TORREYA 



Vol. 32 July-August, 1932 No. 4 



Observations on the flower behavior of the Avocado in Panama 



Alexander F. Skutch 



About the pleasant grounds of the Research House of the 

 United Fruit Company fronting on the Changuinola Lagoon 

 twenty miles west of Almirante in western Panama, where I re- 

 sided during the first half of the year 1929, stood about a dozen 

 well-grown avocado trees {Persea americana Mill.), some of them 

 very large, well-rounded specimens. While the history of these 

 particular trees is not definitely known, and they were undoubtedly 

 planted at widely separated intervals, they all probably represented 

 the usual unpedigreed and ungrafted stock, such as one finds in the 

 dooryard plantings of the natives throughout the region. The heavy 

 solstitial rains abated early in January, and gave way to the de 

 lightful weather which prevails in the region during the early 

 months of the year. The days were generally clear, although the 

 sky was sometimes overcast it seldom rained, and at noon the tem- 

 perature in the shade rarely exceeded 80° F. In such weather, about 

 the middle of January, the earliest avocado trees began to flower, 

 and thence until the middle of March some of the trees were in 

 blossom. At the same time they shed the old leaves of the previous 

 season, and acquired a new covering of bright green. 



Having read a paper by Robinson and Savage (1) on the polli- 

 nation of the avocado in Florida, I was eager to observe for myself 

 the interesting and peculiar floral behavior which they recorded. A 

 friend familiar with tropical fruit trees with whom I discussed the 

 matter seemed to doubt whether the avocado — at least in the trop- 

 ics — actually exhibited the double period of anthesis which these 

 authors describe, which made me the more interested to determine 

 for myself what the situation actually was. Although we have sev- 

 eral excellent accounts of the anthesis of improved and grafted 

 avocados in subtropical California and Florida, I am not aware that 

 anything has been published, at least in the American botanical 



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