12 



INFORMATION TO CORRESPONDENTS ON SPECIAL SUBJECTS. 



The farming lands lying witliin the scope of the Department of Agriculture, 

 covering the half (if a continent, present a diversity of climate and soil not 

 elsewhere found in any one country, and giving rise to an infinity of sugges- 

 tions and inquiries. From some portion of this vast country letters are daily 

 rec ived requesting from the Department information running through the whole 

 range of agricultu al learning, from the agriculture of a State to the cause of the 

 destruction of a leaf, and from the pedigree of some herd of noble animals down 

 to the smallest aphis that sucks the [)lant-life out. 



That tlr se matters may be understood by all, and that the information 

 sought by one may benefit all, it is the intention of the Commissioner to give, 

 in the monthly reports, material that shall serve as a general reply to intelligent 

 questioners. And among the subjects to which attention has been repeatedly 

 called, both by letters and in the return to our circulars, is that of mildew on 

 the grape. 



It is now very generally recognized that mildew is the greatest enemy the 

 grape culturist has to contend against, and the question of profit or loss in the 

 wine-grower's account depends materially upon the absence or presence of this 

 disease. Notwithstanding the importance of the subject, it is somewhat I'emark- 

 able that but little is known with regard to its origin. True, opinions are 

 plentiful, but so widely varied and conflicting that they tend to mystify rather 

 than throw light upon the origin of the malady. 



In a letter recently received from an old, experienced grape-grower, it is 

 observed that mildew never appears until the temperature rises to 85^ or 90^; 

 others attribute its appearance to heavy rains on undrained soils ; again, it is 

 seen on dry grounds in dry weather; and some hold the opinion that the mode 

 of pruning will determine w^iether or not the disease will be prevalent. It is 

 thus obvious that pomologists have not as yet come to any settled opinion with 

 reference to the origin of mildew, and tht; subject is here briefly noticed with 

 a view to direct especial attention to the atmospheric phenomena attendant 

 upon its appearance, as well as to the condition of the soil, and accompanying 

 peculiarities of cultivation. 



It is Avell known that some varieties of grapes are more liable to mildew than 

 others ; the grouping of such as are exempt, or partially so, would also be of 

 great importance in the futui-e improvement of this fruit. There is certainly no 

 subject connected with wine culture in this country of more importance than 

 the disease here noticed. 



The Department is assiduously collecting all noted varieties of the grape, for 

 the purpose of comparing their merits under similar conditions of dim ite. soil, 

 and culture, and solicits the co-operation of all who are interested in the culture 

 of this fruit. Plants of new or valuable varieties will be particularly acceptable; 

 these are not desired for purposes of propagation; the Department will be guided 

 in that matter by the donor, and all instructions, so far as propagation is con- 

 cerned, will be rigidly enforced. 



It may be remarked that no better criterion of a new fruit need be desired 

 than the opportunity of comparing it side by side with the extensive collection 

 of the Department will present. 



These remarks are deemed necessary in order that the intentions of the De- 

 partment may be fully understood by grape-growers and others interested. 



INJURIES BY INSECTS. 



As it is the intention of the Department of Agriculture to commence a series 

 of observations and notes on the various insects injurious to v(>getation, which 



