440 EXPEKIMENT STATION RECORD. [Vol.43 



from the pruned and unpruned trees was in favor of the unpruned trees, 

 which produced a few more first grade fruit. These results indicate that with 

 grapefruit trees of hearing age, severe pruning should be avoided unless it is 

 definitely known that such pruning is necessary and likely to prove beneficial 

 rather than detrimental to crop production. 



Origin of a grapefruit variety having pink-colored fruits, A. D. Shamel 

 (Jour. Heredity, 9 {1920), No. 4, pp. 156-159, figs. 5).— The author illustrates 

 and briefly summarizes the history of the pink-fleshed Foster variety of grape- 

 fruit originating in Florida, and illustrates and describes a pink-fleshed grape- 

 fruit which originated as a bud sport in a Marsh grapefruit tree near River- 

 side, Cal. 



Citrus-fruit improvement: A study of bud variation in the Eureka 

 lemon, A. D. Shamel, L. B. Scott, C. S. Pomeroy, and C. L. Dyer {V. 8. Dept. 

 Agr. Bui. 813 {1920), pp. 88, pis. 7, figs. 22).— This is the fourth of a series of 

 publications summarizing the citrus fruit-improvement investigations of this 

 Department (E. S. R., 39, p. 845). A detailed account is. given of bud varia- 

 tions in the Eureka lemon as determined by means of individual tree perform- 

 ance records and observations. 



As in the previous studies with the orange and grapefruit, it was found 

 that both desirable and undesirable strains of Eureka lemon have been intro- 

 duced into tlie groves through the unintentional propagation of bud variations. 

 Eight strains were studied and are described. The performance of typical 

 individual trees is recorded, and the importance of selecting only fruit-bearing 

 wood from superior parent trees for propagation or for top-working is again 

 emphasized. 



Citrus-fruit improvement: A study of bud variation in the Lisbon 

 lemon, A. D. Shamel, L. B. Scott, C. S. Pomeroy, and C. L. Dyer (U. S. Dept. 

 Agr. Bui. 815 (1920), pp. 70, pis. 8, figs, i^).— This is the fifth of the series of 

 publications summarizing the citrus-fruit improvement investigations of this 

 Department, and treats in a manner similar to that noted above for the Eureka 

 lemon, a study of bud variation in the Lisbon lemon. The results secured in 

 this study are in conformance with those noted for the Eureka lemon. 



Frost protection in lemon orchards, A. D. Shamel, L. B. Scott, and C. S. 

 Pomeroy (U. S. Dept. Agr. Bui. 821 (1920), pp. SO, pis. 3, figs. i5).— This bulle- 

 tin presents detailed records of the proportion of m^erchantable and frozen 

 fruits produced in 5 heated and 5 nonheated acre plats of Eureka and Lisbon 

 lemons during the calendar year 1913, and in 2 comparative plats during the 

 calendar year 1914 in the Corona, Cal., lemon district. 



The data show that in orchards which were protected with an adequate 

 supply of heaters during the cold weather of 1912-13 a large percentage of 

 merchantable fruit was saved and harvested throughout the year. In unheated 

 orchards a large proportion of the lemons picked during the first 6 months 

 following the freeze were frozen or unmerchantable, and the trees did not 

 return to normal production until a year had elapsed. 



Nonheated orchards which had received good care prior to the freeze of 1913 

 and also during that year had returned to normal production by the beginning 

 of 1914, and the heating during the cold period in 1913 had practically no 

 effect on the second season's crop. In unprotected orchards, under comparative 

 conditions, a greater amount of injury was found in the Eureka than in the 

 Lisbon variety. These differences were attributed to the denser foliage of 

 the Lisbon variety rather than to any considerable difference in the hardiness 

 of the two varieties. 



From these investigations it appears that the main effect of protecting trees 

 during one season of low temperatures is in the saving of the erop for the 



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