• Authors:
    • Batista, C.
    • Lima, T.
    • Neves, J.
    • Oliveira, R.
    • Berger, P.
    • Aquino, L.
  • Source: REVISTA BRASILEIRA DE ENGENHARIA AGRICOLA E AMBIENTAL
  • Volume: 15
  • Issue: 5
  • Year: 2011
  • Summary: The objective was to evaluate the application of phosphorus doses in parcels in the cotton crop in the systems of cultivation under irrigation and rainfed, being aimed the higher efficiency of phosphate fertilization, in comparison to the traditional application, only at sowing. The experiment was carried out in Quartzanic Neossoil, in the North region of Minas Gerais. The adopted design was randomized blocks, with three replicates. The treatments were the doses of 50 and 120 kg ha -1 of P 2O 5 applied in four ways: PS, P1, P2 and P3 [100/0; 75/25; 50/50; 25/75% of the dose of phosphate fertilizer applied, respectively at the sowing and at 35 days after the emergence (DAE)], in the irrigated and rainfed crops. Two additional treatments, without P, in the crop without and with irrigation, completed the eighteen studied treatments. The increase of the P doses increased the dry mass of aerial part and the number of reproductive structures at 80 DAE, the relative efficiency of the phosphate fertilization and the productivity of cotton in bull. The response to P doses occurred only under irrigation. The parceled application of the phosphate fertilizer did not increase the efficiency of the fertilization in the cotton farm in Quartzanic Neossoil.
  • Authors:
    • Latif, M.
    • Azhar, A.
  • Source: Journal of Animal and Plant Sciences
  • Volume: 21
  • Issue: 2
  • Year: 2011
  • Summary: This study was conducted during 2001-04 in which four subsurface drainage projects viz; Mardan SCARP Project (MSP), Fourth Drainage Project, Faisalabad (FDP), Chashma Command Area Development Project (CCADP) and Mirpurkhas Tile Drainage Project (MTDP) were assessed for their impact on crop yield in irrigated areas of Pakistan. Quantitative comparison made on the change in pre- and post-project conditions revealed that crop yield significantly improved due to project implementation at all sites. The yield increased from 13 to 94% for most crops. The exception was rice, where it decreased by 23% at MTDP due to shortage of irrigation supplies. Maximum yield increase was observed in CCADP for cotton (80%), sugarcane (94%), wheat (67%); and at MSP for rice (46%). For chilli the maximum increase (147%) was observed at MTDP study site. Low increase in the yield was attributed to the shortage of irrigation supplies during the post-project periods. Limited sub-irrigation resulting from the operation of subsurface drainage systems was also observed to be another factor for low crop yields. Overall quantitative comparison indicated a positive impact of drainage system installation in terms of crop yield improvements.
  • Authors:
    • Sanjani, S.
    • Bannayan, M.
  • Source: Agricultural and Forest Meteorology
  • Volume: 151
  • Issue: 12
  • Year: 2011
  • Summary: Climate variability and weather extremes are principal sources of fluctuations of annual productivity of many crops in arid and semi-arid environments. Temperature and precipitation are the major weather variables that determine the variability of crop yields. In this study, the relationship between weather descriptors and major irrigated crops yield were assessed for Khorasan province in northeast of Iran. Long term daily weather (1984-2007) and crop yield (wheat, barley, sugarbeet, cotton, potato, chickpea, alfalfa) data were analyzed with simple correlation analysis and also the iterative chi-square analysis identified relationships of low and high wheat yield years to maximum and minimum air temperatures within each region. Our results indicated that association between various crop yield and descriptors varied in different study location. As in Bojnourd located in the north of Khorasan yields of the crops studied did not correlate with temperature indicators, whereas in Birjand the relationship between temperature descriptors and crop yields were strong. Correlation between growing season precipitation and wheat, barley, chickpea and sugarbeet yields was positive while cotton yield decreased with increasing precipitation during the growing season. The results of chi-square analysis for wheat yield demonstrated that the critical time in which extreme temperature led to yield loss differed among regions. In Bojnourd, in late April to early May, and excess days (high or low yield years have more days meeting a cardinal value than normal years) with maximum temperature higher than 30 degrees C, wheat yield decreased while in Birjand, cooler maximum temperature (
  • Authors:
    • Santos Junior, V.
    • Silva, H.
    • Aquino, L.
    • Batista, C.
    • Pacheco, D.
  • Source: Bioscience Journal
  • Volume: 27
  • Issue: 2
  • Year: 2011
  • Summary: This paper objective was to evaluate P levels in irrigated crops or rainfed in productivity and P uptake by cotton plant. The experiment was conducted at the Instituto Federal do Norte de Minas (IFNMG), Campus Januaria. The treatments consisted of three P rates (0, 50 and 120 kg ha -1 of P 2O 5) and three cropping systems (Sprinkler, Dripping and Rainfed). It was adopted the randomized block design in factorial design with three replications. At 80 days after emergence (DAE), leaves, stems, and reproductive structures were collected. Each organ was dried, crushed, and P content determined. P content of each organ was calculated. The macro and micronutrients levels in the fifth fully expanded leaf from the apex to the base (leaf index) were determined. The P and S contents were higher in irrigated plants by dripping. The P and Mg highest values were obtained with 120 kg ha -1 de P 2O 5. The irrigated plants had higher P content in shoots compared to those under rainfed. Regardless of the method, irrigation and the highest P rates increased the quantity of reproductive structures, the quantity of the bolls per plant, and seed cotton productivity.
  • Authors:
    • Carvalho, L.
    • Lima, M.
    • Sofiatti, V.
    • Brito, G.
    • Silva Filho, J.
  • Source: Acta Scientiarum - Agronomy
  • Volume: 33
  • Issue: 1
  • Year: 2011
  • Summary: The objective of this study was to identify physiological traits that could distinguish between cotton genotypes that were tolerant or sensitive to water deficits. The experiment was conducted in a completely randomized design through a factorial combination to analyze four genotypes (BRS 187 8H and ACALA SJ-4 - water deficit tolerant; CNPA 7H and SU-0450/8909 - water deficit sensitive) and two water regimes (watered/always irrigated and stressed/with a water deficit imposed at flowering). Irrigation was suspended for the plants in the water deficit treatment groups when their first flowers appeared. Leaf water potential (psipd) was monitored until the plants reached -3.0 MPa predawn, at which point leaf samples were collected for analysis. The plants were reirrigated and monitored for a recovery to 50% of leaf water potential. The maximum photochemical efficiency ( Fv/Fm), chlorophyll content (SPAD index), relative water content (RWC), disruption of the cell membrane via membrane leakage, carbon isotope composition (delta 13C), seed cotton yield and fiber quality were evaluated. The trends in membrane leakage and carbon isotope composition were different between the tolerant and sensitive genotypes under a water deficit, which makes these physiological traits suitable for screening for tolerance to water deficits in cotton.
  • Authors:
    • Chidankumar, C.
    • Siddappa
    • Chandraju, S.
  • Source: Current Botany
  • Volume: 2
  • Issue: 3
  • Year: 2011
  • Summary: Germination of Cotton and Ground nut seeds was made by irrigated with distillery spentwash of different concentration. The spentwash i.e. primary treated spentwash [PTSW] 1:1, 1:2 and 1:3 spentwash were analyzed for their plant nutrients such as nitrogen, phosphorous, potassium and physical & chemical characteristics. Experimental soil was tested for its chemical physical parameters. Cotton and Ground nut seeds were sowed in the prepared land and irrigated with raw water (RW), 1:1, 1:2 and 1:3 (SW: RW) spentwash. The nature of germination of seeds was studied. It was found that, the germination was good (100%) in 1:3 SW irrigation, while very poor in 1:1 SW (25%), moderate in 1:2 SW (80%) and 95% in RW irrigations.
  • Authors:
    • Pendergast, L.
    • Torabi, M.
    • Bhattarai, S.
    • Dhungel, J.
    • Chen, X.
    • Midmore, D.
  • Source: Journal of Plant Ecology
  • Volume: 4
  • Issue: 4
  • Year: 2011
  • Summary: Aims Oxygation refers to irrigation of crops with aerated water, through air injection using the venturi principle or the supply of hydrogen peroxide in the root zone, both using subsurface drip irrigation (SDI) system. Oxygation improves water use efficiency (WUE), producing more yield and, and therefore, optimizes the use of drip and SDI. But the efficiency of oxygation is quite possibly dependent on a number of factors. The primary objective of this study was, therefore, to quantify the effects of oxygation, emitter depths and soil type on crop root zone oxygen content, soil respiration, plant physiological response, biomass yield, quality and WUE of three crop species. Methods This study investigated the potential of oxygation to enhance soil respiration, plant growth, yield and water use efficiencies (WUE) of cotton and wheat in experiments in enclosed heavy-duty concrete troughs (tubs) and pineapple and cotton in field experiments. Experimental treatments in tubs for wheat included comparisons between two soil types (vertisol and ferrosol) and superimposed were two oxygation methods (Mazzei air injector and Seair Diffusion System) compared to a control, and for cotton, emitters at two depths using Mazzei air injectors were compared to a control. The field experiments compared Mazzei air injectors and a control for cotton in Emerald and pineapple in Yeppoon, both in central Queensland, Australia. Important findings In all experiments, soil oxygen content and soil respiration markedly increased in response to the oxygation treatments. The O-2 concentration in the crop root zone increased by 2.4-32.6%, for oxygation compared to control at the same depth. The soil respiration increased by 42-100%. The number of wheat ears, leaf dry weight and total dry matter were significantly greater in Mazzei and Seair oxygation compared to the control. Fresh biomass of wheat increased by 11 and 8%, and dry weight of wheat increased by 8 and 3% in Mazzei and Seair oxygation treatments compared to the control, respectively. Likewise, the irrigation water use efficiency increased with oxygation compared to the control in wheat. The yield, WUE and number of other physiological parameters in wheat were enhanced in vertisol compared to ferrosol. The seed cotton yield in the tub experiment increased with oxygation by 14%, and significant differences for fresh biomass, dry matter and yield were also noted between oxygation and the control in the field. Lint yield and WUE both increased by 7% using Mazzei in the cotton field trial during 2008-09. There were significant effects of oxygation on pineapple fresh biomass, and dry matter weight, industry yield and a number of quality parameters were significantly improved. The total fruit yield and marketable increased by 17 and 4% and marketable WUE increased by 3% using Mazzei. Our data suggest that the benefits of oxygation are notable not only for dicotyledonous cotton but also for monocotyledonous wheat and pineapple representing different rooting morphologies and CO2 fixation pathways.
  • Authors:
    • Guo, R.
    • Xu, H.
    • Lin, T.
    • Tian, L.
    • Cui, J.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 5
  • Year: 2011
  • Summary: Objective: In order to substantially know the weeds community and its characteristics in cotton field under mulch-drip irrigation of the south Xinjiang, an investigation on weeds was conducted. Finally a theoretical base of weeds control was provided in cotton subregions of the Southern prematurity and medium ripening taha. Method: Laid heavy stress on the years of cotton field with drip irrigation in townships of Avati County, weed community and quantities were investigated, including comparing with weeds community under the different mode of cotton. Result: There were a lot of weeds species in different cotton mode, including 9 families 15 kinds. Their main species were gramineous, compositae and chenopodiaceae families which had great effect on cotton growth. Conclusion: Compared with cotton fields under outdoor sowing, conventional irrigation and mulch-drip irrigation, the dry weight of weeds root hade significantly lower. The reason was that enough water and nutrient were supplied in time in cotton field under mulch-drip irrigation. The weeds quantity of annual shallow roots and broad-leaved had tendency to increase. The weeds had two harm peaks in the cotton growth period, and peak harm appeared earlier and continued for longer time.
  • Authors:
    • Zalucki, M.
    • Pufke, U.
    • Davies, A.
  • Source: Agricultural and Forest Entomology
  • Volume: 13
  • Issue: 3
  • Year: 2011
  • Summary: Understanding the spatio-temporal dynamics of insects in agroecosystems is crucial when developing effective management strategies that emphasize the biological control of pests. Wild populations of Trichogramma Westwood egg parasitoids are utilized for the biological suppression of the potentially resistant pest species Helicoverpa armigera (Hubner) in Bt-transgenic cotton Gossypium hirsutum L. crops in the Ord River Irrigation Area (ORIA), Western Australia, Australia. Extensive, spatially-stratified sampling during a season of relatively high Trichogramma abundance found that spatial patterns of pest egg parasitism in the ORIA tend toward heterogeneity, and do not necessarily coincide with host spatio-temporal dynamics. Both patterns of host egg density and mean rates of parasitism are not good indicators of parasitoid spatio-temporal dynamics in ORIA cotton crops. Parasitism rates can be significantly higher within the middle strata of the cotton plant canopy before complete canopy closure, despite a similar number of host eggs being available elsewhere in the plant. Spatial variation in egg parasitism by Trichogramma in Bt-transgenic cotton is evident at the between-field, within-field and within-plant scale, and is not solely driven by host spatial dynamics. These factors should be considered when estimating Trichogramma impact on pest species during biological control and spatio-temporal studies of host-parasitoid interactions in general.
  • Authors:
    • Devraj
    • Jain, P.
    • Promila, K.
    • Duhan, B.
    • Bhattoo, M.
  • Source: Journal of Cotton Research and Development
  • Volume: 25
  • Issue: 2
  • Year: 2011
  • Summary: A field experiment was conducted at Research Farm, CCS, Haryana Agricultural University, Hisar during 2007 and its Regional Cotton Research Station, Sirsa during 2008 to find out the optimum crop geometry and fertilizer doses for Bt cotton ( Gossypium hirsutum L.) hybrids RCH134. A closer spacing of 67.5*60 cm gave significantly higher seed cotton yield (3230 and 3906 kg/ha at Hisar and Sirsa, respectively) than other two spacing i.e. 100*45 and 100*60 cm at both the locations. The highest seed cotton yield (3061 and 3902 kg/ha at Hisar and Sirsa, respectively) was recorded with a fertilizer dose of 125 per cent RDF (187.5-75-75 kg/ha N, P 2O 5 and K 2O) as compared to 75 per cent RDF and 100 per cent RDF at both the locations. The crop geometry, 67.5*60 cm and fertilizer dose of 187.5 kg/ha N, 75 kg/ha P 2O 5 and 75 kg/ha K 2O is ideal for getting higher seed cotton yield of Bt cotton RCH134.