FLORIDA STATE inRTICULTrRAL SOCIETY 



ers all shed pollen during the same hours 

 and they all have first-period flowers open 

 together during other hours. Reduction 

 in the yields of fruit, in solid block plant- 

 ings, is to be expected. It is the inter- 

 planting of trees of different varieties 

 wliich have a reciprocating alternation 

 (such as Panchoy and Taylor furnish) 

 that provides the chances for the greatest 

 number of proper fertilizations through 

 cross-pollination. 



In regard to flower behavior, all vari- 

 eties and seedlings of avocados thus far 

 studied by the authors in California and 

 in Florida are to be grouped into two 

 main classes. 



In one class, which may be designated 

 Class A, the first-period flowers normally 

 open in the forenoon and close during 

 midday to remain closed about 24 hours. 

 Each afternoon another set of flowers 

 opens to shed pollen. Taylor mentioned 

 above is typical of this class. 



In the other group of varieties, Class B, 

 the second-period flowers are normally 

 open during the forenoon and the first- 

 period flowers are open during the after-' 

 noon. Panchoy is in this class. fflffl 



This natural grouping of varieties into 

 two classes is readily revealed when one 

 makes observations on the flowers of sev- 

 eral varieties at frequent intervals during 

 a single day of favorable weather. Tag- 

 ging and numl)ering individual flowers 

 greatly facilitates the observation's for 

 otherwise the shift of sets may not be dis- 

 covered. 



A chart of the records of flower behav- 

 if)r for one entire day of favorable weath- 

 er dearly indicates several imjjortant facts, 

 namclv : — 



1. That for each variety there are 

 normally two different sets of flowers 

 open during the day. 



2. That the first-period flowers on a 

 tree open together and for different hours 

 than do the second-period flowers. 



3. That the various varieties fall into 

 two general classes with reference to the 

 daily sequence of the two sets of flowers. 



4. That the flower behavior of avo- 

 cados is decidedly adapted to cross-polli- 

 nation between varieties which shed pollen 

 in the forenoon and those that have first- 

 period flowers open during the forenoon. 



Cloudy and rainy periods of weather 

 and particularly low temperatures greatly 

 affect the opening and the closing of flow- 

 ers. Such weather throws the sequence of 

 blooming out of stride and the flowers 

 of one or more sets of a variety may be- 

 have with marked irregularity. The first 

 period of opening may be omitted by an 

 entire set. Sets of second-period flowers 

 may fail to shed pollen. A set that nor- 

 mally would open in the afternoon may be 

 retarded until the following forenoon and 

 the firsts of that forenoon may be re- 

 tarded until afternoon, temporarily, giv- 

 ing a reversal for the normal daily se- 

 quence of the variety. Three distinct sets 

 of flowers may be open during a single 

 day. 



Frequently during irregular and off- 

 stride blooming there is an overlapping 

 of different sets and first-period flowers 

 may be open at the time second-period 

 flowers are shedding pollen. There is 

 then an opportunity for close-pollination. 

 When a set of flowers skijis the first- 

 period and has a single opening during 



