Postharvest Storage Losses Associated with Rhizomania in Sugar Beet

Abstract

During storage of sugar beet, respiration and rots consume sucrose and produce invert sugar. Diseases that occur in the field can affect the magnitude of these losses. This research examines the storage of roots with rhizomania (caused by Beet necrotic yellow vein virus) and the effectiveness of rhizomania-resistant hybrids in reducing postharvest losses. Roots of susceptible hybrids from sites with rhizomania had respiration rates 30 days after harvest (DAH) that ranged from 0.68 to 2.79 mg of CO2 kg–1 h–1 higher than roots of the resistant hybrids. This difference ranged from 2.60 to 13.88 mg of CO2 kg–1 h–1 120 DAH. Roots of resistant hybrids from sites with rhizomania had 18 kg more sucrose per ton than roots from susceptible hybrids 30 DAH, with this difference increasing to 55 kg Mg–1 120 DAH. The invert sugar concentration of susceptible hybrids from sites with rhizomania ranged from 8.38 to 287 g per 100 g of sucrose higher than that for resistant hybrids 120 DAH. In contrast, differences between susceptible and resistant hybrids in respiration rate, sucrose loss, and invert sugar concentration in the absence of rhizomania were relatively small. Storage losses due to rhizomania can be minimized by planting resistant hybrids and processing roots from fields with rhizomania soon after harvest.

Sugar Beet Cultivar Evaluation for Storability and Rhizomania Resistance

“…Commercial cultivars currently possess the Rz1 gene for resistance to BNYVV, but resistance breaking strains have been discovered in the United States (1,17). Rhizomania can severely impact yield variables in susceptible cultivars but recently has been shown to impact storability as well (8,28). Even by early December in outdoor piles under ambient conditions, infested roots can suffer significant sucrose reductions (28).…”

“…Other factors can also influence sucrose loss such as scalping, impacts, and wounding during harvest and transport, mud and weeds in piles, and unusually high or low temperatures (2,6,10,13,16,19,33). Disease and drought stress during crop production may also predispose the roots to sucrose loss in storage (8,14,15,27,28). Rhizomania (8,28), curly top (27), Rhizoctonia root rot (15), Aphanomyces root rot (7), and Cercospora leaf spot (24) during crop production have all been shown to lead to increases in sucrose loss in storage.…”

“…Disease and drought stress during crop production may also predispose the roots to sucrose loss in storage (8,14,15,27,28). Rhizomania (8,28), curly top (27), Rhizoctonia root rot (15), Aphanomyces root rot (7), and Cercospora leaf spot (24) during crop production have all been shown to lead to increases in sucrose loss in storage.…”

Influence of Harvest Timing, Fungicides, and Beet necrotic yellow vein virus on Sugar Beet Storage

“…), curly top (Beet curly top virus), Fusarium yellows (Fusarium oxysporum f. sp. betae W. C. Snyder & H. N. Hansen), Rhizoctonia root rot (Rhizoctonia solani Kühn), and rhizomania (Beet necrotic yellow vein virus [BNYVV]) store more poorly than roots produced by healthy plants (15)(16)(17)27,44,(50)(51)(52).…”

“…Because rhizomania is widespread in many production areas, host resistance to BNYVV is required for a sugar beet cultivar to be approved for production by seed committees in the United States (33,42). In addition, BNYVV has been shown to affect sugar beet storage by causing a loss of sucrose (17,49,51). The virus is thought to increase sucrose loss by increasing root respiration (17) or by facilitating microbial growth on the roots that subsequently leads to sucrose reduction (49,51).…”