90 Bulletin 78 



endure well the summer heat in the lower valleys. The culture of 

 pecans will probably never be successful commercially in Arizona, 

 but it will be possible to grow them as ornamental and shade trees 

 and to produce nuts of good quality for family use. The most suit- 

 able varieties of pecans for our conditions are Texas Prolific or 

 Sovereign, San Saba, Colorado, and Frotscher. 



p'ersimmons 



The common American persimmon (Diospyros virginiana) occa- 

 sionally may be found under cultivation in the southern parts of the 

 State. It withstands our summer heat very well if planted in deep 

 alluvial soil and given moderate irrigation. It should thrive even 

 better in the northern parts of Arizona where conditions of tempera- 

 ture are more nearly like those of its native habitat. The culture 

 of Japanese persimmons has not yet gone far enough to justify 

 planting them on an extensive scale. The individual trees scattered 

 about the vState seem to succeed well, but as yet they have not 

 borne fruits. 



PLUMS 



At a very few situations in the mountains of Arizona nearly all 

 varieties of plums succeed. In the hot southern valleys only certain 

 kinds are profitable. These embrace certain varieties of the Ameri- 

 can and Japanese classes. A few of the European varieties will 

 endure the summers for a few years and produce a fairly good 

 quality of fruit, but most of them are short-lived. While prunes 

 may be grown, they are not profitable on a commercial scale in the 

 southern valleys. 



Plums are injured much more by the heat of summer than by 

 the spring frosts, the buds, blossoms, or young fruit rarely being 

 injured seriously by frost. The only season during the past ten 

 years when much injury was done was March 13, 1901, when the 

 mercury fell to 32° in the government shelter, and 37'^ at the Weather 

 Bureau. The various varieties of plums endure the summer con- 

 ditions quite differently, the European varieties being most sensitive 

 to heat. Those enduring heat best belong to the Japanese group, 

 and most of those belonging to the Americ^an group endure summer 

 fairly well. Unless the trees are headed low, the trunks are apt 

 to be injured on the south and southwest sides, the trees dying later. 

 The life of plum trees varies with the variety, that of desirable ones 

 ranging from eight to twelve years. Plums are also subject to the 



