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Soil compaction is a major physical constraint in cotton production. At present, no information is available on the effects of compaction on the root growth and root anatomy of cotton (Gossypium hirsutum L.). Therefore, we studied the effects of subsoiling (shallow (SSS) and deep (DSS)) and crop rotation (pigeon pea (Cajanus cajan) - cotton (PCR) and radish (Raphanus sativus) - cotton (RCR)) on the root growth of cotton in deep Vertisols during 2017-19. Subsoiling significantly increased the shoot and root length. The root-to-shoot ratio was maximum in DSS (33%), followed by PCR (29%) at the vegetative stage. Scanning electron microscopy analysis of the roots indicated a large number of pores and less contraction of xylem and phloem in the subsoiled and rotation treatments than in the control. Furthermore, the SEM-EDAX spectra indicated a greater abundance of major, secondary and micronutrients in subsoiling and crop rotations compared to the control treatment. [ABSTRACT FROM AUTHOR]

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The present study was planned to explore the relationship between soil chemistry with bacterial population of Bt and non-Bt cotton and their phenotypic and molecular characteristics. The pre-plant soil and rhizospheres of Bt and non-Bt cotton were collected and analyzed for some soil parameters and bacterial population. The bacterial isolates were analyzed for their morphological, biochemical, and molecular characteristics. Bacterial population showed a significant (p

This essay engages the problem of agriculture and the market from the point of view of production. India is a nation of small-holder farmers where agriculturalists have been integrated into commercial cash cropping over long-distance commodity chains for a very long time. It is the nature of those markets, their relation to the state, and to the farming household that undertakes agricultural commodity production, that has changed. Through a techno-political history of the cotton seed, I examine new conjunctions between the cultivating household and the market to illustrate the paradox of small-holder commercial agriculture in India. [ABSTRACT FROM AUTHOR]

Integrated management of BT cotton pests was carried in field experiments during the seasons; 2016/2017 (Season I) and 2017/2018 (Season II) in the experimental research farm of Kassala University, Sudan. Four insecticides (imidacloprid, abamectin, profenofos and lufenuron) and three levels of soil applied nitrogen; 43.81 kgha−1, 87.62 kgha−1 and 131.43 kgha−1 were tested at recommended doses. Seven weekly counts of abundant pests (whitefly, jassid, aphid, and mealybug) were done starting 4 weeks before spraying. Post spray counts were done after 3, 10 and 17 days from spraying. Seed cotton yield of various treatments was recorded and economic analysis of the package was calculated. Results indicated that increasing the nitrogen dose result in significant increase in population of sap sucking pests during the pre-spray counts while insecticide treatments significantly reduced the infestation level in the post spray counts. Aphid was found in season I while mealybug was found in season II only in contrast to whitefly and jassid which were found in both seasons. Imidacloprid was the most effective insecticide causing reduction in the level of infestation by the various sap sucking pests in the range of 11.20% -71.66%, followed by lufenuron (with reduction in infestations level ranging between 8.12% to 69.11%) and profenofos (with infestation reduction ranging between 9.88% to 66.74%). On the other hand abamectin was the least effective treatment causing the least infestation reduction in the population of sap sucking pests (ranging between 8.38% to 66.45%). No significant interactions were found between nitrogen and insecticide treatments. Highest seed cotton yield and revenue was associated with imidacloprid combined with various nitrogen levels (causing 46%–63% increase), followed abamectin nitrogen treatments (7%–22%), profenofos and lufenuron nitrogen combinations. Generally, seed cotton yield increases by the increase of nitrogen dose, while the revenue (net benefit) depends on the price of the insecticide used. [ABSTRACT FROM AUTHOR]

Growing a refuge crop is an integral part of transgenic crops with gene(s) from Bacillus thuringiensis (Bt) and a key requirement to delay evolution of Bt resistance in target pests. Poor refuge planting with Bt-cotton in India, for many years, is a major reason for the outbreak of Bt resistance in pink bollworm and consequent erosion in the efficacy of Bt-cotton technology. As a remedial measure, the Ministry of Agriculture, Government of India has directed complete shift to the marketing of Bt-cotton seeds blended with non-Bt refuge cotton seeds (refuge-in-bag; RIB) from this (2020) season onwards. The strengths, weaknesses, opportunities and threats of RIB Bt-cotton combination in the context of known behaviour of cotton lepidopteran pests and prior exposure to the same Bt toxins since 2002, is discussed. Bt-cotton with RIB, if implemented with strong stewardship, will have far-reaching benefits and is expected to delay Bt resistance development in target lepidopteran cotton pests. However, the relevance of RIB for Bt-resistant pink bollworm could be in question. [ABSTRACT FROM AUTHOR]

Despite the fact that temperatures fluctuate on a daily basis in the field, the effect of fluctuating temperature on the susceptibility of pest insects to agricultural management tactics are lacking. We thus tested how the development of Spodoptera littoralis and Heliothis virescens (Lepidoptera: Noctuidae) is influenced by exposure to an insecticidal genetically engineered pulverized powder of, Bollgard II cotton producing the Bt proteins Cry1Ac and Cry2Ab, or an entomopathogenic fungus (Beauveria bassiana) under fluctuating temperatures in comparison with constant temperature. When temperature fluctuated symmetrically around 25 °C either in small range (± 5 °C) or in a large range (± 10 °C) on daily basis, development of both lepidopteran species was positively or not influenced in absence of additional stressors. Both species were affected by Bt-cotton when added at low concentrations to the artificial diet, but their reaction to Bt-cotton did not differ between fluctuating temperatures compared to a constant 25 °C. When H. virescens larvae were dipped into spore suspension of B. bassiana, all larvae reared at constant 25 °C died before pupation, while no detrimental effect of the fungus was visible in the fluctuating temperature regimes. In contrast, S. littoralis was not affected by the fungus in any treatment. Since fungal growth was reduced at fluctuating temperatures, this might have affected the infection rate in H. virescens. The results of this study indicate that fluctuating, compared to constant temperatures, can influence the susceptibility of pest insects to biological control agents, while temperature regimes seem to be less important for the efficacy of insecticidal genetically engineered crops. [ABSTRACT FROM AUTHOR]

Since their commercial introduction in 1996 in the USA, the insect resistant transgenic Bt crops, notably Bt-cotton and Bt-corn, have given effective control of target pests and found overwhelming adoption in several countries. As of 2017, these Bt crops were cultivated in 14 countries on 100 m ha, including 11.4 m ha of Bt-cotton in India, which comprised 53% of 189.8 m ha of all GM crops grown in 24 countries. Such extensive cultivation of Bt crops, incorporated with genes derived from the soil bacterium, Bacillus thuringiensis (Bt), modified to express host-specific insecticidal crystalline (Cry) proteins, has resulted in higher crop yields by 22%, increased farmers' profit by 68% and reduced chemical insecticide applications by 37%, thereby providing social, economic, health and environmental benefits. The reduced chemical sprays have contributed to conservation of parasitoids and predators leading to enhanced biological control in crop systems. Feeding tests carried out with predators like ladybird beetles and green lacewing and also with hymenopteran parasitoids have demonstrated Bt proteins to be safe to these natural enemies. The value of Bt crops in promoting biological control and integrated pest management is discussed. [ABSTRACT FROM AUTHOR]

The present study was planned to explore the relationship between soil chemistry with bacterial population of Bt and non-Bt cotton and their phenotypic and molecular characteristics. The pre-plant soil and rhizospheres of Bt and non-Bt cotton were collected and analyzed for some soil parameters and bacterial population. The bacterial isolates were analyzed for their morphological, biochemical, and molecular characteristics. Bacterial population showed a significant (p < 0.05) positive correlation with clay content, electrical conductivity, organic matter, total nitrogen, and available phosphorus and potassium negative with correlation with pH. Bt cotton showed a non-significant effect on the soil parameters, significant decrease in bacterial population, change in the morphological and biochemical characteristics of rhizobacteria and replacement of four bacterial species with five new ones suggests the potential effect of Bt cotton on its rhizoflora. The rhizosphere of non-Bt cotton cultivated in the fertile agriculture field was found to be the best for bacterial growth. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium hirsutum L.) is one of the most important commercial crops of Afghanistan mainly grown for fiber production; however, its seeds are used as source of edible oil while cotton cake is used as animal feed. With the collapse of the cotton industry in the last four decades due to war, cotton planting has declined drastically in the country resulting in low cotton production (Noori 2018). There are many production constraints resulting in low cotton productivity in the country like poor irrigation infrastructure, low rainfall, less availability of improved variety seeds, sub-optimal fertilizer use especially nitrogen (N) and poor weed management practices etc. (Ibrahimi et al. 2017; Noorzai et al. 2017; Noorzai and Choudhary 2017). At present, the Afghan government is giving prime emphasis to cotton cultivation keeping in view its quality production and congenial agro-climatic conditions in some parts of the country. However, this crop is grown extensively using conventional local cultivars with sub-optimal or over-doses of fertilizer N which adversely affects the cotton productivity and profitability. Moreover, the optimum N application dose for conventional cotton in general and Bt-cotton in particular has not yet been standardized so for cotton growing areas in Afghanistan. Thus, to promote the cotton cultivation with enhanced productivity in Afghanistan we need to use high yielding cultivars like Bt-cotton with redesigned agronomic practices specifically fertilizer N management (Blaise et al. 2014). Therefore, an attempt was made to assess the optimum N dose for Bt-cotton besides its yield performance visà - vis resource-use efficiency under varying N levels in semi-arid region of Afghanistan.

India does not have a clear stand on the release and consumption of genetically modified crops (food). The only approved crop is Bt-cotton, which has put India on the global map as a cotton exporting country. Even so, Bt-brinjal is under moratorium and GM mustard is prevented from undergoing commercial trial. All these decisions are not based on sound scientific principles. Activism against has successfully prevented exploitation of a powerful technology that can contribute to India's food and nutrition security. This article attempts to give a balanced perspective of genetic modification technology as one of the serious options to be considered on case to case basis. Ambivalence will seriously affect India's food security in the future. [ABSTRACT FROM AUTHOR]

Growing areas under transgenic crops have created a concern over their possible adverse impact on the soil ecosystem. This study evaluated the effect of Bt-cotton based cropping systems on soil microbial and biochemical activities and their functional relationships with active soil carbon pools in Vertisols of central India (Nagpur, Maharastra, during 2012-2013). Culturable groups of soil microflora, enzymatic activities and active pools of soil carbon were measured under different Bt-cotton based cropping systems (e.g. cotton-soybean, cotton-redgram, cotton-wheat, cotton-vegetables and cotton-fallow). Significantly higher counts of soil heterotrophs (5.7-7.9 log cfu g−1 soil), aerobic N-fixer (3.9-5.4 log cfu g−1 soil) and P-solubilizer (2.5−3.0 log cfu g−1 soil) were recorded in Bt-cotton soils. Similarly, soil enzymatic activities, viz. dehydrogenase (16.6-22.67 µg TPF g−1 h−1), alkaline phosphatase (240-253 µg PNP g−1 h−1) and fluorescein di-acetate hydrolysis (14.6-18.0 µg fluorescein g−1 h−1), were significantly higher under Bt-cotton-soybean system than other Bt- and non-Bt-cotton based systems in all crop growth stages. The growth stage-wise order of soil microbiological activities were: boll development > harvest > vegetative stage. Significant correlations were observed between microbiological activities and active carbon pools in the rhizosphere soil. The findings indicated no adverse effect of Bt-cotton on soil biological properties. [ABSTRACT FROM AUTHOR]

Transgenic Bt cotton with insect resistance was introduced for commercial cultivation in India in 2002 (Barwale et al. 2004). Bt cotton expressing Cry1Ac is mainly toxic to the bollworm complex (Helicoverpa armigera, Pectinophora gossypiella, Earias insulana and E. vittella). The rapid adoption of Bt cotton technology in India imposes a strong selection pressure on the target pest with a risk of resistance development to Cry toxins including Cry2Ab following the introduction of dual gene BG-II cotton in 2006. Spotted bollworm, Earias insulana infests the cotton crop during the early season as a shoot borer and damages fruiting bodies during mid-season crop growth. Efficacy of Bt cotton hybrids BG-II (Cry1Ac + Cry2Ab) and Bt (Cry1Ac) through leaf (90-95-day-old crop) and square (80-85-day-old crop) bioassay under laboratory conditions, recorded 97-100%mortality on leaves of BG-II, 93%on Bt and 1.3-5.4%on non Bt against 1-day-old larvae of Earias insulana. Observed mortalities on plant squares were 94-100 % in BG-II, 91 % in Bt and 1.3-5.6 % in non-Bt genotypes. Frequency of resistance alleles in field populations of Earias insulana to Cry1Ac protein by using F2 screening procedure was also undertaken. In the present study on F2 screening on 266 isofemale lines of Earias insulana collected from Sirsa (Haryana), Sriganganagar (Rajasthan) and Mansa (Punjab) during 2013-14, 2014-15 and 2015-16, no alleles could be detected conferring major resistance to Cry1Ac in the population of Earias insulana from all three locations. However, evidence for partial resistance alleles in F2 generation of two isofemale lines from Sirsa (Haryana) population was recorded during 2013 but could not be reconfirmed. [ABSTRACT FROM AUTHOR]

Transgenic Bt-cotton produces Bt-toxins (Cry proteins) which may accumulate and persist in soil due to their binding ability on soil components. In the present study, the potential impacts of Bt- and non-Bt genotypes of cotton on soil microbial activity, substrate use efficiency, viable microbial population counts, and nutrient dynamics were studied. Two transgenic Bt-cotton genotypes (CIM-602 CIM-599) expressing cry1 Ac gene and two non-Bt cotton genotypes (CIM-573 and CIM-591) were used to evaluate their impact on biological and chemical properties of soil across the four locations in Punjab. Field trials were conducted at four locations (Central Cotton Research Institute-Multan, Naseer Pur, Kot Lal Shah, and Cotton Research Station-Bahawalpur) of different agro-ecological zones of Punjab. Rhizosphere soil samples were collected by following standard procedure from these selected locations. Results reveled that Bt-cotton had no adverse effect on microbial population (viable counts) and enzymatic activity of rhizosphere soil. Bacterial population was more in Bt-cotton rhizosphere than that of non-Bt cotton rhizosphere at all locations. Phosphatase, dehydrogenase, and oxidative metabolism of rhizosphere soil were more in Bt-cotton genotypes compared with non-Bt cotton genotypes. Cation exchange capacity, total nitrogen, extractable phosphorous, extractable potassium, active carbon, Fe and Zn contents were higher in rhizosphere of Bt-cotton genotypes compared with non-Bt cotton genotypes. It can be concluded from present study that the cultivation of Bt-cotton expressing cry1 Ac had apparently no negative effect on metabolic, microbiological activities, and nutrient dynamics of soils. Further work is needed to investigate the potential impacts of Bt-cotton on ecology of soil-dwelling insects and invertebrates before its recommendation for extensive cultivation.

Bt-cotton germplasm, consisting of 75 genotypes was evaluated against cotton leaf curl disease (CLCuD) under high inoculum pressure in the field and using graft inoculation in glasshouse by visual symptom scoring assessments. None of the tested genotype was found disease free under both evaluation tests. Under field conditions in 2011, 3 genotypes were found resistant, 4 moderately resistant, 3 tolerant, 2 moderately susceptible and one susceptible; in 2012, 3 genotypes were tolerant, 7 moderately susceptible, 5 susceptible and 38 highly susceptible; in 2013, one was moderately susceptible and 51 were highly susceptible with varying degree of percent disease index (PDI) and severity index (SI). However, through graft evaluation in glasshouse, none of the graft inoculated plant was symptomless. All tested genotypes showed disease symptoms with SI values ranging between 5.0 and 6.0, and latent period between 12 and 14 days. Of the 75 genotypes evaluated using graft inoculation, 11 were found susceptible with SI values of 5.0 to 5.4 while remaining 64 were highly susceptible with SI values of 5.5 to 6.0. Inoculated plants of all tested genotypes exhibited severe disease symptoms within 10 days after the appearance of initial symptoms. No reduction in SI value was observed until the end of the experiment i.e., 90 days after grafting. Information generated under the present study clearly demonstrates that no sources of resistance to CLCuD are available among the tested Bt-cotton genotypes. So, a breeding programme is needed to introgress the CLCuD-resistance from other resistant sources to agronomically suitable Bt-cotton genotypes.

Infestation of citrus root knot nematode (Meloidogyne indica) on the roots of citrus and Bt-cotton was found in Gujarat of India. The detection of M. indica and its diagnostic symptoms on some hosts (citrus and Bt-cotton) was recorded and the nematode species was authentically identified as Meloidogyne indica Whitehead, 1968 which was first time described on citrus from Delhi, India. The species is further characterized based on detailed morphological, morphometric descriptions and beta-esterase phenotyping. The present study elucidated information on M. indica for its easy detection, diagnosis, dimension of damages on citrus, and Bt-cotton under Indian conditions. [ABSTRACT FROM AUTHOR]

Long-term changes in land use, climate, and agricultural technologies may affect pest severity and management. The influences of these major drivers can only be identified by analyzing long-term data. This study examines panel data on land use, adoption of genetically modified Bacillus thuringiensis (Bt) insect-resistant cotton, weather, pest severity, and insecticide use on three major cotton pests for 51 counties in China during 1991-2015. Bt cotton had pervasive effects on the whole pest complex in cotton and its management. Adoption resulted in major reductions in insecticide use for bollworm control. The resulting restoration of aphid biological control decreased aphid severity. However, mirid bugs, which have few effective natural enemies in cotton, increased in severity with warming May and reduced insecticide spraying against bollworm. The effects of landscape on pest severity were pest specific. The severity of cotton aphid and mirid bugs decreased with higher land use diversity, but the severity of highly polyphagous cotton bollworm was unrelated to land use diversity. Shares of forest, water body, and unused land area were negatively associated with the severity of mirid bugs, whereas cotton bollworm responded positively to the shares of water body and unused land area. Farmers sprayed insecticides at mild infestation levels and responded aggressively to severe bollworm outbreaks. Findings support the usefulness of Bt-based plant resistance as a component of integrated pest management (IPM) but highlight the potential for unexpected outcomes resulting from agro-ecosystem feedback loops as well as the importance of climate. [ABSTRACT FROM AUTHOR]

The present study was conducted at ICAR-Indian Agricultural Research Institute, New Delhi in a splitplot design replicated thrice with four main-plot treatments, i.e. four combinations of two cotton establishment methods (CEMs) and two planting geometries (PGMs) [M1 – transplanted cotton (90 × 60 cm PGM); M2 – transplanted cotton (120 × 45 cm PGM); M3 – direct seeded cotton (DSC; 90 × 60 cm PGM); M4 – DSC (120 × 45 cm PGM)]; while sub-plot treatments comprised three intercropping systems [S-Ct – sole cotton; Ct + Ok – cotton + okra (1 : 2 row ratio); Ct + Cp – cotton + cowpea (vegetable purpose; 1 : 2 row ratio)]. It can be inferred from the study that transplanted cotton (TPC) with 90 × 60 cm planting geometry in Bt-cotton + vegetable cowpea intercropping system exhibited maximum seed-cotton equivalent yield (SCEY) as well as gross and net returns and other economic indices, followed by Ct + Ok and sole cotton. DSC with 90 × 60 cm PGM in Ct + Ok intercropping system proved superior in terms of SCEY, and gross and net returns besides other economic indices. Based upon yield advantage indices, TPC in 90 × 60 cm PGM under Ct+Cp intercropping system and DSC in 90 × 60 cm PGM under both intercrops were found to be the best options. Crop competition indices also revealed that the inclusion of these intercrops is advantageous because of spatial and temporal complementarity, different rooting pattern and plant architecture to utilize natural resources more efficiently in Bt-cotton-based intercropping systems in the semiarid Indo-Gangetic plains region. [ABSTRACT FROM AUTHOR]

The transfer of plant-produced insecticidal Cry-proteins in the arthropod food web can be affected by a number of environmental and ecological factors. Despite this fact, most studies documenting multitrophic Cry-protein acquisition patterns in arthropods are conducted under controlled conditions whereas the number of field studies is limited. Such field studies, however, are valuable to understand multitrophic allocation dynamics of Cry-proteins under ecologically realistic conditions and are therefore important for the interpretation and design of laboratory hazard studies on genetically engineered (GE) crops. We thus sampled arthropods and plant structures in a field planted with GE dual-gene cotton plants producing the Cry-proteins Cry1Ac and Cry2Ab from Bacillus thuringiensis Berliner over the growing season. Cry-protein concentrations in field-collected plants, herbivores, and predators were quantified and compared with arthropods subjected to tri-trophic laboratory feeding assays. Both, field studies and laboratory assays showed that Cry-protein concentrations strongly decreased with increasing trophic level to values mostly below the detection limit in predators. Under field conditions, in-planta Cry-protein concentrations varied between plant structures and over the season. Concentrations in arthropods were mainly associated with feeding mode, feeding location on the plant, and to a lesser degree seasonality. Compared to plants, arthropods showed lower Cry2Ab:Cry1Ac ratios indicating that Cry2Ab might be less stable than Cry1Ac. Of all predators collected in the field study, we measured highest Cry-protein levels in jumping and crab spiders, predatory flies and some predatory hemipterans. This emphasizes the relevance of these groups for the risk assessment of GE cotton. [ABSTRACT FROM AUTHOR]

The effect of Bacillus thuringiensis toxin Cry1Ac on the behaviour of a laboratory-selected resistant population (72-fold) of Helicoverpa armigera on Bt-cotton was evaluated. Compared with non-Bt-cotton and Cry1Ac toxin incorporated in semi-synthetic diet, resistant larvae reared on Bt-cotton had only 0.13% survival and slower development. The results suggest that Cry1Ac from Bt-cotton exerts a greater toxic effect in terms of larval mortality coupled with decline in larval growth rate compared to semi-synthetic diet. [ABSTRACT FROM AUTHOR]

This study has estimated the technical efficiency of Non-BT cotton and BT cotton production in Pakistan. Those farmers were selected as the respondents for the study that used to cultivate Non-BT cotton and BT cotton varieties. In Pakistan, the NonBT cotton varieties have been promptly substituted with the BT-cotton varieties. This substitution of imported BT-cotton seed is taking into account without considering the local environmental conditions of Pakistan. Thus the main objective of the research was on the comparative efficiency and the productivity analysis of BT-Cotton varieties with those of the conventional non-BT-Cotton varieties. The population of this research covers the area of Rahim Yar Khan of Pakistan. Two hundred and fifteen farms were selected from each of the NonBT-cotton farms and BT-cotton farms. The Cobb-Douglas Stochastic Frontier Analysis (SFA) has been employed to determine the technical efficiency of these growers. Technical efficiency has been found dissimilar under both the situations. The estimated mean technical efficiency of NonBT cotton farmers has been found to be 0.70, and 0.90 is the technical efficiency found in that of the BT cotton farmers. Hence the average output of Non-BT cotton and BT-cotton farms could be increased by 30 and 10 percent, respectively by adopting the technology with an appropriate approach. The results of the inefficiency model reveal that the factors like education, experience and distance from the main market, are the most influential determinants of the technical efficiency in both NonBT and BT-cotton farms. Extension of cotton production required the development of cottonseed that will be suitable for environmental conditions of Pakistan. [ABSTRACT FROM AUTHOR]

TransgenicBt-cotton producesBt-toxins (Cryproteins) which may accumulate and persist in soil due to their binding ability on soil components. In the present study, the potential impacts ofBt- and non-Btgenotypes of cotton on soil microbial activity, substrate use efficiency, viable microbial population counts, and nutrient dynamics were studied. Two transgenicBt-cotton genotypes (CIM-602 CIM-599) expressingcry1 Acgene and two non-Btcotton genotypes (CIM-573 and CIM-591) were used to evaluate their impact on biological and chemical properties of soil across the four locations in Punjab. Field trials were conducted at four locations (Central Cotton Research Institute-Multan, Naseer Pur, Kot Lal Shah, and Cotton Research Station-Bahawalpur) of different agro-ecological zones of Punjab. Rhizosphere soil samples were collected by following standard procedure from these selected locations. Results reveled thatBt-cotton had no adverse effect on microbial population (viable counts) and enzymatic activity of rhizosphere soil. Bacterial population was more inBt-cotton rhizosphere than that of non-Btcotton rhizosphere at all locations. Phosphatase, dehydrogenase, and oxidative metabolism of rhizosphere soil were more inBt-cotton genotypes compared with non-Btcotton genotypes. Cation exchange capacity, total nitrogen, extractable phosphorous, extractable potassium, active carbon, Fe and Zn contents were higher in rhizosphere ofBt-cotton genotypes compared with non-Btcotton genotypes. It can be concluded from present study that the cultivation ofBt-cotton expressingcry1 Achad apparently no negative effect on metabolic, microbiological activities, and nutrient dynamics of soils. Further work is needed to investigate the potential impacts ofBt-cotton on ecology of soil-dwelling insects and invertebrates before its recommendation for extensive cultivation. [ABSTRACT FROM AUTHOR]

Cotton is the most vital role in Indian economy and industrial development. Cotton leaf curl disease (CLCuD) became major problems responsible for decreased productivity during last one and half decade. To find out the role of sowing environment on crop growth indices at different phenological stages, three Bt-cotton hybrids were sown at three different dates of sowings. Late sown crop shows a very poor growth having early occurrence of all phenological stages. Crop growth parameters viz. plant height, dry matter accumulation and LAI were higher in early sown crop as compare to late sown. In diseased plants phenological stages occurred earlier than the healthy plants and showed negative effect on all crop growth indices. Maximum impact of CLCuD on phenological stages occurrence was found at 50% boll formation stage in diseased plants of Pancham-541 in late sown crop. It was also found that effect of CLCuD was less in early sown crop and RCH-791 having some resistant reaction shows less impact of CLCuD. It concludes that early sowing was favourable for a better growth and reproduction of the cotton crop under the CLCuD incidence. RCH-791 may also recommend as best variety among all three for cotton productivity under CLCuD. [ABSTRACT FROM AUTHOR]

Of the several mechanisms that can bring about efficient resource use, the most widelyapplicable one is intercropping systems that can make better use of resources. The aim of this study was to evaluate resource capture and resource use efficiency in transgenic cotton-peanut intercropping system and in their respective sole crops with using 25-50% substitution of recommended dose of nitrogen (RDN) of cotton through farmyard manure (FYM) along with 100 % RDN through urea and control (0N). Apparent crop water productivity, nutrient use efficiency, economic returns and modern intercropping indices (system productivity index, actual yield loss, intercropping advantage index, nitrogen stress factor, etc.) were measured for making better understanding of resource use efficiency. Comparisons of intercropped peanut with sole peanut were emphasized because of shrinking area of peanut in the south-east Asian region represents a threat to agricultural system sustainability. Cotton + peanut intercropping system resulted in improved water productivity (19%), nutrient use efficiency (15-20%) and monetary advantage index (16,709) as measured with modern tools of intercropping indices compared with sole crops of cotton and peanut. Peanut cultivated as sole crop attained the least resource productivity in terms of apparent crop water productivity (0.71 kg m-3), nutrient use efficiency (4.47 kg grain kg N-1) and total factor productivity (0.07). Among fertility levels, substitution of 25% RDN of cotton through FYM maintained higher apparent crop water productivity (17%), monetary advantage index (6%), system productivity index (9%) and nutrient use efficiencies (15-17%) over 100% RDN through urea only. This work provides basis for efficient resource use by peanut intercropping with cotton which simultaneously enhances domestic oilseed production and reduce import load of cooking oil without sacrificing the productivity of main crop of cotton in India and other cotton growing countries of the world. [ABSTRACT FROM AUTHOR]

Current study focused on expression profiling of locally bred Bt-cotton varieties through ELISA and were tested for their efficacy against survival of Helicoverpa armigera in control environment. The population dynamics of five sucking arthropods; whitefly, jassid, aphid, thrips and mites, along the growing season was also monitored and correlated with different meteorological factors. Expression levels of insecticidal protein CrylAb/c were found to vary significantly (P<0.05) among varieties and across different sampling dates. The highest mean expression was recorded in GN-31 and Sitara-008 and the lowest in FH-113 and MG-6 while across sampling dates the highest mean expression was recorded at 30 days after emergence (DAE) which decreased along the season with lowest mean at 120 DAE. A critical expression level of Cryl Ab/c in leaves was found at 770 ± 25 ng g[sup -1], for 95% control of the target insect pests. Sucking pest population was found to be variable among both the cultivars and the sampling dates. A positive correlation was found between rain/ humidity and sucking arthropods population in the sampled cotton plots. © 2014 Friends Science Publishers [ABSTRACT FROM AUTHOR]

This study revealed cultivable diazotrophs in arid and semi-arid regions of Haryana, India, harboring multiple plant growth promoting (PGP) traits, i.e. nitrogenase activity (18.84-337.26 nmol ethylene mg protein h), indole-3-acetic acid production (42.4-1162.7 μg mL), ammonia excretion (0.013-2.561 μg mL), phosphate solubilization (55.8 %), and siderophore production (20.58 %). High diversity among diazotrophic bacterial isolates was deciphered by using amplified ribosomal DNA restriction analysis with MspI and HaeIII. All the isolates positively influenced the growth and yield of Bt-cotton and pearl millet plants under pot house conditions. On the basis of their plant growth promoting potential, 10 efficient bacterial strains were selected. Sequence analysis of these strains revealed two phyla of bacteria in the 16S rRNA library, which consisted of α and γ subclasses of the Proteobacteria and Firmicutes. The dominant group was Firmicutes (80 % of the total isolates), and the most dominant genus was Bacillus. Overall, our study reported bacterial strains with biofertilizer potential and could be considered as an excellent addition to existing beneficial microbes' consortium for growth promotion of Bt-cotton and pearl millet plants in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Arid regions pose a serious problem for crop production by suppressing plant growth. The use of plant growth promoting rhizobacteria (PGPR) as bioinoculant may be promising to enhance the crop yield in arid conditions. In the present investigation, four strains of cultivable bacteria associated with the rhizosphere of Saccharum L. grown in arid region were isolated using N-free media. Assessment of their nitrogen-fixing ability through amplification of nifH gene showed the presence of nifH gene (390 bp) in only one (MDB4) of the four isolates. The nitrogen-fixing potential of this isolate was confirmed by the presence of nitrogenase activity determined using acetylene reduction assay. The diazotrophic MDB4 isolate also exhibited other PGPR traits, such as the production of indole-3-acetic acid (IAA) and ammonia. In pot experiments, inoculation of Bt-cotton seeds with MDB4 enhanced the growth of plants as shown by significant increase in plant height (68.41 %), shoot dry weight (58.44 %) and root dry weight (64.81 %) over untreated control. The MDB4 strain was Gram negative and identified as Brevundimonas sp. on the basis of phenotypic, biochemical, phylogenetic and 16S rRNA gene sequencing data. It is concluded that the MDB4 bacterial strain having different plant growth promoting activities can be considered as a beneficial microbe for sustainable agriculture in arid regions. [ABSTRACT FROM AUTHOR]

The incidence of Jassid, whitefly and tobacco caterpillar was recorded from the South-Western districts of Punjab i.e. Muktsar, Faridkot and Ferozepur during cotton season in 2007. Correlation coefficients were calculated between number of whitefly, jassid, tobacco caterpillar and meteorological parameters. The incidence of jassid and tobacco caterpillar was low as compared to whitefly in all the districts. All the meteorological factors contribute in determining the incidence of different pests, but rainfall has definitely negative impact on the jassid and whitefly population.

Transgenic Bt-cotton now dominates the cotton-growing belt in northwestern China where there are few natural plant refuges to act as sources of moths susceptible to Bt toxin. As an initial step towards developing an insect resistance management (IRM) plan for the pest moth, Helicoverpa armigera, on Bt-cotton in this part of China, we assessed the potential of six crops grown in two configurations to act as refuge hosts for susceptible moth production in both broad-acre and small-holder farms. Egg and larval abundance indicated that H. armigera had a preference for chickpea, pigeon pea, and corn, over cotton, sorghum, and benne (sesame). There were no significant differences in egg or larval abundance between plot and strip configurations of these crop hosts. We found that sorghum was not attractive to H. armigera, contrary to the findings in other cotton production areas. Moreover, chickpea, pigeon pea, and corn were determined to be potential refuge hosts based on egg and larval abundance over the growing season. From the adult moth population dynamics in broad-acre and small-holder farms, the efficiency of alternative refuge crops, and local agricultural practices, we recommend that spring corn be grown as a strip crop as part of an IRM strategy to improve the probability of Bt-susceptible moth production and mating with resistant moths in broad-acre farms. In small-holder farms where current agricultural practices are entrenched, wheat and summer corn should be evaluated as refuge crops in the future. [ABSTRACT FROM AUTHOR]

Cotton plants (genusGossypium) are grown on more than 30 million hectares worldwide and are a major source of fiber. The plants possess a wide range of direct and indirect resistance mechanisms against herbivorous arthropods. Direct resistance mechanisms include morphological traits such as trichomes and a range of secondary metabolites. The best known insecticidal compounds are the terpenoid gossypol and its precursors and related compounds. Indirect resistance mechanisms include herbivore-induced volatiles and extrafloral nectaries that allow plants to attract and sustain natural enemy populations. We discuss these resistance traits of cotton, their induction by herbivores, and their impact on herbivores and natural enemies. In addition, we discuss the use of genetically engineered cotton plants to control pest Lepidoptera and the influence of environmental factors on the resistance traits. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate twenty Bt-cotton genotypes for their resistance to thrips, Thrips tabaci (Lind.) under field conditions in Faisalabad, Pakistan. Thrips population seedling-1 and leaf-1 was recorded from each genotype in 2008 and from these data, six genotypes were selected for final screening trial in 2009. Thrips density per leaf was correlated with abiotic factors, morphological and chemical characteristics to establish basis of resistance mechanism. Results showed that AA-802 and VH-259 with 3.40 and 4.45 thrips per leaf were resistant and susceptible genotypes, respectively and two had significant difference between each other (p<0.05). Weather factors were non-significantly correlated with leaf thrips populations except relative humidity, which was positively and significantly correlated (r=0.451; p = 0.014). Hair density on leaf midrib (r=0.850) and vein (r=0.762) were positively whereas gossypol gland on leaf lamina (r=0.462) were positively correlated with leaf -1 thrips population. Moisture contents, total minerals, protein, lipids, reducing sugar, calcium, magnesium, and zinc were significantly correlated with thrips population. These findings are discussed in comparison with basis of resistance on non-Bt-cotton varieties reported earlier, in the study area. [ABSTRACT FROM AUTHOR]

Cotton is a premier textile fiber and one of the most competitive crops in global agriculture. Though primarily considered as fiber crop cotton is also an important source of oilseed and livestock feed besides providing several other by-products. In fact all parts of the cotton plant are used. Cotton is in harmony with the environment today than ever before. Invention of gin, development of Bt-cotton, etc. are man-made evolution which helped cotton to sustain productivity and global competitiveness. The success story of cotton is that of natural and man-made evolution of sustainability of cotton production and processing over the centuries in the world. The article provides a fascinating glimpse into the evolution and sustainability of cotton crop over the centuries around the world. [ABSTRACT FROM AUTHOR]

Genetically modified (GM) crops have been recognised to be economically beneficial to subsistence farmers and have been projected as essential tools for addressing challenges in hunger, environmental sustainability and international development. Yet the uncertainty of their effects on human health and the undesirable ecological consequences of these organisms have raised concerns on the rapid pace of their production. Regulating the release of these organisms is a critical environmental issue. The Cartagena protocol on bio-safety, the principle legal arrangement for the regulation of these organisms, has ratifications from only 157 countries and has proven to be a weak regulator. Countries like India and Brazil have seen the proliferation of unapproved stealth GM varieties which make regulation even more difficult. In this paper, we explore the debate surrounding the introduction of GM organisms and analyse the effectiveness of existing legal regimes to regulate their use. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the relationship between fertilization and the incidence of insect pests is essential for the management of chemical fertilization and insect pests in modern agroecosystem. In this paper, effects of potassium supply alone and combination of nitrogen and potassium fertilizers on population dynamics and density of cotton aphid Aphis gossypii (Hemiptera: Aphididae) were investigated during seedling stage in Bacillus thuringiensis (Bt)-cotton production system. The results showed that high concentration of potassium fertilizer significantly reduced cotton aphid population density when nitrogen fertilizer was not used. Aphid population dynamics and density at peak time were obviously affected by the combination of nitrogen and potassium fertilizers in different rate, whereas different population dynamics of aphid were showed among different treatments. Compared with potassium fertilizer used alone, the same or significantly reduced aphid densities were observed in combination treatments of 120kg/ha potassium with 108kg/ha and 144kg/ha nitrogen levels in both years. In addition, cotton aphid population density was significantly affected by interaction of nitrogen and potassium fertilizers in field experiments of two years, these results indicated that cotton aphid population density at seedling stage was suppressed by potassium fertilizer and the combination of potassium and nitrogen fertilizers in proper rate (K:N=1:0.9 or 1:1.2kg/ha). Suggesting that proper application of potassium and nitrogen fertilizers should be beneficial to controlling insect herbivores such as cotton aphid and plant growth at seedling stage of Bt-cotton field in Central China. [Copyright &y& Elsevier]

Transgenic Bt-cotton is commercially cultivated on the rationale that it produces toxins that defend the plants primarily from caterpillars damaging cotton bolls. From the context of crop protection, it is important that these bollworms remain susceptible to the toxins, so that their populations are under check. However, if certain individuals are able to survive and breed on the transgenics, they can build populations resistant to the toxins. In one such instance we discovered individuals of Helicoverpa armigera, the most prominent among bollworms in India, surviving on commercial Bt-cotton hybrids containing single (Cry1Ac) and double (Cry1Ac and Cry2Ab) genes in experimental plots of the University of Agricultural Sciences, Raichur campus, India. Analyses of various biological parameters measured through laboratory breeding on the respective hybrids revealed that these surviving individuals could not only complete their life cycle but also reproduce. A proportion of individuals of the succeeding generation were also able to complete their life cycle on the transgenic commercial hybrids. Interestingly, many of the biological parameters of the bollworm across Bt and non-Bt hybrids were mostly comparable. These results not only validate the occurrence of natural populations of H. armigera on Btcotton hybrids, but also provide evidence for its survival and successful reproduction in India. [ABSTRACT FROM AUTHOR]

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Hybrid classification of IRS-1D LISS-III mutispectral satellite data has the potential to infer the Bt-Cotton in a part of Bhatinda District of Punjab in India. Using multidate data with Global Positioning System (GPS) enabled the correlation of spectral statistics in red and near infrared part of the spectrum with the yield of this cash crop in 2008. Spectral reflectance statistics were calculated to develop Normalized Difference Vegetation Index (NDVI). It was possible to develop a correlation by regression analysis of NDVI with yield of Bt Cotton showing R2 value of more than 4.5. A correlation matrix was also generated which shows that NDVI values of Bt cotton has reasonably acceptable correlation with Total Dissolved Solids (TDS) of soil and water also. The correlation was repeated in more than 35 locations within the study area. It shows that satellite data based information has the potential to infer genetically modified variety of crops in terms of area and yield with soil and water quality as variables. [ABSTRACT FROM AUTHOR]

Life history parameters in two generations of endoparasitoid Campoletis chlorideae (Uchida) were examined using Bacillus thuringiensis (Bt)-resistant Helicoverpa armigera (Hübner) larvae feeding on B. thuringiensis toxin Cry1Ac. In the laboratory, Bt toxin was fed to Bt-resistant host larvae continuously in case of Bt treatment and only before or after the host larvae were parasitized in Bt–P and P–Bt treatments, respectively. C. chlorideae pupae developed faster in Bt treatment than non-Bt treatment. The shortened pupal stage duration was mainly because of the feeding of host larvae on Bt-diet before being parasitized. Body length of adult male C. chlorideae developed inside Bt-treated Bt-resistant (Bt–Bt) H. armigera larvae significantly decreased, especially in host larvae feeding on Bt-diet after being parasitized. However, survival, pupal mortality and adult longevity of C. chlorideae were almost unaffected in Bt-resistant H. armigera larvae feeding on Bt-toxin. Furthermore, Bt-treated host larvae had the same effect on the F1 progeny of C. chlorideae as the previous generation, and there was no significant difference between generations. This experiment suggests that there is very limited effect on the life history parameters in two generations of C. chlorideae parasitizing Bt–Bt H. armigera larvae. But both generations of C. chlorideae are affected when Bt-resistant H. armigera larvae fed on Bt toxin for different durations. [ABSTRACT FROM AUTHOR]

China was the first developing country to introduce Bt cotton on a large scale. This paper provides an in-depth economic analysis of Bt cotton production by small-scale farmers in China. Data were collected in 2002 in Linqing County, in Shandong Province and comprised a season-long cotton production monitoring with 150 farmers and complementary household interviews. For quality assessment, the Bt toxin concentration of the various Bt varieties used by the farmers was determined for each plot. All farmers were growing insect resistant Bt cotton varieties. Yet, they sprayed high amounts of chemical insecticides, out of which 40% were extremely or highly hazardous. The paper reviews methodological issues inherent to impact assessment of crop biotechnology and identifies market and institutional failure as possible reasons for continued high pesticide use. Using the damage function methodology the coefficients for both damage control inputs, i.e., Bt varieties (measured as toxin concentration), and insecticide quantity were not significantly different from zero. Results show that absence of enabling institutions and lack of farmer knowledge can considerably limit the benefits of Bt cotton for small-scale farmers. The paper points out the importance to include the institutional conditions in the evaluation of agricultural biotechnology in developing countries. [ABSTRACT FROM AUTHOR]