276 CALIFORNIA FRUITS : HOW TO GROW THEM 



different demands. Here we are again, doing our main business at the 

 old stand, but knowing how to do it better. Have we anything more to 

 expect? Probably nothing from old varieties, for we have prospected 

 them all from a prune-making point of view, taking Coe's Golden Drop 

 plum, or its seedling, for the Silver Prune, and canceling all others as 

 possibly good plums for various uses, but not for prunes. 



Probably our only expectation lies along the line of plant breeding, 

 although nothing to supplant the prune d'Agen has yet been attained. 

 The Giant prune is a large red plum ; several Oregon prunes are simply 

 large red plums. The standard of sugar in the prune d'Agen as grown 

 in California is from 15 to 23 per cent of sugar in the fresh juice, ac- 

 cording to degree of ripeness and localities in which the fruit is grown. 

 The sugar in Pond's Seedling and in the large red plums just named 

 is less than 10 per cent sometimes very much less. But percentage 

 of sugar in the juice is not the whole story; there are tissue or flesh 

 characters which are essential also. Mr. Burbank's Sugar prune an- 

 swers the sugar requirement; it is a free bearer and early ripening 

 variety, and it dries easily though large, and the small dried product 

 thus far made has sold well, but it has not the fine grain nor distinctive 

 flavor of the prune d'Agen, and the pit is large and rough. It becomes 

 a good plum for shipping and possibly for other plum purposes. But 

 Mr. Burbank has held the plum family in training, and his latest intro- 

 duction, the Standard prune, seems to be making good, and in 1914 is 

 being widely planted. 



Others are also working at the problem, and the next generation of 

 California prune growers may attain what the last and present have 

 striven for. .The most promising line at the present time is the search 

 for better types of the prune d'Agen which are found here and there, 

 arising from natural variation. Mr. Leonard Coates of Morgan Hill 

 is giving particular attention to this subject, and has demonstrated the 

 existence of very superior variations. 



POLLINATION OF PLUMS 



The shy bearing of certain plums is probably due to lack of pollina- 

 tion, either through the self-sterility of the variety or lack of acceptable 

 pollinating agencies. Bearing can be induced in many cases, no doubt, 

 by either planting or grafting-in of effective pollinating varieties. But 

 this is not always profitable. For instance, there are many instances 

 proving that the Tragedy can be brought to greater bearing by the 

 presence of Clyman, but an early variety like the Clyman is not worth 

 growing for sale in a late district, though in an early district both are 

 valuable as shipping plums and should be planted together. The Hun- 

 garian is well pollinated by the Peach and the Grand Duke plums. The 

 bearing of Wickson is greatly increased by association with Climax The 

 pollination of plums not not yet, however, been given as much attention 

 as of other fruits. 



