• Authors:
    • Tabatabaei, B. E. S.
    • Maibody, S. A. M. M.
    • Arzani, A.
    • Golabadi, M.
    • Mohammadi, S. A.
  • Source: Euphytica
  • Volume: 177
  • Issue: 2
  • Year: 2011
  • Summary: Grain yield and yield components are the main important traits involved in durum wheat ( Triticum turgidum L.) improvement programs. The purpose of this research was to identify quantitative trait loci (QTL) associated with yield components such as 1000 grain weight (TGW), grain weight per spike (GWS), number of grains per spike (GNS), spike number per m 2 (SN), spike weight (SW), spike harvest index (SHI) and harvest index (HI) using microsatellite markers. Populations of F 3 and F 4 lines derived from 151 F 2 individuals developed from a cross between Oste-Gata, a drought tolerant, and Massara-1, a drought susceptible durum wheat genotypes, were used. The populations were evaluated under four environmental conditions including two irrigation regimes of drought stress at terminal growth stages and normal field conditions in two growing seasons. Two hundred microsatellite markers reported for A and B genomes of bread wheat were used for parental polymorphism analysis and 30 polymorphic markers were applied to genotype 151 F 2:3 families. QTL analysis was performed using genome-wide single marker regression analysis (SMA) and composite interval mapping (CIM). The results of SMA revealed that about 20% of the phenotypic variation of harvest index and TGW could be explained by Xcfd22-7B and Xcfa2114-6A markers in different environmental conditions. Similarly, Xgwm181-3B, Xwmc405-7B and Xgwm148-3B and marker Xwmc166-7B were found to be associated with SHI and GWS, respectively. A total of 20 minor and major QTL were detected; five for TGW, two for GWS, two for GNS, three for SN, five for HI, two for SHI and one for SW. The mapped QTL associated with ten markers. Moreover, some of these QTL were prominent and stable under drought stress and non drought stress environments and explained up to 49.5% of the phenotypic variation.
  • Authors:
    • Ganji, A.
    • Mousavi, S. F.
    • Lee, T. S.
    • Soom, M. A. M.
    • Salemi, H.
    • KamilYusoff, M.
  • Source: African Journal of Agricultural Research
  • Volume: 6
  • Issue: 10
  • Year: 2011
  • Summary: Simulation models that clarify the effects of water on crop yield, are useful tools for improving farm-level water management and optimizing water use efficiency. The main purpose of deficit irrigation is high water productivity with less water supply to plants. In this research, the potential of AquaCrop model in deficit irrigation practice for winter wheat, the main agronomic crop in Gavkhuni river basin, Isfahan province, Iran, was studied. The results of reliability indices such as RMSE, d, E, CRM and deviation percent were 2.31 to 5.63, 0.97 to 1.00, 93 to 99, -0.15 to 0.016 and -0.70 to 12.00% respectively, and showed that, the model overestimated the simulated parameters compared with field data. This difference was more obvious in deficit irrigation treatments. The model provided excellent simulations of canopy cover, grain yield and water productivity. Considering only drought stress and neglecting other stresses such as salinity is the most important limitation of AquaCrop model. In this study, water productivity for the studied crop was in the range of 0.91 to 1.49 kg m -3 and its maximum value was in 40% deficit irrigation treatment. A second-order, yield-water function, obtained in this study is recommended for winter wheat crop. Also, the sensitivity analysis of AquaCrop model was carried out for winter wheat in this arid area in central Iran.
  • 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:
    • Odhiambo, J. J. O.
  • Source: African Journal of Agricultural Research
  • Volume: 6
  • Issue: 1
  • Year: 2011
  • Summary: Much of the smallholder farming sector in Limpopo province of South Africa is located on infertile degraded soils, with nitrogen being one of the predominantly deficient nutrient. The use of green manure legume cover crops in combination with Nitrogen (N) fertilizers is one option for improving N inputs into such farming systems. The objectives of this study were to (1) screen a number of green manure legume cover crop species, mucuna (Mucuna pruriens); sunhemp (Crotalaria juncea), lab-lab (Lablab purpureus); cowpea (Vigna unguiculata) and butterfly pea (Clitoria ternatea) in order to determine their suitability for the region and (2) to determine the effect of the green manure and nitrogen fertilizer on maize yield. The legumes were screened during the winter seasons of 2005 and 2006 and the summer seasons of 2005 - 2006 and 2006 - 2007. The best-bet legumes (mucuna, sunhemp and lab-lab) were then evaluated to determine their effect on maize grain yield with or without nitrogen fertilizer. The treatments imposed were mucuna, sunhemp, lab-lab, and a control with (75 kg N ha(-1)) or without (0 kg N ha(-1)) N fertilizer. Maize was harvested at maturity to determine the grain yield. In the screening trials, legume biomass yield ranged between 41 to 1,672 kg ha(-1), while the N content ranged between 2 to 58 kg N ha(-1) in the winter trials. In the summer trials, biomass yield ranged from 899 to 13,586 kg ha(-1), while the N content ranged between 27 to 302 kg N ha(-1). Maize yield ranged between 4.0 to 6.4 tons ha(-1) in the 2006 - 2007 seasons and between 5.8 to 8.4 tons ha(-1) in the 2007 - 2008 season. Control (-N) treatment had the lowest yield in both seasons. Overall, legume treatments, with or without N fertilizers produced between 19 to 58% more grain yield than control (-N). Of the green manure legumes screened, mucuna, lablab and sunhemp seem to be the most suitable green manure legume cover crops for this area and should be planted in the early summer season to maximize biomass production and N accumulation. Use of green manure legumes has the potential to increase maize yield in smallholder farms in Limpopo province.
  • Authors:
    • Woltering, L.
    • Pasternak, D.
    • Nikiema, A.
    • Claude, Z.
    • Ryckewaert, P.
    • Ratnadass, A.
    • Thunes, K.
    • Zakari-Moussa, O.
  • Source: Acta Horticulturae
  • Issue: 917
  • Year: 2011
  • Summary: The agroecological approach to agroecosystem management relies on two pillars: vegetational diversification and soil biological activity enhancement. Although crop pests and their natural enemies may be diversely affected by measures derived from these principles, those generally result in increased agroecosystem resilience vis-a-vis both aerial and soil pests. Earlier studies by ICRISAT and CIRAD and their partners in West Africa showed the potential of the implementation of these principles for the management of some major pests of both staple food and horticultural crops, and their limitations for others, notably in the water-saving and income-generating systems mixing cereals, legumes, and high-value crops currently promoted in the Sudano-Sahelian zones, such as the drip irrigation-based African Market Garden (AMG) and the water harvesting-based Bio-Reclamation of Degraded Lands (BDL) systems. Pigeon-pea showed potential for trap-cropping tomato fruit worm (TFW) on okra, while Andropogon grass was dismissed for such management of stem-borer on pearl millet, and mixed results were obtained with castor bean and other potential trap crops for panicle-feeding bug management on sorghum. The results presented highlight the potential for mobilizing either aerial or soil-bound biological processes for managing fruit flies (FF), the main pest of grafted jujube tree, and leaf worm, the main pest of the Moringa tree, for sustainable production of these two major crops (in BDL and AMG systems, respectively), without having to rely on synthetic pesticide sprays. Studies on the social acceptability of the proposed management options (e.g., pigeon-pea in okra-based BDL) are also underway. The potential of the Jatropha shrub grown as a live-fence around these systems, either for its top-down effects or via the use of its extracts in an assisted push-pull strategy, is discussed. These studies on targeted pathosystems serve the dual purpose of finding solutions to local problems and contribute more globally to the design of pest resilient agrosystems.
  • Authors:
    • Fahandezh-Saadi, S.
    • Sepaskhah, A. R.
    • Zand-Parsa, S.
  • Source: Agricultural Water Management
  • Volume: 99
  • Issue: 1
  • Year: 2011
  • Summary: Simulation of crop yield allows better planning and efficient management under different environmental inputs such as water and nitrogen application. However, most of the models are complicated and difficult to understand. Furthermore, input data are not readily available. The objectives of this investigation were to use logistic equation to quantify the influence of seasonal water and nitrogen application on maize biomass accumulation and grain yield and to develop empirical models for prediction of maize biomass and grain yield. Logistic equations were fitted to dray matter (DM) yield at different times in the growing season at different irrigation water and nitrogen levels. The parameters of the logistic equations were then fitted to irrigation water and nitrogen as empirical functions. Further, the harvest index (HI) was related to the applied water and nitrogen as another empirical model. The empirical logistic models were used to estimate the DM and grain yield based on data from another experiment in the same area. Results indicated that the empirical models predicted the DM yield during the growing season with an acceptable accuracy, but dry matter (DM) prediction at harvest was very good. The grain yield also was predicted with a very good accuracy. It is concluded that logistic equation along with the presented empirical models for prediction of constants in logistic equation and HI are appropriate for accurate prediction of DM and grain yield of maize at the study region.
  • Authors:
    • Chai, Q.
    • Huang, G. B.
    • Yang, C. H.
    • Luo, Z. X.
  • Source: Field Crops Research
  • Volume: 124
  • Issue: 3
  • Year: 2011
  • Summary: A field experiment was carried out to investigate the effects of alternate irrigation (AI) on the yield, water use and water use efficiency (WUE) of wheat (Triticum aestivum L.)/maize (Zea mays L.) intercropping system in an oasis region of northwest China in 2006-2008. Three planting patterns, i.e., sole wheat, sole maize and wheat/maize intercropping. Three irrigation levels were applied for each treatment during 3 years. Results showed that land use efficiency of wheat and maize was significantly enhanced by intercropping system; land equivalent ratio (LER) of wheat/maize intercropping system in different treatments was all greater than 1.0. Moreover, significant difference in grain yield was observed between intercropping treatment and sole cropping treatment, in which the yield of intercropped wheat was 55.37-74.88% of sole wheat, and intercropped maize was 66.63-78.87% of sole maize. Wheat/maize intercropping treatments increased water use by 1.8-16.4% than half of the total water use of sole-cropping wheat and maize. Compared to sole cropping wheat treatments, wheat/maize intercropping with alternate irrigation significantly improved water use efficiency (WUE) by 30.5-57.7%, 55.5-71.4% and 12.0-19.8%, and increased by 32.7-37.8%, 9.5-15.8% and 4.0-20.8% than sole cropping maize treatments in 2006-2008, respectively. Our results suggest that AI should be a useful water-saving irrigation method on wheat/maize intercropping in arid oasis field where intercropping planting is decreased because of limited water resource.
  • Authors:
    • Mehla, R. S.
    • Punia, M.
    • Ladha, J. K.
    • Khurana, M. L.
    • Chandna, P.
    • Gupta, R.
  • Source: Environmental Monitoring & Assessment
  • Volume: 178
  • Issue: 1-4
  • Year: 2011
  • Summary: Increased use of nitrogenous fertilizers in the intensively cultivated rice (Oryza sativa)-wheat (Triticum aestivum) cropping system (covers a 13.5-ha m area in South Asia) has led to the concentration of nitrates (NO(3)-N) in the groundwater (GW) in Haryana State of India. Six districts from the freshwater zone were selected to identify factors affecting NO(3)-N enrichment in GW. Water and soil samples were collected from 1,580 locations and analyzed for their chemical properties. About 3% (26,796, and 10,588 ha) of the area was estimated to be under moderately high (7.5-10 mg l (-aEuro parts per thousand 1)) and high (> 10 mg l (-aEuro parts per thousand 1)) risk categories, respectively. The results revealed that NO(3)-N was 10-50% higher during the pre-monsoon season than in the monsoon season. Nitrate-N decreased with the increase in aquifer depth (r (2) = 0.99). Spatial and proximity analyses using ArcGIS (9.2) revealed that (1) clay material in surface and sub-surface texture restricts N leaching, (2) piedmont and rolling plains act as an N sink, and (3) perennial rivers bring a dilution effect whereas seasonal rivers provide favorable conditions for NO(3) (-) enrichment. The study concludes that chemical N fertilizers applied in agro-ecosystems are not the sole factor determining the NO(3) in groundwater; rather, it is an integrated process governed by several other factors including physical and chemical properties of soils, proximity and type of river, and geomorphologic and geographical aspects. Therefore, future studies should adopt larger area (at least watershed scale) to understand the mechanistic pathways of NO(3) enrichment in groundwater and interactive role of the natural drainage system and surrounding physical features. In addition, the study also presents a conceptual framework to describe the process of nitrate formation and leaching in piedmont plains and its transportation to the mid-plain zone.
  • Authors:
    • Finetto, G. A.
  • Source: Acta Horticulturae
  • Issue: 890
  • Year: 2011
  • Summary: Afghanistan can be considered the country of the pomegranate fruit because of the excellent quality of the cultivars that thrive there. Afghanistan is a land for 48 leading world cultivars of pomegranate commonly growing in Kandahar, Kapisa, Samangan, Farha, Nenroz and Balkh Provinces. Kandahar Province has historically, widely been known as main production area for its high quality and productivity. Other pomegranate orchards are located along the Arghandab River. Pomegranate ranks 5th after grapes, almond, apricot and apple. The area has decreased from 5667 ha (1996) to 2500 ha (2003). The average yields are in the range of about 8600 kg/ha in Dand district to more than 19000 kg/ha in Arghandab district. Although one estimate says the total production is around 24,000 Mt, a rational estimation is around 15-20,000 Mt, due to the poor production in some areas. Production in the Kandahar Province is approximately 10,000 metric tons; and the main cultivar is 'Kandahari'. Smaller volumes are produced elsewhere in Afghanistan. Elevation is the main restriction in production, with 'Bedana' produced in Nangarhar at or above 1000 m elevation. 'Kandahari' is produced at elevations from 550 m to below 1000 m. Up to now no collection of local cultivars has been carried out by the fruit tree projects funded by international organisations (EC, World Bank, FAO, USAID, DFID, ICARDA, etc.). To meet the high demand of the world market, Afghanistan must increase production levels and improve productivity through better husbandry of pomegranate orchards. In Afghanistan few are commercial orchards, commonly the farmers grow this fruit species in small plots with intercropping, due to very exiguous dimensions of farms (average 0.8 ha per household), dire needs of staple food for their families and an instable political situation. In spite of the good local cultivars few cultural practices such as irrigation, fertilisation, pruning, etc. are applied often in an unsteady way. Due to the health benefits of the fruit (anti-oxidant) several traders in Afghanistan have started to receive orders for pomegranate from outside their traditional markets in the Sub-Continent. So, locally the market for pomegranate does not compare with other more common fruits because the demand is growing rapidly. Pomegranate commercialisation has a typical supply chain that involves the following major players: Grower, Pre-harvest Contractor, Pakistani Importer/Financier, Packaging Company. From harvest to market, wooden baskets (typically 3 sizes, but without uniform size/weight), made of flexible pomegranate tree branches (1st or 2nd year shoots) are used. For export mostly wooden crates are used. Pomegranate is an ideal fresh fruit for Afghanistan to export as they come in a tough outer rind and have good storage properties. So, pomegranate should be considered as one of the most promising crops for support but refrigeration, postharvest handling and promotion should all be applied to this crop.
  • Authors:
    • Perri, E.
    • Ayadi, M.
    • Benincasa, C.
    • Gharsallaoui, M.
    • Khlif, M.
    • Gabsi, S.
  • Source: Scientia Horticulturae
  • Volume: 128
  • Issue: 1
  • Year: 2011
  • Summary: Nowadays, lots of efforts are made in Tunisia for the exploitation of wastewater in agriculture in order to face a very elevated mobilization of resources in water (90%). At Sfax, a Governorate placed in the South of Tunisia, the annual rainfall rarely exceeds 200 mm, so the climate is fairly arid. The significant water deficit can be reduced with the reuse of treated wastewater (TWW). The Sfax wastewater originated from the municipal wastewater treatment plant (WWTP) localized at 5 km in the south of Sfax, Tunisia. This WWTP is an aerated lagoon process receiving industrial wastewaters. Its treatment capacity is 24,000 m 3/day. Part of TWW is sent to the olive crops of El Hajeb, as part of a proposed wastewater use in agriculture. Already the wastewater is used to irrigate olive trees and intercrops such as cotton, oats and sorghum silage (Charfi et al., 1999). The aim of the present work was to determine the impact of the irrigation utilizing wastewater on the quality of the oil. The oils analysed were extracted from olives hand-picked directly from the tree and from olives that have fallen under the trees. Moreover, a study on the olive storage has been made in order to evaluate in which way the collection of the fruit could influence the quality of the oil. The results obtained showed that: - Olive trees benefit from this contribution of water; - irrigation by wastewater has a significant effect in the fatty acid composition; - oils relative to olive trees irrigated with wastewaters are more sensible to the oxidization especially after olive storage; - oils coming from olive trees irrigated with wastewaters are richer in polyphenols; - oils extracted from fallen olives are of poor quality essentially after olives storage and when olive trees are irrigated by wastewater.