Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-05T04:13:29.227Z Has data issue: false hasContentIssue false

Economic threshold levels for Chilo partellus (Lepidoptera: Pyralidae) control on resistant and susceptible sorghum plants

Published online by Cambridge University Press:  10 July 2009

J. van den Berg
Affiliation:
Grain Crops Institute, Agricultural Research Council, Private Bag X1251, Potchefstroom, 2520, South Africa:
G. D. J. van Rensburg
Affiliation:
Grain Crops Institute, Agricultural Research Council, Private Bag X1251, Potchefstroom, 2520, South Africa:
M. C. van der Westhuizen
Affiliation:
Department of Zoology and Nematology, University of the Orange Free State, Bloemfontein, 9300, South Africa

Abstract

The effect of various infestation levels of Chilo partellus Swinhoe on resistant and susceptible sorghum genotypes was assessed under artificial infestation in two field trials, conducted over two seasons. In the first season, infestation levels were 0, 10, 20, 40, 60 and 80 larvae per 2 m plot row. In the second season, additional treatments of one and two larvae per plot were included. A series of all infestation levels on susceptible plants was also included with an insecticide application 5 days after inoculation. Non-linear relationships between infestation level and yield loss were observed. In susceptible plants, small increases in initial larval infestation levels resulted in sharp increases in yield loss. An opposite tendency was observed in resistant plants where a tolerant reaction at lower infestation levels was observed. Gain threshold (GT) value, indicating the yield increase necessary to compensate for control costs, economic injury level (EIL) and economic threshold level (ETL) at which control actions should be initiated were determined for each genotype. Insecticide application on susceptible plants resulted in a 10% reduction in yield loss. However, the yield was still less than that of unsprayed resistant plants. The GT values indicated that insecticide application was economically warranted at an ETL of 20% and 2% of plants with visible symptoms of whorl damage, for the resistant and susceptible genotypes respectively.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alghali, A.M. (1986) Effects of cultivar, time and amount of Chilo partellus Swinhoe (Lepidoptera: Pyralidae) infestation on sorghum yield components in Kenya. Tropical Pest Management 32, 126129.Google Scholar
Bardner, R. & Fletcher, K.E. (1974) Insect infestations and their effects on the growth and yield of field crops: a review. Bulletin of Entomological Research 64, 141160.Google Scholar
Bate, R., Van Rensburg, G.D.J. & Giliomee, J.H. (1990). Flight activity pattern of Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) in the Western Transvaal. Journal of the Entomological Society of Southern Africa. 53, 109111.Google Scholar
Chiang, H.C. (1973) Ecological considerations in developing recommendations for chemical control of pests: European corn borer as a model. FAO Plant Protection Bulletin. 21, 3039.Google Scholar
Chiang, H.C. (1982) Factors to be considered in refining a general model of economic threshold. Entomophaga 27, 99103.Google Scholar
Kfir, R. (1992) Seasonal abundance of the stem borer Chilo partellus (Lepidoptera: Pyralidae) and its parasites on summer grain crops. Journal Economic Entomology 85, 518529.Google Scholar
Nel, A., Krause, M., Hollings, N., Greyling, J. & Dreyer, M. (1993) A guide to the use of pesticides and fungicides in the Republic of South Africa. 332 pp. Directorate of Livestock Improvement and Agricultural Production Resources, Department of Agriculture, Pretoria.Google Scholar
Pedigo, L.P., Hutchins, S.H. & Higley, L.G. (1986) Economic injury levels in theory and practice. Annual Review of Entomology 31, 341368.CrossRefGoogle Scholar
Pretorius, A.J., McLaren, N.W., Van den Berg, J. & Wenzel, W.G. (1996) The sorghum improvement program at the Grain Crops Institute. in: Drought-tolerant crops for southern Africa: Proceedings of the SADC/ICRISAT Regional Sorghum and Millet Workshop,25–29 July 1994,Gabarone, Botswana, Patancheru, India,ICRISAT.Google Scholar
Seshu Reddy, K.V. (1985) Relative susceptibility and resistance of some sorghum lines to stem-borers in Western Kenya. Insect Science and its Application 6, 401404.Google Scholar
Sharma, H.C. (1993) Host-plant resistance to insects in sorghum and its role in integrated pest management. Crop Protection 12, 1134.Google Scholar
Stern, V.M., Smith, R.F., Van den Bosch, R. & Hagen, K.S. (1959) The integrated control concept. Hilgardia 29, 81101.CrossRefGoogle Scholar
Stone, J.D. & Pedigo, L.P. (1972) Development and economic injury level of the green clover worm on soybean in Iowa. Journal of Economic Entomology 65, 197201.CrossRefGoogle Scholar
Tingey, W.M. & Singh, S.R. (1980) Environmental factors influencing the magnitude and expression of resistance. pp. 87113. Breeding plants resistant to insects. New York, Wiley-Interscience Publications.Google Scholar
Van den Berg, J. & Van der Westhuizen, M.C. (1995) Development of a chemical control strategy for Chilo partellus in sorghum. South African Journal of Plant and Soil 12, 105107.Google Scholar
Van den Berg, J. & Van Rensburg, J.B.J. (1991) Unavoidable losses in insecticidal control of Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) in maize and grain sorghum. South African Journal of Plant and Soil 8, 1216.Google Scholar
Van den Berg, J. & Wenzel, W.G. Evaluation of stem borer resistance in the Grain Crops Institute sorghum germplasm collection. in: Proceedings of the 11th South African Maize Breeding Symposium,15–17 March 1994,Summer Grain Centre, Potchefstroom,South Africa In Press.Google Scholar
Van den Berg, J., Van Rensburg, J.B.J. & Pringle, K.L. (1991a) Comparative injuriousness of Busseola fusca (Lepidoptera: Noctuidae) and Chilo partellus (Lepidoptera: Pyralidae) on grain sorghum. Bulletin of Entomological Research 82, 137142.CrossRefGoogle Scholar
Van den Berg, J., Van Rensburg, J.B.J. & Van der Westhuizen, M.C. (1991b) The effect of single and mixed populations of Busseola fusca (Lepidoptera: Noctuidae) and Chilo partellus (Lepidoptera: Pyralidae) on damage to grain sorghum. Journal of the Entomological Society of Southern Africa 54, 231242.Google Scholar
Van den Berg, J., Van Rensburg, G.D.J. & Van der Westhuizen, M.C. (1994a) Host plant resistance and chemical control of Chilo partellus Swinhoe and Busseola fusca (Fuller) in an integrated pest management system on grain sorghum. Crop Protection 13, 308310.Google Scholar
Van den Berg, J., Wenzel, W.G. & Van der Westhuizen, M.C. (1994b) Tolerance and recovery resistance of grain sorghum genotypes artificially infested with Busseola fusca (Fuller) (Lepidoptera: Noctuidae). Insect Science and its Application 15, 6165.Google Scholar
Van Rensburg, J.B.J. & Van den Berg, J. (1992) Infestation patterns of of the stalk borers Busseola fusca Fuller (Lep.: Noctuidae) and Chilo partellus (Swinhoe) (Lep.: Pyralidae) in grain sorghum. Journal of the Entomological Society of Southern Africa 55, 197212.Google Scholar
Walker, P.T. (1981) The relation between infestation by lepidopterous stem borers and yield in maize: methods and results. EPPO Bulletin 11, 101106.Google Scholar
Wiseman, B.R., Davis, F.M. & Campbell, J.E. (1980) Mechanical infestation device used in Fall Army Worm plant resistance programs. Florida Entomologist 63, 425432.Google Scholar