Potato XXII – 9

Seed Treatments

Gary D. Franc

Caution! Do not use treated seed for food, feed or fodder.

Potato seed treatment is an important component of an overall disease management program. Properly suberized and properly treated seed will provide a better, more uniform plant stand. Proper application of the appropriate material is necessary. Too much chemical may prove phytotoxic while inadequate coverage may not provide adequate control. Dust formulations are preferable for cut seed because liquid dip treatments may inhibit wound healing and can spread bacteria. Only high quality seed should be planted and seed treatment will not compensate for a seedlot that is already diseased. Soil should have adequate moisture for emergence at the time of planting and the temperature at planting depth should be at least 45° F.

Product list for seed treatment:

Product	Disease		Product		Remarks
(grouped by active ingredient)
Captan
Captan 5%	Fusarium dry rot	1-2 lb per bushel		Treat whole or cut seed, rates varying with adhesion. Treat within 6 hr of cutting.
Captan 7.5 Dust	Fusarium dry rot	10 oz-1.0 lb per 100 lb cut seed		Treat whole or cut seed, rates varying with adhesion. Treat within 6 hr of cutting.
Fludioxonil
Maxim Maxim MZ Maxim 4FS	Fusarium dry rot, Rhizoctonia, Seed-borne Helminthosporium solani (Silver scurf)	0.5 lb per 100 lb seed potatoes 0.08 – 0.16 fl.oz per 100 lb seed potatoes		Does not control bacterial diseases. Resistance is possible. In seed producing areas, growers should use Maxim MZ
Maneb
Maneb 75 DF	Fusarium dry rot	1 lb per 10 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Maneb 80 WP	Fusarium dry rot	1 lb per 10 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Seed Treatment for Potatoes LD (plus Streptomycin Sulfate)	Fusarium dry rot, Rhizoctonia, Blackleg	1 lb per 100 lb of seed potatoes		Apply for thorough coverage to whole or cut seed.
Mancozeb
Dithane DF	Fusarium dry rot, Seedborne common scab	1.25 lb per 50 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Dithane F-45	Fusarium dry rot, Seedborne common scab	1 qt per 50 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Dithane M-45	Fusarium dry rot, Seedborne common scab	1.25 lb per 50 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Dithane WSP	Fusarium dry rot, Seedborne common scab	1.25 lb per 50 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Manzate 75 DF	Fusarium dry rot, Seedborne common scab	1.25 lb per 50 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Penncozeb 75 DF	Fusarium dry rot	1.25 lb per 50 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Penncozeb 80 WP	Fusarium dry rot	1.25 lb per 50 gal of water		Dip whole or cut tubers, spread treated seed pieces in a cool place if held before planting.
Potato Seet Treater 6%	Fusarium dry rot	1-1.3 lb per 100 lb seed potatoes		Apply for thorough coverage to whole or cut seed.
Potato Seet Treater PS	Fusarium dry rot	1 lb per 100 lb seed potatoes		Apply for thorough coverage to whole or cut seed.
Metiram
Potato Seed Treater	Fusarium dry rot, Seedborne Common Scab	1-1.5 lb per 100 lb seed potatoes		Apply for thorough coverage to whole or cut seed.
Streptomycin-sulfate
Agri-mycin 17	Tuber soft rot and Blackleg	100 ppm (4 oz per 100 gal of water)		Soak cut seed pieces in streptomycin solution for several minutes. A suitable fungicide should be used as an adjunct.
Thiophanate-methyl
TOPS 2.5D	Fusarium (dry rot), Rhizoctonia	1 lb per 100 lb of cut seed		Treat cut seed; resistance of some organisms is possible.
TOPS 5	Fusarium (dry rot), Rhizoctonia	0.5 lb per 100 lb of cut seed		Treat cut seed; resistance of some organisms is possible.
TOPS MZ (plus Mancozeb)	Fusarium (dry rot), Rhizoctonia, Silver Scurf, Late Blight	0.75-1.0 lb per 100 lb of cut seed		Treat cut seed; TOPS MZ is not efficacious against systemic seed-piece infections or airborne (secondary inoculum. Resistance is possible.
In-furrow fungicides
Blocker 10G and 4F	Rhizoctonia stem canker and black scurf		Apply as in-furrow granular 1.65 lb/1000 linear ft. of row (25 lb/A) in 8.5” bands or as in-furrow. Spray 5.2-10.4 fl.oz/1000 linear ft. of row (5 – 10 pt/A) in 8.5” band. Cover during hilling. Use 10 – 2- gal water carrier.		Do not harvest within 45 days of application
Quadris	Rhizoctonia stem canker and black scurf		In-furrow: Apply 0.4 – 0.8 fl.oz/1000 linear feet of row in 5–15 gallons of water in 6-7” band. Cover during hilling.
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.

Categories: Seed treatments, Potato

Date: 02/20/2003