324 



THE AGRICULTURAL NEWS. 



October 7, 1916. 



FRUIT CULTURE. 



CALIFORNIA GRAPE FRUIT AND ITS 



FUTURE. 



On account of the poorrepntation of California grape fruit 

 as a whole, which has led many people to doubt the advisa- 

 bility of extending the cultiiru of this crop in California, 

 Mr. A. D. Shamcl, of the United States Department of Agri- 

 culture contributes to the Monthly Bulletin of the California 

 State CoMinisyioii of Jlorticultuie, a. useful discussion and 

 review of the present position, the main features of which 

 will prove of interest to citrus growers in the West Indies. 



The early plantings of grape fruit in California wi re 

 of Florida varieties which were selected without much knowl- 

 edge of their adaptability to California conditions. It i.s 

 only in recent years that any real knowledge ha.s been 

 developed of the comparative value of .several varieties for 

 that State. Of the varieties fruited so far, one, the ]SIarsh 

 Seedless, stands out clearly as particularly adapted for 

 California conditions and is of genuine commercial value. 

 It is becoming more and more evident that the grape fruit 

 tree planted on rather light, porous and sandy soils produces 

 fruit of superior commercial quality, colour, and te.xture of 

 rind to those planted on the heavier clay soils. That there 

 is a relation between the character of the soil and the 

 commercial quality of the fruit can hardly be doubted. 



As regards the marketing of the fruit, it is said that an 

 early variety is needed, producing fruit which will ripen 

 from October until February for California markets, and 

 this is one of the achievements worthy of the serious 

 attention of citrus breeders and propagators. Under proper 

 conditions, the late grape fruit can usually be held in storage 

 for some time with constantly improving flavour and little 

 loss of weight from shrinkage. These conditions are, first, 

 a uniform, cool temperature; and, second, a uniform condi- 

 tion of humidity of about 90 per cent. 



Proceeding next to a discussion as to the correct name 

 of the fruit, reference is made to the American name of 

 pomolo which was given to this fruit. The author agrees 

 that grape fruit, being more commonly used than pomolo 

 and better established in the j)ublic mind is now a more 

 logical one than pomolo. Iteferenee is made to the fact 

 that Swingle regards grape fruit as Citrus grandis. 



After describing the different varieties, in which refer- 

 ence is again made to the Marsh Seedless, the writer proceeds 

 to deal with the subject of the distribution of plantings. In 

 1915, 600 acres of grape fruit trees were in hearing in 

 California and 1,100 additional acres of trees were under 

 five years of age, from which it is estimated the California 

 output will be more than doubled in the coming live years. 

 The area under cultivation in Florida is very much greater, 

 something like (50,000 acres, while large areas also exist in 

 Porto Piico and Cuba, both of which places make large .ship- 

 ments to the States annually. A comparatively small but 

 rapidly increasing export of grape fruit to the United States 

 from .lamaica and some other foreign grape fruit growing 

 sections is evident from the observations and figures available 

 for study. 



In considering the grape fruit situation in California, 

 it has to be borne in mind that Fkirida or foreign grape fruit 

 is no longer admitted into California on account of the 

 danger of the introduction of insect pests and fungus diseases 

 through this means. Second, the period of ripening of the 



Californian Marsh Seedless grape fruit ia during the summer 

 months when no other known district has a ripe crop avail- 

 able to supply the great Eastern markets. For these and 

 other reasons, it is believed that California has an opportu- 

 nity to develop a strong grape fruit industry provided only 

 the best j.'ossible grades of grape fruit are produced and 

 provided the fruit is allowed to ripen before picking. 



The relation of composition and other characteristics to 

 i|ualiiy of grape fruit has been investigated by the P)Ureau of 

 Chemistry of the I'nited States Department of Agriculture, 

 through the laboratory of by-products, located in Los Angeles. 

 The figures published in the present article show clearly the 

 difference in acid and sugar content between California and 

 Florida grape fruit. There is considerably more acid (about 

 ^•3 per cent.) in the California fruit than in the Florida 

 which has approximately 1 5 pei- cent. The sugar in the 

 Florida fruit is also greater (nearly S per cent.) than in the 

 California fruit (7 percent.). 



In the succeeding section reference is made to variability 

 of the Mirsh Seedless varieties. Some trees have been found 

 to produce habitually fruits containing large numbers of seeds. 

 In some ca.ses this heavily seeded characteristic was found to 

 be correlated with a rough, thick rind and an undesirable 

 shape of fruit. It is said that this type has since been proven 

 to have originated from bud mutations. It has been 

 unintentionally propagated through the ab.sencc of any care- 

 ful system of bud selection based on individual tree 

 performance records. It is important that the standard and 

 valuable type of Marsh Seedless should be isolated in propaga- 

 tion by bud selection based on individual tree performance 

 records. 



The writer in conclusion makes a few remarks in regard 

 to the pruning of grape fruit trees, which may be of interest 

 to readers in the West Indies: — 



'The principle of pruning grape fruit trees is not fully 

 settled. So far as the writer's observations have gone, the 

 best method of pruning for young trees is to lay the founda- 

 tion for strong tops by careful heading, not allowing all of 

 the main branches to arise at one point, and by some careful 

 thinning of the new growth from time to time. It is prob- 

 ably a good plan to cut out most of the distinctly marked 

 sucker growth and when necessary to remove the dead 

 branches. When the period of maximum production begins 

 to wane, it now seems probable that it may be best to cut 

 otf the old tops and grow new ones; in other words, renew the 

 trees. If the type of tree and fruit is not exactly desirable, 

 the time of tree renewal is the proper period for topworking 

 by rcbudding, so that the new tops will be produced from 

 buds instead of frflin sprouts." 



DEPARTMENT NEWS. 



Dr. .J. C llutsuii, B.A., rii.l>., at present Assis- 

 tant Entomologist, Estacion Experimental A£;ronomica, 

 Santiago dc las Vegas, (\iba, has accepted the otler to 

 act as ^wcum <f ?!«??*■ at this OIHco during the absence 

 in Egypt of iMr. tl. A. F>;illou, JLSc, Entomologist ou 

 the statl' of this Department. At the time of writing 

 Dr. Hntson was working in the eastern part of Cuba 

 in co-operation with the Comison de Sanidad Vegetal, 

 on the problem of the Spiny Black Fly on Citrus, a pest 

 that is at present engaging attention in Jamaica. 



Dr. Hutson is expected to.irrive in Barbados early 

 in November. 



