146 NEW HAMPSHIRE COLLEGE 



DEPARTMENT OF BACTERIOLOGY 



The details and results of experiments in treatment of plant 

 diseases during the season of 1S96 have been published in 

 Bulletin No. 45. 



The following experiments have been carried on during the 

 time covered by this report. It being the non bearing year the 

 experiments in the treatment of the diseases of tiie apple in 

 1897 were limited, being directed to the disease of the foliage 

 known as Phyllosticta pirini or leaf spot. As in previous 

 years the Bordeaux mixture has seemed to have but little effect 

 on this disease. During the last three years the apple scab has 

 done comparatively little damage either to the foliage or fruit. 



Qiiince trees were sprayed for the prevention of fungous dis- 

 eases. Orange rust, which is very common in this vicinity, 

 seems to be but little affected by the treatment. Black rot was 

 so trifling in amount, on even the unsprayed trees, that no con- 

 clusions could be drawn. A disease of the foliage, whose 

 identity has not been detei mined, was largely prevented by 

 the spraying. 



Experiments in spraying with Bordeaux mixture against 

 black knot were begun. As the station plum orchard is small 

 and the trees young, they were all sprayed during the time 

 when infection by the summer spores was likely to take place. 

 For the purpose of comparing the development of knots on 

 sprayed and unsprayed trees, a hedge row of choke cherries 

 was made the subject of the experiment. The result of the 

 treatment will not be apparent until spring, when the new 

 knots make their first appearance. 



A substance known as Ceres-pulver was sent to the station 

 for trial as a preventative of smut in oats and barley. It is to 

 be applied by soaking the seed in a solution of it. In our 

 trials there was little smut in any of the grain, but rather less 

 where the seed was treated with Ceres-pulver. 



Experiments on potato scab were continued on the following 

 lines: effect of different fertilizers, stable manure, phosphate, 

 ashes, lime, kainit, on the development of the disease, effect of 

 treatment with corrosive sublimate, formaline, and sulphur as 



