• Authors:
    • Carbonell, R.
    • Perea, F.
    • González, P.
    • Rodríguez-Lizana, A.
    • Ordóñez-Fernández, R.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 79
  • Issue: 3
  • Year: 2007
  • Summary: With the aim of assessing the benefits of crop remains left on the soil surface, a study was carried out on the decomposition and characteristics of residue deposited on a clay soil in southern Spain during the agricultural seasons of 2001/02, 2002/03 and 2003/04, in which a legume-cereal-sunflower rotation was followed. Each of the residues studied possessed a characteristic justifying its inclusion in the rotation. The legume residue (Pisum sativum L. cv. Ideal) supplied the highest amount of nitrogen to the soil since, throughout its decomposition cycle, it lost 76.6% of its initial content in nitrogen, compared to the 48 and 56% of N released by wheat residues (Triticum durum L. cv. Amilcar) and sunflower (Helianthus annus L. cv. Sanbro), respectively. At the beginning of its decomposition cycle, the wheat residue had the lowest mass, and gave the most cover, with values of 65%, which was 8.6 and 20.2% more than the cover estimated for the pea and sunflower residues, respectively. The sunflower residue lasted longest, only losing 18% of its initial cover over 109 days of decomposition, compared to 47% for wheat and 53% for pea. The amount of carbon released was similar for the three residues and was around 500 kg ha(-1). The straw decomposition rates under our conditions indicate that the residue of the most common crops in the area under dry farming makes protection possible during the intercrop period.
  • Authors:
    • Bateman, G.
    • Jenkyn, J.
    • Gutteridge, R.
  • Source: Annals of Applied Biology
  • Volume: 150
  • Issue: 1
  • Year: 2007
  • Summary: Take-all disease ( Gaeumannomyces graminis var. tritici) in wheat crops is known to be suppressed by naturally occurring antagonistic fungi, closely related to the pathogen, that infect grasses and cereals. This form of suppression was re-investigated because of the changing importance and role of grass weeds and grass covers in arable farming. Natural populations of the competitive fungus Gaeumannomyces cylindrosporus, allowed to develop under rye-grass, were more effective than artificially introduced populations in suppressing the development of take-all in following wheat crops. To be effective, the antagonist needs to be present before the start of wheat cropping. Introducing G. cylindrosporus, but not G. graminis var. graminis (a potential antagonist that is faster growing), into a previous crop, or just after the previous crop, sometimes suppressed take-all, but the effect was small. It is concluded that, for any future attempts at biocontrol by these fungi, they should be introduced into a preceding crop not susceptible to take-all. Take-all inoculum in the soil should be at a minimum and effective hosts of the take-all pathogen must not be present as weeds or volunteers.
  • Authors:
    • Moravcikova, P.
    • Kuniak, L.
    • Hozova, B.
    • Gajdosova, A.
  • Source: Czech Journal of Food Sciences
  • Volume: 25
  • Issue: 6
  • Year: 2007
  • Summary: Water-insoluble beta-(1,3)-D-glucan (lichenan) was determined in 43 samples of various cereal (i.e., oats, barley, wheat, millet) and pseudocereal (i.e., buckwheat, amaranth) cultivars using a modified procedure with fungal alpha-amylase (Fermizyme P 300). The content of water-insoluble beta-glucan varied with dependence on the cereal species and cultivars. The highest content was observed in covered oat cultivars (Cyril and the new breeding cultivar PS-100), ranging from 26.7 to 28.2 g/100 g dry matter (d.m.), followed by less traditional cereals such as millet ( Panicum miliaceum), amaranth ( Amaranthus sp.), and buckwheat ( Fagopyrum) - more than 20 g/100 g d. m. A somewhat lower average content of water-insoluble beta-glucan was found in wheat - 12.7-16.2 g/100 g d. m., in spelt wheat - 8.5 g/100 g d. m., and in oats - varying between 15.3 and 18.7 g/100 g d. m.
  • Authors:
    • Marshall, A.
    • Mills, A.
    • Moot, D.
    • Edwards, G.
  • Source: Proceedings of the New Zealand Grassland Association
  • Volume: 69
  • Year: 2007
  • Summary: Lucerne sown immediately or after different forage crop sequences was investigated as a pasture option for post forestry conversion. In this experiment superphosphate and lime were applied in March 2005 before final seedbed preparation and establishment of seven cropping sequences; (1) lucerne sown in April 2005; (2-5) greenfeed cereals (oats or triticale) sown in April 2005 followed by lucerne in October 2005 with or without a rape cover crop; (6-7) winter fallow followed by glyphosate presowing in October 2005 or March 2006. After all crop sequences, lucerne was successfully established and provided 100% control of woody and annual weeds. Average lucerne dry matter (DM) yield was ~7.1 t DM/ha/yr for crops after a cereal. The last crop established also contained no woody weeds but produced 10.0 t DM/ha less over the 2 years due to the long (12 month) fallow. Lucerne sown in April 2005 had to be reestablished the following October. Thus, provided soil temperatures were adequate, lucerne was successfully spring and autumn sown after plantation forests. Lucerne offers flexibility for grazing or conserving in commercial conversions where internal fences and stock water supply are often, initially, inadequate for intensive pasture management.
  • Authors:
    • Davey, M. R.
    • Pua, E. C.
  • Source: Transgenic crops IV
  • Year: 2007
  • Summary: This volume is part of a book series that reviews the progress in cell and tissue culture and genetic transformation methodologies, and presents aspects of the molecular genetics of target crops and the practical applications of transgenic plants. The first 3 volumes cover crop biotechnology before 2001, whereas the last 3 volumes deal with the more recent advances in this field. This book focuses on cereals, vegetables, root crops, herbs and spices. Section I (one chapter) is an introductory chapter that places into perspective the impact of plant biotechnology on agriculture. Section II (7 chapters) focuses on cereals (rice, wheat, maize, rye, pearl millet, barley and oats), whereas section III (7 chapters) covers vegetables (tomato, cucumber, aubergine, lettuce, chickpea, Phaseolus vulgaris and cowpea, carrot and radish). Root crops (potato, cassava, sweet potato and sugarbeet) are included in section IV (5 chapters), whereas herbs and spices (sweet and hot peppers, onion, garlic and mint) are presented in section V (3 chapters). This volume is an invaluable reference for plant breeders, researchers and graduate students in the fields of plant biotechnology, agronomy, horticulture, genetics, and plant and cell biology.
  • Authors:
    • Bandyopadhyay, K. K.
    • Wanjari, R. H.
    • Manna, M. C.
    • Misra, A. K.
    • Mohanty, M.
    • Rao, A. S.
    • Ghosh, P. K.
  • Source: Journal of Sustainable Agriculture
  • Volume: 30
  • Issue: 1
  • Year: 2007
  • Summary: This article deals with the beneficial effect of important legumes on increasing productivity and nutrient use efficiency in various systems. Sorghum, pearl millet, maize, and castor are mainstay in dry lands and marginal and sub-marginal lands. Sorghum yield increased when sown after cowpea, green gram, and groundnut. Grain legumes like groundnut or cowpea provide an equivalent to 60 kg N ha on the subsequent crop of pearl millet. Various studies have shown that among legume/cereal intercropping system, the combination of maize/pigeon pea is considered to be highly suitable with a minimum competition for nutrients, while legume/legume intercropping system, pigeon pea/groundnut system is the most efficient one in terms of resource use-efficiency. In alley cropping system, Leucaena leucocephala (Subabul) prunings provide N to the extent of 75 kg, which benefits the intercrop castor and sorghum. Nitrogen economy through intercropped legume is still a researchable issue because the key point for leguminous crop grown in intercropping system is the problem of nodulation. Incorporation of whole plant of summer green gram/black gram into soil (after picking pods) before transplanting rice resulted in the economizing (40-60 kg N ha -1, 30 kg P 2O 5, and 15 kg K 2O per ha) of rice in rice-wheat system. Similarly, 6-8 weeks old green manure crop of sunhemp or dhaincha accumulates approximately 3-4 t ha -1 dry matter and 100-120 kg N ha -1 which, when incorporated in situ, supplements up to 50% of the total N requirement of rice. Legumes with indeterminate growth are more efficient in N 2 fixation than determinate types. Fodder legumes in general are more potent in increasing the productivity of succeeding cereals. The carryover of N for succeeding crops may be 60-120 kg in berseem, 75 kg in Indian clover, 75 kg in cluster bean, 35-60 kg in fodder cowpea, 68 kg in chickpea, 55 kg in black gram, 54-58 kg in groundnut, 50-51 kg in soyabean, 50 kg in Lathyrus, and 36-42 kg per ha in pigeon pea. Direct and residual effect of partially acidulated material and mixture of rock phosphate + single superphosphate were observed to be better when these were applied to green gram in winter season than to rice in rainy season simply because of legume effect.
  • Authors:
    • Olofsson,J.
    • Hickler,T.
    • Orloff,Steve B.
    • Klonsky,Karen M.
    • Livingston,Pete
  • Source: University of California Cooperative Extension Publication
  • Year: 2007
  • Authors:
    • Surek, D.
    • Karacam, M.
    • Meyvec, K.
    • Akar, T.
    • Avc, M.
  • Source: Wheat production in stressed environments. Proceedings of the 7th International Wheat Conference, Mar del Plata, Argentina, 27 November - 2 December, 2005
  • Year: 2007
  • Summary: Because most of the dryland cereal varieties were improved under fallow/cereal rotation system, their performances in other cropping systems were questionable and reported unsatisfactory by some farmers. Therefore, the objective of this study was to investigate the performances and adaptation of newly registered varieties in different two course rotations for targeted recommendations. 12 cereal varieties were tried on 9 different 23-year-crop rotations plots for three consecutive years, 1999/2000, 2000/2001, 2001/2002. The varieties were 4 barley (malting two rowed Aydanhanm, and feeding Tarm and six rowed Cetin and Avci), 4 durum wheat (Altn, Ankara, Altntas, and Ylmaz), and 4 bread (Dagdas, Gun, Krgz and Mzrak) wheat. The cereal varieties were rotated with fallow, wheat, winter vetch, winter lentil, sunflower, safflower, lentil, chickpea and barley/vetch mixture. Grain and biomass yields, plant height, harvest index, kernel per spike, kernel weight and spike number per square meter were traits determined. Biplot analysis showed that responses of cereal varieties varied in dry (2001), wet and cold (2000) and normal (2003) seasons. Overall evaluations of responses indicated that some varieties adapted more to certain rotations than other varieties such as Aydanhanm for Safflower/cereal rotation. There was a general tendency that Tarm and Gun varieties performed well in winter cold and dry seasons in all rotations. Dagdas yielded pretty well following winter legumes and winter legume/cereal mixture except dry season. Six rowed barleys, Altntas and Ylmaz, were better in mild winter season in all rotations. Traits correlations indicated that spike number per square meter was always positively correlated with grain yields for all experimental seasons. While all yield components had positive contribution to the grain yields in wet season, kernel weight and kernel per spike had negative contribution to grain yields in the dry season. General evaluation showed that cereals succeeding chickpea and spring lentil crops were leading in terms of height, biomass, harvest index and grain yields, except cereals following fallow which were exceptionally superior in dry season. They also had higher kernel weight in dry and normal seasons.
  • Authors:
    • Schumacher, R.
    • Schroeder, K.
    • Li, C.
    • Okubara, P.
    • Lawrence, N.
  • Source: Canadian Journal of Plant Pathology
  • Volume: 29
  • Issue: 3
  • Year: 2007
  • Summary: Soilborne pathogens are important biotic factors in yield reduction in the dryland cereal production region of the Pacific Northwest. Rhizoctonia solani AG-8, Rhizoctonia oryzae, and Pythium spp. are causal agents of root rot, bare patch, and damping-off of wheat ( Triticum aestivum) and barley ( Hordeum vulgare). Although these pathogens can be rapidly and specifically quantified using quantitative real-time PCR, the extraction of Rhizoctonia DNA from agricultural samples is often inconsistent, especially at low pathogen population densities. Using a novel extraction system that uses pressure cycling technology (PCT), we improved the extraction of R. solani AG-8 DNA up to 16-fold and of P. abappressorium DNA up to 2-fold from three types of agricultural soils compared with a bead beating extraction method. PCT also yielded quantifiable amounts of R. solani AG-8 and R. oryzae DNA from lyophilized wheat roots that were otherwise recalcitrant to homogenization. Furthermore, the extractions were so consistent that pathogen quantification generally could be derived from two rather than three or four replicated extracts. Because PCT is performed in a closed system and minimizes sample shearing and heating, it confers a substantial advantage over conventional extraction systems. Here, we report for the first time the application of PCT in a laboratory setting for the improved extraction and quantification of three types of soilborne pathogens in soil samples. The effectiveness of PCT for three soils suggests that it will be beneficial for other hard-to-extract pathogen samples.
  • Authors:
    • Avila, A.
    • Spera, S.
    • Tomm, G.
    • Santos, H.
  • Source: Bragantia
  • Volume: 66
  • Issue: 2
  • Year: 2007
  • Summary: The effects of soil management systems and crop rotations were assessed from 1997 to 2003, in Passo Fundo, Rio Grande do Sul State, Brazil. Four soil management systems (no-tillage, minimum tillage, conventional tillage using disc plough, and conventional tillage using mouldboard plough) and three crop rotation systems (system I (wheat/soyabean), system II (wheat/soyabean and common vetch/maize or sorghum), and system III (wheat/soyabean, common vetch/maize or sorghum and white oats/soyabean)) were compared. The main plot consisted of soil management systems, while the split-plots consisted of crop rotation systems. Energy conversion (energy available/energy consumed) and balance (energy available-energy consumed) during the seven-year period is presented. No-tillage resulted in higher energy conversion and balance (72.44 and 190 766 MJ/ha) than minimum tillage (64.06 and 167 349 MJ/ha), conventional tillage using disc plough (54.35 and 134 982 MJ/ha), and conventional tillage using mouldboard (52.02 and 128 159 MJ/ha), respectively. Wheat in crop rotations presented higher energy efficiency than that in monoculture. Maize had the highest energy efficiency among the crops.