(http://oregonstate.edu/potatoes/seed.htm)

Seed Varieties Produced: Oregon; US acres, Canadian Acres, Other

Selecting and Buying Seed, ....Certification 

Oregon Seed Production

Seed Production Methods

Handling, Cutting and Sanitation

Additional WWW Links
Oregon Seed Production

Information on available Oregon seed stocks by variety and supplier can be found in the current Oregon Seed Growers Directory (scroll down about 13 pages). Grower addresses, phone numbers and e-mail addresses are available elsewhere in the pamphlet.

Further information about Oregon seed, including the latest  Oregon Field Readings, is available through the Oregon Seed Certification Service. Selected seed suppliers for other states and regions are linked under Seed in the  Potato Information Exchange. You may also find it useful to sell or find seed via the Potato Country Magazine seed exchange page. If you have questions about individual seed growers or seed lots for any state or Canadian province, access Seed Certification Agencies for details.

Growers --

Certified pre nuclear seed potatoes are produced by the OSU Foundation Potato Seed Program and supplied to Oregon Seed Growers in various high elevation, isolated regions of the state for increase as Limited Generation stocks according to strict Certification Standards.   Oregon Seed Growers provide high quality seed of a number of chipping, fresh market and processing varieties at competitive prices. More information about Oregon seed is available from the Oregon Seed Potato Growers Association and The Oregon Seed Certification Service.

Seed pieces should be treated with a recommended, currently labeled (see CDMS for current labels),  fungicide such as Maneb, Mancozeb, Thiabendazole or Thiophanate-methyl  immediately after cutting. When possible, seed should be planted soon after cutting into warm (above 45F), moist but not wet soil. For rapid growth and emergence, sprouts should be "peeping" (slightly enlarged) at planting and physiologically active in preparation for rapid growth and emergence.

Extreme care should be taken to maintain seedlot identity throughout the cutting and planting operation. Sanitize cutters and other equipment between plantings to prevent the spread of bacterial diseases, especially bacterial ring rot. Good planting sequence records, sanitation, and isolation of lots is essential in proving the source of ring rot seed in the event of lawsuits.

Bacterial ring rot (Clavibacter michigansis subsp. sepedonicus) is the scourge of the potato industry. It is always introduced to seed farms via seed, soil, or equipment contaminated with the organism. It survives for extended periods (years) only in living potato tissues. In the unlikely event that bacterial ring rot (BRR) is present in seed lots, precautions should always be taken to minimize spread in order to contain the epidemic and identify the contaminated seed lot for possible compensation. The following steps will help reduce BRR infection.
 


The following disinfectants or fumigants are effective against BRR. In general, disinfect by wetting the surface with the product for at least 10 to 45 min and then thoroughly removing residues with water (see also Tables 2 and 3 below).


Recommended planting dates for Oregon range from early March in the Columbia Basin through early June in Christmas Valley. High elevation areas tend to be planted late because of cold soils and the danger of late frosts. By comparison, some Willamette Valley plantings on heavy soils can be delayed into June because of prolonged spring rains.

Top of Page
Home PIE
Back to OSPGA

 Table 2.  1998 Ohio Potato Production Guideline (Bulletin 672) Disinfectant Ratings for Control of BRR
 
Effectiveness of Disinfectants for Control of Ring Rot Bacteria1
Disinfectant
Metal
Wood
Burlap
Betadine*
g
g
g
Chlorine Bleach (10%)
s
s
g
Coal Tar
g
g
g
DeBac**
g
g
g
Ethyl alcohol (95%)
s
g
g
Formaldehyde (1%)
s
g
s
Formaldehyde (2%)
g
g
g
Formaldehyde (4%)
g
g
g
Vesphene*
u
u
s
Zephiran**
g
g
g
Lysol concentrate
u
u
s
Lysol spray
s
g
s
Phenol (5%)
s
s
s
Water
u
u
u
Soapy water
u
u
u
1Materials may not be labeled for use in all production areas; read labels carefully before using.
*Hospital disinfectant
**Quaternary ammonium compound
g = good control after 15-20 minutes
s = very slight survival of bacteria after 15-20 minutes
u = unacceptable control

Table 3.  Materials shown in the following table are commonly used for disinfecting potato
handling equipment and storage facilities for both seed and commercial potato operations1
 
  Effectiveness Inactivation           
Material
Wet Bact, Slime
Dry Bact,
Slime
Org. Matt.
Hard
Water
Corrosive ness
Safety
Conc.
Exp. 
Time
Shelf 
Life
Quaternary 
Ammon. Cpds.
Ex.
Ex.
Slight
No
Slight
Caution
See 
Label
10 min
1-2yr
Hypochlorites, 5.25% bleach
Ex
Ex.
Yes
No, ex. Iron
Yes
Irritant, 
caustic
1:50, 0.1%
10 min
3-4 mo. 
undiluted
Iodine Cpds.
Ex.
Ex.
Slight
No, ex.
iron
Yes
Caution
See 
Label
10 min
1-2 yr.
Phenolics 
Ex.
Ex
Slight
No
No
Oral 
Poison
See
Label
10 min
1-2 yr.
Formaldehyde
Gd.
Poor
No
Yes
No
Unsafe 
Vapors
0.37-1.0%
30 min
1-2 yr.
Copper Sulfate
Gd.
Gd.
No
Yes
Yes
Caution
10lb/100 
gal 
30-60 min
>10 yr. as
solid
1Materials may not be labeled for all producing areas; read labels carefully before using.
Adapted from: Disease Control Guidelines for Seed Potato Selection, Handling, and Planting, Extension Publication PP-877, North Dakota State
University. Registrations may vary. Check with local authorities.

Comments:
Quaternary Ammonium Compounds--Diluted solutions are relatively safe but concentrated form is poisonous. Slightly corrosive, use stainless.
Hypochlorites, 5.25% bleach--Quick acting, inexpensive; caustic to skin and clothing. Use at 1:50 when mixing with water only. For maximum effectiveness, use 1 part 5.25% bleach: 200 parts water; 0.6 parts white vinegar. Very corrosive.
Iodine Compounds--Not for internal use. Becomes ineffective as yellow-brown color is lost. Tamed iodophor compounds work best.
Phenolic Compounds--Provide residual action. These compounds show "phenol" in the list of of ingredients.
Formaldehyde--Use may be canceled. Produces irritating, choking fumes. Not generally recommended.
Copper Sulfate--Not widely used; mostly for soaking crates and bags.

Top of Page
Home PIE
Back to OSPGA
Additional Seed Related Links