12 Department Circular 329, U. S. Dept. of Agriculture 



emphasis placed on the means of prevention rather than on cure. The main 

 object was to lay the necessary groundwork for a more intelligent application 

 of control measures recommended. * * * Next, some disease of general 

 interest, such as tomato late-blight, was taken up from the standpoint of the 

 life history of the causal agent and it was shown how the measures for its 

 control are based upon the seasonal development of the fungus. Finally, the 

 meeting was opened for questions and various local troubles were discussed 

 in a practical way. 



In Florida, instruction was given to growers at vegetable and 

 citrus schools. E. L. Ayers, extension entomologist-pathologist, gave 

 the following account of the citrus work : 



More than 30 citrus schools were held during the year, with a total attend- 

 ance of more than 1,500 citrus growers. Most of these schools were held in 

 April and May, or early enough in the season for the grove owners and care- 

 takers to follow instructions during the ensuing year in the control of citrus 

 diseases and insects, particularly in the control of melanose and rust mite. 

 These sessions ranged from a few hours to all day, and usually two or three 

 lecturers were present. Microscopes, including binoculars, were carried along, 

 and the growers were taught to recognize different diseases and insects. The 

 meetings met with much enthusiasm wherever they were held, and in a number 

 of sections the work was commended by resolutions and the desire expressed 

 for other and more comprehensive meetings in the future. 



(2) Assistance to growers in selecting the kind of spray machinery 

 best fitted to their needs. — By discussing the fundamentals of spray 

 work with commercial orchardists and the manufacturers of ma- 

 chinery, extension plant pathologists frequently w^ere able to assist 

 in developing a supply of machinery which was particularly suited 

 to the crop and to the locality in which the work was to be done. 

 In some States manufacturers were encouraged to exhibit spray 

 machinery, so that farmers might become thoroughly familiar with 

 the equipment that was on the market. Pioneer work was also done 

 during the year by assisting in building stationary spray systems 

 for large orchards. 



It is the farmer with the small acreage who needs most guidance 

 in selecting equipment. The initial cost of effective spray machinery 

 often prevents the man who grows a small acreage of potatoes, or 

 who has a few fruit trees, from giving such crops proper protection. 

 Quantities of spray material and much good labor have been wasted 

 by the use of inferior spray equipment, with the result that the 

 farmer sometimes is worse off than if he made no effort to spraj T . 



(3) Spray rings. — During 1923, a considerable advance was made 

 in the solution of spraying problems by the introduction of plans 

 for cooperative purchase and use of machinery by organizations 

 consisting of several farmers with a common spray problem. The 

 spray ring, by making possible economical use of the best high- 

 power equipment, proved to be a means by which the grower with a 

 small acreage might circumvent the obstacles which had formerly 

 prevented successful control of disease, particularly if arrangements 

 were made to employ an experienced spray man to make the appli- 

 cations for all members. Further development of spray rings will 

 make possible profitable spraying of many crops which now are not 

 being given proper care. 



Increase in the use of combination equipment by farmers went 

 hand in hand with the development of the spray ring. E. L. Nixon, 

 extension plant pathologist of Pennsylvania, reported as follows : 



The matter of reaching the small potato-grower in Pennsylvania with efficient 

 spraying is made less difficult by the existence of a large number of so-called 



