• Authors:
    • Kuper, M.
    • Billaud, J.
    • Faysse, N.
    • Abdellaoui, E.
    • Bouzidi, Z.
    • Errahj, M.
  • Source: Cahiers Agricultures
  • Volume: 20
  • Issue: 1/2
  • Year: 2011
  • Summary: The design and diffusion of technical innovations in large-scale irrigation schemes in Morocco have generally been understood as necessarily stemming from centralized public policies. This situation tends to mask farmers' local initiatives. We analyzed local networks for innovation and coordination practices among local actors, in the case of the introduction of citrus plantations in an agrarian reform cooperative of the Gharb irrigation scheme. These networks and practices appeared as the motor for innovation around which revolved social and technical stakes and an issue of identity construction. Revealing these dynamics provides guidance for renewing the approaches to support farmers and more generally rural communities.
  • 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:
    • Scicolone, B.
    • Consoli, S.
    • Capra, A.
  • Source: Acta Horticulturae
  • Issue: 922
  • Year: 2011
  • Summary: Citrus orchards are economically one of the most important crops in South Italy, where climate is semi-arid with scarce rain and high evaporative demand. One way to optimize water resources in this region is to adopt deficit irrigation (DI) strategies, such as regulated deficit irrigation (RDI). In Mediterranean regions, DI criteria have been widely applied and crop physiological responses to water deficit application have been studied in depth, but the profitability of these strategies in commercial orchards is still largely unknown. The objective of this study was to determine the economic feasibility of DI treatment on orange orchards in Sicily (South Italy), by estimating optimum levels of applied water which provide maximum profit under limited resource availability (e.g. land or water). The applied methodology follows the economic analysis on DI suggested by English in 1990. The analysis of the profit/total costs ratio showed that Deficit Irrigation strategies would increase the generated income, thus being more profitable (up to a maximum of 100%) than the current irrigation water supply management in the area.
  • 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:
    • Detpiratmongkol, S.
    • Chumthong, B.
    • Ubolkerd, T.
  • Source: Proceedings of the 49th Kasetsart University Annual Conference, Kasetsart University, Thailand, 1-4 February, 2011. Volume 1. Subject: Plants
  • Year: 2011
  • Summary: Presently, little is know of the response of sweet potato to different water irrigation amounts. Thus, the purpose of this study was to investigate the effects of different water irrigation amounts on growth and yields of sweet potato. A split plot in randomized complete block design with three replications was used. Six sweet potato cultivars such as Thorpheug, Kai, China, Japan, Pichit 101 and Pichit 1665 were as main plot and sub plot were 4 irrigation regimes based on the ratios of irrigation amount (IW) to cumulative evaporation (E) (i.e., 0.3, 0.5, 0.7 and 1.0). The results disclosed that China cultivar gave the highest growth, total dry weight and root dry weight yield followed by Japan, Kai, Pichit 101, Pichit 1665 and Thorpheug, respectively. Total dry weight and yield significantly increased with increasing the amounts of irrigation from IW/E 0.3 to IW/E 1.0. The lower water regimes increased leaf temperature whereas transpiration rate and total conductance were reduced. However, we were not found the interaction between sweet potato cultivars and water irrigations.
  • 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:
    • Thakur, A.
    • Dalal, R.
  • Source: Advances in Horticultural Science
  • Volume: 25
  • Issue: 1
  • Year: 2011
  • Summary: The root distribution pattern of 17-year-old pineapple orange trees budded on Rough lemon, Cleopatra and Troyer citrange rootstocks were studied by root excavation method at four radial distances, 0-75, 75-150, 150-225 and 225-300 cm from tree trunk, and at three depths, 0-15, 15-30 and 30-60 cm. Fibrous root length density (FRLD) and fibrous root length percentage differed significantly at various depths and radial distances among rootstocks. FRLD was closer to tree trunk on both horizontal and vertical planes. Root density decreased from 0.183 to 0.084, 1.051 to 0.238 and 0.238 to 0.095 cm.cm -3 from 0-15 cm to 30-60 cm depth within 0-75 cm radial distances from tree trunk in trees on Rough lemon, Cleopatra and Troyer citrange, respectively. Cleopatra contains the highest 0.231 cm.cm -3 FRLD as compared to 0.051 cm.cm -3 in Rough lemon and Troyer citrange. Troyer citrange has intensive lateral root development with 84% fibrous roots (FR) within 75 cm radial distance, whereas Rough lemon and Troyer has an appreciable amount up to 225 cm distance (extensive lateral). Cleopatra contained 57% FR in upper soil layer (0-15 cm) (intensive vertical). In Rough lemon and Troyer 54% FR are confined to lower depth 15-60 cm (extensive vertical root development). Troyer and Rough lemon had the same vertical, whereas Rough lemon and Cleopatra showed the same horizontal rooting pattern under arid irrigated ecosystem. Thus, irrigation depth and fertilizer placement should be critically rootstock specific.
  • Authors:
    • Domenikiotis, C.
    • Mplanta, A.
    • Dalezios, N.
  • Source: Journal of Information Technology in Agriculture
  • Volume: 4
  • Issue: 1
  • Year: 2011
  • Summary: Water for food production represents by far the largest share among all uses and its demand keeps growing with increasing population. The lack of water can affect disfavour the economic and social stability of entire regions. New technologies (Earth Observation, Geographic Information Systems) provide the possibility of time and spatial observation for the decision support and management. In this paper applied principles of precision agriculture through variable-rate inputs by the efficient monitoring of crop needs in space and time, defined zones of sustainable production by means of parallelepiped supervised classification using two indices, the soil maps and the DEM and described the process for the computation of crop evapotraspiration ETp for cotton fields in central Creece, a high agricultural productivity area that produces high quality products. The methodology was also used in Project PLEIADeS and new projects SMART and HYDROSENSE. For the data collection cotton fields were used. NOAA/AVHRR images consist the data base for the estimation of Water Limited Growth Environment (WLGE) and Landsat TM satellite images were processed for the extraction of reflectance, NDVI, RGB, ETp, Fractional cover, Kc maps. The objectives of this paper target to calculation of water balance with the use of satellite data and GIS, efficient use of water in water limited environments, improvement of irrigation systems with the use of new technologies, contribution to rational management of water resources in agriculture. Methodology can be applied in large scale areas and extend to other crops using satellite data. The results are in good agreement with ground-truth observations.
  • Authors:
    • Lasram, A.
    • Akkari, T.
    • Dellagi, H.
  • Source: New Medit
  • Volume: 10
  • Issue: 4
  • Year: 2011
  • Summary: This work deals with the regional characteristics of the supplied irrigation effect on the cereal yield in Tunisia. It underlines the value of the knowledge how scientifically brought to farmers. This study analyses the results of an inquiry carried on over seven consecutive years at the level of two categories for farmers practising irrigated wheat farming. The first category of farmers is taking advantage of a set of the technological support actions which related both to the vulgarization of different forms of technological innovations and the miscellaneous forms of support in kind, while the second category of farmers is granted no form of support. The specification of the different regions studied in Tunisia and the comparison of the two farmers categories studied is brought out by the Principal Components Analysis technique and the PLS regression. The mastering of the irrigation waters use, the rationalization of the fertilization as well as the soil exploitation in the north of the country are better valorised by the supported farmers.