Extension Work in Plant Pathology, 1923 15 



aid as is necessary for the proper prosecution of his work. The special work 

 of the field assistant in such a county is to develop and maintain a spray in- 

 formation service * * 



A< one of the important duties of the field assistant is to decide ui»« n the 

 most suitable time for making application, as well as to provide a formula for 

 the preparation of material used in spray or dust, it is necessary for him to 

 have information, as accurate as ]ms-ilile. from day to day regarding the de- 

 velopment of buds, flowers, and leaves of fruit trees in the different zones in the 

 • •ounty: development of parasites and materials most effective in controlling 

 them: and the probable weather conditions during the next few days. He ob- 

 tains his information regarding development of trees and parasites from his 

 own observations on trips about the county, and he is supposed to know the 

 best means of controlling parasites. His information regarding weather is 

 supplied him through cooperation with the office of the United States Weather 

 Bureau at the college. The cooperation of the Weather Bureau is essential to 

 the success of the spray information service. A special weather forecaster is 

 appointed for this purpose by the bureau for April. May. and June, and long- 

 rauge meteorological reports aie sent directly to him. From these reports lie 

 prepares each night a special forecast, which is wired to the counties having 

 special field assistants so as to reach them before midnight. Arrangements for 

 the reception of the telegrams must he made by the farm hureau in each county. 

 Basing his judgment upon the information he has received, the field assistant 

 must decide what is the most opportune time for making an application. 



In Virginia the orchard spray service was managed cooperatively 

 by the departments of plant pathology, horticulture, and ento- 

 mology. F. D. Fromme. plant pathologist. Agricultural Experi- 

 ment Station. Blacksbnrg. Va.. reported as follows: 



A spray calendar is prepared and distributed in advance of the season. This 

 contains advice as to the materials to be used, methods of preparation, and 

 approximate time of application. P^xact dates for spray applications, based on 

 information received from field laboratory workers, are supplied to the orchard- 

 ists during the growing season. The information is obtained from an ento- 

 mologist and a pathologist located in a field laboratory -at -Winchester, from a 

 research entomologist located at Leesburg. and from research men working at 

 Crozet and Blacksburg. 



In West Virginia. E. C. Sherwood, who handled extension work 

 in entomology as well as plant pathology, directed the service per- 

 sonally. He established an office in the fruit-growing territory during 

 the critical spring months, where he was able to observe conditions 

 which had a bearing on spraying. Using the data obtained from 

 such observations, he prepared and issued timely spray notices, which 

 were printed in local papers and also mailed to all growers who de- 

 sired them. With the assistance of the horticulturist and county 

 agents field instruction was given to farmers in spray practice, im- 

 provement of equipment, and methods of spray mixing. This spray 

 service was supplied on request to 300 growers whose combined hold- 

 ings represented about 500.000 bearing trees. 



TKUCK-CKOP SPRAYING 



Active work was conducted in the Southern States in extending 

 spray practice to truck crops. In South Carolina and Florida. 

 initial demonstrations led to an increase in the spraying of the cu- 

 cumber crop. Marked progress was made also in the watermelon 

 -pray program in South Carolina. 



SELECTING SEED FREE FROM DISEASE 



The most important activities of extension workers in connection 

 with seed -election were efforts to control the virus diseases of potato 

 and the root, stalk, and ear rots of corn. 



