Cotton in the United States of America and Mexico.

This chapter provides information on the various cotton growing states of the USA and Mexico and the major cotton pests, diseases and weeds in these states and their management strategies.

Effects of Nitrogenous Fertilization and some Insecticides on the Natural Enemies of Transgenic Bt Cotton Pests

Field assessment of integrated management of BT cotton pests was carried out in two consecutive seasons; 2016/2017 and 2017/2018 in the experimental research farm of the Kassala University, Sudan. Four insecticides (imidacloprid, abamectin, profenofos, and lufenuron) from different chemical groups and with a different mode of action and three levels (43.81 kgha-1, 87.62 kgha-1, and 131.43 kgha-1) of soil-applied nitrogen were tested in the IPM package. Insecticides were applied at the recommended doses. A total of 7 weekly counts of prevailing natural enemies [Chrysoperla carnea (Stephens) and Aenasius bambawalei Hayat] were carried out for 4 weeks before spraying and 3 weeks post spraying starting the 3rd week from spraying. Results indicated that nitrogen level exerted no significant effects on the populations of prevailing natural enemies; C. carnea and A. bambawalei. Based on average post spray counts and percentage reduction over the control, all insecticide treatments significantly reduced the population of the natural enemies. Imidacloprid and profenofos exerted the highest reduction of C. carnea population followed by abamectin and lufenuron (56.03, 48.25, 07.78 and 06.61% respectively) in the first season, while profenofos, imidacloprid, lufenuron, and abamectin induced the highest reductions (55.94, 45.05, 17.57 and 17.33% respectively) in the second season. On the other hand, reductions in A. bambawalei population (abundant in season 1 only) followed the order; imidacloprid, lufenuron, abmectin, and profenofos (03.95, 02.63, 202.63, and 01.32%, respectively). Interactions between nitrogen fertilization and insecticide were not significant as measured by the population of prevailing natural enemies.

Study on Population Changes of Important Sucking – Pests (Aphis Gossypii (Glov.) and Bemisia Tabaci (G.) in the New Varieties Second Plant (After Canola) in the Golestan Province of Iran.

Investigating the population dynamic of important cotton pests on new cotton varieties is important. Cotton cultivars have important pests such as thrips, aphids, whitefly and bollworm. Considering the premature cultivars with proper yield for second cultivation in cotton-growing Golestan province at the north of Iran, this study seems necessary. This genotypes was cultivated with 9 treatments in 4 replicates. A completely randomized block design was carried out in Hashem Abad research station in a spray-free plot with the dimensions of 30 × 80 cm in 2018-2019 years. According to the results of this study, analysis of variance of two years showed that the yield of N2G80 with 1538 g in the plot with 41.7% lint percentage had the highest yield, and M13 with 685 g in the plot and 35.8% lint percentage in the lowest yield they had.The infestation rate of the genotypes tested in the population of green aphid of cotton in K880-2 and Golestan® cultivars was 48.88 and 40.31 in aphid with the highest density, and the SKT-133 and TBL-60 genotype respectively with 27.15 and 29.11 aphids per leaf had the least infestation. The amount of infestation of the genotypes tested to the population of whitefly cotton on the N2G80 and TBL-60 genotype was 90.76 and 68.86 whitefly in the leaf with the highest infestation and N2G80 and TBL-60 genotype respectively with 40.05 and 75.51 white fly in leaf were the least infested. Correlation coefficient between traits was equal to 0.55. The number of bolls per plant was not correlated with other traits including boll weight, lint percentage, aphid and white fly.

Transgenic cotton and sterile insect releases synergize eradication of pink bollworm a century after it invaded the United States

Invasive organisms pose a global threat and are exceptionally difficult to eradicate after they become abundant in their new habitats. We report a successful multitactic strategy for combating the pink bollworm (Pectinophora gossypiella), one of the world’s most invasive pests. A coordinated program in the southwestern United States and northern Mexico included releases of billions of sterile pink bollworm moths from airplanes and planting of cotton engineered to produce insecticidal proteins from the bacteriumBacillus thuringiensis(Bt). An analysis of computer simulations and 21 y of field data from Arizona demonstrate that the transgenic Bt cotton and sterile insect releases interacted synergistically to reduce the pest’s population size. In Arizona, the program started in 2006 and decreased the pest’s estimated statewide population size from over 2 billion in 2005 to zero in 2013. Complementary regional efforts eradicated this pest throughout the cotton-growing areas of the continental United States and northern Mexico a century after it had invaded both countries. The removal of this pest saved farmers in the United States $192 million from 2014 to 2019. It also eliminated the environmental and safety hazards associated with insecticide sprays that had previously targeted the pink bollworm and facilitated an 82% reduction in insecticides used against all cotton pests in Arizona. The economic and social benefits achieved demonstrate the advantages of using agricultural biotechnology in concert with classical pest control tactics.

Insect resistance management in Bacillus thuringiensis cotton by MGPS (multiple genes pyramiding and silencing)

The introduction of Bacillus thuringiensis (Bt) cotton has reduced the burden of pests without harming the environment and human health. However, the efficacy of Bt cotton has decreased due to field-evolved resistance in insect pests over time. In this review, we have discussed various factors that facilitate the evolution of resistance in cotton pests. Currently, different strategies like pyramided cotton expressing two or more distinct Bt toxin genes, refuge strategy, releasing of sterile insects, and gene silencing by RNAi are being used to control insect pests. Pyramided cotton has shown resistance against different cotton pests. The multiple genes pyramiding and silencing (MGPS) approach has been proposed for the management of cotton pests. The genome information of cotton pests is necessary for the development of MGPS-based cotton. The expression cassettes against various essential genes involved in defense, detoxification, digestion, and development of cotton pests will successfully obtain favorable agronomic characters for crop protection and production. The MGPS involves the construction of transformable artificial chromosomes, that can express multiple distinct Bt toxins and RNAi to knockdown various essential target genes to control pests. The evolution of resistance in cotton pests will be delayed or blocked by the synergistic action of high dose of Bt toxins and RNAi as well as compliance of refuge requirement.

EXPLORATION OF PREDATORY SPIDERS ON COTTON PESTS IN SPRAYED AND UN-SPRAYED COTTON FIELDS OF CCRI-SAKRAND-SINDH-PAKISTAN

Explorations of predatory spiders were carried out from sprayed and unsprayed cotton crop grown at Central Cotton Research Institute Sakrand, Sindh-Pakistan during the period of May-October 2016 and 2017. During the research findings eight species of predatory spiders were explored and identified from cotton field which were Philodromus cespitum, Thanatus formicinus, Thyene imperialis, Oxyopes salticus, Cheiracanthium erraticum, Plexippus Paykulli, Lycosa tista and Pardosa birmanica. The activity of predatory spiders started in the month of May and June in the initial stage of cotton crop during the both years. The maximum spider population was noted in the months of July and August, when cotton crop was fully mature. The population of predatory spiders increased 61 in un-sprayed plot and 28 in sprayed in 2016 and 43 numbers of predatory spiders in un-sprayed plot and 22 in the sprayed plot during 2017. The maximum mean number of spiders was found to be 69 in un-sprayed plot and 36 in sprayed plot in 2016 as compared to 54 and 26 in 2017. Number of spiders were lesser in the month of September and October, the population of spiders decreased with the less population of sucking insect pests due to mature age of cotton crop in both plots in 2016 and 2017. There is a dire need to explore the insecticide effects on the predatory spiders of Pakistan and protection to keep the spiders safe from indiscriminate use of insecticides on cotton crop as they are bio-control agents and contribute their big part in the agriculture ecosystem, food chains and control of arthropods.