S. M. Purushothaman ¹, Ambili S. Nair ¹, B. Renjan ¹, K. Karthikeyan ¹

Affiliations
1 Regional Agricultural Research Station, Pattambi, Kerala, IN

Abstract

Spotted pod borer, Maruca vitrata (Geyer) is a major constraint in the production of grain cowpea. The pest causes losses in grain yield of cowpea ranging from 20 to 60 per cent. In order to manage the pest, field experiments were conducted at four farmers fields during rabi 2010-2011. The study revealed that the pest can be managed effectively by spraying profenophos @ 1ml/litre at the time of flowering, Bacillus thuringiensis @ 1g/litre one at the time of flowering and next one was at 15 days later, Beauveria bassiana @ 20 g/litre at the time of flowering and other one was at 15 days interval and carbaryl @ 4 g/litre at the time of flowering. At harvest, the treatments recorded the per cent pod borer incidence of 6.99, 7.40, 7.86 and 8.96, respectively. Significantly higher grain yield was recorded in profenophos (817.18 kg/ha), Bacillus thuringiensis (754.89 kg/ha) and Beauveria bassiana (748.66 kg/ha) and carbaryl (669.31 kg/ha) treated plots.

Keywords

Spotted Pod Borer, Maruca vitrata, Bacillus thrungiensis, Cowpea.

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K. Karthikeyan ¹, Sosamma Jacob ², S. M. Purushothaman ¹

Affiliations
1 Regional Agricultural Research Station, Kerala Agricultural University, Pattambi-679306, Kerala, IN
2 College of Horticulture, Kerala Agricultural University, Vellanikkara-6, Thrissur, Kerala

Abstract

Field evaluation of two egg parasitoids, Trichogramma japonicum Ashmead against rice stem borer, Scirpophaga incertulas (Walker), and Trichogramma chilonis Ishii against leaf folder, Cnaphalocrocis medinalis (Guenee), was carried out in farmers' fields in three locations at Karakkad village, Palakkad district, Kerala, during three seasons in 2003 and 2004 in comparison with insecticide application. Release of T. japonicum @ 100000/ha followed by application of azadirachtin 1 per cent against yellow stem borer reduced dead hearts from 12.21 to 91.02 per cent and from 27.4 to 58.2 per cent over insecticide application during kharif and rabi seasons, respectively. Incidence of white ears was reduced by 72.41 to 92.86 per cent. T. chilonis reduced leaf folder damage by 41.68-98.60 per cent over conventional insecticide application. Release of egg parasitoids in rice resulted in an increase of yield by 25.79-45.13 per cent over insecticide treated plots, with a mean cost-benefit ratio of 1:2.6 and 1:1.9 in parasitoid released and insecticide applied plots, respectively.

Keywords

Cnaphulacrocis medinalis, Rice, Scirpophaga incertulas, Trichogramma chilonis, Trichogramma japonicum.

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K. Karthikeyan ¹, S. Jacob ², S. M. Purushothaman ¹

Affiliations
1 Regional Agricultural Research Station, Kerala Agricultural University, Pattambi 679306, Kerala, IN
2 College of Horticulture, Kerala Agricultural University, Vellanikara, Thrissur, IN

Abstract

Four field experiments conducted to evaluate the efficacy of cartap hydrochloride @ 1 kg a.i./ha in comparison with check insecticide carbofuran during 1999 (I crop season), 2000 (I crop season) and 2001 (I and II crop seasons) showed that cartap hydrochloride treatment in nursery five days before pulling rice seedlings had reduced incidence of dead hearts (35.6 %) and white ear (28.4 %) caused by yellow steniborer, Scirpophaga incertulas Walker and reduced leaf damage by leaf folder, Cnaphalocrocis medinalis Guenee by 47.7 percent with increased grain yield in comparison with check insecticide (carbofuran) drenched seedlings. The cartap hydrochloride drenched seedlings supported higher population of natural enemies like spiders (Tetragnatha sp.) while other natural enemies like damselflies (Agriocnemis sp.), green mirid bugs (Cyrtorhinus lividipennis) and larval parasitoids (Stenobracon sp.) were on par with the untreated plots.

Keywords

Carbofuran, Cartap Hydrochloride, Leaffolder, Natural Enemies, Rice, Stem Borer.

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