Indian Journal of Nematology
Year : 1982, Volume : 12, Issue : 1
First page : ( 73) Last page : ( 78)
Print ISSN : 0303-6960. Online ISSN : 0974-4444.

Effect of temperature on larval emergence from Cysts of Heterodera avenae

Bhatti D. S., Malhan Indra

Department of Nematology, Haryana Agricultural University, Hissar, India

Received:  June,  1981.

Abstract

Larval emergence at constant temperatures, i.e., 10, 15, 20, 30 and 40°C from old and new cists of H. avenae was studied. At fluctuating room temperature larval emergence from only old cysts was studied. The contents of field-collected cysts were also recorded during April, 1973 to November, 1974. In all, there were 100 cysts in four replicates at each temperature. The weekly observations revealed that differences in larval emergence from old cysts at 10°C, 15°C and 20°C were significant. As was evident from total hatch, the optimum temperature, the maximum larval emergence took place at l8°C. This points to the possible existence of optimum temperature between 15°C and° 20°C. For larval emergence from new cysts, there was significant increase at 15°C as compared to 10°C, a significant decline at 20°C and little emergence at higher temperatures. This indicated that for larval emergence from new cysts the optimum temperature might be between 10°C and 15°C. Thus, there appeared to be different temperature optima for larval emergence from old and new cysts of H. avenae. The monthly observations on contents of the field-collected cysts did not show any much greater variation except a slight decline during winter months.

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