as wettable powder (50WP) and as emulsifiable concentrate (95EC). The shelf life of the WP and EC lasted for about three months only except for luyang dilaw formulated product which still toxic at six months after formulation.