Pathogenicity of fungi collected in northern Ghana to Striga hermonthica

Abstract

Thirteen fungal species were isolated from diseased plants of Striga hermonihica (Del.) Benth in northern Ghana. The pathogenidty of 12 isolates of the fungal species iQcludSng Curvularia fallax Boed, Fusarium equheti (Corda) Sacc., Fusarium equiseti var. buUatum (Sherb.) Wollenw., F. oxysporum Schlecht, F. soiani (Mart) Sacic., Macrophomina phaseoTma (Tassi) Goidan, and Sclerotium rolfsii (Sacc.) were evaluated against 5. hermtmthica xmder controlled environmental cooditions. All isolates were pathogenic to 5. hermonthica when propagated on whe at ( Triticum aestivum. L.) grains and incorporated pre-plan ting into the soil. However, their virulence difiEered. TWo isolates off. oxysporum and one isolate of F. soiani reduced the emergence of S. hermonthica by 88%. 98%, and 76%, respectively. Sorghum {Sorghum bicolor (L.) Moench) yield was increased by 26% when 5. hermonthica was controHed. In contrast, in the control treatment with 5. hermcmthim no yield could be obtained. The P. oxysporum isolates were not pathogenic on sorghum. Germination tests indicated that the F. oxysporum isolates were highly pathogenic to S. hermonthka seeds. Although the F. soiani isolate reduced the emergence afS. hermonthica in the pot experiments, it did not inlluetice germination. This indicates that pathogens may attack different stages in the life cycle of S, hermontkica.

Bioherbicidal effect of fumonisin B1, a phytotoxic metabolite naturally produced byFusarium nygamai, on parasitic weeds of the genusStriga

“…Many species of fungi, particularly Fusarium spp., are common and widespread on S. hermonthica in Sudan, Ghana and Mali as well as on S. asiatica in Madagascar (Abbasher, 1994;Ciotola et al ., 1995;Nirenberg et al ., 1998). In pot and field experiments, it was shown that isolates of Fusarium nygamai Burgess & Trimboli collected from Sudan, as well as F. oxysporum Schlecht isolates from Ghana, have potential to effectively control S. hermonthica (Abbasher & Sauerborn, 1992;Kroschel et al ., 1996;Sauerborn et al ., 1996a). Parasitic weeds generally damage their host plants even before emergence above ground.…”

Field assessment of Fusarium oxysporum based mycoherbicide for control of Striga hermonthica in Nigeria

“…These results confirm that the mycoherbicide applied pre-sowing using spotapplication can significantly reduce Striga incidence under field conditions in the Nigerian savanna. The efficacy of F. oxysporum in our field trials indicate that it Abbasher and Sauerborn, 1992;Ciotola et al, 1995;Kroschel et al, 1996;Abbasher et al, 1998;Marley et al, 1999) have shown that Fusarium based mycoherbicides applied pre-sowing reduce Diarra et al (1996) and Ciotola et al (2000) show that F. oxysporum can be effective in the control of Striga under field conditions. These reports agree with our results.…”

“…They reported up to 92% reduction in S. hermonthica emergence due to application of F. oxysporum isolate M12-4A. Earlier reports showed that F. oxysporum isolates reduced Striga emergence from between 88 to 100% when applied pre-sowing (Ciotola et al, 1995;Kroschel et al, 1996; 1999). In addition, the quantity of mycoherbicide used by this method is lower than with the other methods, thus maybe suitable for use in small farms.…”

“…The potential of Fusarium oxysporum as a bio-control agent for the control of S. hermonthica in WCA has been reported (Ciotola et al, 1995;Diarra et al, 1996;Kroschel et al, 1996;Abbasher et al, 1998;Marley et al, 1999). Isolates of F. oxysporum from S. hermonthica have been shown to infect only Striga spp.…”

Striga

“…This has provided the smallholder farmers with a diversity of options to control the parasites. Several researchers have extensively documented these potential options to combat Striga which have been classified into the most commonly used terms: cultural and mechanical control options including hand-pulling, crop rotation, trap-cropping, intercropping, appropriate improvement of soil fertility, and planting methods (Berner et al, 1995;Kuchinda et al, 2003;Hess and Williams, 1994;Hess and Dodo, 2004;Samake et al, 2006;Gworgwor, 2007;Khan et al, 2002Khan et al, , 2006Khan et al, , 2008Eltayb et al, 2013;Hooper et al, 2015); chemical control method such as application of chemical herbicides Kanampiu et al, 2007a;Kanampiu et al, 2007b) and biological control approaches using the pathogenic fungus Fusarium oxysporum as a mycoherbicide, or insects (Abbasher et al 1995(Abbasher et al , 1998Kroschel et al 1996;Marley et al, 1999Marley et al, , 2005Hess et al 2002;Elzein and Kroschel, 2004;Yonli et al, 2006;Zahran, 2008;Venne et al, 2009;Zarafi et al, 2015;Watson, 2013). Recently, the potential of the plant growth promoting rhizobacteria (PGPR) of the genus Bacillus (B. subtilis, B. amyloliquefaciens) and Burkholderia (B. phytofirmans) as Striga biocontrol agent has been surveyed by Mounde (2014).…”