• Authors:
    • Pettigrew, W. T.
    • Dowd, M. K.
  • Source: Journal of Cotton Science
  • Volume: 16
  • Issue: 1
  • Year: 2012
  • Summary: The value of whole cottonseed and cottonseed products has increased as demand has grown from the dairy and food related industries. Although cottonseed composition has previously been documented to be affected by variety, planting date, and irrigation, interactions between varieties and irrigation regimes have not been adequately described. Six different varieties were planted on two planting dates and grown under irrigated or dryland conditions to document how varieties interacted with irrigation regimes to impact various seed composition traits. Variety was a major source of variation for all the seed composition traits quantified. Individual seed mass variation among varieties could explain some of the seed composition variation observed, particularly for protein. For many of these seed composition traits, variety also interacted statistically with irrigation regimes to impact trait expression. Most seed composition traits of the varieties responded in the same direction to irrigation, but there was sufficient variety variation in the response that significant interactions were produced. 'ST 5599BR' often exhibited a different irrigation response compared to the other varieties, particularly for the different fatty acid components. These results indicate that a pairing of varieties and management practices could be utilized to help achieve desired seed composition traits. Although lint production is the primary economic incentive for cotton producers, improved cottonseed composition offers an important, consistent, and reliable secondary revenue stream for producers.
  • Authors:
    • Hamilton, G.
    • Bickerton, M.
  • Source: Environmental Entomology
  • Volume: 41
  • Issue: 3
  • Year: 2012
  • Summary: Bell pepper plots intercropped with flowering plants were measured for improving biological control provided by natural enemies of the European corn borer [ Ostrinia nubilalis (Hubner)]. The intercropped plants Dill, Anethum graveolens L.; coriander, Coriandrum sativum L.; and buckwheat, Fagopyrum escuelentum Moench; were established on the edge of two pepper plots and compared with nonintercropped control plots. Predation by the three species Orius insidiosus Say; Coleomegilla maculata DeGeer; and Chrysoperla, sp. Stephens, was monitored by installing O. nubilalis egg masses on sentinel plants in 2008, 2009, and 2010. To assess negative impacts of alternative prey on O. nubilalis egg predation, green peach aphid, Myzus persicae (Sulzer) populations were monitored via whole-plant counts in 2009 and 2010. Myzus persicae densities on pepper plants peaked in June or July and then declined rapidly. Predation on O. nubilalis eggs increased rapidly after aphid populations declined. Aphid populations were reduced in two out of three field-seasons in intercropped plots. Seasonal predation by O. insidiosus was significantly higher in the intercropped system four out of five field-seasons and one field season by C. maculata. Results indicate that biocontrol of O. nubilalis can be improved by intercropping with flowering plants, although this capacity may depend on the abundance of alternative prey.
  • Authors:
    • McLean, E.
    • Dissette, N.
    • Bilski, J.
    • Soumaila, F.
  • Source: International Journal of AgriScience
  • Volume: 2
  • Issue: 4
  • Year: 2012
  • Summary: Coal fly ash (FA) has a potential to be used as a soil amendment for growing plants. Toxicity of heavy metals present in FY, FA high salinity, and high pH of coal FA may potentially restrict or even prevent plant growth on the media with high concentration of FA. Sphagnum peat moss (SPM) shows a potential to ameliorate coal FA based plant media by improving the texture of such media, making media less harder, decreasing high pH of the media, and potentially binding heavy metals present in FA. Therefore, the aim of this study was to determine the effects of growth media containing differing concentration of FA and/or sphagnum peat moss (SPM) on growth of selected plants. The following plant species have been tested: barley ( Hordeum vulgare), oats ( Avena sativa), rye ( Secale cereale), wheat ( Triticum aestivum), Regreen; a hybrid between wheatgrass ( Agropyron cristatum) and winter wheat ( Triticum aestivum), Triticale; a hybrid between wheat ( Triticum aestivum) and rye ( Secale cereale), and perennial ryegrass (Lolium multiflorum). The addition of SPM to FA based plant growth media expressed ameliorative role, allowing the growth of seedlings on such media. In addition, our results indicate that the transfer of heavy metals from coal FA to plants and possibly to a food chain either did not exist or was very low.
  • Authors:
    • Ostgarden, J.
    • McLean, E.
    • McLean, K.
    • Bilski, J.
    • Lander, M.
  • Source: Electronic Journal of Environmental, Agricultural and Food Chemistry
  • Volume: 11
  • Issue: 5
  • Year: 2012
  • Summary: This study focuses on the environmentally friendly utilization of coal combustion residue, fly ash (FA) containing significant amounts of heavy metals. Knowledge about the potential use of FA as a component of growth media for plants is fragmentary. Preliminary experiments tested the possibility to grow cereal crops on media composed exclusively of FA. The analysis of seven different FA from lignite and semi-bituminous coal from North Dakota and Montana sources using inductively coupled plasma emission spectrophotometry showed high concentrations of heavy metals in coal (up to, in mg/kg): As:65, Cd:3.9, Co:38, Cr:77, Li:109, Mn:1547, Pb:106, Ni:41, V:306. Seedlings of rye, wheat, oats, barley, triticale, and regreen (hybrid between wheat and ryegrass) were planted in Petri dishes (10 cm in diameter) in growth media containing FA from lignite coal, FA from semi-bituminous coal, bottom ash, and Fargo clay soil as the control. Each treatment was performed in 3 replications, and each experiment was repeated 3 times. Germination rates, plant growth analysis, and dry matter yield were determined 2-3 weeks after planting. Germination rates and dry matter yield of oats, winter wheat and regreen were greater (10-20% above controls) in media composed of coal ash, but rye, barley, and wheat seedlings were affected by FA in media. These results show the potential for the utilization of FA as a growth media for cereal crops. Therefore, these plants might be used as green cover preventing wind erosion over the coal ash piles. However, this issue requires additional in depth investigation, including a thorough chemical analysis of plant material.
  • Authors:
    • Schlegel, A.
    • Halvorson, A.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 5
  • Year: 2012
  • Summary: Limited irrigation management practices are being used in the Central Great Plains to conserve water by optimizing crop water use efficiency. Limited irrigation may reduce total crop biomass production and amount of crop residue returned to the soil. Crop residue production within four no-till (NT) crop rotations [continuous corn ( Zea mays L.) (CC); corn-winter wheat ( Triticum aestivum L.) (CW); corn-winter wheat-grain sorghum ( Sorghum bicolor L. Moench) (CWS); corn-winter wheat-grain sorghum-soybean [ Glycine max (L.) Merr.] (CWSSb)] was measured and changes in soil organic carbon (SOC) and total soil nitrogen (TSN) stocks were monitored for 10 yr. Crop residue yields varied with crop being produced and with rotation, as did residue N and C returned to the soil. The C/N ratio of the residue varied with crop. The SOC and TSN pools increased with time in all rotations. The rate of gain in SOC and TSN mass for each rotation was 717, 477, 335, and 270 kg SOC ha -1 yr -1 and 114, 92, 87, and 84 kg TSN ha -1 yr -1 for the CC, CW, CWS, and CWSSb rotations, respectively, in the 0- to 30.5-cm soil depth. The rate of change in SOC and TSN mass was lowest with CWSSb (8.7 Mg residue ha -1 yr -1) and highest with CC (12.0 Mg residue ha -1 yr -1). Approximately 6.8 to 7.6 Mg residue ha -1 yr -1 would be needed to maintain SOC stocks under limited irrigation.
  • Authors:
    • Moffet, M.
    • Menalled, F.
    • Miller, Z.
    • Ito, D.
    • Burrows, M.
  • Source: Plant Disease
  • Volume: 96
  • Issue: 8
  • Year: 2012
  • Summary: Wild grasses, crops, and grassy weeds are known to host Wheat streak mosaic virus (WSMV) and its vector, the wheat curl mite (WCM). Their relative importance as a source of WSMV was evaluated. A survey of small-grain fields throughout Montana was conducted between 2008 and 2009. Cheatgrass was the most prevalent grassy weed and the most frequent viral host, with 6% infection by WSMV in 2008 ( n=125) and 15% in 2009 ( n=358). By mechanically inoculating plants with WSMV in the greenhouse, the highest susceptibility was found in rye brome (52.1%), jointed goatgrass (80.9%), and wild oat (53.9%). Quackgrass, not previously reported as a host, was susceptible to WSMV (12.7%). Mite transmission efficiency from susceptible grass species was lower than from wheat, and grass species must be a host for both WSMV and the WCM to serve as a virus source. WCM transmission was more efficient than mechanical transmission. Overall, results indicate that grass species can serve as a viral reservoir, regional variation in a weed species' susceptibility to WSMV cannot explain geographic variation in epidemic intensity, and crop species and closely related weeds (e.g., jointed goatgrass) remain the best reservoirs for both WSMV and the WCM.
  • Authors:
    • Reicosky, D.
    • Porter, P.
    • Baker, J.
    • Ochsner, T.
    • Krueger, E.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 4
  • Year: 2012
  • Summary: Recent proliferation of large dairies has prompted concern regarding environmental impacts of associated corn silage production and high-rate manure application. Our objectives were to compare environmental impacts and forage production of monocrop corn ( Zea mays L.) silage and rye ( Secale cereal L.)-corn silage double-crop systems with multiple corn planting dates and high-rate manure application near Morris, MN. From 2007 to 2009, corn for silage was seeded into a silt loam as a monocrop in early and mid-May and as a double-crop after rye in mid-May and early June. Manure was fall applied annually at average total N and P rates of 393 and 109 kg ha -1, respectively. Double-cropping reduced total forage dry matter (DM) yield 2 of 3 yr and reduced corn DM yield 15 to 25%. Soil NO 3-N to 90 cm accumulated at an average rate of 71 kg N ha -1 yr -1 with monocropping, but accumulation was not observed with double-cropping. Soil organic C concentration from 0 to 5 cm increased in the monocrop (18%) and double-crop (26%) systems over 3 yr. Average soil solution NO 3-N concentration was high with monocropping (52 mg L -1) and double-cropping (37 mg L -1), but estimated leaching load averaged only 8 kg ha -1 yr -1. Fall and spring ground cover was often less than 10% with monocropping but was usually greater than 30% with double-cropping. The primary environmental concerns identified for monocrop corn silage were soil NO 3-N buildup and inadequate ground cover. Double-cropping addressed each concern but often decreased forage production.
  • Authors:
    • Carver, B.
    • Obert, D.
    • Mornhinweg, D.
  • Source: Journal of Plant Registrations
  • Volume: 6
  • Issue: 2
  • Year: 2012
  • Summary: STARS 1006B (Reg. No. GP-200, PI 659760), STARS 1007B (Reg. No. GP-201, PI 659761), STARS 1008B (Reg. No. GP-202, PI 659762), STARS 1009B (Reg. No. GP-203, PI 659763), STARS 1010B (Reg. No. GP-204, PI 659764), STARS 1011B (Reg. No. GP-205, PI 659765), STARS 1012B (Reg. No. GP-206, PI 659766), and STARS 1013B (Reg. No. GP-207, PI 659767), are winter, six-rowed, feed barley ( Hordeum vulgare L.) germplasm lines developed cooperatively by the USDA-ARS, in Stillwater, OK, and Aberdeen, ID as sources of resistance to Russian wheat aphid [RWA; Diuraphis noxia (Kurdjumov)] and greenbug [GB; Schizaphis graminum (Rondani)]. Each resistant line is in a 'Post 90' background and comparable with 'Post 90' (PI 549081) in yield, test weight, heading date, and height in the absence of RWA and GB. Each line is highly resistant to both RWA and GB and has a wide area of adaptation ranging from irrigated production in the northwestern United States to dryland production in the southern plains, where both RWA and GB can be problematic.
  • Authors:
    • Thomashow, L.
    • Weller, D.
    • Mavrodi, O.
    • Mavrodi, D.
    • Parejko, J.
  • Source: Microbial Ecology
  • Volume: 64
  • Issue: 1
  • Year: 2012
  • Summary: Certain strains of the rhizosphere bacterium Pseudomonas fluorescens contain the phenazine biosynthesis operon ( phzABCDEFG) and produce redox-active phenazine antibiotics that suppress a wide variety of soilborne plant pathogens. In 2007 and 2008, we isolated 412 phenazine-producing (Phz +) fluorescent Pseudomonas strains from roots of dryland wheat and barley grown in the low-precipitation region (
  • Authors:
    • Samac, D.
    • Vance, C.
    • Temple, S.
    • Somers, D.
    • Tesfaye, M.
    • Radmer, L.
  • Source: Plant and Soil
  • Volume: 351
  • Issue: 1/2
  • Year: 2012
  • Summary: Background and aims: Enhanced aluminum (Al) resistance has been observed in dicots over-expressing enzymes involved in organic acid synthesis; however, this approach for improving Al resistance has not been investigated in monocots. Among the cereals, oat ( Avena sativa L.) is considered to be Al resistant, but the basis of resistance is not known. Methods: A hydroponic assay and hematoxylin staining for Al accumulation in roots were used to evaluate Al resistance in 15 oat cultivars. Malate and citrate release from roots was measured over a 24 h period. A malate dehydrogenase gene, neMDH, from alfalfa ( Medicago sativa L.) was used to transform oat. Results: Oat seedlings were highly resistant to Al, as a concentration of 325 M AlK(SO 4) 2 was needed to cause a 50% decrease in root growth. Most oat cultivars tested are naturally resistant to high concentrations of Al and effectively excluded Al from roots. Al-dependent release of malate and Al-independent release of citrate was observed. Al resistance was enhanced in a transgenic oat line with the highest accumulation of neMDH protein. However, overall root growth of this line was reduced and expression of neMDH in transgenic oat did not enhance malate secretion. Conclusions: Release of malate from oat roots was associated with Al resistance, which suggests that malate plays a role in Al resistance of oat. Over-expression of alfalfa neMDH enhanced Al resistance in some lines but was not effective alone for crop improvement.