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[en] This study was designed to manage insect pests of Bt cotton through the manipulation of different eco-friendly techniques. A perusal of data, based on the overall performance of different treatments reflected that lowest population of jassids (0.29) was observed in bio-control treated Bt cotton followed by bio-control treated conventional cotton (0.41). Mean per leaf population of thrips was found lowest in insecticide treated Bt cotton (0.97) which was statically at par with bi-control treated conventional cotton (0.95), biocontrol treated Bt cotton (1.09) and colour traps treated Bt cotton (1.50). In case of white flies, bio-control treated Bt cotton and bio-control treated conventional cotton again proved effective in maintaining the population at lower levels per leaf (0.33 and 0.35 respectively). No bollworms infestation was recorded in transgenic cotton whereas higher attack of the same was observed in the untreated conventional cotton block. The best results were achieved with the application of bio-control agents in combination with Bt cotton resulting in least infestation by insect pests and maximum seed yield of 3657 kg/ha. The population of Chrysoperla carnea was significantly higher in Bt and conventional cotton treated with bio-control agents as compared to the other treatments. The parasitism percentage of Trichogramma chilonis was observed significantly higher in bio-control treated conventional cotton. The studies manifested that combination of bio-control technology with Bt cotton effectively preserves the local beneficial insect fauna indicating its potential to be used as integrated management system against different insect pests of cotton. (author)
[en] Nineteen varieties of cotton of different countries of origin were subjected to tests for determination of physical properties of fibre viz., length (mm), length uniformity (%), short fibre index (SFI %), strength (g/tex), elongation (%), fineness (Micronaire value), reflectance (Rd value) and yellowness (+b value), using the Uster HVI system, Egypt (Giza 70), Egypt (Giza 88), India ( MCU 5), USA (Elpaso), Egypt (Giza 86), Sudan (Barkat) and CIS (Sultop) had better overall fibre length, strength and length uniformity %, and low SFI %, Pearson correlation of these physical properties was also determined. A strong positive correlation was found among fibre length, strength and length uniformity while all three of these properties exhibited a strong negative correlation with SFI %. (author)
[en] Nine upland cotton varieties/strains were tested over 36 environments in Pakistan so as to determine their stability in yield performance. The regression coefficient (b) was used as a measure of adaptability, whereas parameters such as coefficient of determination (r2) and sum of squared deviations from regression (s/sup 2/d) were used as measure of stability. Although the regression coefficients (b) of all varieties did not deviate significantly from the unit slope, the varieties CRIS-5A. BII-89, DNH-40 and Rehmani gave b value closer to unity implying their better adaptation. Lower s/sub 2/d and higher r/sub 2/ of CRIS- 121 and DNH-40 suggest that both of these are fairly stable. The results indicate that, generally, adaptability and stability parameters are independent of each in as much as not all of the parameters simultaneously favoured one variety over the other excepting the variety DNH-40, which was stable based on majority of the parameters. Principal component analysis revealed that the first two components (latent roots) account for about 91.4% of the total variation. The latent vectors of first principal component (PCA1) were smaller and positive which also suggest that most of the varieties were quite adaptive to all of the test environments. (author)
[en] In the paper carried out generalization of experimental results on specific isobaric thermal capacity, heat conductivity and thermal diffusivity coefficients of raw cotton of sort 9326-B and its components on the basis of similarity theory
[en] Full text: The boll weevil eradication programme in the United States began in 1983 to rid the cotton belt of the boll weevil, Anthonomus grandis Boheman. To date, the boll weevil has been eradicated from nearly 11 million acres of cotton in Virginia, North Carolina, South Carolina, Georgia, Florida, most of Alabama, Middle Tennessee, Texas, Southern California, and Arizona, as well as from the neighboring regions of the Mexicali Valley, Sonoita, and Caborca in Mexico. The programme is currently operating in an additional 4.8 million acres of cotton in Mississippi, Tennessee, Missouri, Arkansas, Louisiana, Oklahoma, Texas, and New Mexico. Further, pending positive grower referenda, the programme is scheduled to expand in 2005 to include the remaining 0.32 million acres in the Lower Grande Valley and the Northern Blacklands region of Texas. This will result in 100% of the US cotton celt being involved in boll weevil eradication, with 68% having completed eradication and the remaining 32% nearing eradication. Nationwide eradication is expected by 2008. The remarkable environmental, biological, and economic benefits realised in the eradicated regions make boll weevil eradication one of the most important agricultural programmes in the history of the USA The success of the boll weevil eradication programme, however, hinges on two separate, yet interdependent operational components: technical and managerial. In addition to providing a summary of the boll weevil eradication programme in the USA, this report reviews the technical and administrative methods and materials that are essential for success of the boll weevil eradication programme and perhaps any other area-wide pest control and eradication programme. (author)
[en] In 2009, 4088 hectares of genetically modified (GM) cotton were planted in Tolima (Colombia), however there is some uncertainty about containment measures needed to prevent the flow of pollen and seed from regulated GM fields into adjacent fields. In this study, the gene flow from GM cotton varieties to conventional or feral cotton plants via seed and pollen was evaluated. ImmunostripTM, PCR and ELISA assays were used to detect gene flow. Fifty six refuges, 27 fields with conventional cotton and four feral individuals of the enterprise Remolinos Inc. located in El Espinal (Tolima) were analyzed in the first half of 2010. The results indicated seed mediated gene flow in 45 refuges (80.4 %) and 26 fields with conventional cotton (96 %), besides pollen mediated gene flow in one field with conventional cotton and nine refuges. All fields cultivated with conventional cotton showed gene flow from GM cotton. Two refuges and two feral individuals did not reveal gene flow from GM cotton.
[en] The effect of nitrogen fertilization levels on seed cotton yield responses of cultivars from Andalusia was studied during two consecutive years. To obtain preliminary information for improving nutrient management, the analysis of nitrate and potassium (K) was performed in petiole extracts at critical times (flowering, boll-setting, boll growth) during the growth cycle. Significant differences among cotton cultivars were found for petiole nitrate and K concentrations. The highest petiole nitrate and K concentrations were found in cultivar Crema 111 with 4,140 and 14,180 mg k-1 respectively. These concentrations were affected by N treatment and sampling date. The relationships among petiole nutrient concentrations and seed cotton yield depended on sampling date, cultivar and year. The highest association between petiole nitrate and yield was found early in the season in 2003 (r 0.918 and r = 0.965 for Crema 111 and Sor Angela respectively). The analysis of petiole extracts for controlling plant nutritional status and optimize seed cotton yield requires a systematic assessment as critical values in nutrient concentration for seed cotton yield may differ depending on cultivar, soil type, sampling date and crop management. The technique of petiole analysis used in this paper might be useful for detecting genotypes with improved nutrient uptake or use efficiency. (Author) 31 refs.
[en] Fifteen phenotypically diversified genotypes were evaluated for seven characters in relation to earliness. According to analysis of variance, the genotypes differed significantly for all the characters studied. They varied from 6.5 to 9.3 in sympodial node numbers; 19.5 to 43.1 cm in sympodial length; 3.5 to 6.1 cm in internode length; 80.6 to 149.4 cm in plant height; 34.7 to 79.2 cm in leaf size; 2.9 to 4.4 gm in boll weight; 34.3 to 93.4 % in earliness (bolls opened at 125 days after planting) and 59.5 to 126.2 gm in seed cotton yield. It is also observed that none of the genotypes was simultaneously favored with all the earliness characters; however two varieties, CRIS-134 and CRIS- 220 were generally favored with greater number of earliness characters against the other genotypes. Therefore, these can be regarded as short season cottons. These short season genotypes produced sympodial branches at below 7.3 nodes; short sympodial branches under 23.8 cm; short internodes upto 4.3 cm; shorter plants of 96.9 cm; smaller leaves upto 37.9 cm; moderate bolls weighing upto 3.4 gm; percent of open bolls upto 89.9 at 125 days after planting. It is assumed that short season cotton in Pakistani conditions could be considered as 125 to 150 day crop. Thus if these two short season cottons were picked at 150 days, they would have opened more than 95% of their bolls. Both the short season cottons though gave significantly lower yields than many other varieties in the test, yet CRIS-220 still gave an acceptable yield because some of the long season cottons such as BH-118 yielded even less (62.3 gm) than both the short season cottons. Thus yield may be more related to genetic potential of a variety rather than earliness. A third variety CRIS-226 not favored with as many earliness criteria as CRIS-134 or CRIS-220, showed moderate sympodial length (26.4 cm) and boll weight (3.4 gm) While this variety opened maximum percent of bolls (93.4 %), it still gave fairly good yield of 116.4 gm. Our results therefore generally reveal that all the morphological traits studied have fairly good relationship with earliness and hence could reliably be used as selection criteria for breeding short season cottons. (author)
[en] The research work was conducted at Central Cotton Research Institute (CCRI), Multan during the normal crop growing season 2002-03, including fourteen varieties, (thirteen from Punjab and one from Sindh province) with the aim to find out the earliness in the said varieties. From the experimental results it is concluded that CIM-443 produced significantly lowest main stem node number of first sympodial branch (4.6) followed by CIM-240 and Krishma (5.7). while the highest main stem node bearing first sympodial branch number was recorded in variety CIM-1100. The less number of days to first flower was taken by variety CIM-443 followed by CIM-240, while the more number of days were recorded in variety CIM-1100. Therefore, it is concluded that CIM-443 is the earliest maturing variety among all the fourteen varieties.(author)
[en] A field study was conducted to evaluate the effect of K fertilizer on nitrogen use efficiency and cotton yield. The experimental design was a split-plot randomized complete block with four replications, the main plots representing N rates (120, 180, 240 kg N/ha) and the sub-plots representing K rates (0, 50, 100, 150 kg K2 O/ha). The results showed that seed cotton yield increased with increasing K levels applied under each rate of N ( except N 120 ). The highest seed cotton yield was obtained with the combined treatment N 240 K 50 (6442 kg/ha ). This treatment gave also the optimum potassium use efficiency ( 42 % ). The potassium use efficiency decreased and the nitrogen use efficiency (at 180 days of harvest ) increased with the increasing rate of K applied (Authors)