DISEASES OF TOMATOES 



249 



Diseases of Tomatoes. Leaf Spot. — One of the most prevalent 

 and widely distributed diseases of the tomato is the leaf spot, 

 sometimes called the " rust." The presence of this disease is 

 indicated by the appearance of small, circular, brown spots on the 

 lower leaves. The infection gradually progresses upward on the 

 plant, the leaves dying in the order of their infection as the season 

 advances (Fig. 151). In the case of a severe attack the vines are 



A 





. — Unsprayed tcjinato jjiant, budl.\ 

 by leaf spot. Lower leaves dead. 



Ijot has been effectively cuiitrolied. 



so weakened that their later fruits fail to develop properly. On 

 untrained vines, the death of the lower leaves so exposes the fruits 

 that they are likely to sunscald. This disease can be readily con- 

 trolled by spraying with Bordeaux mixture (Fig. 152). Applica- 

 tions should be made at intervals of two weeks, beginning as 

 soon as the plants are set in the field and continuing until the 

 close of the picking season. 



