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Optimal rates of 2,4-dichlophenoxyacetic acid foliar application for control of common scab in potato


Thompson, HK and Tegg, RS and Corkrey, R and Wilson, CR, Optimal rates of 2,4-dichlophenoxyacetic acid foliar application for control of common scab in potato, Annals of Applied Biology, 165, (2) pp. 293-302. ISSN 0003-4746 (2014) [Refereed Article]

Copyright Statement

Copyright 2014 Association of Applied Biologists

DOI: doi:10.1111/aab.12138


Applications of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) to the foliage of potato plants can reduce common scab, a tuber disease. However, in prior research effective applications at 200 mg L−1 2,4-D resulted in phytotoxic side effects with reduced tuber yield and quality. This study showed that minimal significant threshold rates from 8.3 to 23.6 mg L−1 2,4-D reduced disease incidence in pot trials, and from 10.8 to 41.0 mg L−1 minimised disease severity in both pot and field trials. In only one pot trial, significant phytotoxicity was found with rates of 100 mg L−1 or greater, reducing mean total tuber mass per plot and 38 mg L−1 or greater, reducing mean mass per tuber. Notably, within the field trial, a more reliable plant growth system for estimation of yield, no significant impacts were observed. Disease control was associated with decreased sensitivity of tubers to thaxtomin A, the phytotoxin produced by the common scab pathogen essential for disease induction. The amount of residual 2,4-D in tubers at harvest varied with cultivar, Russet Burbank accumulating more 2,4-D than Desiree. Application rates less than 100 mg L−1 resulted in levels of 2,4-D below the Australian standard maximum residue limit. These data suggest that applications of 2,4-D at low rates could provide a commercially suitable control strategy for common scab.

Item Details

Item Type:Refereed Article
Keywords:2,4-D, auxin, non-fungicidal foliar sprays, Solanum tuberosum, Streptomyces scabies
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Horticultural production
Research Field:Horticultural crop protection (incl. pests, diseases and weeds)
Objective Division:Plant Production and Plant Primary Products
Objective Group:Horticultural crops
Objective Field:Field grown vegetable crops
UTAS Author:Thompson, HK (Dr Hannah Thompson)
UTAS Author:Tegg, RS (Dr Robert Tegg)
UTAS Author:Corkrey, R (Dr Ross Corkrey)
UTAS Author:Wilson, CR (Professor Calum Wilson)
ID Code:93968
Year Published:2014
Web of Science® Times Cited:1
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2014-08-25
Last Modified:2017-11-06

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