Among the biological pest and weed control, fungi outstand as one element of comprehensive, multifaceted pest control program. Fungi belong to a family of eukaryotic organisms. The kingdom of listed microorganisms is Fungi. This group of microorganism is used to control pests and weeds in the agricultural sector. Some create diseases to crops, while some act as food. The most used type is the fungi that work against pests and, insects and weeds. They aggressively compete for space and nutrients with harmful microorganisms. They apply the concept of competitive exclusion (Jim, 2010).
The fungi show aggression to pests by overrunning their cuticle. This means only the near creatures die. B. Bassiana has been used to control cabbage looper. The fungus species called Metarbizium anisopliae are highly effective on soil pests. Fungi have also been used in glasshouses (Emden & service, 2004, pp, 170) Theriaphis trifolii, Lucerne aphid became a pressing pest of the Lucerne in Australia in seventies. Exotic fungi species called Zoophthora radicans were imported from Israel. The fungi were tested and multiplied in the laboratories. Z. radicans became effective. It is currently used to control aphid in Lucerne field (Jim, 2010, pp, 41).
The hyphomycetes are the mostly used classification in the control of pests. The species of the microbe can be produced in large scale in the laboratories and used in mass management of insect pests. Most fungi in this family are found in the soil. They can result into natural outburst of their own if the environmental factors are conducive. Some strains of fungal strains, which are produced commercially, are used in the control of many pests. It is not forgotten that these incorporate mealy bugs, caterpillars among others. It is noteworthy that the strain of hyphomycetes mostly used is Beauveria bassiana. “A group of fungi called entomopathogenic fungi kill insects. Other species mostly used are Verticillium lecanii, Paecilomyces spp Hirsutella spp, and Metarhizium anisopliae” (Jim, 2010, pp, 41).
Some Endophytic fungi belonging to genus Neotyphodium e.g. N.coenophialum usually produces alkaloids. These alkaloids are exceedingly harmful to a wide range of vertebrate and invertebrate herbivores. The alkaloids guard the grass against herbivore. Rummage grass containing Neotyphodium endophytes is used in forage production programs. Fungal strains that reduce the presence of herbivores like insects are used. Entomophthorales is a fungus that is used in the agricultural sector. This group can practically cause mass destruction of insect host population. It is one of the fungi group and acts on aphids. There is no current large scale production of entomophthorale (Helen et al., 2010, pp 150).
Application of fungi as biological pest management requires tactics to realize the full potential of the method. They should be used when the pest is seen. The execution period should coincide with the host life cycle which can easily make contact with spores. Nymph stage is the best application stage for grasshoppers. The fungal products should not be applied during severe weather conditions. The potency of the spore is reduced by drastic weather conditions. People should always be vigilant of the fungi used around them. The effect can spread to unintended field. The intended crops must be inoculated thoroughly while avoiding spill-over to unintended areas. Fungi have some advantages over other pest and weed control methods that make it one of the preferred control methods. The fungi are extremely gentle on human beings, plants and animals. This makes it a safe and better method of weed and pest control strategy. Large-scale production of fungi is remarkably easy in-vitro. The parasitic fungus of the group hyphomycete is comparatively easy. This makes it a cheaper option for biological pest control than bacterial method. The formulas of the produced fungal pesticides are in spore form. It can get on easily on hand appliance technology like the spray rigs. The same product can be used to control many pests and weeds due to their nature of a wide spectrum action (Heikki & James 2003, pp, 55).
Concentration of fungicides must be high for the action to be realized. This brings down the cost efficacy of fungi products. It is noteworthy that Fungi usually two weeks to act on the target pests and weeds. The broad-spectrum nature of the fungi may not be beneficial. Some important insects like parasitoids, pollinators and predators, may be swept away if are in the Lucerne field (Burge, 1988, pp 41). The killing of the nonstarter organisms may interfere with the overall yield of crops. Environmental factors affect the efficacy of fungi. Humid conditions and prolonged sun exposure inactivate spores hence rendering them inactive. The extreme environmental situations may withhold the effectiveness of the fungi.
List of References
Emden, H & Service, M 2004, Pest and Vector Control, United Kingdom, Cambridge university press, pp 170.
Jim, M 2010, Fungi for the biological control of insect pests, Extension. Web.
Burge, M 1988, Fungi in biological control system, United Kingdom, Manchester University, pp 41.
Heikk, M & James, M 2003, Biological, benefits and risks. United Kingdom Cambridge, University Press, pp 55.
Helen E. et al 2010, The Ecology of Fungal Entomopathogens, London, Heidelberg, pp 150.