Junk, 1920J HORTICULTUKi: M\) 



2353. PuBCT, Earl. The productive mortality of prunes. Better Fruil 13 J : 9-10, 38-40. 

 March, 1919. — -This is a general discussion <>f factors causing decline in pr< ductivity of plum 

 (prune) trees. Particular attention is paid to heart rot, rool borers, general care of the trees 

 and cultural practices, either of which may be instrumental in causing premature reduction of 

 vitality and fruit bearing capacity of a tree. Based on statistical evidence, compai 

 yields of young and old trees in two counties of Oregon are given. A. E. Mv 



2351. Pkucy, Haul. Filbert culture a new orchard industry in Oregon. Better Fruit 

 13 12 :7-S. June, 1919. — -A brief discussion of the history, present status, and future possi- 

 bilities of growing lilberts in Oregon. — A. /.'. Murneek. 



2355. Pkhold, A. I. The Union's viticulture industry. South African Jour. Indust. 

 2:318-326. 1919. 



2356. Pillsbuuv, J. P. Report of the division of horticulture. North Carolina Agric. 

 Exp. Sta. Ann. Kept. 41: 56-57. [1919.] — This is a brief report of experiments with hybridi- 

 zation of V. rotundifolia with other species of Vitis, and investigations as to the besl stocks 

 and methods of propagation for English walnuts in the south, together with a study of wal- 

 nut-hickory hybrids, investigation to determine the means of improvement of certain plum 

 varieties, and hybridization of bramble fruits to determine varieties of raspberries suitable 

 for the south. — R. A. Jehle. 



2357. Popenoe, Wilson. The avocados of Mexico: A preliminary report. Ann. Kept. 

 ( alifornia Avocado Assoc. 1918-1919: 58-7-1. PL 3-13. — Mexico, on account of its great size 

 and almost endless series of environmental conditions offers the greatest opportunities for 

 avocado investigations. This paper is a report upon the first 6 months' work, the author 

 having previously spent 16 months in Guatemala engaged in similar studies. Four chief 

 races of avocadoes recognized, all found in Mexico. The West Indian race seems to be 

 the true Persea americana of Miller, formerly known as Persea gratissima of Gaertner. Not 

 yet found in an indigenous state. The Guatemalan race is also probably Persea americana 

 though this is not considered as proved till indigenous trees are found. The Mexican race 

 occurs abundantly in an indigenous state and as it appears quite distinct will probably be 

 shown to belong to the species Persea drimy folia as established in 1831 by Chamisso and 

 Schlechtendahl. The Chinini race is suggested to include certain forms in southern Veracruz 

 which will probably be referred to Persea schiedeana of Nees, reduced by Meissner in 1864 to 

 the rank of a botanical variety of P. americana. 



The West Indian race is adapted to lowlands near the sea while both Mexican and Guate- 

 malan races thrive best on inland tablelands at elevations of 4000 to 6000 feet. Evidence accu- 

 mulates that avocados «prefer heavy clay soils. Until very recently all commercial planta- 

 tions in Mexico were composed of seedlings. In productiveness the races rank as follows: 

 Guatemalan, Mexican, West Indian, and Chinini. The Mexican race does not fully deserve 

 the condemnation it has received in California. After visiting Atlixco in order to examine 

 parent trees and settle a much discussed point in regard to the true classification of the 

 Fuerte and Puebla varieties, the author concludes that Puebla is a true Mexican while Fuerte 

 is probably a hybrid, not representative of any group but appears to be sui generis. — J. E. 

 Coit. 



2358. Popenoe, Wilson. Agricultural explorations in Mexico. California Citrograph 

 4: 83-71, 73. 4 fig- 1919. — This is paper No. 3 from the Journal of Wilson Popenoe, Agricul- 

 tural Explorer for the University of California. Descriptions of tropical fruits studied at 

 Oaxaca, June 21-24; Tapachula, June 27- July 3; La Tacualpa, July 4-8; and Puerto Mexico, 

 July 14, 1918. The following are included: The Hicaco, chrysobalamus icaco; Chicozapote, 

 Achras zapota; Guanabana, Armaria muricata; Papauce, Annona dicersifolia (illustrated); 

 Anona, Annona squamosa; A. purpurea; A. reticulata; Papaya. Carica papaya; Avocado, 

 Persea americana (ill.); Pacaya, Chamaldorea Sp.; Jacote Maranon; Anacardium occidenlale ; 

 Tamarindo, Tamarindus indica; Mango. Mangifcra indica; Nance. Brysonima crassifolia; 



