• Authors:
    • Qi, X. F.
  • Source: Research of Agricultural Modernization
  • Volume: 33
  • Issue: 2
  • Year: 2012
  • Summary: Based on the statistical data of crop yields, cropland areas and agricultural inputs in the period from 2001 to 2010, the amounts of carbon absorption and emission of the farmland ecosystems in Dezhou were calculated, and the spatial-temporal variations and impact factors of carbon absorption and emission were analyzed. Carbon absorption of farmland ecosystem in Dezhou showed a trend from 2001-2010 and the carbon absorption of wheat, corn as the main food crops was significantly higher than other crops. The carbon emission showed the change of the increases after first reduces in Dezhou from 2001 to 2010. As the different the direction of agricultural development and the development characteristics in different counties there were different carbon emission; the carbon emission of chemical fertilizer was a larger proportion and a decreasing trend in the five ways of carbon emissions; carbon absorption was far greater than the amount of carbon emissions in Dezhou from 2001 to 2010 and there were a strong carbon sink of the farmland ecosystem. The correlation analysis results showed that carbon absorption was significantly positive correlated with the yields of wheat, corn and cotton. Significant positive correlations were observed between carbon emission and agrochemical inputs, power and fuels consumption, and cultivation and irrigation management.
  • Authors:
    • Rajakumar
    • Kuchanur, P. K.
    • Nidagundi, J. M.
    • Konda, C. R.
  • Source: Electronic Journal of Plant Breeding
  • Volume: 3
  • Issue: 1
  • Year: 2012
  • Summary: Twenty two Bt cotton hybrids were evaluated for seed cotton yield and fibre quality parameters over three environments viz., Agricultural Research Station, Siruguppa (E-1), Main Agricultural Research Station, Raichur (E-2) and Agricultural Research Station, Bheemarayanagudi (E-3), during Kharif 2010-11. The seed cotton yield ranged from 1478 to 2203 kg/ha among the Bt cotton hybrids. Pooled data of seed cotton yield revealed that two hybrids viz., MRC 7347 BG II (2203 kg/ha) and ACH 177-2 BG II (2054 kg/ha) recorded numerically superior seed cotton yield over the check, MRC-7351 BG-II (2053 kg/ha). The data on 2.5 per cent span length ranged from 29.2 mm to 33.6 mm, while the fibre strength of the hybrids ranged from 21.7 g/tex to 23.9 g/tex. Fibre fineness or micronaire value ranged from 3.9 to 4.6 g/inch. None of the hybrids were found to be stable across all the test environments indicating the need to undertake extensive testing of Bt cotton hybrids for recommending region specific hybrids possessing high yielding potential coupled with desirable fibre quality parameters.
  • Authors:
    • Amanullah, M. M.
    • Rajendran, K.
    • Vaiyapuri, K.
  • Source: Madras Agricultural Journal
  • Volume: 99
  • Issue: 1/3
  • Year: 2012
  • Summary: Field experiments were conducted during winter 2006-07 and 2007-08 at Tamil Nadu Agricultural University, Coimbatore to find out the effect of drip irrigation on the productivity and water use efficiency in Bt-cotton ( Gossypium hirsutum L.). The experiments were laid out in a randomized block design replicated four times. The treatments consisted of drip irrigation at 0.40, 0.60, 0.80 and 1.0 ET c (Crop evapotranspiration) compared with farmers' method (flood irrigation method). The results revealed that application of water to Bt-cotton through drip resulted in better growth, higher seed cotton yield and better quality of lint than the surface method. The yield advantage due to different irrigation schedules through drip based on ETc was 26.2 and 12.8% over surface method during 2006-07 and 2007-08, respectively. Among the irrigation through drip, irrigation at 0.80 ET c recorded better growth and gave higher seed cotton yield than irrigation at 0.60 ET c. The water use efficiency with drip irrigated Bt-cotton was 44.4% higher than the flood method of irrigation.
  • Authors:
    • Pereira, L. S.
    • Alves, I.
    • Fernando, R. M.
    • Rodrigues, G. C.
    • Paredes, P.
    • Rosa, R. D.
    • Allen, R. G.
  • Source: Agricultural Water Management
  • Volume: 103
  • Year: 2012
  • Summary: This paper is the second of a two-part series, with the first part describing the SIMDualKc model, an irrigation scheduling simulation tool that employs the dual crop coefficient approach for calculating daily crop ET and then performs a water balance for a cropped soil. The model was applied, calibrated and validated for rainfed and basin irrigated maize (Coruche. Portugal), rainfed and surface irrigated wheat (Aleppo, Syria), and furrow irrigated cotton (Fergana, Central Asia). Results show good agreement between available soil water content observed in the field and that predicted by the model. Results indicate that the calibrated model does not tend to over- or underestimate available soil water over the course of a season, and that the model, prior to calibration, and using standard values for many parameters, also performed relatively well. After calibration, the average growing season maximum estimation errors were 10 mm for maize, 8 mm for winter wheat and 9 mm for cotton, i.e., respectively 3.6, 2.9 and 5.0% of total available water. Results indicate that the separation between evaporation and transpiration and the water balance calculation procedures are accurate enough for use in operational water management. The indicators used for assessing model performance show the model to accurately simulate the water balance of several crops subjected to a variety of irrigation management practices and various climate conditions. In addition, the model was applied to alternative irrigation management scenarios and related results are discussed aiming at assessing the model's ability to support the development of alternative active water management strategies.
  • Authors:
    • Ashraf, M. Y.
    • Mehboob-ur-Rahman
    • Sarwar, M. K. S.
    • Zafar, Y.
  • Source: Pakistan Journal of Botany
  • Volume: 44
  • Issue: 2
  • Year: 2012
  • Summary: Water scarcity is an important factor limiting cotton production worldwide particularly in Pakistan. To identify drought tolerant genotypes, it is vital to understand their genetic variation for different biochemical traits under water limited conditions. In the present study, 24 genotypes of cotton (Gossypium hirsutum L) were evaluated under two irrigation regimes viz., well watered (W-1) and limited water (W-2) conditions. Before physiological maturity, cotton leaves were collected and analyzed for nitrate and nitrite reductase activities, and total free amino acids. At maturity, data regarding yield and yield parameters were recorded. Significant reduction in case of all the activities of nitrate and nitrite reductase, and yield parameters was observed under W-2 condition in all the genotypes; however, total free amino acids were substantially increased under W-2 condition. Correlation between the yield parameters of cotton and biochemical traits was determined. Non-significant correlation between nitrate reductase activity and yield parameters was observed under limited water condition. The genotypes evaluated exhibited decrease in the activities of nitrate and nitrite reductase whereas total free amino acids accumulation was higher under drought conditions that showed comparatively higher yield. This study shows that these biochemical traits were regulated genetically and environmentally in the tested cotton genotypes. It was concluded that these biochemical traits can be used as biochemical markers for screening cotton germplasm for drought tolerance as well as for evolving high yielding drought tolerant varieties of this crop. The findings are useful in bridging plant biochemistry and molecular biology for identifying and selecting genes involved in conferring drought tolerance in cotton.
  • Authors:
    • Bosch, D. D.
    • Franklin, D. H.
    • Truman, C. C.
    • Potter, T. L.
    • Strickland, T. C.
    • Hawkins, G. L.
  • Source: SOIL & TILLAGE RESEARCH
  • Volume: 122
  • Year: 2012
  • Summary: Assessment of erosion impact on soil carbon and nitrogen loss and redistribution within landscapes is needed to develop estimates of soil carbon sequestration potential, soil quality management plans, and to evaluate potential for transport of sediment bound agrochemicals. We used variable intensity rainfall simulations to quantify the effects of tillage, conventional and strip, and antecedent soil water content on sediment-bound carbon and nitrogen loss from a Tifton loamy sand located in the southeastern Atlantic Coastal Plain (USA). Carbon and nitrogen loss via erosion of silt. +. clay sized versus sand sized sediment particles were quantified. Antecedent water content had no effect on mean sediment loss within tillage treatments, but losses from conventional till treatments were significantly greater than from strip till. Sediment lost as silt. +. clay was from 58 to 78% of the total under conventional and from 30 to 39% under strip tillage. The fraction of sediment lost as silt. +. clay versus sand was greater under conventional tillage than under strip tillage. Within-event sediment carbon enrichment compared to the top 2. cm of soil was 0.9-7.2 for conventional and 0.6-3.7 for strip tillage. The strip till silt. +. clay fraction had significantly higher carbon content than the strip till sand fraction and the conventional till silt. +. clay fraction. Carbon loss from treatments was directly proportional to sediment loss. However, the conventional till treatments lost 4.6-6 times more carbon from the silt. +. clay sized fraction and 1.9-4.8 times more carbon from the sand sized fraction than strip till treatments. Results suggest that the higher proportion of silt. +. clay fraction sediment loss from conventional till may deplete nitrogen enriched organic matter while decreased erosion from strip till may serve to increase retention of organic nitrogen. Findings also indicate that an approach that adjusts loss estimates of organic carbon and nitrogen by using wet-sieved subsamples for analysis followed by standardization against total bulk sediment loss accounts for introduced errors from both sub-sampling efficiency and disturbance.
  • Authors:
    • Howell, T. A.
    • Evett, S. R.
    • Schwartz, R. C.
    • Colaizzi, P. D.
    • Gowda, P. H.
    • Tolk, J. A.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 2
  • Year: 2012
  • Summary: Relatively few radiation transfer studies have considered the impact of varying vegetation cover that typifies row crops, and methods to account for partial row crop cover have not been well investigated. Our objective was to evaluate a widely used radiation model that was modified for row crops having sparse to full vegetation cover. The radiation model was combined with geometric view factors based on elliptical hedgerows that account for the spatial distribution of row crop vegetation, and this approach was compared with the more commonly used clumping index approach. Irradiance measurements included transmitted and reflected visible and shortwave, outgoing longwave, and total net radiation. The model used optimized parameters for corn ( Zea mays L.), grain sorghum [ Sorghum bicolor (L.) Moench], and cotton ( Gossypium hirsutum L.). The elliptical hedgerow and clumping index approaches resulted in similar model agreement; however, the former resulted in up to 7.3 W m -2 smaller RMSE and up to 7.5 W m -2 smaller mean bias error compared with the latter. Both approaches resulted in similar model sensitivities to inputs, which varied 25%. Calculated shortwave irradiance fluxes were most sensitive to leaf area index (LAI; -3.25), canopy width (-1.94), ellipsoid leaf angle parameter (-0.77), and visible leaf absorption (-5.54) when LAI=2.95 m 2 m -2, and visible soil reflectance (0.89) when LAI=0.21 m 2 m -2. Calculated outgoing longwave irradiance and net radiation were most sensitive to the soil directional brightness temperature (0.55 and -0.61, respectively) when LAI=0.21 m 2 m -2.
  • Authors:
    • Nariya, J. N.
    • Khanpara, M. D.
    • Butani, A. M.
    • Kapadiya, H. J.
  • Source: Journal of Cotton Research and Development
  • Volume: 26
  • Issue: 1
  • Year: 2012
  • Summary: FLD's with participation of farmers' in production technology was conducted in seven districts of Saurashtra. Thirty four, 50 and 50 farmers were selected for FLD's during 2005-2006, 2006-2007 and 2007-2008, respectively. Varietal, fertilizer, irrigation and inter cropping components were conducted in FLD's. Results indicated that 8.83 per cent average seed cotton yield was increased over improved varieties. In fertilizer components, there was no effect of DAP on seed cotton yield, however without DAP clearly showed the average saving of Rs. 1743/ha. The reduction of 3.98 per cent seed cotton yield was recorded in alternate furrow irrigation, but the cost of cultivation of Rs. 3370/ha was decreased as compared to local practices. In inter cropping practices, 10.13 per cent seed cotton yield was increased over local practices. Overall results clearly indicated that an additional net return of Rs. 5130, 3831, 1002 and 859 was recorded in improved varities, intercropping, irrigation and fertilizer components, respectively. Looking to the over all of three years average results with four improved production technologies of FLD's, recorded a increase of 4.6 per cent in seed cotton yield, reduced by 3.12 per cent in cost of cultivation and increased net return of 9.95 per cent with a net profit of 3371 Rs/ha during three years of cropping season.
  • Authors:
    • Lawton-Rauh, A.
    • Agudelo, P.
    • Leach, M.
  • Source: Plant Disease
  • Volume: 96
  • Issue: 1
  • Year: 2012
  • Summary: Rotylenchulus reniformis is a highly variable nematode species and an economically important pest in many cotton fields across the southeastern United States. Rotation with resistant or poor host crops is a method for management of reniform nematode. We studied the effect of six planting schemes covering four 120-day planting cycles on the predominant genotype of R. reniformis. Rotations used were: (i) cotton to corn; (ii) susceptible soybean to corn; (iii) resistant soybean to cotton; (iv) corn to cotton; (v) continuous susceptible soybean; (vi) continuous cotton. After each 120-day cycle, amplified fragment length polymorphisms (AFLPs) produced from four primer pairs were used to determine the effect of crop rotation on the predominant genotype of reniform nematode. A total of 279 polymorphic bands were scored using four primer combinations. Distinct changes in genotype composition were observed following rotations with resistant soybean or corn. Rotations involving soybean (susceptible and resistant) had the greatest effect on population structure. The characterization of field population variability of reniform nematode and of population responses to host plants used in rotations can help extend the durability of resistant varieties and can help identify effective rotation schemes.
  • Authors:
    • Sood, A.
    • Jalota, S. K.
    • Buttar, G. S.
    • Bhushan, B.
  • Source: INDIAN JOURNAL OF AGRICULTURAL SCIENCES
  • Volume: 82
  • Issue: 1
  • Year: 2012
  • Summary: Cotton cultivation in semi-arid region of Indian Punjab is considered as most risky crop as its yield is very sensitive to weather parameters like rain and temperature. In future due to global warming increase in the temperature is expected, which is most likely to influence the growth and yield of this fiber crop like other cereal crops. Studies on the effect of temperature on the growth and seed yield of Bt cotton in this region are lacking. The present 2-year field and 15-year simulation studies concern to simulate the effect of temperature on duration of pheno-phases and seed yield of Bt cotton hybrid RCH 134 and also on crop water productivity. Simulations were run for 15 years (1991-2005) using the already customized CropSyst model. The simulated results indicated that with increase in temperature from 28 to 32degreesC, cotton seed yield was reduced to half (from 4 700 to 2 300 kg/ha) following a linear relation with high coefficient of determination (0.97), and the reduction was more with increased temperature during sowing to flowering stage than other pheno-phases. Total evapo-transpiration (ET) during crop period and crop water productivity was also decreased with increased temperature. Relationship of cotton seed yield was linear with ET and quadratic with total water supply (rain+irrigation). Real crop water productivity (yield/ET) and apparent crop water productivity (yield/irrigation water) were 0.3620.129 and 0.4850.120 kg/m 3, respectively.