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Ethiopia is one of cotton-producing countries and export part of its products to the international market. Cotton continued to be cultivated in Ethiopia for many centuries both in irrigation and rain-fed systems. The country has a huge potential to produce cotton in different agroecology that absorbs the large and young work force. Considering the suitable environmental conditions to grow the crop and the availability of cheap manpower, the Ethiopian government has given priority to develop the textile and garment sectors since the last two decades. The existing textile industries in the country are cotton-based and are in their booming stage. On the other hand, availability and quality of raw material is not satisfying the growing demand. In order to support the increasing number of textile and garment industries, supply of quality and enough raw material in a sustainable manner is crucial. Therefore, this review details information based on primary and secondary data, which are related to the country's potential for cotton production, the characteristics of cotton, available cotton varieties, marketing systems, and cotton initiatives working in the sector. This work also tries to pinpoint multi-dimensional problems facing cotton production, marketing and quality management systems and indicates possible solutions for the betterment of the sector. [ABSTRACT FROM AUTHOR]

This paper discusses relation between fiber quality parameters and yarn quality, presenting results of the quality assessment of Pakistan’s five popular cotton varieties. Abadgar-901 was found to have highest effective length followed by Tarzen-1 when compared to other fibers studied and the Sattari showed the least effective length. Whereas, Tarzen-1 showed highest tenacity, Sindh-1 was second to that, yet Nayab-78 showed the least strength of the studied cotton fibers. Further, it was also found that except Nayab-78, all the other cotton varieties were found to have fineness value of premium cotton standards, however, Nayab proved to be a coarse fiber, Sindh-1 was finest fiber of them all. Moreover, Sattari was found to be the whitest in color when measured for CIE and Berger whiteness index, Nayab-78 followed it just after and the Abadgar proved to be the least white compared to the studied cotton varieties. [ABSTRACT FROM AUTHOR]

Natural resistance in cottonseed to Aspergillus flavus infection has not been explored to date. A green fluorescent protein (GFP) expressing A. flavus strain was used to assess the resistance of seed from 35 cotton varieties from Gossypium arboreum, G. barbadense, and G. hirsutum. Mature cotyledons devoid of seed coat were wounded, inoculated, and assessed for innate resistance to A. flavus infection. Of the initial 35 varieties tested, we observed a range of resistance to infection in representatives of all three species. A subset of 15 representatives was further analyzed. Within this group, G. arboreum cultivar A2 186 and G. hirsutum cultivar SA 1582 were most resistant to fungal infection. The most susceptible cultivar in this group was G. hirsutum SA 1595. The remaining 12 representatives tested in the secondary screen (3 G. arboreum, 3 G. barbadense, and 6 G. hirsutum lines) exhibited intermediate resistance. We did not observe any relationship between species and resistance. Within each species, there was a range of responses to fungal infection. Future studies using this methodology to screen additional diploid and tetraploid cotton lines may enable us to identify naturally resistant germplasm that can be used to develop cotton with enhanced resistance to fungal infection. [ABSTRACT FROM PUBLISHER]

To determine the effect of water deficit on growth characteristics of 27 cotton cultivars (GossypiumhirsutumL.), two separate experiments were performed in laboratory and glasshouse in Fars Province,Zarin-Dasht city(28° 36′ N, 54° 41′ E) in August 2015. In both experiments, which last for 10 days, a completely randomized block design with three replications was used. The main factor was water-deficit levels ((0, −4, and −12 MPa in laboratory and (0 and −8 MPa) in glasshouse experiments), and the subsidiary factor was different cotton cultivars. The sensitivity to water deficit was compared based on factors such as germination rate, shoot and root lengths, fresh and dry weights, seed energy, and seed vigor. The results of both experiments indicated that Oltan, Opal, Pak, Armaghan, Super-Elit Golestan, Super-Elit Bakhteghan, SB-35, Super-Elit Arian, Khandagh, Tabela-18, and Sahel cultivars are more resistant and therefore are suitable candidates to increase plant density and uniformity in the farm. [ABSTRACT FROM PUBLISHER]

Being macronutrient, K+is involved in a number of metabolic processes including stimulation of over 60 enzymes. The present study was conducted to investigate whether K-priming could alleviate the effects of salinity on the growth and nutrient status of cotton seedlings. The seeds of two cotton cultivars, namely FH-113 and FH-87, were primed with solutions of three potassium sources (KNO3, K2SO4and K2HPO4) using three concentrations (0%, 1.25% and 1.5%) of each potassium source. After 1 week of germination, the seedlings were subjected to salinity (0 and 200 mMNaCl) stress. The results showed that salinity significantly affected growth and nutrients status of cotton seedlings. The K-priming alleviated the stress condition and significantly improved dry matter as well as nutrient uptake in cotton seedlings. Of the priming treatments pre-sowing treatment with KNO3(1.5%) was most effective in increasing shoot and root lengths and biomass of cotton seedlings. The seedlings raised from seed treated with KNO3(1.5%) showed varied accumulation of cations (Ca2+, Na+and K+) and faced less oxidative stress irrespective of cotton cultivars under salt stress. The results suggested that pre-sowing seed treatment with KNO3(1.5%) might be recommended for synchronized germination and sustainable production of cotton crop under saline environments. [ABSTRACT FROM AUTHOR]

Plants can have detrimental effects on biological control agents by affecting their prey or host quality. Thus, it is important to understand the tri-trophic interactions between plants, herbivores and natural enemies when implementing biological control programmes. Studies have shown that both morphological and chemical traits of host plants can affect the third trophic level. Cotton plants are known to produce alkaloids such as gossypol, a sesquiterpene aldehyde that can confer resistance against herbivorous arthropods. Nevertheless, little is known about the effect of gossypol on biological control agents. In this study, we investigated how three cotton cultivars (BRS Rubi, BRS Safira and BRS Verde) differing in gossypol content affect development and growth of predatory coccinellids,Eriopis connexaandHarmonia axyridis, feeding on the cotton aphidAphis gossypiireared on those cultivars. The results show that the cultivar BRS Rubi (highest gossypol content) had a sub-lethal effect on the development and growth of both Coccinellidae species compared with the other cultivars. Overall, the cultivar BRS Rubi reduced slightly fecundity, net reproductive rate and intrinsic rate of natural increase for both Coccinellidae species. However, because aphid populations stay short periods of time in the field, and adult coccinellids may supplement its diet with alternative prey and plant material this sub-lethal indirect effect of gossypol may not have a detrimental effect on field biological control of cotton aphid by eitherE. connexaorH. axyridis,thus suggesting a compatibility between plant resistance and biological control agents. [ABSTRACT FROM PUBLISHER]

Cotton breeders should have knowledge of traits that affect lint yield before embarking on a breeding program. Twelve diverse germplasm lines of upland cotton were used to investigate the effects of lint turnout, days to maturity, boll weight, number of bolls/plant, plant height, number of seeds/boll, boll width, boll length, seed index, number of locs/boll, number of fibers/seed, fiber density, on lint yield. The 12 lines were planted at two locations each during 2011 and 2012 at Stoneville, Miss. Simple correlation coefficients were subjected to path-coefficient analysis and direct and indirect effects were determined. Across all cultivar groups, lint turnout (0.52), plant height (0.43), number of bolls/plant (0.29), and boll weight (0.22) had the highest direct effects on lint yield. They were also positively and significantly correlated with lint yield. Boll length, fibers/seed, fiber density, number of locs/boll, and days to maturity were negatively correlated and with minimal impact on lint yield. Different path relationships between the naked seed and fuzzy seed groups and the okra and non-okra leaf groups were observed. For the okra leaf cultivars, lint turnout and plant height had the highest direct effects on lint yield. For the non-okra group on the other hand, boll weight and plant height had the highest direct effects; boll weight and number of bolls/plant had the highest direct effects on lint yield for the naked seed cultivars, whereas plant height, lint turnout, and boll weight had high direct effects on lint yield for the fuzzy cultivars. [ABSTRACT FROM PUBLISHER]

Bacterial seed and boll rot is a newly emerging cotton disease in Pakistan. Twenty-one cotton varieties were screened to find resistance source against the disease. None of these was found to be resistant. Five cotton varieties (CIM-595, MK2, BT-986, BT-986 & SG-1) having 700–1400 Area under disease progress curve (AUDPC) units were found to be moderately resistant to the disease. SLH-317, FH-942, BT-222, BT-666, MNH-457 ranging from 1401–1700 AUDPC units were moderately susceptible while MNH-456, SLH-336, 9811, FH-942, MNH-886 susceptible to boll rot. Seven varieties (FH-114, FH-113, BT-7, BT-212, SLH-BT-4, BT-212 and FH-941) were highly susceptible to bacterial seed and boll rot indicated by 2001–2300 AUDPC units. Biochemical tests identified bacterial isolates asPantoea agglomerans. Different inoculation techniques were assessed for bacterial pathogenicity and symptoms of boll rot were only observed in needle punctured bolls. One, two and three weeks old bolls were mechanically inoculated by injecting bacterial suspension to evaluate the boll’s age impact on disease severity. Maximum severity was observed in two weeks old bolls. Red cotton bugs (Dysdercus cingulatus) were fed on artificially inoculated diseased bolls and then transferred on healthy bolls. Diseased symptoms were noticed on healthy cotton bolls. Bacterial colonies were recovered and red cotton bug was confirmed as the disease-transmitting vector. [ABSTRACT FROM AUTHOR]

The esterase enzymes are a major component of insect detoxification systems and play a crucial role in hydrolyzing lots of xenobiotic compounds. Among insect, generalist herbivores can exhibit developed biochemical defences as a result of exposing to a wide range of plant chemical compounds. To overcome this ability, host plants may affect the level of hydrolases in herbivore insects feeding on. To examine this hypothesis, in the present study total esterase activity was investigated in a highly polyphagous whitefly,Bemisia tabaci,reared on six different varieties of cotton,Gossypium hirsutum. Results showed significant differences in esterase activity ofB. tabacifeeding on the host plant varieties. The highest esterase activities were detected in whiteflies feeding on Sk-Tb and Siokra varieties, whereas those whiteflies that feed on Hopicala variety exhibited the least esterase activities. Our findings highlight the important role of host plants in detoxification ability of herbivore insects. The importance of these findings in biology of insect pests and their applications in integrated pest management programmes ofB. tabacihave been discussed in detail. [ABSTRACT FROM PUBLISHER]

We studied the effects of feeding on different cotton cultivars with different gossypol contents on the development, reproduction and food plant utilization of three successive generations of Cotton Bollworm, Helicoverpa armigera (Hübner). Significantly higher larval survival rates were observed in three successive generations of H. armigera fed on cotton cultivar “ZMS13”compared with cultivars “M9101” and “HZ401”. There was a significant decrease in fecundity in the first generation compared with the second and third generations of cotton bollworms fed on “M9101” and “ZMS13”. Cotton bollworm generation significantly influenced mean relative growth rate, relative growth rate and relative consumption rate. The relative growth rate significantly decreased in three successive generations of H. armigera fed on the high-gossypol cultivar “M9101” compared with those fed on low-gossypol cultivar “ZMS13”. However, a significantly higher relative growth rate was recorded in the third generation than in the first generation fed on “M9101”. Measurements of development and food utilization at the individual and population levels over more than one generation ought to provide a more meaningful prediction of long-term and population dynamics of the cotton bollworm. [ABSTRACT FROM AUTHOR]

Five upland cotton varieties (Gossypium hirsutum L.) (Aleppo 118, Aleppo 33/1, Aleppo 90, Raqqa 5, and Deir-Ezzor 22) were evaluated under different salinity indices [0, 50, 100, and 200 mM sodium chloride (NaCl)] for 56 days. During the course of the experiment, plant size (HT), leaf number (LN) and leaf area (LA), chlorophyll SPAD (Soil Plant Analyses Development), chlorophyll (Chl) a and b content, and osmotic potential were measured in both control and salt-stressed plants for all tested varieties. Salt-stress application reduced the HT and LN of all varieties, whereas LA decreased as salinity level increased for all tested varieties comapared to their respective control expect for Deir-Ezzor 22 variety. Our data showed that LA, Chl a and b, and chlorophyll SPAD can be used to discriminate between salt-tolerant varieties and salt-sensitive ones. In this respect, Deir-Ezzor 22 variety differed by showing high salt tolerance relative to Aleppo 118 and Aleppo 33/1 varieties. Therefore, this investigation aimed for a better understanding of the different responses presented among these varieties toward salt treatment. [ABSTRACT FROM AUTHOR]

The effect of five cotton cultivars (Varamin, Mehr, Bakhtegan, Sahel, Saiokra) on the fitness of Tetranychus urticae was assessed by determining the developmental time and fertility life-table parameters for mites on leaf discs at 25 ± 1°C, 70 ± 10% relative humidity and 16:8 hours light:dark photoperiod. To investigate this effect, the duration of each life stage, longevity, reproduction rate and fertility life-table parameters including intrinsic rate of natural increase (r m), net reproductive rate (R 0), mean generation time (T), doubling time (DT) and finite rate of increase (λ) of the two-spotted spider mite on different cotton cultivars were calculated. The results indicated that the Varamin cultivar was the most suitable one for two-spotted spider mite among the tested plants because of its shorter immature developmental period and higher reproduction and intrinsic rate of natural increase, whereas Bakhtegan was the least suitable cultivar because of the longer immature developmental time and the lowest reproduction rate and intrinsic rate of natural increase. The lowest r m value suggests an antibiosis resistance in this cultivar in comparison with other cultivars. [ABSTRACT FROM AUTHOR]

Genotypic differences in potassium (K) uptake and utilization were compared for eight cotton cultivars in growth chamber and field experiments. Four of the cultivars ('SGK3', 'SCRC18', 'SCRC21' and 'SCRC22') typically produce lower dry mass and the other four ('Nannong8', 'Xiangza2', 'Xinluzao12' and 'Xiangza3') produce greater dry mass in K-deficient solution (0.02 mM). The mean dry weight of seedlings (five-leaf stage) of cultivars with greater biomass was 155% higher than that of cultivars with lower biomass yield under K deficiency. However, all the genotypes had similar dry matter yields in K-sufficient solution (2.5 mM). Thus, the four cultivars with superior biomass yield under low K medium may be described as K efficient cultivars while the inferior cultivars may be described as K inefficient. Although seeds of the studied cultivars originated from different research institutes or seed companies, there were little differences in seed K content among them, irrespective of their K efficiency. Consequently, there were no significant differences in K accumulation in seedlings (4 d after germination in a K-free sand medium) just before transferring to nutrient solutions. However, the K efficient genotypes, on average, accumulated twice as much K at 21 d after transferring to K-deficient solution (0.02 mM). A much larger root system as well as a slightly higher uptake rate (K uptake per unit of root dry weight) may have contributed to the higher net K uptake by the K efficient cultivars. In addition, the K efficiency ratio (dry mass produced per unit of K accumulated) and K utilization efficiency (dry mass produced per unit of K concentration) of the K efficient cultivars exceeded those of the K inefficient genotypes by 29% and 234%, respectively, under K deficiency. On average, the K efficient cultivars produced 59% more potential economic yield (dry weight of all reproductive organs) under field conditions even with available soil K at obviously deficient level (60 mg kg-1). We noted especially that the four K inefficient cultivars studied were all transgenic insect-resistant cotton, suggesting that the introduction of foreign genes (Bt and CpTI) may affect the K use efficiency of cotton. [ABSTRACT FROM AUTHOR]

A two-year field experiment was conducted to determine the effects of removal of early-fruiting branches (REFB) on yield, quality, and endotoxin expression in transgenic Bt (Bacillus thuringiensis) cotton (Gossypium hirsutum L.). Two early-fruiting branches of field-grown cotton plants were removed and retained at squaring to form the REFB and the control treatments, respectively. Lint yield, yield components, fibre quality, and Cry1Ac protein concentration in the first fully expanded young leaves on the main stem were measured. Results show that lint yields were increased by 5.1 and 5.5% with REFB compared with control in 2004 and 2005, respectively. There was no difference in fibre quality in the first two harvests between REFB and control, but fibre strength and micronarie in the third harvest were improved with REFB. Levels of total N, soluble protein, and Cry1Ac protein as well as glutamic-pyruvic transaminase (GPT) activity in leaves were higher in REFB than in the control. Laboratory bioassay showed significant enhancement of the control efficacy by REFB in terms of Helicoverpa armigera (Hubner) neonate mortality for both years. It is suggested that REFB might be a potential practice for enhancing transgenic Bt cotton production. [ABSTRACT FROM AUTHOR]

The growth of cotton (Gossypium hirsutum L.) was evaluated in a 6 × 5 factorial experiment with 6 boron (B) levels (0.0, 0.5, 1.0, 1.5, 2.0, and 3.0 mg dm-3), 5 cultivars ('CNPA 8H', 'BRS Aroeira', 'BRS Antares', 'BRS Sucupira', 'BRS Ipe'), and 3 replications. As B increased in the soil, leaf B concentrations increased linearly in 'BRS Aroeira' and 'CNPA 8H', and quadratically in 'BRS Ipe' and 'BRS Sucupira'. The concentrations of B in the leaves and in the soil increased with the B increasing in the soil. The agronomic characteristics evaluated showed 'BRS Aroeira' and 'BRS Sucupira' responding more and BRS responding less to the B doses applied. The variation in the effFiciency of B utilization was: 'BRS Aroeira' > 'CNPA 8H' = 'BRS Antares' > 'BRS Sucupira' > 'BRS Ipe'. Cultivar 'BRS Aroeira' had the greatest potential to respond positively to the addition of B to the soil. [ABSTRACT FROM AUTHOR]

Cotton farmers in Gujarat, western India, faced a novel decision matrix when Delhi gave provisional approval, in March 2002, to Mahyco–Monsanto Biotech Ltd. to release three Bt-cotton varieties. These varieties represented India's first legally commercialised transgenics: official seeds. Unofficial transgenic seeds were also available to farmers both as unpackaged, unbranded ‘loose seeds’ – mostly F2 progeny of a popular but banned transgenic variety – and as packaged, branded local gray-market Bt cultivars not approved by government. This essay utilises original field research to analyse the reasoning frame of farmers in choosing which seeds to plant. It finds that Bt cotton varieties were valued by farmers for reduction of pest damage, pesticide cost and thus improvement of yields and income. Second, choices among Bt varieties are complex, riding on seed-cost differentials between official and stealth cultivars and variable fit of varieties to local agronomic conditions. Third, some farmers chose non-Bt cultivars, for various reasons, including preference for organic cultivation – though some considered Bt cotton compatible with organic agriculture. Cotton farmers in Gujarat have in effect naturalised transgenic varieties, slotting them into familiar strategies to hedge risks. [ABSTRACT FROM AUTHOR]

Cottons of the same and different varieties were processed on the SDL MDTA/Quickspin System. The tenacity of the resultant yarns at various yarn counts was measured by the Uster Tensorapid. Tukey's Studentized Range Test (a statistical test) was used to determine the difference among the cotton samples in terms of their respective yarn strength. This work demonstrates how the simultaneous adoption of the SDL MDTA/Quickspin System and Tukey's Studentized Range Test can differentiate between cottons of the same and different varieties quickly and objectively. [ABSTRACT FROM AUTHOR]

Cotton is an important crop in many countries in sub-Saharan Africa (SSA). Cotton varieties transformed with genes from Bacillus thuringiensis (Bt) are resistant to a number of lepidopteran bollworm pests of cotton. Bt cotton varieties have been widely adopted in Australia, China, India, the USA and elsewhere. To date, South Africa is the only country in SSA that has planted Bt cotton, but many other African countries are soon to do so. This paper reviews IPM in a number of African countries and considers the possible contribution that Bt cotton might make to IPM for African smallholders. [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]

The development of Bt crops is one of the most significant advances in crop protection technology of the past fifty years. Current Bt crops are based on highly specific insecticidal Cry proteins of Bacillus thuringiensis. Foliar Bt insecticides based on the same proteins have been used for more than forty years and have a remarkable safety record, with no known detrimental effects reported on vertebrate or non-target invertebrate populations. Bt cotton and Bt corn have been widely adopted by farmers in the United States, with acreage averaging 40-50% of the area planted with cotton or corn in 2002. Concern has been raised about the safety of Bt crops. However, most evidence shows that these crops, like foliar Bt insecticides, are safe for non-target organisms, especially in comparison to chemical insecticides. Evidence for safety comes from knowledge of Cry protein mode of action as well as from studies of the effects of Cry proteins on non-target organisms tested in the laboratory and under operational growing conditions. These studies indicate that Bt crops, owing to their high degree of safety, can serve as the cornerstone for more environmentally sound integrated pest management programs. [ABSTRACT FROM PUBLISHER]

Bacillus thuringiensis (Bt) provides one of the most prominent biologically based pesticides. Bt affords a high degree of safety to the environment, non-target organisms and humans in combination with its effectiveness in controlling numerous insect pests. These features fill a pressing need to produce food and fiber for a growing population without eroding environment and health. Extensive safety testing and a history of human exposure without adverse effects have proven Bt to be one of the most important reduced risk pesticides. Not only is Bt effective against targeted pests, but it is safe enough to humans to be exempted from many of the precautions that apply to conventional synthetic chemical pesticides. [ABSTRACT FROM PUBLISHER]

In low-input agricultural systems that characterize most of the developing world, nutrient-efficient crop cultivars may play significant role in improving crop productivity. Phosphorus (P) deficiency is a common phenomenon in cotton growing areas of Pakistan, however the farmers are reluctant to apply it due to its price and fear of lack of response. A solution culture experiment was conducted to evaluate 10 commonly grown cotton cultivars for their relative efficiency to utilize deficiently and adequately supplied P, using Johnson's solution. Phosphorus deficiency markedly reduced shoot dry weight (SDW), root dry weight (RDW), whole plant dry weight controlled by plant P contents under P deficient conditions, suggesting an internal regulation in addition to the influence exerted by external P supply. The conclusions from experiment were that differences in growth existed among cotton cultivars exposed to same P concentration in the growth medium. Cultivars, which were efficient in both P-acquisition and P-utilization, were efficient accumulators of biomass under adequate as well as deficient level of P supply. [ABSTRACT FROM AUTHOR]

The structure, physical characteristics, and mechanical properties of 24 varieties of the Gossypium hirsutum species are reported. It is shown that the average crystallite orientation is a good index of fibre properties. Analysis of the mechanical data in terms of two single-phase structural models indicates that the intrinsic stiffness of the crystallites in the longitudinal and lateral directions is different for different varieties. [ABSTRACT FROM AUTHOR]