466 



Potato Leaf-curl. 



[NOV., 



POTATO LEAF-CURL. 



Walter P. Wright. 



Potato Leaf-curl (Macrosporium solani) is a disease which 

 is causing great trouble to growers in many parts of the country, 

 but particularly to those in the south of England. The 

 indications of the disease are generally well known and a 

 description of their more important features is given in the 

 Board's Leaflet on the subject (No. 164). The shoots come 

 through the soil very slowly, and frequently there are numerous 

 gaps in the rows. The foliage is very small, and the leaflets 

 are much curled. In rare cases the plant improves, and gives 

 a moderate crop, but in the great majority, it remained stunted, 

 and the rows fail to fill out. In most attacks of curl the seed 

 tuber fails to decay, and remains perfectly hard. The crop 

 is very small, often consisting merely of three or four tiny 

 tubers. 



Treatment of Seed. — Wherever curl has given trouble special 

 consideration should be given to the question of the stock 

 of seed to be used in the following year. If seed produced 

 at home is to be utilized, special treatment should be given 

 to it. The seed should be carefully selected immediately it 

 is lifted in the autumn, sound, fairly large tubers of two to 

 three ounces in weight being preferred to very small ones. 

 In no case should it be put away in a clamp and left until 

 planting time the following spring. The sets should be stored 

 in shallow boxes in a cool building, not too dry, but frost- 

 proof. Southern growers put the potatoes singly in the 

 boxes, standing them on end with the principal eyes upper- 

 most. Certain of the Scottish dealers, however, prefer to 

 put the sets on their sides three or four layers deep. It might 

 be thought that the advantage gained in being able to store 

 a larger quantity by the latter plan would be lost in the weaker 

 growth that would be made ; the sprouts on the lower layers 

 are, in fact, much weaker and looser than those on the upper, 

 but having handled a considerable number of boxes so treated, 

 the writer finds that when the sets are ultimately laid out,, 

 the sprouts quickly harden and stiffen, giving quite satis- 

 factory plants. 



In the case of early varieties there should be decided signs 



