Relation of Weather to Crops 107 



WALNUTS 



The Arizona walnut (yMg/aw5 wa/or), native in canyons and river 

 valleys in parts of Arizona, is grown tD some extent as a shade and 

 ornamental tree. It appears one of the hardiest and best adapted 

 of all our deciduous trees. The Persian, or so-called English walnut, 

 which is grown quite extensively in parts of California, succeeds 

 well in valley soils in Arizona with abundant irrigation, when grafted 

 on the native walnut stock. On its own roots, however, and usual- 

 ly on the roots of the California black walnut, the English walnut 

 has not been a success. There is a number of fine large English 

 walnut trees grafted on Arizona walnut stock in the Upper Gila 

 Valley, some of which have borne regularly for 15 years or more. A 

 few thrifty English walnut trees also are growing about Tucson. 

 Mr. C. R. Biederman's work in grafting and growing French, 

 German, and English walnuts has so much of promise for the future 

 of the walnut industry in the Southwest that the Experiment 

 Station was led to issue Bulletin No. 76, "Walnut Growing in 

 Arizona." This describes in full Mr. Biederman's methods of graft- 

 ing and discusses the possibilities of commercial walnut growing 

 in Arizona. By virtue of their late blooming habits and dense 

 foliage, French walnuts appear best adapted to our climatic con- 

 ditions. Some of the more promising of these are the Franquette and 

 the Marquette. 



WATERMELONS 



Watermelons of prime quality are easily grown at the lower 

 altitudes and in the valleys throughout central and southern Ari- 

 zona. The period during which melon seed germinates extends 

 from March (the time in the month depending on the season) 

 until October. Most of the early varieties germinate earlier in 

 March than the later ones, the Augusta starting the earliest of any 

 tested at the Farm, but no varieties make much growth until the 

 mercury ceases to fall below freezing at the ground. Seed planted 

 before the latter part of March germinates very slowly and during 

 the early stages the young plants are sometimes injured by frost 

 and usually show little promise of giving better results than those 

 planted later; but the first planted are ordinarily the first to 

 produce ripe melons. Those planted during the early part of 

 April ordinarily grow without interruption by cold, but usually 

 ripen their melons a week or so later than those planted in March. 

 During the warm weather of May and June, while the maximum 



