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Ft. Collins sugar beet germplasm evaluated for rhizomania and storage rot resistance in Idaho, 2019
Full text linkRhizomania caused by Beet necrotic yellow vein virus (BNYVV) and storage losses are serious sugar beet production problems. To identify sugar beet germplasm lines with resistance to BNYVV and storage rots, 30 lines from the USDA-ARS Ft. Collins sugar beet program and four check cultivars were screened. The lines were grown in a sugar beet field infested with BNYVV during the 2019 growing season in a randomized complete block design with 6 replications. At harvest on 15 October 2019, roots were dug and evaluated for rhizomania symptoms and then placed in an indoor commercial sugar beet storage building. After 129 days in storage, samples were evaluated for the percentage of root surface area covered by fungal growth or rot. Rhizomania symptom development was uniform and other disease problems were not evident in the plot area. We were unsuccessful in establishing plants for entry 24, so data for only 29 entries were collected. The BNYVV susceptible check plots (Check 1 and Red beet) had 100% foliar symptoms and high root disease ratings. Resistant check 3 had 0 % foliar symptoms and a low root rating which indicates that resistance based on two genes is holding up. Single gene resistance (Checks 2 and 4) had foliar ratings ranging from 14 to 24% indicating single gene resistance is not completely effective, but the root ratings were still good. Four entries (4, 8, 13, and 23) had a level of BNYVV resistance similar to resistant check 3 based on both foliar and root ratings. A number of the entries had resistance to fungal rots in storage, but only entries 4, 8, and 13 performed well for all three variables. Some entries may serve as a starting point for identifying additional sources of resistance to BNYVV and storage rots
Experimental sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2018
Full text linkRhizomania 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, 12 experimental cultivars were screened by growing them in a sugar beet field infested with BNYVV in Kimberly, ID during the 2018 growing season in a randomized complete block design with 6 replications. At harvest on 26-27 September 2018, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. After 136 days in storage, samples were evaluated for surface rot, weight loss, and sucrose loss. Surface root rot ranged from 22 to 79%, weight loss ranged from 22 to 32%, sucrose losses ranged from 50 to 82%, and estimated recoverable sucrose ranged from 803 to 6,246 lb/A. Given these response ranges, selecting cultivars for rhizomania resistance and combining this resistance with storability will lead to considerable economic benefit for the sugar beet industry
Data-driven models for canopy temperature-based irrigation scheduling
Full text linkNormalized crop canopy temperature, termed crop water stress index (CWSI), was proposed over 40 years ago as an irrigation management tool but has experienced limited adopted in production agriculture. Development of generalized crop-specific upper and lower reference temperature is critical for implementation of CWSI-based irrigation scheduling. The objective of this study was to develop and evaluate data driven models for predicting reference canopy temperatures needed to compute CWSI for sugarbeet and wine grape. Reference canopy temperatures for sugarbeet and wine grape were predicted using machine learning and regression models developed using measured canopy temperatures of sugarbeet, grown in Idaho and Wyoming, and wine grape, grown in Idaho and Oregon, over 5 years under full and severe deficit irrigation. Lower reference temperatures were estimated using neural network models with Nash-Sutcliffe model efficiencies exceeding 0.88 and root mean square error less than 1.1 degree Celsius. The relationship between well-watered canopy temperature minus ambient temperature and vapor pressure deficit was represented by a linear model that maximized the regression coefficient rather than minimized the sum of squared error. The linear models were used to estimate upper reference temperatures nearly double values reported in previous studies. Daily CWSI calculated as the average of 15-min values determined between 13:00 and 16:00 MDT for sugarbeet and 13:00 and 15:00 local time for wine grape was well correlated with irrigation events and amounts. A quadratic relationship between daily CWSI and midday leaf water potential of Malbec and Syrah wine grape was significant (p<0.001) with an R2 of 0.67. The data driven models developed in this study to estimate reference temperatures permit automated calculation of CWSI for effective assessment of crop water stress, however, wet canopy conditions or solar radiation < 200 W m-2 can result in irrational values of CWSI. Automated calculation of CWSI using the methodology of this study would need to check for wet canopy or low solar radiation conditions and omit calculation of CWSI if determined to be probable
2020 Idaho soft white winter wheat quick facts
Full text linkThe respective fact sheets list key production recommendations for southern Idaho for the respective crops that ensure growers have easy and timely access to information. Specific recommendations vary depending on the specific type of wheat that is grown. These extension publications include fertilizer recommendation rates, irrigation management and scheduling, pest, disease, and weed management, as well as planting decision recommendations for timing and seeding rate
Genetic diversity of sugar beet under heat stress and deficit irrigation
Full text linkIn the light of climate changes and globalwarming, as well as the rapid expansion in sugar beet (Beta vulgaris L.) cultivation in Egypt, the development of sugar beet varieties with improved tolerance to high temperature and deficit irrigation is of great importance. The objective of this studywas to evaluate sugar beet genotypes under high temperatures and deficit irrigation conditions for further identification and selection of heat and drought tolerant genotypes. In the current study, a panel of 18 sugar beet breeding lines produced at the USDA–ARS–NWISRL, Kimberly, ID, and the commercial sugar beet cultivar Kawimera were evaluated for yield and quality under high temperature. Six promising lines in terms of yield and quality were further evaluated under both high temperature and deficit irrigation for two growing seasons.
All lines performed differently under deficit irrigation, indicating a high degree of genetic variability in the evaluated lines. Additionally, yield traits showed negative effect due to deficit irrigation. A significant positive correlation was observed between stress tolerance index (STI), and average root and sugar yields under stressed and non-stressed conditions. A linear relationship between STI and average root and sugar yields indicates that STI is a reliable stress index to select high yielding genotypes under both optimum- and deficit-irrigation conditions. USKPS25 and USC944-6-68 breeding lines are most likely adapted to deficit irrigation and high temperature and suitable to be utilized in the proposed sugar beet breeding programs in Egypt
Comparison of nutrient management recommendations and soil health indicators in southern Idaho
Full text linkAdvanced soil tests are being developed to help improve the estimation of plant available nutrients in order to better match fertilizer additions with plant needs as well as provide a measure of soil health, in some instances. The Soil Health Tool (SHT) has been developed with both goals in mind, yet it has not been tested for use in semi-arid regions such as southern Idaho. In the present study, we compared the use of the SHT for making fertilizer recommendations vs. using the standard regional method as well as evaluated the SHT soil health score (SHS) relative to crop yields and quality. The SHT was designed to analyze samples for 0-15 cm depth and regional guidelines call for deeper soil sampling (0-30 cm or 0-60 cm). In order to determine N fertilizer applications, use of the tool without accounting for depth, would recommend greater N application (~138 kg/ha) than the current regional methodology. However, it does appear that by accounting for depth in the SHT can provide similar available N estimates for the top 30 cm of soil. While N mineralization was not well predicted utilizing the method included in the SHT or from the regional methodology, the average estimated available N for these soils (47 kg/ha) was similar to the N mineralization value used in the current regional methodology (50 kg/ha). The P fertilizer recommendations were more similar between the two methodologies with the SHT recommending, on average 4.7 kg/ha less P than the regional method. The lower P recommendation are likely due to a lack of accounting for the effects of high calcium carbonate levels on the P availability from fertilizers in this region. The SHS was highly correlated with measures of soil C but was not positively correlated to crop yield. In some instances, increasing SHS resulted in decreases in crop quality as the addition of manure increased soil C but also created other potential problems such as high salt contents and release of late season N. With modification to more accurately represent irrigation conditions and including sampling to greater soil depths, this test may be tailored to better estimate soil nutrient status and provide better fertilizer recommendations for the region
Long-term water retention increases in degraded soils amended with cross-linked polyacrylamide
Full text linkPolymer hydrogels, cross-linked polyacrylamide co-polymer (XPAM) and K-polyacrylate (XPAA), increase soil water availability under drought, but their long-term effects are unknown even though such knowledge is important for assessing economic feasibility at the farm-scale. This 9-yr, outdoor study amended an irrigated, calcareous silt loam with a one-time, 0.25% or 0.5% dry wt. (5.6 or 11.2 Mg/ha) application of either XPAM or XPAA; and included an untreated control and untreated, uneroded topsoil. Soil water retention and plant available water (PAW, g H2O per g dry soil) were measured in soil samples collected in spring for 7 of the 9 years. Across all years, the 2% XPAM produced the greatest PAW (0.318) and the PAW of other treatments followed in the order: 0.5% XPAM > 0.25% XPAM > Topsoil > 0.25% XPAA = 0.5% XPAA = control (0.224). In all years, the 0.25% XPAM and 0.5% XPAM treatments increased soil PAW relative to the control, i.e. their PAW ratios exceeded unity. Topsoil PAW exceeded that of the control in 6 of the 7 years measured. The PAW of 0.25% XPAM and 0.5% XPAM peaked in year one after application and declined linearly with time (P<0.03), at -0.0036 /yr and -0.0044/yr, respectively. Hence, the half-life of the XPAM-related water-retention benefit is 10 to 16 years. In this study, soil water-retention benefits from XPAM amendments exceeded projections proposed by the industry (5 years in soil) and suggests that the cost-benefit of farm-scale XPAM applications might be more favorable than previously anticipated
2020 southern Idaho hard winter wheat quick facts
Full text linkThe respective fact sheets list key production recommendations for southern Idaho for the respective crops that ensure growers have easy and timely access to information. Specific recommendations vary depending on the specific type of wheat that is grown. These extension publications include fertilizer recommendation rates, irrigation management and scheduling, pest, disease, and weed management, as well as planting decision recommendations for timing and seeding rate
2020 southern Idaho hard spring wheat quick facts
Full text linkThe respective fact sheets list key production recommendations for southern Idaho for the respective crops that ensure growers have easy and timely access to information. Specific recommendations vary depending on the specific type of wheat that is grown. These extension publications include fertilizer recommendation rates, irrigation management and scheduling, pest, disease, and weed management, as well as planting decision recommendations for timing and seeding rate
Influence of environmental conditions on extracellular and intracellular antibiotic resistance genes in manure-amended soil: A microcosm study
Full text linkExtracellular and intracellular antibiotic resistance genes (eARGs and iARGs) possess significant differences with respect to their mobility and availability to bacteria, thus it is important to understand their partitioning, persistence, and fate in the environment. The objectives of this study were to: (i) modify the protocol of a commercial DNA extraction kit to sequentially extract extracellular and intracellular DNA (eDNA and iDNA) from the same soil sample; and (ii) determine the effect of temperature (5, 20, and 35C), water holding capacity (25, 50, and 75% of WHCmax), and freeze-thaw (-20/20C) on the abundance of two ARGs [sul1 and tet(M)], class 1 integron-integrase gene (intI1), and 16S rRNA gene in soils treated with dairy manure. To assess the efficiency of the eDNA/iDNA method, we performed spiking and recovery experiments with a gene that codes for a green fluorescent protein (gfp). When soils were spiked with a whole-cell preparation of gfp-containing E. coli, the recovery of the gfp gene was on average 0.2% and 1.2% for eDNA and iDNA, respectively. Soils were also spiked with the gfp gene itself, which showed that nearly 80% of the DNA could not be recovered. Results from the microcosm experiments indicate that extracellular and intracellular sul1, tet(X), intI1, and 16S rRNA genes are resilient and not readily affected by temperature, WHC, or freeze-thaw cycles. The intracellular gene levels decreased only slightly during the 56-day incubation period. The extracellular gene levels (when detectable) decreased dramatically by day 7, then leveled off thereafter, which may have been caused by adsorption to soil particles and/or degradation. Absolute gene abundances (per g of dry soil) were one to two orders of magnitude higher in iDNA than in eDNA fractions, but were similar when normalized to the 16S rRNA gene throughout the incubation period, indicating that enrichment of eARGs and iARGs did not occur. It is important for the scientific community to standardize total, as well as, extracellular/intracellular DNA extractions in order to readily compare results between laboratories