1206 EARLE V. HARDENBURG 



For many years, the Long Island growers have been getting most of 

 their seed from Maine. In 'recent years, the decreasing quality of Maine 

 seed has resulted in the use of some seed from Vermont and New York. 

 Seed for the other three regions is almost entirely used within the county 

 where it is grown. Occasionally there is an exchange of seed between 

 growers within the neighborhood. Long Island growers have learned 

 that it is not profitable to use, as seed, stock that has been grown on Long 

 Island for more than one year. An experimental plot at Southampton 

 is shown in figure 131 (page 1158), which demonstrates the difference in 

 results to be expected between new stock from Maine, and Maine stock 

 grown for one year on Long Island. The 45.8 per cent of growers on Long 

 Island using part home-grown seed and part bought seed, shown in table 

 43, represent the extent to which one-year Long Island stock originally 

 imported from Maine was used in 1912. Most of the seed stock from Maine 

 is purchased in the fall to be shipped in the very early spring, since storage 

 facilities on Long Island are very meager and the crop is planted late in 

 March or early in April. The seed stock of the other three regions is 

 in most cases stored at home along with the bulk of the harvested crop. 



,The necessity of a change of seed on Long Island is due to several factors. 

 The abnormally long period between harvest and planting, much oi which 

 includes the warm or hot temperatures of late summer and early fall, is 

 not favorable to potato storage. The soil temperature of this region during 

 the later growing season is apparently so high as to seriously reduce the 

 vigor of the stock for seed, in spite of the high average yields obtained. 

 The problem is therefore one of soil, of growing-season and storage tem- 

 peratures, and of length of storage season as influencing the condition of 

 the seed at planting time. 



Emerson (1914) compared yields from seed cultivated for some time 

 in Nebraska, with those from seed raised under straw mulch and from seed 

 recently introduced from the Red River Valley of North Dakota. He 

 found that, whereas the cultivated seed of Nebraska rapidly deteriorated 

 under hot growing-season temperatures, by mulching with straw between 

 planting and blossoming time he was able to so reduce the soil temperature 

 as to maintain vigor and obtain practically as good yields from seed so 

 raised as from seed just introduced. Stuart (1913 a) studied the influence 

 of environment on seed by introducing seed of thirteen English varieties 

 of identical origin from both England and Scotland, and growing it con- 

 tinuously in Vermont for six years. The average increase in yield of the 

 Scotch seed over that of the seed from England varied from 10.9 to 2713.9 

 per cent. Results similarly striking were obtained by Macoun (1905) in 

 four varieties grown over a period of twenty years ,at Ottawa. He had 

 practiced seed selection each year for twelve years and had thus been able 

 to maintain the original yield of the stock. Four years of adverse con- 

 ditions followed, during which the yield of each variety decreased decidedly. 



