Expression of insecticidal protein in transgenic Bacillus thuringiensis (Bt) is lower in cotton reproduction organs, especially during boll development period. The current study investigated the effects of nitrogen fertilization under nitrogen deficit on boll development and Bt toxin content in boll shell, which is the first target of boll worm harm. The protein synthesis and degradation in thi...

Insect pests may have a severe impact on cotton production in Australia. Key pests are Helicoverpa spp which are well adapted to exploit cropping systems and often evolve resistance to pesticides. Until recently adoption of IPM has been restricted by a lack of nondisruptive tools. IPM must be founded on a thorough understanding of the ecology of pest and beneficial species, their interaction wi...

Determining the influence of soil environmental factors on degradation of Cry1Ac protein from Bt cotton residues is vital for assessing the ecological risks of this commercialized transgenic crop. In this study, the degradation of Cry1Ac protein in leaves and in buds of Bt cotton in soil was evaluated under different soil water content and temperature settings in the laboratory. An exponential ...

No. Poster–73 IMPACT OF COTTON LEAF CURL DISEASE (CLCuD) ON YIELD AND QUALITY OF FIBRE IN Bt COTTON IN PUNJAB Daljeet Singh, J.S. Gill, R.K. Gumber and Ramandeep Singh Punjab Agricultural University, Regional Station, India Cotton is one of the most important cash crops in India. Cotton leaf curl disease (CLCuD) , caused by a single stranded circular Gemini virus consisting of DNA A and two sat...

Plants modified to express insecticidal proteins from Bacillus thuringiensis (referred to as Bt-protected plants) provide a safe and highly effective method of insect control. Bt-protected corn, cotton, and potato were introduced into the United States in 1995/1996 and grown on a total of approximately 10 million acres in 1997, 20 million acres in 1998, and 29 million acres globally in 1999. Th...

Transgenic crops producing Bacillus thuringiensis (Bt) toxins for insect pest control have been successful, but their efficacy is reduced when pests evolve resistance. Here we review the definition of field-evolved resistance, the relationship between resistance and field control problems, the theory underlying strategies for delaying resistance, and resistance monitoring methods. We also analy...

Transgenic cotton is very effective in controlling targeted pests such as cotton bollworm (Helicoverpa armigera). However, increases in spider mite (Acari: Tetranychidae) populations have been reported in fields of transgenic cotton. The objectives of our laboratory experiments were (i) to determine host plant preference (transgenic or non-transgenic cotton) of T. turkestani females and (ii) to...

Large scale planting of Bt crops began in 1996 and grew quickly to more than 10 million ha per year. The cumulative area of Bt crops grown globally from 1996 to 2002 exceeded 62 million ha, enough to cover the states of California and Iowa. More than 99% of this area was planted with either Bt corn or Bt cotton producing Bt toxins Cry1Ab or Cry1Ac to kill larvae of lepidopteran pests. These Bt ...

Fitness costs of resistance to Bacillus thuringiensis (Bt) crops occur in the absence of Bt toxins, when individuals with resistance alleles are less fit than individuals without resistance alleles. As costs of Bt resistance are common, refuges of non-Bt host plants can delay resistance not only by providing susceptible individuals to mate with resistant individuals, but also by selecting again...

This article analyzes effects of insect-resistant Bt cotton on pesticide use and agricultural productivity in Argentina. Based on farm survey data, it is shown that the technology reduces application rates of toxic chemicals by 50 per cent, while significantly increasing yields. Using a damage control framework, the effectiveness of Bt versus chemical pesticides is estimated, and technological ...