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Dry Heat and Hot Water Treatments for Disinfesting Cottonseed of Fusarium oxysporum f. sp. vasinfectum

Permanent URL:
http://handle.nal.usda.gov/10113/48476
Abstract:
The potential of low- and high-temperature dry heat, and hot water treatments, for disinfesting cottonseed of Fusarium oxysporum f. sp. vasinfectum was investigated. Naturally infected seeds from Louisiana were air-heated at 30, 35, and 40°C for up to 24 weeks. Seed harvested from bolls inoculated with race 4 of F. oxysporum f. sp. vasinfectum were incubated in dry heat at 60, 70, and 80°C for 2 to 14 days, or were immersed in 90°C water from 45 s to 3 min. The effects on seed germination and vigor of hot water treatment and a subset of the high-temperature dry heat treatments were also examined in seeds of a Pima (Gossypium barbadense) and an Upland (G. hirsutum) cultivar. Low- or high-temperature dry heat did not eliminate Fusarium spp. from the seed, although seed infection declined more rapidly with higher incubation temperatures. High-temperature dry heat treatments effective in eliminating fusaria also significantly reduced seed vigor in both the Pima and Upland cultivars. Seed from all times of immersion in hot water were less frequently infected with Fusarium spp. than nontreated seed. Incidence of seed infection did not differ significantly among immersion times ranging from 75 s to 3 min. Immersion in 90°C water did not reduce germination or vigor at exposure times < or = 120 s and < or = 150 s for seeds of Pima and Upland cotton, respectively. Results from the hot water treatments suggest that thermotherapy may be optimized to provide a tactic to prevent the spread of virulent F. oxysporum f. sp. vasinfectum genotypes into uninfested areas through infected seed.
Author(s):
Bennett, Rebecca S. , Colyer, Patrick D.
Subject(s):
Gossypium hirsutum , Gossypium barbadense , cotton , Fusarium oxysporum f. sp. vasinfectum , plant pathogenic fungi , hot water treatment , heat treatment , seed-borne fungi , seed-borne diseases , disinfection , seed treatment , seed germination , vigor , cottonseed , planting seed , disease incidence , optimization , Louisiana
Format:
p. 1469-1475.
Note:
Includes references
Source:
Plant disease 2010 Dec., v. 94, no. 12
Language:
English
Year:
2010
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
File:
Download [PDF File]
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.