Evolution of Helicoverpa armigera resistance to Bacillus thuringiensis (Bt) cotton producing Cry1Ac is progressing in northern China, and replacement of Cry1Ac cotton by pyramided Bt cotton has been considered to counter such resistance. Here, we investigated four of the eight conditions underlying success of the refuge strategy for delaying resistance to Cry1Ac+Cry2Ab cotton, a pyramid that ha...

Transgenic Bt cotton may have reduced susceptibility to aflatoxin contamination as a result of pink bollworm resistance. During 1995 and 1996, Bt cottonseed from several commercial fields in Arizona contained aflatoxin levels unacceptable for dairy use. Comparison of cottonseed with and without BGYF (bright-green-yellow fluorescence) from one highly contaminated (>6,000 ppb aflatoxin Bj) Bt see...

Introduction Cotton plants from the genus Gossypium are well defended against arthropod herbivores by a broad range of resistance mechanisms. These include direct mechanisms like trichomes and the production of toxins and indirect mechanisms like the emission of volatiles or extra-floral nectaries to attract and retain natural enemies1. One of the best understood resistance trait of cotton is t...

Bt cotton is a GM crop into which a gene of the soil bacterium Bacillus thuringiensis has been transferred to make it resistant to major lepidopteran insect pests. It was developed by the US company Monsanto and, as one of the first GM crop technologies, it became commercially available in the mid1990s. Since then, the technology has spread rapidly in the US, Australia, as well as in several de...

Transgenic cotton that has been engineered to produce insecticidal toxins from Bacillus thuringiensis (Bt) and so to resist the pest cotton bollworm (Helicoverpa armigera) has been widely planted in Asia. Analysis of the population dynamics of H. armigera from 1992 to 2007 in China indicated that a marked decrease in regional outbreaks of this pest in multiple crops was associated with the plan...

Long-term ecological effects of transgenic Bacillus thuringiensis (Bt) crops on nontarget pests have received limited attention, more so in diverse small holder-based cropping systems of the developing world. Field trials conducted over 10 years in northern China show that mirid bugs (Heteroptera: Miridae) have progressively increased population sizes and acquired pest status in cotton and mult...

Transgenic crops producing Bacillus thuringiensis (Bt) proteins have become a primary tool in pest management. Due to the intensive use of Bt crops, resistance of the fall armyworm, Spodoptera frugiperda, to Cry1F maize has occurred in Puerto Rico, Brazil, and some areas of the southeastern U.S. The sustainability of Bt crops faces a great challenge because the Cry1F-maize resistant S. frugiper...

manipulation of different genes in crop plants to get desirable characters has become an important tool of plant biotechnology. in the current study, cotton variety mnh-786 was modified for its characteristics to show resistance against lepidopteran insects and herbicide by transformation of cry1ac+cry2a and gtgene cloned in a different cassette under 35s promoter. mature embryos of cotton mnh-...

Cotton (Gossypium hirsutum L.) is an important fiber crop in Pakistan with significant economic importance. Transgenic, insect-resistant cotton (carrying a gene from Bacillus thuringiensis (Bt)) was inducted the cotton-based cropping systems of during 2002, and now sown >90% fields country. However, concerns are rising that Bt would decrease productivity winter crops (sown after cotton), lea...

The slow diffusion of new technology in the agricultural sector in less developed countries has long been a puzzle to development economists. While most of the current empirical research on technology adoption focuses on credit constraints and learning spillovers, this paper examines the role of individual risk attitudes in the decision to adopt a new form of agricultural biotechnology in China...