20 ANNUAL REPORTS O* DEPARTMENT OP AGRICULTURE, 1 
washing or treating potato tubers grown on regulated lands, local 
growers financed and erected a $200,000 processing plant. 
The potato rot nematode survey in tne Northwestern St 
ready access to numerous potato lots in cellars, storages, and grading 
operations, and made if possible to collect soil samples in these loca- 
tions and from refuse piles and waste dumps. Such soil samples inci- 
dentally obtained direct from intimate associat ion with tin- potato host 
were ideal places in which to detect golden nematode cysts in case 
parasite were present in that region. Accordingly, :»7^ samples 
of such soil collected from L42 location- were forwarded to the 
Bureau's Hickville, Long Island, laboratory for the standard wash- 
ing and screening procedure. No t race of golden nematode \\ as found 
in any of them. 
Potato Rot Nematode Limited to Small Area in Idaho 
The potato rot nematode, long present in northern Europe as a 
rot-producing parasite on potato tubers, is known on the American 
continent from only two localities — a small area near Aiberdeen, 
Idaho, and on a few potato farms in the Province of Prince Edward 
Island, Canada. The Idaho infestation was recognized in 1943, and 
this nematode was reported from Prince Edward Island in 1945. 
Survey- by Canadian authorities in 1946 revealed no wide-])]. -ad 
infestat ion on Prince Edward Island, nor was it found in the 14 north- 
eastern State- scouted by Bureau and State officials. Neither in these 
survey.- nor in additional search made in L947 I s incidental to golden 
nematode surveys in New York and New England was any rot 
nematode disclosed. 
In December r.H v rot nematode infestation was reported in a second 
county ill Idaho. A survey was then undertaken cooperatively with 
the State- of California, Colorado. Idaho. Montana, Nevada, On 
Utah, and Washington to determine whether the nematode was pres- 
ent elsewhere in the Northwestern State-. It was carried out during 
the period of the spring potato movement from storage to market. 
largely in March and April 1949. At this season the tuber rot symp- 
toms produced by the internally developing nematode- are most evi- 
dent and large volume- of potatoes can be examined during the 
grading process. In these operation- 221,643 bushels oi potatoes, 
representing the crops of 1,024 growers in 66 count ies, were examined. 
Oi this total, 128,914 bushels coming from 702 farm- were seen in 11 
Idaho counties. Samples of all suspected tubers found were referred 
for technical determination to nematode expert- in Idaho or in the 
Bureau of Plant [ndustry, Soils, and Agricultural Engineering, but 
no case of rot nematode was encountered outside the known infested 
area in Idaho. This fortunate outcome, especially when considered 
in conjunction with the negative results from the previous surveys, 
seem- to indicate that the potato pot nematode is not widely preva- 
lent in our important potato producing area-, outside of tin* small 
section in Idaho, where incidence is in general light and limited to 
ess than 20 farms. 
