March, 1921. 



SCiENTiPiC AGRICULTURE. 



115 



About 20 years ago sulphur dusting was tried occa- 

 sionally on grapes, but about 1911 orchard experiments 

 in dusting were begun in New York State by Cornell 

 Station. These were continued for about seven years 

 or until it was conclusively demonstrated that dusting 

 was both efficient and practicable, aud a satisfactory 

 substitute for liquid spraying. 



Nova Scotia furnishes an interesting example of 

 changing methods in spraying, due to the investigations 

 by Messrs. Sanders, Kelsall and Brittain. These gen- 

 tlemen have devised improved mixtures for b«'th liquid 

 and dust spraying. Up to 1912 Standard Bordeaux was 

 the fungicide used by the fruit growers; then lime-sul- 

 phur was substituted. When this proved unsatisfactorj- 

 a modified Bordeaux with an excess of lime was em- 

 ployed. 



Dusting was introduced about 1916, and gradualh' 

 made headwav ^ith improvements in the manufacture 

 of dust products. In 1918, 1919 aud 1920 the 90-10 

 sulphur arsenic dust (90 per cent sulphur and 10 per 

 cent lead arsenate) and copper arsenic dust (10 per 

 cent copper sulpliate, 5 per cent arsenate of lime, and 

 85 per cent hydrated lime) were used. In 1921 both 

 the sulphur and the Bordeaux methods will lie used by 

 the fruit growers of that province. 



Up to 1920 no du.sting material has been found that 

 controlled sucking insects satisfactorily, but the 1920 

 experiments in California against the Pear Thrips, with 

 5 per cent "Nico dust" which ccntaius 5 per cent Black 

 Leaf 40 and pulverized Kaolin, and those in Nova Scotia 

 against p.syllids with nicotine sulphate with sulphur and 

 arsenate of lead, give strong hojies that the difficulty 

 has been largely overcome. It will be possible for the 

 future to use a 3 — in — 1 combination dust against fungi 

 and biting and sucking insects. 



In this very incomplete review an attempt has been 

 made to make clear the chief outstanding events in the 

 story of spraying mixtures. These are : — 

 1. — The use of Paris Green against biting insects, be- 

 tween 1860-1870. 

 2. — The introduction of Bordeaux mixture as a fungi- 

 cide, about 188.5. 

 3. — The introduction of lime-sulphur, first as a contact 



insecticide and later as a fungicide in 1906. 

 4. — The use of lead arsenate and calcium arsenate as in- 

 secticides against biting insects. 

 5. — The use of Kerosene emvdsion ami tobacco extracts 



as contact insecticides. 

 6. — The practicability of combining the more important 

 insecticides and fungicides in one mixture for spray- 

 ing purposes, thus saving much time in spraying 

 operations. 

 7. — The manufacture of spray materials in finely pow- 

 dered form and the introduction of dust-spraying, 

 making for much saving of time. 

 8. — A better knowledge of the chemical reactions that 

 occur when different spraying materials are brought 

 together, and of the physiological action of these 

 mixtures on the leaves of plants. 

 9.— A better knowledge of the life history of insects and 

 fungi, so that the spray applications are made at 

 times when they will be most effective. In other 

 words, the spray calendars are now based on the 

 stage of develo]jment of plant, insect and fungus, 

 and not as formerly on the almanac. 

 10. — Closely connected witli developments in spraying 

 is the develojiment of spraying outfits, which this 

 paper does not attempt to discuss. 

 In conclusion, it is a pleasure to note the part taken 



by Canada in the story of spraying mixtures, although 

 she has in most cases followed the lead of the United 

 States and Europe. 



Mention has alreadj' been made of the splendid in- 

 vestigations carried on in Nova Scotia by Sanders, Kel- 

 sall and Brittain in connection with lime-sulphur in- 

 jury, and with the making of dust mixtures, but credit 

 should be given to Saunders and Reed, of London, Ont- 

 ario, for their early experiments (1871)) with various 

 chemicals for the control of the potato beetle, to Cliue of 

 Winona and McMichael of Waterford for their experi- 

 ments with orchard insecticides and fungucides from 

 1883 to 1887, to Prof. Craig of the Dominion Experi- 

 mental Farm for experiments on the control of apple 

 scab and otlier diseases with Bordeaux and other fun- 

 gicides (1890-1894), to Dr. Fletcher for his experiments 

 on the control of many injurious insects, and to the Ont- 

 ario Agricultural College for experiments with lime- 

 sulphur and other substances against the San Jose scale. 



LITERATURE. 



Lodeman, E.G. — The Spraying of Plants- 

 1896. 



-Macmillan, 



Howard, L. 0. — Progress in Economic Entomology — 

 Year-Book, U.S. Dep. Agric, 1899. 



Galloway, B. T. — Progress in the Treatment of Plant 

 Diseases in the United States. — Year-Book, U.S. 

 Dep. Agric, 1899. 



Fulmer, H. L. & Caesar, L.— Lime Sulphur Wash— Bui. 

 177, 0. A. C, 1909. 



Crandall, C. S.— Bordeaux Mixture— Bui. 135, 111. Agr. 

 Exp. St. 1909. 



Hai-court, R. & Fulmer, H. L. — Insecticides and Fungi- 

 cides, Bui. 195, O. A. C, 1912. 



Lutman, B, P. — Some Studies on Bordeaux Mistiu-e — 

 Bui. 196, Vermont Agr. Exp. St., 1916. 



Reddick, D. & Crosby, C. R. — Dusting and Spraying Ex- 

 periments with Apples — Bui. 369, Cornell, 1916. 



O'Kane, W. C. et al. — Arsenical Residues after Spraj'- 

 ing. Bui. 183. New Hamphire Agr. Exp. St., 1917. 



Petch, C. E. — Dusting Experiments — Rep. Ent. Soc, 

 Ont., 1916, 1917. 



Caesar, L. — Dusting Experiments — Rep. Ent. Soc. Ont., 

 1916, 1917. 



Sanders, G. E. — Apple Spravintr. Rep. Que. Pom. Soc, 

 1917. 



Lochhead, W. — Class Book of Economic Entomologv — 

 Blakistons, 1919. 



Whetzel, H. H.— History of Phytopathology, W. B. 

 Saunders Co., 1918. 



Sanders, G. E. & Kelsall, A.— Proc N.S. Ent. Soc. 1919. 



Brittain, AV. H. — Spraying and Dusting — Report N.S. 

 Fruit Growers Assoc. 1920. 



Whetzel, II. II.— The Present Status of Dusting— Proc. 

 2nd. meeting N.Y. State Hort. Soc, 1920. 



Wlietzel, H. H.— Spraying— Dep. Circ 20, Mass., 1920. 



Sanders, G. E. & Kelsall, A.— Dusts and Dusting for In- 

 sect and Fungus Control — Sci. Agric, Vol I 

 .\o. 1, 1921. 



