Biological Control of the Weed Sesbania exaltata Using a Microsclerotia Formulation of the Bioherbicide Colletotrichum truncatum

摘要: Colletotrichum truncatum, grown on rice grain (3 to 4 weeks, 22°C 24°C) produced a fungus-infested mixture of microsclerotia and conidia (spores) in a ratio of ~9:1, respectively. Greenhouse tests this formulation (0.4 50 mg finely-ground fungus-rice product) which applied pre-emergence 5 cm2 soil surface, caused 22% 96% hemp sesbania plant mortality, after 14 days. Post-emergence treatment (fungus-rice aqueous formulation; 2.4 × 105 ml-1, 30% unrefined corn oil 0.2% Silwet L-77 surfactant) weeds surviving the pre-emergence application, resulted 93% Based greenhouse results, field were undertaken: 1) treatment (fungus-rice formulation at cm-2), 2) post-emergence product oil, Silwet) only treatment, 15 days planting 3) pre-emergence treatment followed by weeds. Control treatments were: autoclaved sans fungus, unrefined corn (30% unrefined water) untreated plants. Planting dates were: early season (April-May), early-mid (June-July), late-mid (July-August), and late (September-October). Weed mortality was recorded at for the pre-plus post-treatment, 30 for pre-emergence only post-treatment only. The season, caused 67% (3-yr average) within post-emergence treatment caused 91% In late-mid-season, minimal (80%. Results suggest that seasonal environmental conditions are important efficacy C. truncatum-rice product when pre- or onerous weed.