CITRUS DISEASES. 93 



tried out during the season just past, and found wanting in so far 

 as scab control was concerned. 



The situation arises then of two available materials, one effective 

 but injurious, the other only partially effective but otherwise de- 

 sirable. An attempt to arrive at a satisfactory solution of this dif- 

 ficulty is given as part of the suggested spray program. 



The great difficulty in deciding upon the time of spraying and 

 the number of applications, lies in the fact that it is impossible to 

 know just when the principal bloom period will occur, or how many 

 secondary blooms will follow. A heavj^ flush and bloom mav be ex- 

 pected any time after the first of the year, but may not come until 

 March in some districts. Following this there is scattering bloom 

 and new growth until late April when, between that period and 

 the middle of June, a second heavy bloom generally occurs. Through- 

 out the balance of the year scattering, bloom may occur at any time ■ 

 very often in August or the late fall months. New leaves, of course' 

 are coming on at practically all times. This seasonal variation makes 

 It practically impossible to lay down any set program, but rather 

 an attempt must be made to outline a tentative scheme to cover all 

 possibilities, leaving to each grower the task of fitting it to his own 

 individual circumstances. 



Bearing in mind that all young growth is susceptible, it would 

 theoretically be necessary to spray throughout the year, an impos- 

 sible course. Practically, the best that can be hoped for is to give 

 a limited number of applications at such times as thev will accom- 

 plisli a maximum amount of .good. 



Where the scab does not thivaten to become serious, lime-sul- 

 phur or other similar sulphur compounds should be used the first 

 application being given shortly before the first bloom and flush of 

 the season begins to expand. This is to be followed bv another as 

 soon as the bloom is at its height. The third application will come 

 from a week to ten days later. Other applications may follow at 

 the same or much greater intervals of time, all depending upon the 

 rate of progress of the bloom, the coming of secondarv flushes and 

 above all upon the weather. Periods of bright, sunny weather will 

 make spraying unnecessary.- wet, cloudy weather will necessitate 

 frequent, careful applications; These points must be decided by 

 each grower for himself. 



Some growers have adopted the system of spraying once a week 

 ough the bloom period, making a total of eleven or twelve appli 

 ions. This IS unnecessary; three or four at the proper time being 



