• Authors:
    • Joshi, A. K.
    • Dixon, J.
    • Waddington, S. R.
    • Li, X.Y.
    • Vicente, M. C. de
  • Source: Food Security
  • Volume: 3
  • Issue: 1
  • Year: 2011
  • Summary: Variation in water availability is a major source of risk for agricultural productivity and food security in South Asia. Three hundred and thirty expert informants were surveyed during 2008-09 to determine the relative importance of drought and water-related constraints compared with other constraints limiting the production of four major food crops (wheat, rice, sorghum, chickpea) in five broad-based South Asian farming systems. Respondents considered drought an important constraint to crop yield in those farming systems that are predominantly rainfed, but associated it with low yield losses (well below 10% of all reported losses) for crops in farming systems with well-developed irrigation. In these systems, other water-related constraints (including difficult access to sufficient irrigation water, the high cost of irrigation, poor water management, waterlogging and flooding of low-lying fields) were more important. While confirming the importance of drought and water constraints for major food crops and farming systems in South Asia, this study also indicated they may contribute to no more than 20-30% of current yield gaps. Other types of constraint, particularly soil infertility and the poor management of fertilizer and weeds for the cereals, and pests and diseases for chickpea, contributed most yield losses in the systems. Respondents proposed a wide range of interventions to address these constraints. Continued investments in crop-based genetic solutions to alleviate drought may be justified for food crops grown in those South Asian farming systems that are predominantly rainfed. However, to provide the substantial production, sustainability and food security benefits that the region will need in coming decades, the study proposed that these be complemented by other water interventions, and by improvements to soil fertility for the cereals and plant protection with chickpea.
  • Authors:
    • Souza, R. F. de
    • Medeiros, M. A. de
    • Marouelli, W. A.
    • Resende, F. V.
  • Source: Horticultura Brasileira
  • Volume: 29
  • Issue: 3
  • Year: 2011
  • Summary: The efficient use of water and the environmental diversity are crucial to the balance and sustainability of the organic production system of tomatoes. The present study aimed to evaluate the organic production of tomato cultivated as a single crop and in consortium with coriander, under sprinkler and drip irrigation. The experiment was carried out at an organic production area on the Federal District of Brazil. The experimental design was randomized blocks with treatments arranged in a 2*2 factorial (two irrigation systems * two cropping schemes). No significant interaction between the both factors occurred, and there was no significant effect of the cropping scheme over the evaluated variables. Although the crop cycle has been reduced when tomato was drip irrigated, the fruit yield was not affected by the irrigation systems. The larger reduction in the stand of plants observed under sprinkler irrigation has been compensated by an increase in the number of fruits per plant, without a change on the fruit mass. The smaller volume of soil explored by the tomato roots associated with the higher incidence of South American tomato pinworm ( Tuta absoluta) and mainly powdery mildew ( Leveillula taurica) may have limited the yield of drip irrigated tomato. The fruit decay rate on sprinkle irrigated plants was twice the rate found on the drip irrigated system.
  • Authors:
    • Rajanna, M. P.
    • Sheshshayee, M. S.
    • Mohankumar, M. V.
    • Udayakumar, M.
  • Source: ARPN Journal of Agricultural and Biological Science
  • Volume: 6
  • Issue: 7
  • Year: 2011
  • Summary: Rice is an extensively consumed cereal crop, which serves as a major source of carbohydrate in human diet. Rice cultivation requires more than 50% of the total irrigation water used for agriculture. Therefore saving irrigation water without much compromising with grain yield in rice cultivation is an important global agenda. In the present study the relevance of several drought tolerance traits in improving grain yield of rice under aerobic condition is studied. Analysis of variance indicated significant genetic variability among all plant traits. Grain yield was significantly correlated with root volume, root weight, total biomass total leaf area and Delta 13C. Path analysis indicated that root traits like root length and root weight positive direct effect on grain yield. Above ground traits like SLA, TDM, and TLA had direct positive direct effects on grain yield. The direct of Delta 13C on grain yield was negligible. Root length had highest positive indirect effect on grain yield via root volume. These results indicated that root play a pivotal role in improving grain yield. Yield displayed highest H 2BS, where as Δ 13C displayed moderate heritability among the germplasm accessions.
  • Authors:
    • Muthukrishnan, P.
    • Fanish, S. A.
  • Source: Madras Agricultural Journal
  • Volume: 98
  • Issue: 7/9
  • Year: 2011
  • Summary: Field experiment was conducted at farmer's field at Palani taluk of Dindigul district in Tamil Nadu during kharif 2008 with the objective of evaluating the drip fertigation on water saving and Water Use Efficiency (WUE) in intensive maize based intercropping system. The experiment was laid out in strip plot design with three replications. The experiment consisted of 9 fertigation levels in main plot and 4 intercrops in sub plot. Among the different fertigation levels, higher maize grain yield of 7300 kg ha-1 was recorded under drip fertigation of 100 per cent RDF with 50 per cent P and K through water soluble fertilizer (WSF) followed by application of 150 per cent RDF through drip (7050 kg ha -1). The yield increase over drip irrigation with soil application of fertilizer was 39 per cent. Drip irrigation helped to save water up to 43.65 per cent compared to surface irrigation method. Among the different intercrops tested, higher WUE of 21.0 kg ha -1 mm -1 was observed under maize+vegetable coriander intercropping system.
  • Authors:
    • Gill, M. S.
    • Bhale, V. M.
    • Deshmukh, M. S.
    • Narkhede, W. N.
    • Gadade, G. D.
    • More, S. S.
  • Source: Indian Journal of Agronomy
  • Volume: 56
  • Issue: 2
  • Year: 2011
  • Summary: A field experiment was conducted for three consecutive years (2005-2007) at Parbhani to find out most productive and profitable cropping system. Among the different cropping systems, highest wheat [( Triticum aestivum L.) emend. Fiori & Paol] equivalent yield (19.9 t/ha) and net monetary returns (Rs 107.8*10 3/ha) were obtained from soybean [ Glycine max (L. Merr.)]-onion ( Allium capa L.) cropping system, followed by turmeric ( Curcuma domestica L.)+castor ( Ricinus communis L.) (WEY-14.0 t/ha, and NMR Rs 89.8*10 3/ha). The soybean-onion system also recorded maximum net monetary advantage per unit time (Rs 573/ha/day), employment (374 mandays) and water use efficiency (221 kg/ha-cm), followed by turmeric+castor intercropping system. The highest nutrient uptake was recorded in sorghum [ Sorghum bicolor (L.) Moench]-wheat followed by maize ( Zea mays L.)+cow-pea ( Vigna sinensis L.)-wheat and maize-wheat cropping systems. The highest soil nutrient status was observed in cotton ( Gossypium sp.)-summer groundnut ( Arachis hypogaea L.) followed by soybean-onion cropping systems.
  • Authors:
    • Amarasekera, P.
    • Sangakkara, U. R.
    • Stamp, P.
  • Source: Acta Agronomica Hungarica
  • Volume: 59
  • Issue: 2
  • Year: 2011
  • Summary: Maize is the most important upland cereal in tropical Asia, grown in both major and minor seasons under rainfed conditions. Due to the inadequate rainfall in the minor season, the crop is subjected to water stress, and irrigation helps to produce high yields. Smallholders who grow maize on flat beds in their allotments often use surface flood irrigation whenever irrigation water is available, which leads in most instances to inefficient use of this valuable resource. A field study was carried out over two minor seasons in Sri Lanka to determine the impact of different schedules of irrigation, developed on the basis of time intervals (3-, 7-, 14- or 21-day intervals or no irrigation as a control), which can easily be practised by smallholders, on the root development, shoot growth, seed yield and water use efficiency of maize. Irrigation at 3-day intervals produced fine roots in the top layers of the soil. Increasing the time interval between irrigation schedules to 7, 14 or 21 days reduced the percentage of fine roots, but developed more, heavier roots in the lower soil layers, as determined by root length densities (RLD) and root weight densities (RWD). Longer irrigation intervals or lack of irrigation resulted in a smaller number of heavier roots in the soil profile. The leaf water potential was affected to a greater degree than shoot water content or relative water content. The seed yield and harvest index were highest when maize was irrigated at 7-day intervals. In contrast, irrigation water use efficiency (IWUE) was highest at an irrigation interval of 14 days. The potential for optimizing water use in surface irrigation in flat beds while obtaining high yields in a tropical Asian minor season, when maize is subjected to moisture stress under smallholding conditions, is presented on the basis of this study.
  • Authors:
    • Cella, A. J. S.
    • Ferraz, E. de C.
    • Barros, H. B.
    • Santos, E. R. dos
    • Capone, A.
    • Santos, A. F. dos
    • Fidelis, R. R.
  • Source: Revista Ceres
  • Volume: 58
  • Issue: 6
  • Year: 2011
  • Summary: The genetic diversity is one of the most important parameters evaluated by plant breeders in the early stages of a genetic improvement program. The objective of this paper was to evaluate the genetic divergence by means of multivariate techniques, among 48 soybean genotypes grown in irrigated lowland in the State of Tocantins, in order to select parents of hybrids for the production of oil and meal, as well as varieties of the panel, intended for human consumption. The experiment was conducted in the county Formoso do Araguaia - Tocantins, Brazil, in the cultivation of irrigated lowland, in the inter-cropping 2010. The experimental design was a randomized block with four replications. There was observed variability among the genotype tested. The Tocher's method, UPGMA and Canonic Variables agreed among themselves, and found four distinct groups. The following hybrids are promising for the production of soybean oil and meal for the M-Soy 8766, M-Soy 9144, A-7002 and M-soy 9056 with Amaralina RR crosses between and M-Soy 8766, M-Soy 9144 and Amaralina RR with BRSMG 790A, BRS 257, BRS 216 and BRS 213, are listed in order especially soybeans for human consumption.
  • Authors:
    • Aster, D.
    • Awulachew, S. B.
    • Erkossa, T.
  • Source: Agricultural Sciences
  • Volume: 2
  • Issue: 3
  • Year: 2011
  • Summary: Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the sub-Saharan Africa's (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by poor soil, water and crop management practices. This study simulated the water productivity of the crop under varying soil fertility scenarios (poor, near optimal and none limiting) using hybrid seeds under rainfed conditions using the FAO Aqua-Crop model. The result indicated that grain yield of maize increased from 2.5 tons.ha -1 under poor to 6.4 and 9.2 tons.ha -1 with near optimal and non-limiting soil fertility conditions. Correspondingly, soil evaporation decreased from 446 mm to 285 and 204 mm, while transpiration increased from 146 to 268 and 355 mm. Consequently, grain water productivity was increased by 48% and 54%, respectively, with the near optimal and non-limiting soil fertility conditions. The water productivity gain mainly comes from reduced evaporation and increased transpiration without significantly affecting water left for downstream ecosystem services. Therefore, this has a huge implication for a basin scale water management planning for various purposes.
  • Authors:
    • Elazegui, D. D.
    • Chupungco, A. R.
    • Nguyen, M. R.
  • Source: Philippine Journal of Crop Science
  • Volume: 36
  • Issue: 2
  • Year: 2011
  • Summary: This study discusses the seed system, production and marketing of eggplant, Solanum melongena L., considered as one of the most important vegetable crops in the Philippines. Data analyzed were obtained from focus group discussions in major eggplant producing provinces of Pangasinan, Batangas and Quezon; key informant interviews with representatives of government agencies and seed companies, and traders; and secondary sources such as government reports and other publications. The eggplant seed system is generally organized, involving public and private sectors. There are different varieties available in the market but seed developers do not opt for seed registration nor plant variety protection because of the rigorous process involved. Instead, seed companies adopt well-established seed production and quality control strategies and vigorous marketing and promotion to improve sales. Commercial growers of eggplant adopt hybrid seeds, while open-pollinated varieties (OPVs) are mainly used for small-scale production. Between 2000 and 2009, eggplant production increased by 21% despite a relatively lower increase (6%) in area planted. Average yield ranged 8-10 mt ha -1. Eggplant production is profitable, but major problems include fruit and shoot borer (FSB) infestation, bacterial wilt, irrigation supply and climate-related problems. Production involves intensive use of pesticides, bearing some implications on human health and environment. This should call the attention of Local Government Units which are in the forefront of providing extension services. Moreover, research and development should continuously receive adequate support to address these concerns. Research and development thrusts could include varietal improvement of eggplant and alternative pest control strategies such as integrated pest management (IPM) technology and intercropping. The current effort on R & D of Bt eggplant addresses the problem of FSB and heavy dependence of farmers on pesticides. With the stringent regulatory system of the Philippines on the commercial propagation of GM crops, adverse impact on human health and environment will be curtailed.
  • Authors:
    • Rao, I. M.
    • Schmidt, A.
    • van der Hoek, R.
    • Bernasconi, S. M.
    • Frossard, E.
    • Douxchamps, S.
    • Oberson, A.
  • Source: Plant and Soil
  • Volume: 341
  • Issue: 1-2
  • Year: 2011
  • Summary: The integration of multipurpose legumes into low-input tropical agricultural systems is needed because they are a nitrogen (N) input through symbiotic fixation. The drought-tolerant cover legume canavalia (Canavalia brasiliensis) has been introduced for use either as forage or as a green manure into the crop-livestock system of the Nicaraguan hillsides. To evaluate its impact on the subsequent maize crop, an in-depth study on N dynamics in the soil-plant system was conducted. Microplots were installed in a 6-year old field experiment with maize-canavalia rotation. Direct and indirect (15)N-labelling techniques were used to determine N uptake by maize from canavalia residues and canavalia-fed cows' manure compared to mineral fertilizer. Litter bags were used to determine the N release from canavalia residues. The incorporation of N from the amendment into different soil N pools (total N, mineral N, microbial biomass) was followed during the maize cropping season. Maize took up an average of 13.3 g N m(-2), within which 1.0 g N m(-2) was from canavalia residues and 2.6 g N m(-2) was from mineral fertilizer, corresponding to an amendment N recovery of 12% and 32%, respectively. Recoveries in maize would probably be higher at a site with lower soil available N content. Most of the amendment N remained in the soil. Mineral N and microbial N were composed mainly of N derived from the soil. Combined total (15)N recovery in maize and soil at harvest was highest for the canavalia residue treatment with 98% recovery, followed by the mineral fertilizer treatment with 83% recovery. Despite similar initial enrichment of soil microbial and mineral N pools, the indirect labelling technique failed to assess the N fertilizer value of mineral and organic amendments due to a high N mineralization from the soil organic matter.