AN"THEAC]SrOSE OF THE MANGO IN FLOEIDA. 



13 



the condition of the weather at blooming time. Given clear dry 

 weather, a good crop of fruit may be expected. Given, on the 

 other hand, rainy weather at blooming time and a failure is practi- 

 cally certain. The only way of telling with certainty that a particular 

 region is suitable for the profitable production of mangos is to have 

 a combined crop and weather record over a sufficiently long term 

 of years to give a fair average. The precipitation records alone are 

 somewhat unreliable. However, the main limiting factor in the suc- 

 cessful production of this fruit on the southeast coast of Florida is 

 the anthracnose fungus, which is induced by rainy weather, so a 

 study of the precipitation records for this locality, together with such 

 crop records as are available, is of considerable value. Figures 3 

 and 4 show the number of rainy days during the months of Febru- 

 ary and March, respectively, for the period for which a record exists, 

 1898 to 1913, inclusive, and figure 4 also shows a crop curve for the 

 past four years. The lack of fruit in 1911 was due to the fact that the 

 trees were defoliated the preceding fall by a West Indian hurricane 

 and did not bloom. The 

 curve for the years 1910, 

 1912, and 1913 shows 

 the relation between the 

 precipitation at bloom- 

 ing time and the crop. 

 There are no bloom 

 records prior to 1912, so 

 to some extent this makes the data unreliable. For example, there 

 might be only five days of rain in a certain month, and it might fall at 

 such a time as to cause no damage; or, on the other hand, there might 

 be five consecutive days of rain at the time that the flowers were open- 

 ing, which would probably be sufficient to cause the loss of the crop. 

 It would seem, however, that such a combination of circumstances 

 might be expected to be a rather rare occurrence and that an opinion 

 as to the suitability of this region might be predicated on such pre- 

 cipitation records as these with a reasonable degree of certainty. 



The records for Miami which are given in figures 3 and 4 cover a 

 period of 16 years and show the mean number of rainy days for 

 February to be 2.81 and for March 4.56. The number of seasons 

 below normal for this term of years for February is 8 and for March 

 11. It is clearly seen here that the seasons of 1912 and 1913 have 

 been decidedly abnormal as regards precipitation. 



Wester's ^ experiments, which have been previously referred to, 

 were conducted at Miami during the springs of 1906 and 1907. It 

 will be seen by referring to figures 3 and 4 that these two seasons 

 were comparatively dry, and this undoubtedly accounts for the 





13 5 7 9 11 13 15 17 19 





i9 lltil517 19 2iaJ5. 



1 f HHIli Ip 







Fig. 2. — Diagram showing the blooming periods, March 1-20, 1912, 

 and March 7-26, 1913. The dark areas show rainy days. 



1 Op. cit. 



