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MTB-951 is a plant pathogen ( Drechslera monoceras), which was isolated from native Echinochloa spp. in Japan. The conidia of this pathogen were used as the herbicidal active ingredient to control Echinochloa crus-galli L. The herbicidal efficacy of MTB-951 on E. crus-galli was drastically increased with an increasing water depth of between 1 and 10 cm. The efficacy also was increased when shoots were lodged by pushing down on them with a stainless steel net so that all parts of the weed were submerged. These results suggest that the contact area of the leaf surface of E. crus-galli with water is important for infection and that lodging the shoots of E. crus-galli might be effective in increasing the herbicidal efficacy. In order to find other methods to lodge the weed, we investigated several materials, of which diisononyl phthalate (DINP) was found to be the most effective. Using this material as a model, the effect of lodging on the herbicidal efficacy of MTB-951 was examined. The lodging ratio (ratio of the number of the plants lodged on the water surface to that of the total plants) was increased with an increased amount of DINP, between 0.5 and 8 kg ha−1. The herbicidal efficacy of MTB-951 also was increased by DINP and a positive correlation was observed between the lodging ratio and herbicidal efficacy. These results indicate that lodging, which can increase the contact area between the leaf surface and water, enhances the herbicidal efficacy of MTB-951. [ABSTRACT FROM AUTHOR]

The conidia of a plant pathogen ( Drechslera monoceras[Drechsler] Subram. et Jain [= Exserohilum monoceras[Drechsler] Leonard et Suggs]), MTB-951, which was isolated from native Echinochloa species in Japan, were used as the herbicidal active ingredient. The effects of δ-aminolevulinic acid (ALA) on the efficacy of foliar-applied MTB-951 on Echinochloa crus-galli L. were examined. First, foliar-applied MTB-951 exhibited almost no efficacy when no dew period was provided. However, the efficacy increased depending on the length of the dew period. MTB-951 and ALA exhibited an additive effect on E. crus-galli under 3 day dew conditions, although they exhibited a significant synergistic effect under no-dew conditions. When the leaves of E. crus-galli were immersed in deionized water containing the conidia of MTB-951, cellular electrolyte leakage from the leaves was observed. The ALA increased the electrolyte leakage by MTB-951 synergistically. Also, ALA increased the number of lesions on the leaves of E. crus-galli caused by MTB-951 under light conditions but failed to increase the number under dark conditions. These results suggest that ALA promotes infection with MTB-951 for E. crus-galli through its photodynamic action. [ABSTRACT FROM AUTHOR]

MTB-951 is a potential mycoherbicide using a fungal plant pathogen (Drechslera monoceras) isolated from nativeEchinochloaspecies in Japan. Conidia of this pathogen were used as the active ingredient and the effect of temperature on its properties was examined in a laboratory. The optimum temperature for conidium germination was broad between 15 and 35°C and no difference in the germination ratio existed within this temperature range. Mycelial growth was the fastest at 25°C but was slower outside of the range 15–35°C. When leaves ofEchinochloa crus-galliL. were immersed in deionized water containing the conidia, cellular electrolyte leakage from the leaves was observed. However, no electrolyte leakage occurred from leaves of rice (Oryza sativaL.) under the same conditions. The occurrence of electrolyte leakage fromE. crus-galliwas dependent on the temperature and was the highest at 25°C. Herbicidal activity of MTB-951 againstE. crus-galliwas high between 25°C and 30°C, but decreased at 35°C in a glass vessel. In the present study, it was revealed that the physiological and herbicidal properties of MTB-951 depended on the temperature. [ABSTRACT FROM AUTHOR]

MTB-951 is a potential mycoherbicide using a fungal plant pathogen ( Drechslera monoceras) isolated from native Echinochloa species in Japan. Conidia of this pathogen were used as the active ingredient and its herbicidal performance was examined in a greenhouse. The efficacy of MTB-951 on Echinochloa crus-galli L. was higher in deep water (7–9 cm) than in relatively shallow water (3–5 cm). In a postemergence application, the efficacy decreased as the leaf stage of E. crus-galli proceeded between the 1 and 2.5 leaf stage. For example, the control ratio (%) of E. crus-galli was 95% when applied at the 1 leaf stage, and 72% at the 2.5 leaf stage in 5 cm water. Generally, mycoherbicidal efficacy was less when applied pre-emergence rather than postemergence. Efficacy was also influenced by the duration of submergence in deep water. For example, when water depth was kept at 5 cm for more than 7 days after application and then decreased down to 3 cm, the efficacy was high. However, when the water depth was kept at 5 cm for less than 7 days, the efficacy was low. Efficacy was lower under high temperatures (35°C/25°C, day/night) than under low temperatures (25°C/15°C, day/night). Water management, application timing and temperature are important factors on herbicidal efficacy of MTB-951 to control E. crus-galli. [ABSTRACT FROM AUTHOR]