• Authors:
    • Mahajanashetti, S. B.
    • Kunnal, L. B.
    • Basavaraja, H.
    • Acharya, S. P.
    • Bhat, A. R. S.
  • Source: Agricultural Economics Research Review
  • Volume: 24
  • Issue: 2
  • Year: 2011
  • Summary: The nature and extent of crop diversification in the Karnataka state has been analyzed by collecting secondary data for a period of 26 years from 1982-83 to 2007-08. Composite Entropy Index (CEI) and multiple linear regression analysis have been used to analyze the nature and extent of crop diversification in the state. The CEI for different crop groups has shown that almost all the crop groups have higher crop diversification index during post-WTO (1995-96 to 2007-08) than during pre-WTO (1982-83 to 1994-95) period, except for oilseeds and vegetable crops. There has been a vast increase in diversification of commercial crops after WTO. Crop diversification is influenced by a number of infrastructural and technological factors. The results have revealed that crop diversification influences production. The study has suggested that the creation of basic infrastructural facilities like sustained supply of irrigation water, markets, fertilizer availability, proper roads and transportation is an essential pre-requisite for creating enabling conditions for fostering the process of agricultural development and crop diversification, as most of these parameters are found to influence the nature and extent of crop diversification.
  • Authors:
    • Tello-Marquina, J. C.
    • Gómez-Vázquez, J.
    • Santos-Hernández, M.
    • Pérez-Vargas, M.
    • Palmero, D.
    • de Cara, M.
  • Source: Acta Horticulturae
  • Issue: 914
  • Year: 2011
  • Summary: Cherry tomato crops were introduced in the late 1990s in the continental areas of southeast Spain. These fields had been previously cultivated with dry land crops as grapevine, olive, and cereal. After two years of cultivation, different soil-borne diseases widely appeared. The main disease observed was the root rot caused by Phytophthora parasitica, killing the plants during harvest period, concurring with the maximum demand of water from plants. The importance of the mycosis in the area together with the lack of control were the aim to first search for the inoculum sources, and then study the preservation of this oomycete in the infested soils for a long period time. Regarding the inoculum sources, no Phytophthora was found in seeds or seedlings from commercial nurseries sampled from the studied area, but the pathogen was isolated from the irrigation pools. Phytophthora parasitica was also isolated from the soils of the home gardens within the surrounded area, and even from the wheels of the tractors used in these fields. About the preservation study, a total of 92 samples from 42 different fields naturally infested with P. parasitica were analysed. All samples have been kept under laboratory conditions in sealed plastic bags. Only 20.58% of all samples preserved the oomycete for 4 years (48 months), and 18.18% for 5 years (57 months). These results can explain the rapid dissemination of the disease and its difficult control in the area.
  • Authors:
    • Aibar, J.
    • Cirujeda, A.
    • Zaragoza, C.
  • Source: Agronomy for Sustainable Development
  • Volume: 31
  • Issue: 4
  • Year: 2011
  • Summary: Management practices, geographical gradients and climatic factors are factors explaining weed species composition and richness in cereal fields from Northern and Central Europe. In the Mediterranean area, the precise factors responsible for weed distribution are less known due to the lack of data and surveys. The existence of weed survey data of year 1976 in the Zaragoza province of the Aragon region, Spain, offered us the opportunity to compare present weed species with weed species growing 30 years ago. No detailed comparison of changes in weed species composition in cereal fields in that period of time has been conducted in the Mediterranean area. Here a survey was conducted in the Aragon region from 2005 to 2007. Weeds were surveyed in 138 winter cereal fields in ten survey areas where winter cereals are the main crops, using the same methodology applied 30 years ago. In the Zaragoza province, 36 fields were chosen in the same municipalities than in the previous survey. Several management, geographic and climatic variables of each field were recorded and related to weed species with multivariate analysis. Diversity index were calculated and related to survey area and altitude. Our results show that out of the 175 species only 26 species were found in more than 10% of the surveyed fields. The main species were Papaver rhoeas, Lolium rigidum, Avena sterilis and Convolvulus arvensis found in more than half of the surveyed fields. L. rigidum was related to dryland, while the other species were found overall. Furthermore, we found that management, geographical and climatic factors were significantly related to weed species distribution. In particular altitude, survey areas, irrigation and herbicide use in post-emergence were the most driving factors explaining weed species distribution. Species richness was higher in survey areas with extensive management practices and increased with altitude excepting a very productive area with intensive management practices at high altitude where richness was as low as in the irrigated lowlands. The main differences found between the 1976 and the 2005-2007 surveys were (1) the striking increase of grass weeds, (2) the high decrease of mean weed species number found in each field declining from 9 to 3 and (3) the frequency decrease of many weed species probably caused by agriculture intensification in that period of time. The growing importance of other weed species is probably related to their adaptation to minimum tillage, which is a widespread technique nowadays.
  • Authors:
    • Lawn, R. J.
    • Gaynor, L. G.
    • James, A. T.
  • Source: Crop & Pasture Science
  • Volume: 62
  • Issue: 12
  • Year: 2011
  • Summary: The response of irrigated soybean to sowing date and to plant population was evaluated in field experiments over three years at Leeton, in the Murrumbidgee Irrigation Area (MIA) in southern New South Wales. The aim was to explore the options for later sowings to improve the flexibility for growing soybean in double-cropping rotations with a winter cereal. The experiments were grown on 1.83-m-wide raised soil beds, with 2, 4, or 6 rows per bed (years 1 and 2) or 2 rows per bed only (year 3). Plant population, which was manipulated by changing either the number of rows per bed (years 1 and 2) or the within-row plant spacing (year 3), ranged from 15 to 60 plants/m 2 depending on the experiment. Two sowings dates, late November and late December, were compared in years 1 and 3, while in year 2, sowings in early and late January were also included. Three genotypes (early, medium, and late maturity) were grown in years 1 and 2, and four medium-maturing genotypes were grown in year 3. In general, machine-harvested seed yields were highest in the November sowings, and declined as sowing was delayed. Physiological analyses suggested two underlying causes for the yield decline as sowing date was delayed. First and most importantly, the later sown crops flowered sooner after sowing, shortening crop duration and reducing total dry matter (TDM) production. Second, in the late January sowings of the medium- and late-maturing genotypes, harvest index (HI) declined as maturity was pushed later into autumn, exposing the crops to cooler temperatures during pod filling. Attempts to offset the decline in TDM production as sowing was delayed by using higher plant populations were unsuccessful, in part because HI decreased, apparently due to greater severity of lodging. The studies indicated that, in the near term, the yield potential of current indeterminate cultivars at the late December sowing date is adequate, given appropriate management, for commercially viable double-cropping of soybean in the MIA. In the longer term, it is suggested that development of earlier maturing, lodging-resistant genotypes that retain high HI at high sowing density may allow sowing to be delayed to early January.
  • 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:
    • Galusha, T. D.
    • Jackson, D. S.
    • Mason, S. C.
    • Griess, J. K.
    • Pedersen, J. F.
    • Yaseen, M.
  • Source: Crop Science
  • Volume: 51
  • Issue: 4
  • Year: 2011
  • Summary: Grain processors would benefit from information about the production environment and the influences of the sorghum [ Sorghum bicolor (L.) Moench] hybrid on food-grade flour properties. The objective of this study was to determine the effects of environment and hybrid on rapid-visco-analysis (RVA) flour properties of commercially available food-grade sorghum. A randomized complete block experiment was planted in 12 environments, which included the 2004 and 2005 growing seasons and irrigated and dryland water regimes in eastern, central, and west central Nebraska, and a dryland, low-N environment in eastern Nebraska. The environment accounted for 71-85% of the total variation in RVA parameters, while the hybrid accounted for 11-23% and the environment-by-hybrid interaction, 1-3%. Unfortunately, the results of this experiment suggest that it is difficult to predict the effect that environment will have on resulting sorghum-flour parameters. Although of secondary importance in terms of total variation in sorghum-flour RVA properties, the choice of hybrid predictably and significantly contributes to sorghum-starch viscosity properties. Food-grade hybrids were grouped based on viscosity properties into those best suited for dry-mill and alkaline-cooked products (Asgrow Orbit; Sorghum Partners NK1486) and those best suited for porridge, consumable alcohol, and ethanol production (Kelly Green Seeds KG6902; NC+ Hybrids 7W92; Asgrow Eclipse; and Fontanelle W-1000). These results were consistent with those previously reported for grain density.
  • Authors:
    • Kalamkar, S. S.
  • Source: Agricultural Economics Research Review
  • Year: 2011
  • Summary: District-wise growth and the reasons behind stagnation in the productivity of important agricultural crops in Maharashtra are considered. Secondary data for the period 1960/61 - 2004/05 is used to analyse the growth pattern of production and productivity, and the regional variations of stagnation for cereals, pulses, oilseeds, cotton and sugarcane. Agricultural growth constraints are identified and district-level interventions to overcome the problems of stagnation are suggested. Measures for growth in TFP are recommended that include watershed development and rainwater harvesting, the supply of good quality inputs, greater research into increasing crop yields, and flexible credit facilities. Greater horticultural production and irrigation, and the development of drought-resistant, high yielding variables more suited to the agro-climate of the State are also suggested.
  • 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:
    • Bueckert, R.
    • Gan. Y.T.
    • Liu, L. P.
    • Rees, K. van
  • Source: Field Crops Research
  • Volume: 122
  • Issue: 3
  • Year: 2011
  • Summary: Oilseed and pulse crops have been increasingly used to diversify cereal-based cropping systems in semiarid environments, but little is known about the root characteristics of these broadleaf crops. This study was to characterize the temporal growth patterns of the roots of selected oilseed and pulse crops, and determine the response of root growth patterns to water availability in semiarid environments. Canola ( Brassica napus L.), flax ( Linum usitatissimum L.), mustard ( Brassica juncea L.), chickpea ( Cicer arietinum L.), field pea ( Pisum sativum L.), lentil ( Lens culinaris), and spring wheat ( Triticum aestivum L.) were tested under high- (rainfall+irrigation) and low- (rainfall only) water availability conditions in southwest Saskatchewan, in 2006 and 2007. Crops were hand-planted in lysimeters of 15 cm in diameter and 100 cm in length that were installed in the field prior to seeding. Roots were sampled at the crop stages of seedling, early-flower, late-flower, late-pod, and physiological maturity. On average, root length density, surface area, diameter, and the number of tips at the seedling stage were, respectively, 41, 25, 14, and 110% greater in the drier 2007 than the corresponding values in 2006. Root growth in all crops progressed rapidly from seedling, reached a maximum at late-flower or late-pod stages, and then declined to maturity; this pattern was consistent under both high- and low-water conditions. At the late-flower stage, root growth was most sensitive to water availability, and the magnitude of the response differed between crop species. Increased water availability increased canola root length density by 70%, root surface area by 67%, and root tips by 79% compared with canola grown under low-water conditions. Water availability had a marginal influence on the root growth of flax and mustard, and had no effect on pulse crops. Wheat and two Brassica oilseeds had greater root length density, surface area and root tips throughout the entire growth period than flax and three pulses, while pulse crops had thicker roots with larger diameters than the other species. Sampling roots at the late-flower stage will allow researchers to capture best information on root morphology in oilseed and pulse crops. The different root morphological characteristics of oilseeds, pulses, and wheat may serve as a science basis upon which diversified cropping systems are developed for semiarid environments.
  • Authors:
    • Bueckert, R.
    • Gan, Y. T.
    • Liu, L. P.
    • Rees, K. van
  • Source: Field Crops Research
  • Volume: 122
  • Issue: 3
  • Year: 2011
  • Summary: Root distribution patterns in the soil profile are the important determinant of the ability of a crop to acquire water and nutrients for growth. This study was to determine the root distribution patterns of selected oilseeds and pulses that are widely adapted in semiarid northern Great Plains. We hypothesized that root distribution patterns differed between oilseed, pulse, and cereal crops, and that the magnitude of the difference was influenced by water availability. A field experiment was conducted in 2006 and 2007 near Swift Current (50°15′N, 107°44′W), Saskatchewan, Canada. Three oilseeds [canola ( Brassica napus L.), flax ( Linum usitatissimum L.), mustard ( Brassica juncea L.)], three pulses [chickpea ( Cicer arietinum L.), field pea ( Pisum sativum L.), lentil ( Lens culinaris)], and spring wheat ( Triticum aestivum L.) were hand-planted in lysimeters of 15 cm in diameter and 100 cm in length which were pushed into soil with a hydraulic system. Crops were evaluated under low- (natural rainfall) and high- (rainfall+irrigation) water conditions. Vertical distribution of root systems was determined at the late-flowering stage. A large portion (>90%) of crop roots was mainly distributed in the 0-60 cm soil profile and the largest amount of crop rooting took place in the top 20 cm soil increment. Pulses had larger diameter roots across the entire soil profile than oilseeds and wheat. Canola had 28% greater root length and 110% more root tips in the top 10 cm soil and 101% larger root surface area in the 40 cm soil under high-water than under low-water conditions. In 2007, drier weather stimulated greater root growth for oilseeds in the 20-40 cm soil and for wheat in the 0-20 cm soil, but reduced root growth of pulses in the 0-50 cm soil profile. In semiarid environments, water availability did not affect the vertical distribution patterns of crop roots with a few exceptions. Pulses are excellent "digging" crops with a strong "tillage" function to the soil due to their larger diameter roots, whereas canola is more suitable to the environment with high availability of soil water that promotes canola root development.