Performance of Bt cotton against sucking pests (original) (raw)
Related papers
Insect Infestation on Bt. and Non-Bt. Cotton Cultivars
Food Science and Quality Management, 2014
A field study was carried out to examine the resistance potential of promising cotton cultivars to insect pest infestation, during the year 2012. Five cotton varieties were examined for their resistance against insect pests including Hari Dost, Shahbaz-95, NIAB-78, Sindh-1 and Bt Cotton. The insect pests monitored in this study included thrips, jassid, whitefly and bollworms. The experimental process for monitoring the insect pests was initiated on 15 th June 2012 and lasted on 12 th October, 2012. The results showed that thrips population was significantly (P<0.01) lowest (6.28/plant) on Haridost, against 9.22/plant on NIAB-78, 13.79/plant on Bt cotton 14.89/plant on Sindh-1. while the highest thrips population (15.21/plant) was recorded on Shahbaz-95. The peak thrips population was noted on 12 th July observation on all three verities while on Bt cotton, the peak thrips population was recorded on 19 th July. Bt Cotton. The peak activities of jassid was recorded in the month of August. Overall mean showed that the signifactly highest (P<0.01) population of jassid was recorded as (3.59/leaf) on Sindh1 followed by Bt cotton (2.81/leaf), Shahbaz (2.80/leaf), Niab-78 (2.19/leaf) and Hari dost (1.63/leaf). Similarly, whitefly was found active in month of July and Augest. Significantly, more population (P<0.01) was recorded on Sindh-1 (3.20/leaf) and minimum on Haridost (1.40/leaf). Bollworms infestation was significantly lowest (P<0.01), (2.04/plant) on Bt cotton against 2.56/plant on NIAB-78, 3.04/plant on Haridost, 3.22/plant on Sindh-1; while the highest bollworms population (3.36/plant) was observed on cotton variety Shahbaz-95. Bt cotton variety showed considerable resistance against bollworm complex, while NIAB-78 also showed some resistance against sucking. The infestation of sucking insect pests on haridost. Shahbaz and Sindh-1 as compared to Bt cotton. The infestation of thrips, and whitefly was peaked in the month of July. While Jassid was found most active in August. Bollworms appeared in first week of July and remained active in the field in relatively higher population upto the mid of September and later decreased to negligible level.
Indian Journal of Agricultural Sciences
Genetically engineered cottons expressing ä-endotoxins from Bacillus thuringiensis have been adopted on a largescale worldwide. Therefore, we studied the efficacy of Bt cottons for the management of bollworms, their effects on nontarget insects, and seedcotton yield under insecticide protected and unprotected conditions. Helicoverpa armigera and Earias vittella damage was significantly lower in Bt than in non-Bt cottons, while no significant differences were observed in egg-laying by H. armigera. The populations of major non-target sucking insect pests such as Amrasca biguttula biguttula, Bemisia tabaci, Aphis gossypii, Oxycarenus laetus, Dysdercus koenigii and Nezara viridula and the generalist predators, viz Cheilomenes sexmaculatus, Chrysopa spp., and spiders did not differ significantly between Bt and non-Bt cottons. Insecticide application resulted in resurgence of cotton aphid and whitefly, possibly because of elimination of natural enemies or better growth of plants uder protected conditions. Abundance of bollworms, non-target pests, and generalist predators was significantly greater before insecticide sprays than after insecticide application, except in a few cases. Bollworm damage was lower and seedcotton yields higher in Bt than in non-Bt cottons. The present studies indicated that Bt cotton hybrids are effective for the management of bollworms and yield more, and do not have any adverse effects on the abundance of generalist predators.
Seasonal incidence of sucking pests and their natural enemies in Bt cotton
Field studies were undertaken on the Agronomy Instructional Farm, CPCA, SDAU, Sardarkrushinagar to study the seasonal incidence of sucking pests of Bt cotton. The pest sequence study was undertaken in the five different cultivars viz., Ajit-155, Dinkar-7, Vikram-5, Jackpot and GTHH 49 BG II of Bt cotton. It was observed that the Bt cotton was invaded first between the third week of July to second week of August by group of sucking pests viz., aphid, jassid, thrips, whitefly and their damage continued throughout the crop season. Later on two another sucking pests viz., mealybug and mite were infested in Bt cotton crop during the second and last week of September, the period of activity of these two pests were also remained till the harvesting of crop.
Evaluation of pest management practices against sucking pests of Bt cotton
The Indian Journal of Agricultural Sciences
The impact of non-pesticide farmer’s practice (Jind district, Haryana) adopted by a group of farmers on pestpopulation, natural enemies and yield parameters was studied and compared with Integrated Pest Management strategyand pesticide based farmers’ practice within same villages where this group has implemented their pest managementstrategy in Bt cotton. Comparison of population per three leaves of sucking pests (average of 3 years) indicated lowestpopulation of whitefly (adult), jassid and thrips (nymph and adult) in IPM module (7.18, 3.37 and 7.17) followedby NIFP, non-insecticidal farmer’s practice (7.70, 3.48 and 7.62) and FP, farmer’s practice (9.64, 4.14 and 9.69)respectively. While studying the interaction among sucking pest and natural enemies it was interesting to note thatthe population, in both the cases, increased gradually and after attaining the peak activity there was a declining trend.Socio-economic studies also supported the above results. In present study,...
Preliminary Evaluation of the" Next Generation" of Bt Cotton
1999
The next generation of Bollgard ® cotton was evaluated for agronomic and insecticidal efficacy under central Arizona growing conditions. Two novel lines were compared with their recurrent parents, DP50 and DP50B. There were no seasonlong differences observed among the varieties in most plant development and insect parameters. However, DP50 had significantly lower emergence than the other lines tested (possibly related to seed quality). The lower plant population may have been responsible for greater whitefly abundance observed on two dates mid-season. During early-season ratings of secondary "pests" (15 DAP) (scaled on damage and/or presence), the two test lines received lower ratings for thrips and flea beetle when compared with DP50, DP50B and DP50Bu (untreated for Lepidoptera). However, these difference are likely as a result of the difference in seed treatments that the two test lines received (Gaucho ® ) and the others did not. This seed treatment does have known activity against thrips and beetle pests. In mid-season, the two test lines received lower ratings for beet armyworm when compared to DP50, DP50B and DP50Bu (although, not significantly different from DP50B or DP50Bu). Efficacy against pink bollworm (PBW) was assessed one time at the end of the season (we were limited to this time, so as to not affect yield), and DP50 was the only variety in which PBW exit holes were observed and PBW larvae collected. However, the low Lepidoptera pressure experienced during the season limited assessments of the two novel lines' efficacy toward PBW. There was no significant difference in yield (bale/A) among the varieties. Although, one of the test lines had a lower lint turnout than each other variety. The two novel Bollgard lines performed well under our growing conditions, but continued evaluations will be necessary under more conditions and more insect pressures before "varietal" performance and gene efficacy can be assessed adequately.
Impact of Insect Resistant Cotton
Boll guard I & II were introduced in 2002 and 2006 by Mahyco Monsanto with Genetic Engineering Appraisal Committee, Govt. of India. Indian cotton farmers adopted Bt hybrid cotton between 2002-2013 reaching 92% of the cotton area and 95% of the production, replacing conventional hybrids/ varieties of all the species in both rainfed and irrigated conditions. Bt hybrid cotton was presumed to produce record highest average productivities in India and other major cotton growing countries also in 2007 and 2012 with a decline after 2008 due to excess rains. Farmers invested Rs. 1500-1750/-Acre could prevent 24-28% cotton yield losses by consuming 2.3 times more fertilizers, 35% herbicides and 22% growth regulators. Although it was reported three times returns compared to non Bt cotton due to severe inflation pressure farmers profitability got reduced and went unrest in 2011. Seed producers, marketing companies, input dealers and female labourers were major beneficiaries. Bollworms sprays were reduced to zero but sucking pests sprays were almost doubled with low volume more costly insecticides. The pest management cost remain unchanged in this decade. In conclusion, Bt cotton won the confidence of farmers for its bollworm resistance except refugea regultion. Govt. efforts for price control stabilized margin for farmers but eroded due to escalating weed management and hand picking costs after 2008. Yield gap analysis found N, Zn, Mg and B were limiting optimum yields, besides post emergence herbicides, rain water conservation/ supplemental irrigations can break present productivity levels and reduce cost of production. Public sector research agencies should follow Public private partnership model adopted by Gujarat Agriculture University, Surat for conversion Bt Hybrid-6 and 8. They need to meet farmer's expectations by developing transgenic insect and herbicide resistant cotton varieties and prove in farmers fields. Breeders must meet consumer's expectations inorder to compete with polyester fibre to get sustainable demand. Bt hybrid cotton impact on economy, input output efficiencies, reducing cost of production, policies affecting farmers profits, R&D efforts and BMPs across globe were reviewed.
2012
To study the comparative efficacy of the insecticides viz., bifenthrin (Talstar 10 EC), spinosad (Tracer 240 SC), lambda cyhalothirn (Karate 2.5 EC), flubendiamide (Belt 480 SC) and spinothelin (Radiant 125 SC) on four cultivars of cotton were evaluated against spotted bollworm and integrated with the host plant resistance of BT cotton cultivars. These insecticides were sprayed twice i.e. on August 6 and September 4, 2008. The cotton varieties Bt-101, CIM-496, Bt-121, and MNH-786 were sown following two factors split plot protocol in Randomized Complete Block Design replicated three times in the experimental field of Cotton Research Centre, Sahiwal during 2008. Spinothelin was found highly effective against spotted bollworm followed by Spinosad. Bt cottons showed more resistance as compared to non-Bt varieties. The variety Bt-101 showed minimum infestation level of squares, flowers and bolls followed by Bt-121.
Cotton is worldwide growing crop and important source of fiber and oils. In Pakistan largest area was cultivated by cotton crop. Due to growing of Bt cotton in Pakistan, chewing pest of cotton not a problem but sucking pest was cause greater damage as reduction of yield. Red cotton bug is a sucking pest which cause staining in cotton due to this yield was reduced. Red cotton bug feed on the bolls of cotton due to this oil content and boll size becomes reduced. For last few years red cotton bug becomes a major pest of cotton in Pakistan and cause staining of lint due to this fiber quality become reduced. For assessment of red cotton bug damage and other pest status in Punjab level, farmer of the five cities (Multan, Shujabad, Muzaffargarh, Kot Addu and Pakpattan) were visit and structured questionnaire were asked in Urdu language. Total four hundred cotton grower was visited in above mention cities. Cotton grower in Punjab, Pakistan 88.8% identifies this pest (red cotton bug). Results showed that last year armyworm status high (82.0%) in cotton crop and cause greater problem. Red cotton bug status was medium (73.3%) in last few years in Punjab, Pakistan. In Punjab cotton grower 54% cotton grower said red cotton bug cause staining of lint in cotton. So Bt cotton adoption in large area cause the breakout of secondary pest to become a primary pest also cause the induction of resistance in primary pest. Now in Punjab, red cotton bug and dusky cotton bug becomes a major pest of cotton.