Myrothecium verrucariaisolates and formulations as bioherbicide agents for kudzu

Abstract

The fungus Myrothecium verrucaria (MV) has previously been shown to have potential as a bioherbicide for kudzu (Pueraria lobata ) control. It has also been shown that MV wild-type (MV-wt) often forms sectors, when grown on various nutrient media. Experiments compared MV-wt and MV sector efficacy when grown on agar or on rice grains. In greenhouse evaluations of sectors, applied as foliar sprays in water or in other formulations (corn oil, surfactant, and corn oil plus surfactant) for efficacy against kudzu seedlings, some sectors possessed bioherbicidal activity equal that of MV-wt, but others exhibited lower activity. Without a dew period, aqueous formulations of MV-wt, a yellow sector, and a white sector provided zero control, but all three isolates were active without a dew period when formulated in corn oil, Silwet L-77 surfactant, and in surfactant plus corn oil. Generally, the yellow sector was less effective than the other two isolates in any formulations, and the MV-wt and white sector provided approximately 100% mortality of the test plants. Dew (10 h) increased weed control to 100, 33, and 65%, respectively, for MV-wt, the yellow sector and the white sector. All isolates provided nearly 100% control in the oil and surfactant formulations with a dew period compared to treatments receiving no dew. Soil incorporation studies were also performed to compare MV-wt efficacy of preparations grown on agar versus growth on rice grains. Higher efficacies (1.75 Á3.3-fold increase) were obtained from rice grain preparations compared to preparations grown on agar, when preparations were incorporated at several rates into soil prior to planting. Cell-free extracts of the MV-rice cultures were also phytotoxic to kudzu seedlings up to the eight-to 10-leaf growth stage. Thus, formulation, growth media, and the application method are important determinants in the efficacy of MV and MV sectors on kudzu seedlings.

Evaluation of a Fungal Strain, Myrothecium roridum F0252, as a Bioherbicide Agent

“…So far, there have been several studies on the formulations and their applications of Myrothecium species to fields and greenhouses, and the interaction between bioherbicide and herbicide (Boyette et al, 2008;Hoagland et al, 2007;Vincent et al, 1999). According to Boyette et al (2007), when M. verrucarium was applied alone, the post-emergence provided no control of purslanes and spurges, but when formulated with a surfactant, Silwet L-77, caused 85-95% and 90-95% mortality to purslanes and spurges weed species, respectively.…”

Effect of Lasiodiplodia pseudotheobromae Isolates, a Potential Bioherbicide for Amaranthus hybridus L. in Maize Culture

“…Due to the development of herbicide resistance and a trend towards a chemically free environment, biological control using plant pathogens (bioherbicides) has been considered (Hoagland, 2007). The phytotoxic metabolite from Lasiodiplodia pseudotheobromae used during the current study had no adverse effect on the tested crop, but showed a bioherbicidal effect on all the tested weeds.…”

Effectiveness of Myrothecium roridum for controlling water hyacinth and species identification based on molecular data

“…The results indicated that M. roridum isolate KKFC 408 had the highest disease severity when compared with the other isolates and the control treatment. In these fungal genera, several species of Myrothecium have been developed as a mycoherbicide for controlling the water hyacinth and other water weeds such as M. roridum (Liyanage and Gunasekera, 1989) and M. verrucaria (Hoagland et al, 2007;Okunowo et al, 2010).…”

“…(Martyn and Freeman, 1978) Alternaria eichhorniae (Shabana et al 1995) Cercospora rodmanii (Conway and Freeman, 1977;Charudattan, 1986), Rhizoctonia solani (Shahjahan et al, 1987) and Myrothecium roridum (Liyanage and Gunasekera, 1989). In these fungal genera, several species of Myrothecium have been developed as a mycoherbicide for controlling the water hyacinth and others weeds such as M. roridum (Liyanage and Gunasekera, 1989), Myrothecium verrucaria (Hoagland et al, 2007;Okunowo et al, 2010). There are numerous enzymes that M. roridum can produce such as the cellulases enzyme, which hydrolyzes the β-1,4-D-glycosidic bonds within the cellulose molecules of the plant (Akiba et al, 1995;Baer and Gudmestad,1995;Zaldivar et al, 2001;Moreira et al, 2005;Okunowo et al, 2010).…”