DISEASES OF PLANTS. 999 



The author daims that the infection of the young trees could only- 

 have been through the conidia formed during 1892, as the old knots had 

 been removed in the fall of 18913 before any ascospores were formed. 

 This point is of economic interest in showing that a serious attack of 

 the disease may follow from the conidia formed during the summer 

 months as well as through the ascospores formed during the winter and 

 early spring. 



Spraying orchards and potato fields, L. E. Jones { Vermont Sta. 

 Bui. 44, pp. 81-102, figs, 14). 



Synopsis. — A report is given on the relation of weatlier of 1894 to plant diseases, 

 apple and pear scab and the means for its repression, results of spraying potatoes 

 in 1894, observations upon the date of planting potatoes, and on the prevention 

 of potato scab. 



delation of weather of 1894 to plant diseases (p. 82). — Owing to the 

 remarkably dry season of 1894 there were no serious attacks of para- 

 sitic fungi, some plants escaping almost entirely. While plant diseases 

 ■were not troublesome the dry weather brought conditions resulting in 

 unusual insect activity. The results shown on the sprayed plats, while 

 not as marked as in previous years, still gave enough difference over the 

 unsprayed crop as to indicate that spraying will be profitable. 



Apple and pear scab (pj). 82-93). — Illustrated notes are given on the 

 cause of apple and pear scab and the results of a series of experi- 

 ments conducted for its repression are reported. Three varieties of 

 apple trees and 1 of pears were sprayed with Bordeaux mixture, dif- 

 ferent lots of the trees receiving 4, 5, 6, and 7 applications. The results 

 given showed that for that year 4 sprayings were sufficient. The gains 

 as shown by the character of the fruit produced were 23, 24, and 27 per 

 cent for the apples and 117 per cent for the pear trees. Directions are 

 given for the preparation and application of the fungicide. 



Results of spraying potatoes in 1891 (pp. 93-98). — Applications of 

 Bordeaux mixture were given to the potato plants, but owing to the 

 dry season but little disease was noticed. There were, however, severe 

 ravages of grasshoppers and flea beetles. The use of the usual insecti- 

 cides seemed to have little effect, but it was noticed that those plants 

 which had been sprayed with Bordeaux mixtnre escaped serious injury. 

 From the treated i^lats an increased yield over the check plats was 

 secured, due no doubt to the combined fungicidal and in secticidal effect 

 of the Bordeaux mixture. The author thinks he is warranted in recom- 

 mending the use of Bordeaux mixture on either early or late varieties 

 of potatoes during either a wet or dry season. Paris green may be 

 added to the mixture for the destruction of the Colorado beetle. 



Obsercations on the date of planting potatoes (pp. 98-100). — In the 

 Annual Report of the station for 1893, p. 55 (E. S. K., 6, p. 908), the 

 author called attention to the greater liability to disease of late planted 

 potatoes. Ordinarily the early crop of potatoes is less i^rod active than 

 the later, owing to the fact of the tubers usually maturing in July, the 

 driest month of the year, but in 1894 the season was so peculiar that 



