The influence of fusarium species on sweet potato plant performance, root yield and quality
Abstract
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Sweet potato (Ipomoea batatas (L.) Lam.) is a global important food crop, that has recorded an increase in the consumption, and demand for especially organically produced sweetpotatoes in recent years. Organic sweet potato growers however, face challenges due to the limited options available to manage soilborne diseases and pests that reduce sweetpotato root yield and/or quality, of which Fusarium spp. are a common culprit. This presents a growing need for information under an organic sweetpotato production system. The first part of the study evaluated five commonly grown sweet potato cultivars for their tolerance to Fusarium isolates, as well as their yield under field conditions over a two year period. The study revealed that infection by Fusarium isolates resulted in reduced plant vigor, which varied among cultivars. Similarly, the occurrence of Fusarium root rot in storage varied among cultivars, with Centennial proving to be most susceptible compared to Covington. An invitro inoculation study then demonstrated the potential use of Fourier Transform Infrared Spectroscopy to detect changes in root quality following infection by Fusarium. The last part of the study was conducted in collaboration with an organic sweet potato grower to develop a strategy of using cover and/or green manure crops, by evaluating their effects on plant health, weed suppression and root yield in organic production systems. The results showed that tilling the cover crops into the soil as green manure prior to transplanting sweet potato slips resulted in healthier sweet potato plants, greater weed suppression and greater root yield compared to plots without cover crops. Collectively, cultivar selection and incorporation of cover crops in sweetpotato production could minimize the effects caused by Fusarium spp.
Degree
M.S.
Thesis Department
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