Control of morningglory species using Fusarium solani and its extracts

Abstract

Natural products of an isolate of Fusarium solani App. & Wr. NRRL 18883 grown on rice medium were discovered to be phytotoxic to morningglory. This isolate was evaluated for biocontrol potential on morningglory species including ivyleaf [Ipomoea hederacea (L.) Jacq.], multicoloured (I. tricolor Cav.), paimleaf (I. wrightii Gray), pitted (I. lacunosa L.), purple moonflower (I. turbinata Lag.), red (I. coccinea L.), sharppod (I. cordatotriloba Dennstedt), smallflower (Jacquemontia tamnifolia (L.) Griseb], and tall [I. purpurea (L.) Roth] morningglory. When sprayed at a concentration of 10 g fungus‐infested rice per 50 ml of water, this isolate caused phytotoxic damage including necrosis, chlorosis, growth inhibition, and mortality. Deleterious effects were recorded in all species, ranging from necrotic spots to death, depending on the species. Mortality ranged from 0% at 3 weeks for purple moonflower to 89% for smallflower morningglory. Soil‐drench application (10–20 ml fungal material per 150 g soil) caused wilting and death. Root lengths of 7‐ and 10‐day‐old plants were reduced between 19 and 89% by soil‐drench application and 17–84% by spray application. Whole plant length reduction of 7‐ and 10‐day‐old plants ranged from 0 to 96%, and 39 to 96% for soil‐drench and spray applications, respectively. Testing of F. solani on weed and crop species showed that most broadleaved species were sensitive but monocotyledons were immune. Tests of the phytotoxic extract for known phytotoxins such as common trichothecene (deoxynivalenol) and non‐trichothecene compounds (fusaric acid, moniliformin, fumonisins) were negative. This is the first report of the use of F. solani against morningglory.

Keywords:

• biocontrol
• morningglory
• Fusarium solani
• mycoherbicide
• natural product