DISEASES OF PLANTS. ()(ji) 



been observed in ( 'alifornia for some time, Imt until 1900 did not oc-casion very serious 

 (lama<j;e. Durin<i that summer 50 per cent of the prune crop in one locality was 

 destroyed and in another it was estimated that 25 per cent of the apricots were seri- 

 ously affected. As there appeared to be a tendency on tlie part of the disease to 

 spread throughout tlie State, a brief report is given describing tlie disease and giving 

 suggestions for its i)reventive treatment. It is recommended that all mununy fruits 

 be collected and destroyed and trees given thorough spraying with Bordeaux mix- 

 ture, one application to be given before the blossoms open and a second after the 

 fruit has set. It is believed that the use of a winter wash consisting of Ihne, salt, 

 and sulphur would doubtless be effective against the brown rot. In the case of late 

 rii)ening varieties a third spraying should be given after the others as recommended 

 above, but in this case a copper acetate solution is to bo preferred, as the Bordeaux 

 mixture would stain tlie fruit at this time. 



A new disease of bananas {Queensland Ai/r. Jour., 11 {1903), No. 4, p. 284). — 

 A brief note is given of the nematode disease of bananas in Egypt, whicli has been 

 noted (E. S. R., 14, p. 581). This disease is said to have been noted some time since 

 in Australia and to have been investigated by the pathologist of the; department of 

 agriculture of that country. 



Brunissure of the grape, J. Dufour {Prog. A(/r. et Vit. (Ed. L'Est), 33 {1902), 

 No. 36, pp. 279, 280) .—According to the author the disease known in France as 

 brunissure has been attributed to a number of different causes, among them fungi, 

 various insects, physiological causes, etc. In the present contribution he gives a 

 description of a form of the disease which has been quite prevalent during the past 

 season, which is characterized by the presence of minute larvre on the surface of the 

 diseased leaves. When examined microscopically these larviu seem to resemble to a 

 considerable degree those of Phyiopixis vitis. There are said also to be certain acarids 

 of the genus Phyllocoptes which cause a form of brunissure on cherries, plums, nut 

 trees, I'tc. It is believed that these insects are widely distril)uted and that they are 

 the evident causes of certain forms of the disease which is generally described under 

 the name brunissure. 



A cause of brunissure, L. Ravaz {Prog. Agr. et Vit. {Ed. L'Est), 23 {1902), No. 

 43, pp. 4S1-4S6). — According to the author's investigations brunissure seems to 

 attack certain varieties of the grape more than others, and apparently those grafted 

 upon certain stock are the most susceptible to the disease. There ajjpears to be a 

 relation also between the disease and the productivity of the varieties, those yielding 

 most aljundantl)' being most subject to the disease. The tendency to disease may 

 be diminished bj- close pruning so as to reduce the production of fruit, and by stim- 

 ulating the vegetative growth through the use of fertilizers, irrigation, and cultiva- 

 tion, or by the selection of vigorous resistant stocks. 



On the possibility of combating the downy and powdery mildew of 

 grapes by a combined fungicide, J. M. Guillon {Compt. Rend. Acad. Sci. Paris, 

 135 {1902) , No. 4, pp- 361, 263). — A study has been made of mixtures of sulphur and 

 the principal copper fungicides in order to ascertain whether a combination of tlie 

 two might not be jiractically useful in controlling both these diseases. In general 

 the sulphur, either sublimed or triturated, remained on the surface of the liquid, but 

 the author found that thoroughly mixing the sulphur with the lime of the Bordeaux 

 mixture or the carbonate of soda in Burgundy mixture would cause its complete 

 susjiension in the liquid for a considerable time. The suspension of the sulphur can 

 be further brought about by the use of a small amount of resin. When used with 

 verdigris the sulphur should be thoroughly mixed and the liquid of the fungicide 

 kept agitated. In no case was the adhesive property of the fungicide lessened by the 

 presence of the sulphur, and the mixture of sulphur and copper seemed to be 

 advantageous for the control of ])oth diseases. 



Experiments for the prevention of gray rot, L. Ravaz {Prog. Agr. et Vit. 

 {Ed. Ty' Ext), 23 {1902), No. 35, pp. 250-253) .—Dwr'mg, the past season the attadk of 



