ANTHEACKOSE OF THE MANGO IF PLOEIDA. 7 



fungicide. ' They did not develop on the peduncles, however, which 

 points very strongly to infection having taken place through the 

 blossoms. The panicles on the unsprayed tree began to show diseased 

 spots on the pedicels and peduncles before their growth in length was 

 more than half complete, and practically all of the blossoms blighted, 

 the one fruit which set being in the extreme top of the tree. Plate 

 IV, figures 1 and 2, shows the t37pical condition of a bhghted panicle 

 as compared with one in full bloom which has not yet developed any 

 sign of the disease. 



SPRAYING EXPERIMENTS IN THE WINTER AND SPRING OF 1913. 



As during the preceding season, the mangos bloomed quite gener- 

 ally during the winter. The buds began to swell about December 18. 

 Most of the bloom was shed by January 10 and not 1 per cent of this 

 bloom set fruit. 



The buds on two large seedling trees on the Roop place were begin- 

 ning to push out on December 24, and one of these was selected to be 

 sprayed every other day to test the efficacy of spraying to control the 

 blossom-bhght form of the disease. It was considered that this 

 would be a thorough test, as the blighting of the blossoms is the 

 normal thing with the winter bloom. Mr. Roop states that these 

 trees have bloomed regularly in the winter for the past six years, but 

 have never set fruit from this bloom. Spraying was begun on Decem- 

 ber 24 and continued every third day until January 16. At this time 

 the fruit had set, and the spraying was continued every fourth day 

 until February 3 . At this time the young fruits had reached a diam- 

 eter of one-fourth to three-eighths of an inch, and the next two spray- 

 ings were applied at 7-day intervals. Two more were applied at 

 approximately 10-day intervals and the last on March 22 after a 

 lapse of 14 days, when the fruit was about half grown. The dates on 

 which spray was appHed follow: December 24, 26, 28, 30; January 1, 

 3, 6, 8, 10, 13, 16, 20, 24, 28; February 3, 10, 17, 26; March 8, 22. 



While the tree bloomed profusely, only a fair crop was set. By 

 this is meant that the tree could have carried twice as much fruit 

 without being unduly burdened. ' The blossoms on fully ^half of the 

 panicles bhghted, and all of those on the unsprayed tree blighted. 



This experiment was carried a step farther in March by spraying 

 a portion of a Totafari tree in the Subtropical Garden at Miami every 

 day from March 17 to April 1; that is, while the bloom was pushing 

 out and developing. This was evidently too much spraying, for, 

 while no disease developed, no fruit was set and the young fohage 

 was scorched. 



It should also be noted that the fruit on the seedHng tree on the 

 Roop place received no spray after it was. half grown, but it was 

 clean and free from disease when harvested the middle of May, 

 almost two months after the last spraying. 



