22 N. H. AGR. EXPERIMENT STATION. [Bulletin 151 



has shown that, owing to the readiness with which sulfur mixtures are washed 

 from the tree, frequent applications will be necessary to control diseases in 

 rainy seasons. No fungicide has proven so uniformly efficient as Bordeaux. 



Arsenate of lead has given no injury when combined with lime-sulfur. 

 Slight injuries have resulted from Paris green in commercial lime-sulfur when 

 there was no excess of lime. Arsenite of lime has given no injury when used 

 with lime-sulfur accompanied by an excess of lime. 



Some of the above results have already been made public in Press Circular 

 No. 13 and Bulletin No. 144 and other data will be published later. 



Fungous Diseases. 



A study has been made of diseases as they have occurred. Special attention 

 has been given to some of the diseases of the apple, tomato and bean. The 

 investigations on the apple and tomato diseases are being carried on under 

 the Adams Fund. 



Leaf Spot of Apple. — Notes have been taken and inoculation experiments 

 made to determine the time when infection takes place. The results indicate 

 that the fungus seldom gains entrance to the host after the middle of June 

 but that on water sprouts and other tender growth the leaves may be infected 

 several weeks later. The fact that the disease makes its beginning so early 

 in the season shows the importance of early sprayings. The past season has 

 been a good one for the demonstration of the relation of Sphaeropsis cankers 

 to leaf spot. The leaves beneath these cankers have frequently been found 

 to be covered with spots while those near by would be practically free from the 

 disease. The destruction of these cankered limbs would do much toward 

 preventing the leaf spot as well as the black rot of the fruit, for these two 

 diseases have been found to be due to the same fungus as produces the cankers. 



Apple Scab.— The spraying experiments mentioned above have shown the 

 importance of the applications before the blossoms open in the control of apple 

 scab. Apples but slightly affected with this disease when allowed to stand 

 in the barrels for considerable time before being placed in cold storage, have 

 been found later to have developed the disease to such an extent that they 

 were scarcely marketable. It is important that, apples should be stored 

 as soon after gathering as possible even if entirely free from disease. 



Fruit Spot of Apple. — This disease was rather fully discussed in an earlier 

 report and is still under investigation. It has not been so serious the past 

 season as in other years. 



Tomato Diseases. — Investigations are being made upon several tomato 

 diseases. It is thought that when the data is complete the results will be of 

 both scientific and practical interest. 



Cooperation. 



The spraying experiments of the summer of 1909, described above, were 

 carried out in cooperation with the Bureau of Plant Industry of the United 

 States Department of Agriculture, each party bearing one half the expense 

 of the work. 



For the past two years the head of the department has worked in coopera- 

 tion with the Bureau of Plant Industry in attempting to secure a more com- 



