THE MONTHLY BULLETIN. 409 



Tuber Moth. 



Stress was laid upon the importance of the tuber moth question. 

 Potatoes harboring this moth, he said, and shipped to other states, had 

 resulted in a quarantine in three or four sections or states, and led to the 

 destruction of Avhole carloads of California potatoes in still other states, 

 with much loss to the .shippers. Clean potatoes only should be shipped 

 or the people must expect these quarantines and this destruction 

 continued, and even increased. 



A Timely Suggestion. 



He sugsested that many of our foothill valleys — as also on the plains 

 — wherethe soil, sunshine and water insure large crops of ideal pota- 

 toes and where there are no insect or fungoid pests, should produce 

 seed potatoes which would meet every requisite of the most painstaking 

 grower. There was an opportunity for any alert rancher in any of 

 these favored localities to produce clean seed. 



The Control of the Tuber Moth. 



In speaking of the tuber moth, W. H. Volck, county horticultural com- 

 missioner of Santa Cruz County, stated that the tuber moth had existed 

 for many years in California, and that it had undoubtedly become as 

 much of' a pest as natural conditions would permit. 



Hilling to Control Tuber Moth— Be spoke of an experiment to control 

 the tuber moth by hilling, which was conducted on both adobe and 

 sandy lands. Some of the rows of potatoes in sandy and adobe lands 

 were hilled just before the tubers were setting, or about July 15th. 

 Other rows in both the two types of soil received the same treatment a 

 month or six weeks later. The hilling was performed in a thorough 

 manner, first with the plow, and then finished with a hand hoe. In the 

 adobe soil care was taken to fill in around the stems of the plants with 

 soil as free from clods as possible. The potatoes were harvested in 

 September, and the percentage of Avorm-infested tubers was determined 

 by weight. In the early hilled adobe land 16.5 per cent of the potatoes 

 Avere wormy; in the early hilled sandy land 9.9 per cent were wormy; 

 in the late hilled adobe land 42.3 per cent were wormy ; in the late hilled 

 sandy land 22.3 per cent were wormy. The importance of early hilling 

 could be easily seen from the above figures. The hilling must be 

 properly done."^ It was necessary, he said, to cover the tubers with from 

 four to six inches of finely pulverized earth. In order to do this the 

 rows should not be less than forty inches apart. The hilling must be 

 finished with the hand hoe, as no plow could properly draw the earth 

 in around the stems of the plants. 



Treatment hij Soaking — The hilling method did not, however, solve 

 the problem of storage, where the worms might have time to mature into 

 moths, lay numerous eggs and, perhaps, infest the greater portion of 

 the tubers. This was the most serious part of the problem to the grower. 

 No fumigation process had been devised which would kill the worms 

 inside the tubers without rendering those so trea+ed unfit for use. Some 

 of the growers had observed that the early rains before digging had 

 lessened the trouble from this pest. By experimenting along these lines 

 it was found that a soaking period of thirty-six hours was sufficient to 

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