BUREAU OF PLANT INDUSTRY. 341 



Onion investigations. — During the past year seed of the Denia 

 onion has been distributed to some twenty localities in the south- 

 western part of the United States. Although it is yet too early to 

 publish results from any of these experiments, the results of last 

 year's trials, together with those achieved at the New INfexico Agri- 

 cultural Experiment Station with seed imported by the Department 

 of Agriculture and from other sources, justif}'' further work on this 

 crop. 



Celery investigations. — The methods of culture practiced by the 

 celery growers in the vicinity of both Stockton and Los Angeles, Cal., 

 were studied during the season. The workings of cooperative mar- 

 keting as carried on by the California Vegetable Union were also 

 investigated. A representative of the Department also visited the 

 Florida celerj^ region during the harvesting season and investigated 

 the causes of the late harvest, as well as the cultural practices fol- 

 lowed in bringing this crop forward for market. 



Saveet-potato investigations. — A study of the varieties of sweet 

 potatoes has been continued. The variety collection has been main- 

 tained and plants of leading market sorts have been distributed for 

 trial in new localities. An investigation of some of the troubles of 

 sweet potatoes while in storage has been undertaken in cooperation 

 with another office of the Bureau of Plant Industry. The investiga- 

 tion of the value of desiccated sweet potatoes as stock food has been 

 continued. Samples aggregating several hundred pounds have been 

 dried, these being sufficient to demonstrate the practicability of the 

 process. Analyses of the dried product indicate a high value as stock 

 food. 



Vegetable testing. — The study of varietal differences in garden 

 vegetables and their practical importance has been continued under 

 the immediate charge of Dr. W. W. Tracy, and material progress has 

 been made, not onl}' in our knowledge of such differences but in 

 directing attention to their importance. A number of the largest 

 packers and canners have appealed to the Department for suggestions 

 and advice as to the best varietal type for their particular purpose 

 and how best to obtain seed which will uniformly develop into plants 

 of that type. This study has made it clear that in some instances 

 superior varieties have been ignored by seedsmen, so that it is very 

 difficult to obtain seed in commercial quantity, because seed of such 

 varieties can not be as profitably grown and handled at the same 

 price as that of some of the more common sorts. 



The importance of uniformity of stock and the practical possibility 

 of effecting a great improvement in this respect by wisely directed 

 line breeding have been studied and material improvement in methods 

 has been developed. The work of preparing a set of bulletins on the 

 growing of superior strains of vegetable seeds has been continued, 

 and a publication on growing the seed of sweet corn, peas, and beans 

 has been issued, while others on growing seed of cruciferous and 

 cucurbitaceous plants are in preparation. 



Fertilizer experiments with truck crops, — The fertilizer experi- 

 ments inaugurated at Norfolk, Va., and in the Long Island area have 

 been continued, and a very important observation has grown out of 

 this work, namely, the value of potash in the form of sulphate as 



