BUREAU OF PLANT INDUSTRY. 271 



vantageous to retain the buttons on the fruit. Methods have accord- 

 ingly been worked out whereby the fruit may be colored without 

 removing the buttons. The effect of temperature and humidity 

 on the coloring process has been determined and apparatus devised 

 for conveniently modifying these conditions. The experimental 

 work on this problem is about completed. 



Citrus-canker eradication. — The continuation of the cooperative 

 campaign for the eradication of citrus canker conducted in coopera- 

 tion with Florida, Alabama, Mississippi, Louisiana, and Texas has 

 progressed satisfactorily. No extensive epidemics of canker oc- 

 curred in any of the cooperating States. Slight infections were 

 found in Florida, Alabama, and Mississippi. In Texas and Lou- 

 isiana the infections were less frequent and less serious than in former 

 years. 



DATES. 



The largest new factor in the date industry has been the large- 

 scale introduction of the Saidy date from Egypt and the successful 

 propagation of several thousand of these imported offshoots under 

 conditions that insure the rapid building up of a stock of home- 

 grown palms. With this variety perhaps best adapted to the Impe- 

 rial Valley and the Hayany alreacly proved satisfactory for the Salt 

 Eiver Valley, the area devoted to commercial date culture (now 

 largely limited to the Coachella Valley, owing to the exacting nature 

 of the Deglet Noor variety) will be greatly enlarged in the near 

 future. A bulletin has been issued describing the Saidy variety, cov- 

 ering its history, the conditions suitable to its culture, etc., and physi- 

 ological studies have been conducted on this and other varieties which 

 throw light on many problems previously perplexing. 



Rooting offshoots is no longer a matter of serious difficulty. Im- 

 provements in the technique of date maturation have been worked 

 out, and storage experiments are under wa3\ Pollination studies 

 show marked differences in the viability of pollen from different 

 males and indicate the necessity for careful selection. The use of 

 hold-over pollen, quite general on early-blooming varieties, has been 

 shown to be a practice of doubtful value, though further studies will 

 be necessary. These pollination studies are of particular importance 

 in the breeding of new and superior varieties, a field already demon- 

 strated as of decided promise. 



SMYRNA FIGS. 



Renewed interest in figs as the basis of a fruit industry in Cali- 

 fornia has been awakened by the popularity of canned figs. The 

 Smyrna fig has been found to lend itself particularly well to canning, 

 and a large part of the present crop will be handled in this way. 

 Insect-bearing caprifigs have been supplied to the growers of Smyrna 

 figs from the Maslin orchard at Loomis, Calif., leased to the Depart- 

 ment of Agriculture, and cuttings of especially promising caprifigs 

 and new seedling varieties of hybrid origin (such as the nonsplitting 

 Stanford) have been supplied to cooperators for trial. The planting 

 of caprifig orchards in a number of protected places has been en- 

 couraged, and the prospect of a serious shortage of fig insects 

 (Blastophaga) in future years is now rather remote. 



