BUREAU OF PLANT INDUSTRY. 275 



opment of excellent foundation stock ; in fact, the department's stock 

 of the leading commercial sorts, when placed in comparison with the 

 commercial run of the variety as handled in several producing re- 

 gions, has invariably given a better account of itself than the local 

 product. Now that the variety studies have been published, it is 

 proposed to use the collection as the basis for careful breeding and 

 selection work. In addition to this, in cooperation with the Office of 

 Experiment Stations through its station at St. Croix in the Virgin 

 Islands, seed of a number of the important varieties of sweet pota- 

 toes has been obtained, and seedlings are now being grown from this 

 supply with the hope that sorts more desirable than any now avail- 

 able may be produced. It is impossible to produce and ripen sweet- 

 potato seed in the open in the latitude of AVashington, D. C, 

 because of the shortness of the growing season, but under the tropical 

 conditions of the Virgin Islands a seed supply can be obtained. 



PEAS. 



Studies of the Alaska variety. — ^For two years samples of peas 

 of the Alaska variety, which are used as the basis of a very 

 large percentage of the acreage planted for canning purposes, 

 have been obtained in the open market and grown side by side 

 in the trial grounds. In 1923 the growing tests of Alaska peas com- 

 prised 219 samples secured in this way. Of these samples, 11 proved 

 to be true to name with no ofF-type plants; 16 were off-type only in 

 the slightly greater length of the vines, while the production and 

 character of the pods would admit them to cultivation for canning 

 purposes; and 67 additional samples showed less than 10 plants per 

 rod of row of off-type peas and vines. Of the remainder there were 

 51 samples which showed from 10 to 25 plants per rod having long 

 vines not characteristic of the Alaska variety. The samples that had 

 more than 25 plants per rod of long vines numbered 39, while 35 

 samples were either not Alaskas or were so-called " wild Alaskas " or 

 field peas. In this test of 219 samples offered in the open market by 

 the trade 4.6 per cent Avere high-grade Alaskas, 7.4 per cent showed 

 only off-type vines, and 31.1 per cent had less than 10 plants per 

 rod off-type in character. Of these samples, 94 could be used for 

 canning purposes, but 125 samples were such decided departures 

 from the Alaska type that they could not be successfully handled in 

 commercial plantings by canners. 



The results of the tests in 1923 parallel very closely those of 1922 

 and furnish a fairly true index, it is believed, of the character of 

 the seed being offered to the trade by the commercial seedsmen of 

 the country. It must be borne in mind, however, that while this 

 analysis has been made from the standpoint of the canner, whose 

 requirements are very much more exacting than those of the market 

 gardener or home gardener, it is the large commercial interests, 

 such as the canning industry, that are most seriously affected when 

 the supply of seed falls into one of the categories below the grade 

 which can be tolerated by the industry. The planting of extensive 

 acreages of spurious or off-type Alaska peas in the eastern part of 

 the canning territory during recent years has resulted in very great 

 losses to the growers as well as to the canners. In fact, some of the 

 off-type Alaskas contained field peas which mature with the Alaskas 

 but give an entirely different reaction in processing. The presence 



