286 Bulletin 145. 



Experimental work at various places throughout the country has 

 shown that the Bordeaux mixture is the most efficient fungicide. 

 Results obtained by the Division of Vegetable Pathology, both in 

 nurseries and orchards, are especially encouraging. Work on a large 

 orchard in Virginia, during 1893, made it clear that for the particular 

 region early sprayings alone did not at all suffice, and that no very early 

 applications are necessary for the treatment of this disease in the 



orchard. Un sprayed trees were badly 

 defoliated early in August, while trees 

 which received two rather late spray- 

 ings — one after the leaves were well 

 formed, and another within the course 

 of a month — were well protected. If 

 thoroughly done, two sprayings seem 



^ , , ^ ,,. , to suffice. From the above piece of 

 lb;. — Spores of the leaf-blight . 



fungus. work, moreover, we learn that in treat- 



ing 16,000 trees, the cost for two 

 sprayings was less than two cents per tree. As mentioned in con- 

 nection with the other pear diseases, the 50-gallon formula of Bor- 

 deaux is to be recommended. 



4. Occurrence in Nurseries and Remedies. 



In the nursery the principal damage is done to seedling pears, and 

 further injury is usually to be attributed to the leaf-spot. As pre- 

 viously mentioned, the budded stock is much less frequently affected 

 by the leaf-blight. Seedling pears throughout the state, and generally 

 throughout the country, suffer seriously from it. The youngest foliage 

 is first affected, and often the leaves fall early in the season. Later in 

 the season the sunken reddish areas on the tips of the branches indi- 

 cate the disease on those parts, and Sorauer has shown that in the latter 

 places the disease may readily pass the winter. In this country Fair- 

 child has also corroborated these views. 



The premature hardening or ripening of the young wood prevents 

 the budding operation; or, if budding is not entirely prevented, the 

 early cessation of growth in the formative cambium of the stock renders 

 a perfect union of the woods difficult to secure. 



The results of all properly conducted experiments upon nursery stock 

 indicate that Bordeaux mixture as a fungicide is essential to success 



