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Commercial sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2012
Get PDFRhizomania caused by Beet necrotic yellow vein virus (BNYVV) and storage losses are serious sugar beet production problems. To identify sugar beet cultivars with resistance to BNYVV and evaluate storability, 26 commercial cultivars were screened by growing them in a sugar beet field infested with BNYVV in Kimberly, ID during the 2012 growing season in a randomized complete block design with 4 replications. At harvest on 3 October 2012, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. After 134 days in storage, samples were evaluated for surface rot, weight loss, and sucrose loss. Surface root rot ranged from 35 to 94%, weight loss ranged from 7.9 to 14.0%, sucrose losses ranged from 37 to 81%, and estimated recoverable sucrose ranged from 811 to 7,112 lb/A. Given these response ranges, selecting cultivars for rhizomania resistance and combining it with storability will lead to considerable economic benefit for the sugar beet industry
Soil management and conservation: Irrigation: Methods
Get PDFIrrigation applies water to soil to improve crop production. The three main methods of irrigation are surface, sprinkler and micro. Surface irrigation is used on 85% of the irrigated land in the world. It generally requires lower capital investment because the soil conveys water within the field, rather than pipes or tubing used for sprinkler or microirrigation. Water application is more controlled with sprinkler and microirrigation and these irrigation methods can be automated easier than surface irrigation. There are many variations of irrigation methods and types of irrigation equipment. The purpose of this article is to describe the irrigation methods primarily used for agricultural production
Comparison of sprinkler droplet size and velocity measurements using a laser precipitation meter and photographic method
Get PDFKinetic energy of water droplets has a substantial effect on development of a soil surface seal and infiltration rate of bare soil. Methods for measuring sprinkler droplet size and velocity needed to calculate droplet kinetic energy have been developed and tested over the past 50 years, each with advantages, disadvantages, and limitations. A laser precipitation meter and photographic method were used to measure droplet size and velocity from an impact sprinkler at three pressures and one nozzle size. Significant differences in cumulative volume drop size distributions derived from the two measurement methods were found, especially at the highest operating pressure. Significant differences in droplet velocities were found between measurement methods as well. Significant differences were attributed to differences in minimum drop sizes measured; 0.5mm for the photographic method versus 0.2 mm for the laser precipitation meter. The laser precipitation meter provided smaller cumulative volume drop size distributions compared to the photographic measurement method. The laser precipitation meter tended to provide greater drop velocities which were attributed to altitude differences at experimental sites. The difference in calculated droplet kinetic energy per unit volume based on drop and size velocity data from the laser precipitation meter and the photographic method ranged from +12.5 to -28%. The laser precipitation meter generally provided a lower estimate of sprinkler kinetic energy due to the measurement of a greater proportion of smaller drop sizes. Either method can be used to obtain drop size and velocity sprinkler drops needed to calculate sprinkler kinetic energy. The laser precipitation meter requires less skill and labor to measure drop size and velocity
In-field rates of decomposition and microbial communities colonizing residues vary by depth of residue placement and plant part, but not by crop genotype for residues from two Cry1AB Bt corn hybrids and their non-transgenic isolines.
Get PDFThe adoption of Bt corn has been largely overshadowed by concerns about their unintended effects on human health and the environment. Residues of transgenic Bt crops decomposed more slowly than their non-transgenic isolines in one laboratory study, although no mechanism to explain these observations was proposed. If Bt crop residues were to decompose more slowly in field soils, changes in carbon cycling and nutrient availability could result. We compared the in-field decomposition rates and diversity of decomposers colonizing residues of two Cry1Ab Bt corn hybrids, active against the European corn borer, with their non-transgenic isolines in litterbags placed in a Nebraska field. After five months, we found no significant differences in either the rates of residue mass loss or in the bacterial, fungal or microarthropod communities colonizing the transgenic versus the non-transgenic residues. Instead, both residue mass loss and detritivore colonizers were significantly affected by residue placement (surface versus buried) and plant part, demonstrating that environmental factors and residue quality, not the presence of the Cry1Ab protein, were the key drivers of residue decomposition and detritivore colonization in this study
Use of standardized procedures to evaluate metal leaching from waste foundry sands
Get PDFAs part of the casting process, foundries create sand molds and cores to produce ferrous and non-ferrous metal castings. After the process, a portion of the sand is discarded and becomes waste foundry sand (WFS). The aim of this study was to quantify metals (i.e. Ag, Ba, Cd, Cr, Cu, Ni, Pb, and Zn) in leaching extracts from a variety of waste molding and core sands from ferrous and non-ferrous foundries using the Extraction Procedure, Toxicity Characteristic Leaching Procedure, and ASTM water extraction procedure. The WFS metal extract concentrations were compared to those found in virgin silica sands and Argentinean and U.S. hazardous waste laws to determine if the WFSs met toxicity limits. The majority of the WFS extracts analyzed, regardless of metal cast and binder type, contained metal concentrations similar to those found in virgin sand extracts and were below levels considered hazardous. Consequently, it appears most WFSs can be beneficially used as a substitute for virgin aggregate in geotechnical and agricultural applications without causing risk to human health and the environment
Surfactant effects on the water-stable aggregation of wettable soils from the continental USA
Get PDFSurfactants may affect soil structure differently depending upon the soil or the quality of rainfall or irrigation water. This study examined whether the water-stable aggregation of 11 wettable soils was affected by surfactants and the water in which the soils were sieved. The study also examined whether the wettable soils’ water drop penetration time (WDPT) was affected by surfactants, water drop quality, and elapsed time since the surfactants were applied. Two nonionic surfactants and a surfactant-free water control were sprayed (by misting) upon air-dry soil, then WDPT was measured 1 and 72 h thereafter. Subsequently, this treated soil was slowly wetted with an aerosol to its water content at a matric potential of 3 kPa, then immediately sieved for 600 s in water that contained either appreciable or few electrolytes. Water-stable aggregation, quantified as mean weight diameter (MWD), varied widely among soils, ranging from 0.10 to 1.36 mm. The MWDs were affected (at p = 0.06) by surfactant treatments, depending upon the soil but not sieving water quality. Surfactants affected the MWD of an Adkins loamy sand and Feltham sand, two of the three coarsest textured soils. Although WDPTs never exceeded 5 s, depending upon the soil WDPTs were affected by surfactant treatments but not by water drop quality. After surfactant application, WDPTs generally decreased with time for three soils but increased with time for one soil. Findings suggested that surfactants interacted (1) with clay mineralogy to affect MWD and (2) with soluble calcium to affect WDPT for certain soils. Surfactant treatments but not water quality affected bothMWDand WDPT for some but not all of 11 wettable, US soils
Regression modeling weather and biolsolids effects on dryland wheat yields in Eastern Colorado, 2001-2012
Get PDFIn the western Great Plains, climate dictates dryland wheat (Triticum aestivum, L) productivity. Producers use inorganic N fertilizers to improve crop yields in this region, while municipalities recycle sewage biosolids in the area. Will biosolids (from the Littleton/Englewood, CO Wastewater Treatment Plant) applications to western Great Plains dryland agroecosystems interact with weather to affect wheat production? To this end, we regressed crop yields on weather variables from 2000 through 2011 at a site about 40 km (approximately 25 miles) east of Byers, CO (Byers). We used SAS (Proc Reg) to develop several multiple regression models to predict crop yields. Our model of choice included four weather parameters for Byers wheat production. Regression variables included September and May precipitation and October and May monthly mean temperatures. Biosolids or nitrogen fertilizer application did not appear in our chosen model. We validated the wheat models using weather data and yields from the Colorado State University (CSU) Crops Testing Program from Akron, Burlington, Lamar, and Yuma, CO. According to t-tests comparing mean observed and predicted yields, the Byers model predicted yields from 2000-2011 at these locations with a +5.3% mean absolute error. A positive result of these analyses is that biosolids produced the same crop yields as commercial N fertilizer from 2001 through 2011
Management of curly top in sugarbeet with seed and foliar insecticides
Get PDFCurly top in sugarbeet can result in severe yield losses and is caused by Beet severe curly top virus (BSCTV) and other closely related Curtovirus spp. which are vectored by the beet leafhopper. Neonicotinoid seed treatments (Cruiser, NipsIt, and Poncho) have been shown to be an effective supplement to host resistance, but measures to extend control beyond the duration of seed treatment efficacy needs to be investigated. In 2012, a field study was arranged in a randomized complete block design with 8 replications and planted with the cultivar B-42. The 16 treatments included untreated and Poncho Beta treated seed with and without 6 foliar insecticides (applied 7 days before and 6 days after release of viruliferous beet leafhopper) and just Poncho and Poncho Votivo treated seed. On 22 Jun (59 days after planting), 6 beet leafhoppers per plant were released to ensure good disease pressure. Visual foliar ratings on the 15 Aug and 15 Sep indicated some seed and foliar treatments reduced (P < 0.0001) symptoms by 13 to 60% compared to the check. Root yields were increased (P < 0.0001) by 8 to 18% compared to the check. Estimated recoverable sucrose was increased (P < 0.0001) by 12 to 21% compared to the check. After the seed treatments lose efficacy, it would appear that the pyrethroid insecticides Asana and Mustang may be applied to help reduce curly top and aid in the control of other pests and insecticide resistance management
Recommending Soil Copper Thresholds for Potato Production in Idaho
Get PDFA rising concern with the application of dairy wastes to agricultural fields is the accumulation of copper in the soil. Copper sulfate from cattle footbaths is washed out of dairy barns and into wastewater lagoons. Potato growers are concerned about this issue, as many of the predominant dairy producing areas in Southern Idaho are also in Idaho’s established potato production regions. The objective of this project was to evaluate potato growth and copper plant uptake for potatoes grown under low, moderate, and excessively high soil copper concentrations. This study was conducted in 2011 in a greenhouse setting at the USDA ARS Kimberly Research Station. To establish an effective copper response curve, 6 rates of copper sulfate (0, 100, 200, 300, 400, and 500 mg/kg soil) were applied to either a Portneuf silt loam or a Wolverine sand. Treatments were replicated four times in a complete randomized block design. Root copper concentrations increased rapidly at relatively low soil copper concentrations for the Wolverine sand. In contrast, root copper concentrations appear to level off at soil copper concentrations of 100 mg/kg for the Portneuf silt loam, suggesting that copper toxicities are likely a much greater issue on sandy soils than on silty soils. We recommend potato production soil extractable threshold copper levels to be 25 and 375 mg/kg for sandy and silty soils, respectively. Producers are urged to test for extractable copper in soils receiving copper containing wastewater
Potato cultivar response to seasonal drought patterns
Get PDFThe ability to minimize potato yield and quality losses due to drought can be greatly improved by understanding the relative responses of different cultivars to seasonal variations in water supply. To address this need, we initiated a two year field experiment to determine the responses of the six potato cultivars to different seasonal drought patterns, including 1) full season irrigation at 100% ET, 2) irrigation at 100% ET terminated during late bulking , 3) full season irrigation at 70% ET , 4) irrigation at 70% ET terminated during late bulking , and 5) a gradual reduction in irrigation from 100% ET during tuber initiation through early bulking, to 70% ET during mid-bulking, and 50% ET through late bulking. GemStar Russet and Ranger Russet, two medium-late maturing cultivars, generally produced the highest yields across the range of drought treatments, but both were fairly sensitive to changes in drought severity. Alturas, a late maturing cultivar, produced relatively high yields with full irrigation, but exhibited the greatest sensitivity to increasing drought severity, particularly when severe late-season water deficits were imposed. Yields for the early maturing cultivar Russet Norkotah were relatively low overall, but it was the least sensitive to changes in drought severity, particularly when late season drought was imposed. Russet Burbank produced comparatively high total yields across the range of drought treatments, but U.S. No. 1 yields were substantially reduced by each seasonal drought pattern. However, it was less sensitive to changes in drought severity than GemStar Russet, Ranger Russet and Alturas. Total and U.S. No. 1 yields for Summit Russet were low for each drought treatment and it exhibited intermediate sensitivity to changes in drought severity. GemStar Russet had the highest water use efficiency based on U.S. No. 1 yield