THE MONTHLY BULLETIN. 563 



short season climate will produce an earlier maturin.^ crop than seed 

 stock grown in a long season climate. For example, all the early potato 

 growers throughout the south and east of the United States take 

 advantage of this fact by securing seed stock grown iii the north where 

 the seasons are short. Just what effect the soil has upon the value of 

 seed potatoes when taken to another locality has not been fully worked 

 out. 



If the potato grower is so situated with reference to climatic con- 

 ditions that he can raise and select his own seed stock, the method 

 described above for securing good seed potatoes may solve for him and 

 his community the seed potato problem. But how shall those wlio have 

 to depend upon the market for their seed supply determine when they 

 are purchasing good seed and when they are not — especially if they 

 can not tell from an examination of the stock Avhether it will be pro- 

 ductive ? It would certainly be a great improvement over present con- 

 ditions if it were possible to go into the open market and find a suffi- 

 cient supply of seed potatoes which would be free from disease, true to 

 name, free from mixture and of the proper size and uniformity for 

 good seed potatoes, even if we did not know whether they had the 

 further quality of productiveness; and it is to be hoped that a supply 

 of such seed stock will become more easily available. However, the 

 State of California has gone a step in advance of this with the idea of 

 making it possible for potato growers to obtain good seed potatoes, and 

 to know when they are purchasing such stock. The California state 

 legislature passed a bill at its last session establishing a standard for 

 good seed potatoes and making it possible, through the working out of 

 this bill, for the potato grower to know when he is purchasing good 

 stock. This bill is known as the California Certified Seed Potato Act. 

 The principal features of this measure are as follows : 



Any one desiring to grow seed potatoes for certification must have 

 his crop inspected at least three timas during the season. Once during 

 the blooming period, at which time the field must not shoAv a mixture 

 of more than 250 hills per acre, and the field rogued of all mixed plants. 

 It must not show more than 500 weak hills per acre or more than 50 

 hills affected with blackleg, and the weak plants must be removed at 

 this time. A second inspection is made at the time the plants are 

 maturing, when at least 100 hills per acre are dug ; and not over 5 per 

 cent of the hills shall show less than 30 per cent of the weight of an 

 average hill. A third inspection is made after the crop is harvested 

 and graded. The selected stock must be absolutely free from infection 

 of eelworm, larva of tuber moth, wart disease, or powdery scab ; and 

 shall be practically free from net necrosis or late blight. The potatoes 

 must not be seriously infected with scab or Rhizoctonia, not over 5 per 

 cent light infection of scab or 10 per cent light infection of Rhizoctonia, 

 not over 8 per cent light infection of wilt disease, and not over 2 per 

 cent deep infection of wilt. They must be free from mixture of colors 

 or distinct types, and reasonably free from cuts, bruises, or second 

 growth. Not over 5 per cent of the tubers shall weigh less than 11 

 ounces, and not over 5 per cent shall weigh more than 12 ounces. 



Wherever potatoes meet these requirements the grower shall receive a 

 certificate to this effect to go with every package of potatoes, which 



