Experimental sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2012

Rhizomania 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 experimental 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 34 to 90%, weight loss ranged from 8.4 to 15.4%, sucrose losses ranged from 33 to 72%, and estimated recoverable sucrose ranged from 1,997 to 7,601 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

Commercial sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2013

Rhizomania 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, 28 commercial cultivars were screened by growing them in a sugar beet field infested with BNYVV in Kimberly, ID during the 2013 growing season in a randomized complete block design with 4 replications. At harvest on 11 October 2013, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. After 123 days in storage, samples were evaluated for surface rot, weight loss, and sucrose loss. Surface root rot ranged from 6 to 86%, weight loss ranged from 4.5 to 14.8%, sucrose losses ranged from 30 to 75%, and estimated recoverable sucrose ranged from 917 to 8,686 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

Experimental sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2013

Rhizomania 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, 24 experimental cultivars were screened by growing them in a sugar beet field infested with BNYVV in Kimberly, ID during the 2013 growing season in a randomized complete block design with 4 replications. At harvest on 11 October 2013, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. After 123 days in storage, samples were evaluated for surface rot, weight loss, and sucrose loss. Surface root rot ranged from 7 to 76%, weight loss ranged from 6.6 to 11.6%, sucrose losses ranged from 32 to 66%, and estimated recoverable sucrose ranged from 1,643 to 8,308 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

Commercial sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2010.

Rhizomania 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, 28 commercial cultivars were screened by growing them in a sugar beet field infested with BNYVV in Kimberly, ID during the 2010 growing season in a randomized complete block design with 4 replications. At harvest on 18 October 2010, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. Storage samples were evaluated for fungal growth known to correlate with sucrose loss. Depending on cultivar, surface root discoloration (rot and fungal growth) ranged from 1 to 14%. Overall, the commercial cultivars had an average sucrose reduction of 27% after 112 days in storage. Improving cultivar performance for resistance to sucrose loss in storage and rhizomania has the potential to lead to considerable economic benefit to the sugar beet industry

Commercial Sugar Beet Cultivars Evaluated for Rhizomania Resistance and Storability in Idaho, 2009

Rhizomania 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, 22 commercial cultivars were screened by growing them in a commercial sugar beet field naturally infested with BNYVV in Declo, ID during the 2009 growing season in a randomized complete block design with 4 replications. At harvest on 13 October 2009, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. Storage samples were evaluated for fungal growth known to correlate with sucrose loss. Depending on cultivar, surface fungal growth ranged from 5 to 42% by 18 February 2010. Overall, the commercial cultivars had an average sucrose reduction of 33% after 131 days in storage. Improving cultivar performance for resistance to sucrose loss in storage and rhizomania has the potential to lead to considerable economic benefit to the sugar beet industry

Experimental Sugar Beet Cultivars Evaluated for Rhizomania Resistance and Storability in Idaho, 2009

Thirty-four experimental sugar beet cultivars and five commercial check cultivars were evaluated in a commercial sprinkler-irrigated sugar beet field near Declo, ID where winter wheat was grown in 2008. The field trial relied on natural infection for rhizomania development. The plots were planted on 20 Apr 09 to a density of 142,560 seeds/A, and thinned to 47,520 plants/A on 8 Jun. Plots were four rows (22-in . row spacing) and 24 ft long. The experimental design was a randomized complete block design with four replications per cultivar. The crop was managed according to standard cultural practices. The plants were mechanically topped and the center two rows were collected with a mechanical harvester on 13 Oct. At harvest the roots were evaluated for rhizomania (Rz rating) using a scale of 0-9 (0 = healthy and 9 = dead). The percent sucrose at harvest was established based on two eight-root samples from each plot. The samples were submitted to the Amalgamated Tare Lab (determined percent sucrose, conductivity, nitrates, and tare). At harvest, eight roots per plot were also placed in a mesh onion bag, weighed, and placed in an indoor commercial sugar beet storage facility in Paul, ID on 14 Oct set to hold 35°F. On 18 Feb 10, the roots were evaluated for the percentage of surface area covered by fungal growth. On 22 Feb 10 roots were retrieved after 131 days in storage and evaluated for weight and percent sucrose (via gas chromatography). Only samples from the same plots were compared, when establishing percent reduction in sucrose at harvest versus storage. Data were analyzed using the general linear models rocedure (Proc GLM-SAS), and Fisher’s protected least significant difference was used for mean comparisons. Root rots and other disease problems other than rhizomania were not evident in the plot area. Rhizomania was uniform based on foliar symptoms, but root symptom development was minimal. Nevertheless, there were significant differences among cultivars for all variables, except fungal growth on the root surface in storage. B-101 was borderline for rhizomania resistance, since cultivars with ratings over 3.0 are considered susceptible. Root yield averaged 37 tons/A which was higher than Idaho’s average of 31 tons/A (USDA-National Ag. Stat. Service). Surface fungal growth ranged from 4 to 30% and surface root rot ranged from 1 to 20%, depending on cultivar. By the end of the storage season, weight loss ranged from 3.1 to 7.1% and sucrose losses ranged from 23 to 57%. Thus, improving storability in sugar beet cultivars to reduce sucrose losses could have considerable economic benefit

Experimental sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2011

Rhizomania 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, 24 experimental cultivars were screened by growing them in a sugar beet field infested with BNYVV in Kimberly, ID during the 2011 growing season in a randomized complete block design with 4 replications. At harvest on 18 October 2011, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. Storage samples were evaluated for fungal growth known to correlate with sucrose loss. Depending on cultivar, surface root discoloration (rot and fungal growth) ranged from 2 to 37%. Overall, the experimental cultivars had an average sucrose reduction of 38% after 120 days in storage. Improving cultivar performance for resistance to sucrose loss in storage and rhizomania has the potential to lead to considerable economic benefit to the sugar beet industry

Influence of Rhizoctonia-bacterial Root Rot Complex on Storability of Sugarbeet

The Rhizoctonia-bacterial root rot complex can lead to yield loss in the field but may also lead to problems with sucrose loss in storage. Thus, studies were conducted to investigate if placing sugarbeet roots suffering from root rot together with healthy roots could compromise the ability of the healthy roots to retain sucrose. Over a three year period, root samples from three commercial cultivars were compared in storage as a healthy (eight healthy roots) or rotted (eight healthy roots + one rotted root) treatment inside an outdoor storage pile. The experiment was arranged as a split block (healthy in one half of block and rotted in the other) with the whole blocks arranged in a randomized complete block design with four replications. Samples were retrieved from storage in December, January, and February and evaluated for discolored and frozen root area, weight loss, and sucrose reduction and recovery. When comparing the healthy to the rotted treatment over the nine year x sampling date combinations, the Wilcoxon signed-rank test indicated the median change for discoloration (7% increase), frozen area (14% increase), sucrose loss (5% loss), and recoverable sucrose (689 kg/ha less or 8% reduction) were significantly different from zero (P = 0.008, 0.031, 0.007, and 0.008, respectively). These data indicate that the Rhizoctonia-bacterial root rot complex not only leads to yield loss in the field but can also negatively affect neighboring healthy roots in storage leading to additional sucrose losses

Experimental sugar beet cultivars evaluated for resistance to rhizomania and storability in Idaho, 2010

Twenty-seven experimental sugar beet cultivars and five commercial check cultivars were evaluated in a sprinkler-irrigated sugar beet field near Kimberly, ID where sugar beet were grown in 2009. The field trial was conducted in a field that contained Portneuf silt loam soil and relied on natural infection for rhizomania development. The plots were planted on 26 Apr 10 to a density of 142,560 seeds/A, and thinned to 47,520 plants/A on 12 Jun. Plots were four rows (22-in. row spacing) and 24 ft long. The experimental design was a randomized complete block design with four replications per cultivar. The crop was managed according to standard cultural practices. The plants were mechanically topped and the center two rows were collected with a mechanical harvester on 18-19 Oct. At harvest the roots were evaluated for rhizomania (Rz rating) using a scale of 0-9 (0 = healthy and 9 = dead). The percent sucrose at harvest was established based on two eight-root samples from each plot. The samples were submitted to the Amalgamated Tare Lab (determined percent sucrose, conductivity, nitrates, and tare). At harvest, eight roots per plot were also placed in a mesh onion bag, weighed, and placed in an indoor commercial sugar beet storage facility in Paul, ID on 19 Oct set to hold 35°F. On 7 Feb 11 roots were retrieved after 112 days in storage and evaluated for weight, percentage of surface area covered by rot or microbial growth, and percent sucrose (via gas chromatography). Only samples from the same plots were compared, when establishing percent reduction in sucrose at harvest versus storage. Data were analyzed in SAS (Ver. 9.2) using the generalized linear mixed models procedure (Proc GLIMMIX), and least squares means (? = 0.05) were used for mean comparisons. Root rots and other disease problems other than rhizomania were not evident in the plot area. Rhizomania was uniform based on foliar and root symptoms. There were significant differences among cultivars for all variables, except surface root rot. B-103 was susceptible to rhizomania as expected, but C-31 had a higher foliar reading than expected. Root yield averaged 33.3 tons/A which was higher than Idaho’s average of 31.0 tons/A (USDA-National Ag. Stat. Service). By the end of the storage season, weight loss ranged from 6.0 to 11.4% and sucrose losses ranged from 19 to 33%. Thus, improving storability in sugar beet cultivars to reduce sucrose losses could have considerable economic benefit