J. S. Virk ¹, K. S. Brar ¹, A. S. Sohi ¹, Maninder Shenhmar ¹

Affiliations
1 Department of Entomology, Punjab Agricultural University Ludhiana, 141 004, Punjab, IN

Abstract

Studies were carried out during 2003 and 2004 to find out the release technology of Trichogramma chilonis Ishii (weekly releases from July to October @ 1, 50, 000 ha) for the management of cotton bollworms. Releases as tricho-card (100, 150 and 200 points/ ha) were compared with adult releases. On the basis of incidencc of bollworms among fruiting bodies (17.63 and 16.79%), green bolls (26.87 and 14.14%), parasitization of Helicoverpa armigera (Hubner) eggs (17.41 and 19.64%) and seed cotton yield (8.24 and 9.26 q/ha). The releases as adult proved better. Releases at 200 points/ ha was better than releases at 100 and 150 points/ha.

Keywords

Bollworms, Cotton, Release Technology, Trichogramma chillonis.

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J. S. Virk ¹, K. S. Brar ¹, A. S. Sohi ¹

Affiliations
1 Punjab Agricultural University, Department of Entomology, Ludhiana 141004, Punjab, IN

Abstract

The role of trap crops on the parasitisation efficiency of TricllOgramma chilonis was studied at farmer's field at village Khuban (Distt. Ferozepur). Maize, sorghum, pearl millet and marigold were tested as trap crops. One row of trap crop was grown after every 20 rows of cotton crop along with pure crop of cotton. The egg parasitoid was released 13 times during July to September at weekly interval @ 1, 50,000 per hectare. Need based applications of comparatively safe insecticides were also made. The highest mean parasitization (10.48%) was observed when sorghum was used as trap crop and it was significantly higher than all other treatment. The parasitisation when marigold was used as trap crop was also higher (8.08 %) than pure cotton. The mean incidence among green bolls was lowest (2.74 %) when sorghum was used as trap crop and it was significantly lower than other treatments except when marigold (3.52 %) and pearl-millet (3.8 %). The seed cotton yield in pure cotton was lowest (13 q/ha) which was on par with maize (13.1 q/ha) but these were significantly lower than other treatments. The yield was significantly highest (14.8 ql ha) when sorghum was used as trap crop.

Keywords

Bollworms Complex, Cotton, Parasitization, Trap Crop, Trichogramma chilollis.

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J. S. Virk ¹, K. S. Brar ¹, A. S. Sohi ¹

Affiliations
1 Department of Entomology, Punjab Agricultural University, Ludhiana 141004, Punjab, IN

Abstract

Six cultivars, namely, LD 327, LH 1556, Ganga Kaveri-151, Ankur 651, Dbaval-2 and LHH 144 were e,'aluated for testing efficacy of Trichogramma chilonis Ishii. T. chilonis was released 13 times during July to September at weekly interval @ 1,50,000 per ha. Four sprays of compatible insecticides were given during this period. The lowest bollworm incidence among intact fruiting bodies was recorded in LD327 (1.40%) which was on par with Ankur 651 (2.06%) and LHH144 (2.10%) but significantly lower than other cultivars. There was no significant difference in mean bollworm incidence among green bolls, parasitization, and seed cotton yield in various cultivars.

Keywords

Bollworms Complex, Cotton, Hybrids, Parasitization, Tricllogramma chilonis, Varieties.

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