• Authors:
    • Price, A.
    • Saini, M.
    • van Santen, E.
  • Source: 2005 Southern Conservation Tillage Systems Conference, Oral Proceedings, Clemson University
  • Year: 2005
  • Summary: An integral component of a conservation-tillage system in corn (Zea mays L.) and cotton (Gossypium hirsutum L.) is the use of a winter cover crop. A field experiment was initiated in 2002 to evaluate winter weed dynamics following various winter cover crops in both continuous cotton and a corn and cotton rotation. Winter cover crops included black oats (Avena strigosa Schreb.); two crimson clover entries (Trifolium incarnatum L.); two cultivars of forage rape (Brassica napus L. var. napus), spring and winter; oil radish (Raphanus sativus var. oleiformis Pers.); three cultivars of turnip ( Brassica rapa L. subsp. rapa); white lupin ( Lupinus albus L.); and a mixture of black oat and lupin. Two-year conservation-tillage rotational sequences included conventionally tilled continuous corn and cotton winter fallow systems as controls. The 10 conservation-tillage, winter cover-crop systems investigated were three continuous cotton systems that alternated a winter legume (lupin or clover), six cotton-corn systems, where lupin preceded cotton and radish, rape, or turnip preceded corn, and a cotton-corn system that had a lupin-black oat mixture as a winter cover crop every year. Use of lupin or 'AU Robin' clover resulted in weed biomass reduction of up to 80% and 54%, respectively, in weed biomass compared to the fallow system. The highest yielding corn-cotton conservation tillage rotation with a winter cover yielded 200 lbs/acre more that the continuous cotton winter fallow system. Continuous conventional corn with winter fallow yielded 30 bu/acre less than the highest yielding 2-yr, conservation tillage winter crop system.
  • Authors:
    • Abou-Alaiw, W.
    • Al-Abed, D.
    • Zhang, S. L.
    • Parani, M.
    • Chennareddy, S.
    • Sairam, R.
    • Goldman, S.
  • Source: In Vitro Cellular & Developmental Biology - Plant
  • Volume: 41
  • Issue: 4
  • Year: 2005
  • Summary: The development of robust plant regeneration technology in cereals, dicots and ornamentals that is in turn coupled to a high-frequency DNA transfer technology is reported. Transgenic cereals that include maize, Tripsacum, sorghum, Festuca and Lolium, in addition to dicots that include soybean, cotton and various ornamentals such as petunia, begonia, and geranium have been produced following either somatic embryogenesis or direct organogenesis independent of genotype. Coupled with these regeneration protocols, we have also identified several interesting genes and promoters for incorporation into various crops and ornamentals. In addition, the phenomenon of direct in vitro flowering from cotyledonary nodes in soybean is described. In in vitro flowering, the formation of a plant body is suppressed and the cells of the cotyledonary node produce complete flowers from which fertile seed is recovered. This in vitro flowering technology serves as a complementary tool to chloroplast transformation for developing a new transgenic pollen containment strategy for crop species. Recently, the center has undertaken to screen the expression response of the 24 000 Arabidopsis genes to nitric oxide. This signaling molecule upregulated 342 genes and downregulated 80 genes. The object here was to identify a population of promoters that can be manipulated by using a signaling molecule. In addition, in keeping with the mission of enhancing greenhouse profitability for North West Ohio growers, we cloned a number of genes responsive for disease resistance from ornamentals that play an important role in disease management and abiotic stress. We have constructed a plant transformation vector with CBF3 gene under the rd29A promoter for engineering cold and freezing tolerance in petunia. Leaf discs of Petunia * hybrida v26 were used for Agrobacterium-mediated transformation, and 44 hygromycin-resistant T0 plants were obtained. The presence of CBF3 gene was confirmed in all the transgenic plants by PCR and Southern analyses.
  • Authors:
    • Dhyani, S. K.
    • Singh, R.
    • Sharma, A. R.
  • Source: Indian journal of soil conservation
  • Volume: 33
  • Issue: 1
  • Year: 2005
  • Summary: Maize and wheat are the most important crop grown in sequence largely under rainfed conditions, with low inputs and traditional practices in the outer western Himalayan region of India. Deficiency of moisture and nutrients is primarily responsible for low productivity of these crops. The conventional practices for alleviating these stresses such as summer ploughing, use of organics, intercropping with legumes, mulching, haloding (interculturing), earthing-up and ploughing immediately after harvesting of maize are gradually being discontinued by the farmers due to various emerging problems. This article reviews the effects of tillage and mulching on moisture conservation and nutrient use in the maize-wheat cropping system. Field studies at different locations of this region have shown the beneficial effects of resource conserving technologies for improving productivity of maize and following wheat. The results have suggested that the conventional repetitive tillage operations including deep ploughing can be dispensed with, and equally good or even higher yields can be obtained with minimum or zero tillage along with mulching or residue management practices over a period due to improved soil environment. Live mulching with weeds, annual legumes or pruned biomass of perennial legumes in alley cropping systems are beneficial for efficient conservation of soil, moisture and nutrients for higher productivity in maize-wheat cropping system. There is a need for adopting diversified farming systems approach for improving productivity of crops as well as other enterprises for greater livelihood security of the farming community in this region.
  • Authors:
    • Salmond, G.
    • Swan, L.
  • Source: Australian Cottongrower
  • Volume: 26
  • Issue: 3
  • Year: 2005
  • Summary: In a field in Australia, the influence of growing different rotation crops on the level of Fusarium oxysporum f.sp. vasinfectum (Fov) in the soil was monitored over three years in a summer field crop rotation experiment. In the 2001-02 and 2002-03 seasons of the trial, the same crop was grown on the same plot. The maize plots were a forced fallow during 2002-03. In 2003-04, the entire trial was oversown with cotton cv. Nu Emerald RR. Mung bean plots were replanted with Sicot 14B six weeks later. In glasshouse pot trials, soil naturally infested with Fov was used to examine different rotation options over five crop cycles with cotton oversown across all treatments in the final cycle. In the field, significantly more cotton plants survived until maturity following a bare fallow rotation compared to cotton plants grown following either maize, cotton or sorghum crops. The greatest percentage of cotton plant death and severity of disease in cotton occurred where soyabean or mung bean crops had previously been grown. In the glasshouse, rotation cycles that included a fallow treatment either one or two crops before growing cotton generally resulted in less severe Fusarium wilt (lower MDI) compared to cycles where a fallow treatment was not included occurred early in the cycle. Crops with larger root systems (sunflower, broccoli, lucerne, maize, sorghum) had more disease (higher MDI) in the following cotton compared to crops with smaller root systems (fallow, chickpea, field pea, millet, pigeon pea), after these crops had been grown for four continuous cycles, reflecting the role of residue and organic matter in pathogen survival and disease incidence. Fov has been isolated from mature plants growing in these pot trials including sunflower (5%); maize (4%); sorghum (3%) (roots only); mung bean (24%); field pea (20%); vetch (20%); pigeon pea (12%); chickpea (4%); and lucerne (4%) (stems and roots). Further research into rotation options and the roles of crop residue, organic matter and green manuring of crops in relation to pathogen survival are discussed.
  • Authors:
    • Rosenberg, N. J.
    • Brown, R. A.
    • Thomson, A. M.
    • Izaurralde, R. C.
    • Benson, V.
  • Source: Climatic Change
  • Volume: 69
  • Issue: 1
  • Year: 2005
  • Summary: Here we simulate dryland agriculture in the United States in order to assess potential future agricultural production under a set of general circulation model (GCM)-based climate change scenarios. The total national production of three major grain crops - corn, soybeans, and winter wheat - and two forage crops - alfalfa and clover hay - is calculated for the actual present day core production area (CPA) of each of these crops. In general, higher global mean temperature (GMT) reduces production and higher atmospheric carbon dioxide concentration ([CO 2]) increases production. Depending on the climatic change scenarios employed overall national production of the crops studied changes by up to plus or minus 25% from present-day levels. Impacts are more significant regionally, with crop production varying by greater than 50% from baseline levels. Analysis of currently possible production areas (CPPAs) for each crop indicates that the regions most likely to be affected by climate change are those on the margins of the areas in which they are currently grown. Crop yield variability was found to be primarily influenced by local weather and geographic features rather than by large-scale changes in climate patterns and atmospheric composition. Future US agronomic potential will be significantly affected by the changes in climate projected here. The nature of the crop response will depend primarily on to what extent precipitation patterns change and also on the degree of warming experienced.
  • Authors:
    • Hanna, W. W.
    • Timper, P.
  • Source: Journal of Nematology
  • Volume: 37
  • Issue: 2
  • Year: 2005
  • Summary: Pearl millet ( Pennisetum glaucum) has potential as a grain crop for dryland crop production in the southeastern United States. Whether or not pearl millet will be compatible in rotation with cotton ( Gossypium hirsutum), corn ( Zea mays), and peanut ( Arachis hypogaea) will depend, in part, on its host status for important plant-parasitic nematodes of these crops. The pearl millet hybrid 'TifGrain 102' is resistant to both Meloidogyne incognita race 3 and M. arenaria race 1; however, its host status for other plant-parasitic nematodes was unknown. In this study, the reproduction of Belonolaimus longicaudatus, Paratrichodorus minor, Pratylenchus brachyurus, and Meloidogyne javanica race 3 on pearl millet ('HGM-100' and TifGrain 102) was compared relative to cotton, corn, and peanut. Separate greenhouse experiments were conducted for each nematode species. Reproduction of B. longicaudatus was lower on peanut and the two millet hybrids than on cotton and corn. Reproduction of P. minor was lower on peanut and TifGrain 102 than on cotton, corn, and HGM-100. Reproduction of P. brachyurus was lower on both millet hybrids than on cotton, corn, and peanut. Reproduction of M. javanica race 3 was greater on peanut than on the two millet hybrids and corn. Cotton was a nonhost. TifGrain 102 was more resistant than HGM-100 to reproduction of B. longicaudatus, P. minor, and M. javanica. Our results demonstrated that TifGrain 102 was a poor host for B. longicaudatus and P. brachyurus (Rf
  • Authors:
    • Ellis-Jones, J.
    • Tripathi, B. P.
  • Source: Renewable Natural Resources Management for Mountain Communities
  • Year: 2005
  • Summary: Agriculture is the main source of livelihood for most people in hillside areas of Nepal, and soil fertility is largely maintained through the use of organic manure. Discussions with farmers indicated five principal soil fertility management practices (manure, chemical fertilizer, compost based on leaf litters, growing legume crops, and in-situ manuring). Farmers identified five soil productivity indicators (crop productivity, soil characteristics (particularly soil colour), management requirement, species of weeds, diseases, and pests, and termites). Historical trends (increasing crop intensification, decreasing livestock numbers, increasing use of chemical fertilizers, reduced labour availability, and change in the climate over the last 30-40 years) showed a decline in soil productivity. Scored causal diagrams on soil fertility drawn from focus group discussions indicated that the primary causes of declining soil fertility and crop productivity are a decrease in available manure, increased cropping intensity, low use of chemical fertilizers, and change in climate. Scientific evaluation confirmed that altitude, farming system, and land types affected the availability of soil nutrients. Organic C, total N, available P and exchangeable K increased in less intensive farming systems, which were at higher altitudes. These nutrients as well as available Fe, Mn, and B in soil significantly increased in rainfed upland (bari) compared with irrigated lowland (khet). Covering manure with black plastic sheets resulted in faster decomposition as well as increased total N and exchangeable K. Covered manure applied to summer rainfed maize and upland rice as well as irrigated lowland spring maize increased grain and straw yields between 13 and 36% when compared with uncovered manure. Both farmers' indigenous knowledge and their criteria were as useful as scientific evaluation in assessing soil fertility improvements. Therefore, farmers' knowledge and criteria should be considered when monitoring soil fertility and crop productivity in farmer trials.
  • Authors:
    • Wang, X. B.
    • Cai, D. X.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 21
  • Issue: 6
  • Year: 2005
  • Summary: Field experiments on surface soil mulch with emulsified bituminous materials and fertilizer management based on conservation tillage practices for spring maize were conducted in dry farmland of Shouyang in Shanxi Province (China), to determine the impacts of tillage, surface mulch with emulsified bituminous materials and fertilizer rate on soil temperature, soil water, and crop seedling emergence and yields, and to evaluate the integrated management of conservation tillage, emulsified bituminous mulch and fertilizer application in dry farming for promoting agricultural production. Compared with the conventional tillage methods, using emulsified bituminous mulch under no-tillage soils caused the increases of 0.5-2degreesC for surface temperature during the seedling stage, above 18% for the number of maize seedling emergence, approximately 5% for maize yields, 21 mm for the 0-200 cm soil moisture contents, and 12 mm for water use during the growing season. The study provides information for improving tillage-mulching-fertilizer application management of dry farming.
  • Authors:
    • Scott, A. W.,Jr.
    • Westphal, A.
  • Source: Crop Science
  • Volume: 45
  • Issue: 1
  • Year: 2005
  • Summary: Rotylenchulus reniformis Linford & Oliveira is increasing in incidence in cotton-growing areas throughout the southern USA east of New Mexico. Cotton (Gossypium hirsutum L.) cultivars resistant to R. reniformis are currently unavailable. Management depends on a crop sequence with nonhosts of the nematode. In South Texas, the sequence of cotton with grain sorghum [ Sorghum bicolor (L.) Moench] or corn ( Zea mays L.) has become a standard practice. To improve farm efficiency, the implementation of rotation crops that are economically superior to grain sorghum is desirable. Eighteen cultivars of soybean [ Glycine max (L.) Merr.] were tested in nonfumigated and in fumigated sandy loam soil infested with R. reniformis to evaluate nematode resistance of soybean under field conditions. Shank application of 1,3-dichloropropene at a 38-cm depth reduced R. reniformis population densities at the 15- to 60-cm depth compared with preseason counts. The effect of each soybean cultivar on the growth and yield of a subsequent cotton crop was compared with the impact of grain sorghum and fallow. High-yielding cultivars of soybean (HY574, Padre, DP7375RR, and NK83-30) with reniform nematode-suppressing potential were identified among cultivars within maturity groups 5, 6, 7, and 8. In contrast, cotton yields following the susceptible cultivars Santa Rosa-R, Vernal, and DP6880RR were on average 25% lower than those following grain sorghum. The enrichment of cotton sequences with reniform nematode-resistant soybean cultivars is viable when the proper cultivars are chosen, whereas the use of reniform nematode-susceptible soybean cultivars is discouraged. The effective use of R. reniformis-resistant soybean cultivars to manage R. reniformis in cotton will depend on a number of additional economic parameters not studied in these experiments.
  • Authors:
    • Xue, Y. F.
    • Yang, Z. J.
    • He, F.
    • Wang, Z. H.
    • Wu, J. C.
  • Source: Acta Agriculturae Boreali-Sinica
  • Volume: 20
  • Issue: 6
  • Year: 2005
  • Summary: The results of studies in dryland in the west of Henan Province showed that different technological measures played an important role in growth and development, yield, soil moisture and precipitation utilization of maize. The yield of maize in all 13 treatments in the experiment was improved by 1.92-20.51%. The best ones were the treatments of straw mulching combined with nutrient water-retaining agent, which increased the yield by 15.38-20.51%. The second ones were the treatments of nutrient water-retaining agent, which increased the yield by 11.53-14.10%. The efficiency of precipitation utilization in 13 treatments improved yield by 0.45-3.60 kg/mm/ha, respectively. The best ones were also the treatments of straw mulching combined with nutrient water-retaining agent, which increased the yield by 2.70-3.60 kg/mm/ha. The results of all treatments showed that the comprehensive technology is an effective way to improve precipitation utilization. The effect of nutrient water-retaining agent treatments was the best ones among all the treatments of water-saving agents.