• Authors:
    • Kumari, S.
  • Source: Journal of Agricultural Science
  • Volume: 4
  • Issue: 1
  • Year: 2012
  • Summary: This study critically assessed the influence of frequent availability of water i. e. drip irrigation and mulch on optimum leaf area development of potato that control light interception and soil moisture conservation. Crop growth was stimulated in terms of early pick up of leaf areas that quickly covered the ground and improved transpiration efficiency. Drip irrigation increased water use efficiency three times as compared with furrow irrigation (conventional method of irrigation). Black Polyethylene mulch (25 m) conserved soil moisture, raised soil temperature by 9degreesC, stimulated shoot, solon and root growth, increased the total tuber number and yield but reduced the grade of tubers. Drip irrigation may prove a viable tool for source-sink alteration; stimulating early stolon initiation combined with ability to quick ground cover and sustained leaf growth for new tuber initiation for seed production as well as extended tuber bulking of early formed tubers for obtaining maximum yield with 50% saving of irrigation water and efficient use of nitrogen fertilizer.
  • Authors:
    • Sauer, T.
    • Soolaneyakanahally, R.
    • de Gooijer, H.
    • Bentrup, G.
    • Schoeneberger, M.
    • Brendle, J.
    • Zhou, X.
    • Current, D.
  • Source: Journal of Soil and Water Conservation
  • Volume: 67
  • Issue: 5
  • Year: 2012
  • Authors:
    • Holou, R. A. Y.
    • Stevens, G.
  • Source: GCB (Global Change Biology) Bioenergy
  • Volume: 4
  • Issue: 3
  • Year: 2012
  • Summary: The objective of this research was to determine the optimum nitrogen fertilizer rate for producing sweet sorghum (a promising biofuel crop) juice, sugar, and bagasse on silt loam, sandy loam, and clay soils in Missouri. Seven nitrogen fertilization rates were applied, ranging from 0 to 134 kg N ha -1. Regardless of the soil and year, the juice content of sweet sorghum stalk averaged 68.8% by weight. The juice yield ranged from 15.2 to 71.1 m 3 ha -1. Soil and N rate significantly impacted the juice yield ( P
  • Authors:
    • Finlay, L. A.
    • Hulugalle, N. R.
    • Weaver, T. B.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 27
  • Issue: 2
  • Year: 2012
  • Summary: Cover crops in minimum or no-tilled systems are usually killed by applying one or more herbicides, thus significantly increasing costs. Applying herbicides at lower rates with mechanical interventions that do not disturb or bury cover crop residues can, however, reduce costs. Our objective was to develop a management system with the above-mentioned features for prostrate cover crops on permanent beds in an irrigated Vertisol. The implement developed consisted of a toolbar to which were attached spring-loaded pairs of parallel coulter discs, one set of nozzles between the individual coulter discs that directed a contact herbicide to the bed surfaces to kill the cover crop and a second set of nozzles located to direct the cheaper glyphosate to the furrow to kill weeds. The management system killed a prostrate cover crop with less trafficking, reduced the use of more toxic herbicides, carbon footprint, labor and risk to operators. Maximum depth of compaction was more but average increase was less than that with the boom sprayer control.
  • Authors:
    • Jensen, C. R.
    • Jacobsen, S. -E
    • Liu, F.
  • Source: Field Crops Research
  • Volume: 128
  • Year: 2012
  • Summary: The aim of the present review is to highlight the possibilities of a sustainable crop production in the arid Mediterranean region, which is predicted to suffer from increasingly severe droughts in the future due to climate changes, in addition to increased problems with soil salinity and increased temperatures. Annual rainfall in the region varies between 300 and 1000 mm, covering arid, semi-arid and wet ecosystems. As stress factors often act together, it is important sometimes to focus on multiple stresses affecting the crop, instead of looking at the individual stress separated from the rest. The rainfed farming systems are the most important in the Mediterranean countries. The question is if we can overcome mild to medium level of abiotic stresses by agronomic means. It might be done by using different crops of increased drought and salinity tolerance, and utilizing their stress adaptation mechanisms to optimize crop productivity. However supplemental irrigation used as deficit irrigation has the potential to overcome periods of low rainfall or high temperatures. It is suggested that improvements in crop production may arise from several strategies such as early sowing enabled by minimum tillage, increased use of organic manure, and an efficient weed control. Further, crop rotations will play an important role in improving weed control, minimizing disease risk, and increasing nitrogen availability. Introduction of drought and salt tolerant crop species as quinoa, amaranth and Andean lupin may result in more resilient crop rotations and high value cash crop products. Genotypic increases may arise from selection for early vigour, deep roots, increased transpiration efficiency, improved disease resistance, and high assimilate storage and remobilization. A range of crop and management strategies might be combined for a specific target environment in order to optimize crop productivity. These combinations can then be used as a guidance to future decision support systems for crop production at limited water supply under arid Mediterranean conditions. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Baetens, J. M.
    • Vandepitte, J.
    • Audenaert, K.
    • Waegeman, W.
    • Landschoot, S.
    • De Baets, B.
    • Haesaert, G.
  • Source: Journal of Plant Pathology
  • Volume: 94
  • Issue: 1
  • Year: 2012
  • Summary: Models for predicting Fusarium head blight (FHB) and deoxynivalenol (DON) content in wheat provide farmers with a tool for preventing yield loss and mycotoxin contamination. Due to the complex nature of FHB, these models typically take only a subset of explanatory variables as inputs, such as weather conditions during anthesis and, to a lesser extent, field-specific variables and crop characteristics. We present a thorough statistical analysis of a broad spectrum of variables that affect FHB and DON content, using an unique database of field observations covering nine years. This study unveils new variables that play an important role in FHB incidence and DON content. Evidence is brought forward demonstrating the effect of species interactions on DON content and the effect of weather conditions during the vegetative growth stage. Indeed, temperature from November till May was positively correlated with FHB and DON content, whereas relative humidity was negatively correlated with DON content in November and December. In a broader view of the divergent results obtained regarding FHB and DON content in wheat crops, this study underscores that the prediction of FHB and DON content should be seen as two distinct goals.
  • 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:
    • Tivet, F.
    • Khamxaykhay, C.
    • Rattanatray, B.
    • Jullien, F.
    • Quoc, H. T.
    • Lestrelin, G.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 27
  • Issue: 1
  • Year: 2012
  • Summary: Over the past half-century, major efforts have been made worldwide to develop sustainable alternatives to agricultural tillage. In line with these efforts, two main research development initiatives have supported the experimentation and dissemination of conservation agriculture (CA) in Laos. Here we present the results of a 4-year monitoring and evaluation study conducted in 21 villages targeted for dissemination. In a context of rapid transition to intensive commercial agriculture in Laos, CA has become an important constituent of agricultural landscapes. However, there are significant variations in adoption rates across the study region. Statistical and qualitative evidence suggests that experimentation and adoption are not contingent upon farm-level variables such as capital, labor, age and education. While access to land helps shape local decision-making, the land tenure threshold under which farmers are not willing to experiment with alternative cropping systems is relatively low and highly variable in both space and time. Rather, experience and awareness of land degradation, production costs, social cohesion and leadership appear to be key factors in explaining most variations in local adoption rates. These results indicate that the practice of CA is not necessarily incompatible with smallholder farming. However, while complex crop associations and rotations are necessary for integrated weed control and reduced chemical use, their diffusion would require a broader transformation of the agricultural industry and the current market demand.
  • Authors:
    • Rocha, H. S.
    • Souza, A. P. de
    • Carvalho, D. F. de
    • Lima, M. E. de
    • Guerra, J. G. M.
  • Source: Revista Brasileira de Engenharia Agrícola e Ambiental
  • Volume: 16
  • Issue: 6
  • Year: 2012
  • Summary: This study was carried out in the municipality of Seropedica-RJ, in order to determine, under organic farming and no tillage system, the yield of eggplants under different irrigation depths and cropping systems (intercropped with legumes and alone). The experimental design was in randomized blocks in a split plot design with four replications. The plots were characterized by the treatments corresponding to different water depths (40, 70, 100, 120% ETc), and the sub plots, the intercropping systems with cowpea and eggplant alone. Cropping systems did not influence the final yield of eggplant. However, considering the different irrigation depths, the highest commercial yield (65.41 Mg ha -1) was obtained for a total depth of 690.04 mm (106.8% ETc). The lower applied depth provided lower quality of fruit compared with that observed in the higher depths. The rate of fruit discard was 3 and 14%, respectively, for the higher and lower depths of irrigation.
  • Authors:
    • Darshana
    • Pandey, A.
    • Pandey, R. P.
    • Ostrowski, M.
  • Source: Irrigation and Drainage
  • Volume: 61
  • Issue: 2
  • Year: 2012
  • Summary: In this study, simulation and optimization models were assembled for the optimization of irrigation systems and their operation. The simulation model CROPWAT was used for estimation of the crop water requirement, time and depth. The evolutionary algorithm (GANetXL) was used for the optimal planning of cropping pattern, maximization of net benefits and minimization of irrigation water requirements for the study area of Holeta catchment, Ethiopia. The study area encompasses three command areas, i.e. farm A, farm B and Tsedey State Farm, and five different type of crops, i.e. potato, tomato, apple, peach and winter wheat. The simulation results of the CROPWAT model illustrated that crop water requirement for apple was highest (993 mm), followed by peach (908 mm), tomato (470 mm), potato (443 mm) and wheat (294 mm). The study reveals that fruit crops have more crop water requirements than cereals. The results of the GANetXL show that when the cropped area and water allocated was varied between extreme values, 23% of water can be saved. The total benefit from the study area can be enhanced by USD 34 ha -1 and can be helpful in improving the economic conditions of the farmers.