Phyllosticta leaf blight of millet is caused by the fungus Phyllosticta penicillariae. Little is known about the conditions that favor disease development, but the pathogen is disseminated by air-borne spores and movement of infested crop debris. The pathogen survives between millet crops in and on infested crop debris and contaminated seed.
Phyllosticta leaf blight affected plants are stunted, yellow, and have numerous small lesions. These lesions have dark brown margins surrounding a light brown necrotic center. Individual lesions may coalesce, giving leaves a tattered appearance. Leaf margins are often necrotic. Small, dark fungal fruiting bodies (pycnidia) are apparent in diseased tissues. Yield loss estimates are not available for the High Plains.
No biological control strategies have been developed for Phyllosticta leaf blight.
Cultural control practices have not been developed for Phyllosticta leaf blight, but a three-year or longer crop rotation, incorporation of infested crop debris, and the planting of pathogen free-seed likely will reduce disease incidence and severity.
Broad spectrum seed treatments should be used routinely.
Product List for Phyllosticta Leaf Blight:
Pesticide |
Rate per 100 lb seed |
Application Frequency (days) |
Remarks |
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Captan—various formulations available |
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Captan 75 |
6-9 oz |
Seed treatment |
Broad spectrum, but weak against Pythium |
|
Fludioxonil |
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|
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Maxim 4FS |
0.034-0.068 fl oz |
Seed treatment |
Suppression of Fusarium and Rhizoctonia spp. |
|
Thiram |
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42-S Thiram |
8 fl oz |
Seed treatment |
Broad spectrum |
|
Thiram 50WP |
8 oz |
Seed treatment |
Broad spectrum |
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The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality. |
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Categories: Millet, Disease, Phyllosticta Leaf Blight
Date: 03/22/2005