105 



len" but he has this season again used such pollen for more than 

 50 clusters of flowers. Another grower has used old pollen to a 

 considerable extent. None of his 1922 pollen gave any germina- 

 tion when tested in April, 1923. When apprised of this condi- 

 tion he remarked, "That seems to explain the poor results I ob- 

 tained last year from the use of old pollen." 



Dr. W. R. Faries states that several years ago, probably in 

 1918, he used pollen of the year before to pollinate early blooms 

 in January when no males were out and got no fruit to set. 



Apparently, however, nearly all growers have proceeded with 

 confidence in the traditions and practices of the Old World date- 

 growers and have very generally attributed such failures as they 

 have experienced from using old pollen to incidental conditions 

 rather than to the complete death of the old pollen. A con- 

 clusive pollination test of old pollen has not been made. It 

 could best be made from the first female flowers to open in spring, 

 employing the bagging method to exclude any stray pollen. 

 A few such tests would readily show whether old pollen which 

 does not germinate on various culture media can function directly 

 on the pistils. 



The germination tests of the pollen of date palms have been 

 made only during the present season of bloom. It is perhaps pos- 

 sible that under unusually favorable conditions pollen may some- 

 times remain viable from one year to another. But in the exten- 

 sive tests made this year no old pollen has shown any trace of 

 being viable. 



The practices of hand pollination now employed require that 

 pollen be kept during the season for use from day to day as 

 needed. This raises the question of how long pollen will remain 

 viable. Several lots of pollen collected early in the season, some 

 as early as February 19, 1923, have given excellent germination 

 as late as April 12, following. This pollen remained viable 

 during a period of nearly two months.' Such evidence indicates 

 that when pollen is properly cared for it can be kept and used 

 with success during one season of bloom. 



The direct germination test on a culture medium makes it pos- 

 sible to determine only a few hours in advance of its contemplated 

 use in pollination whether a given lot of pollen is viable or not. It 



1 Tests as late as May 31 also gave good germination, suggesting that date 

 pollen dies at some time during the summer. 



