THIRTY-FOURTH FRUIT-GROWERS^ CONVENTION. 



173 



conduits, as in the orange groves of Riverside County, a great saving 

 in the requirement per tree is effected. 



At the Tempe Cooperative Date Garden in a heavy adobe soil, but 

 surrounded with alfalfa fields which are copiously irrigated, the soil 

 water has raised so that the trees have received no direct irrigation for 

 a year and a half. While this provides for the water requirements of 

 the orchards, of the effects on the ripening of the fruit I will speak a 

 little later. 



SOIL REQUIREMENTS. 



That dates may be grown upon a great variety of soils has been fully 

 demonstrated in this country, as well as in their home, but we still have 

 to gain much experience as to soil adaptations of different varieties. 



At the Tempe garden growth of all varieties upon the brown adobe 

 soil of the Salt River bottoms is very rank and luxuriant, and the 

 production of fruit all that could be expected. It is evident, however, 

 that the ripening of the fruit is a good deal retarded by moisture which 

 the soil retains, and it seems evident that many varieties of fruit are 

 of a more soft vsyrupy nature grown here than in the dry hot sands at 

 Mecca. 



A situation where the drainage is bad and irrigation or flood waters, 

 not readily removed should be avoided. Witli the heavier soils it is very 

 important that baking and cracking should be prevented by prompt 

 cultivation as soon as the ground can be worked after irrigation. In 

 short, good drainage and aeration of the soil are as essential to the 

 date as to ordinary crops. 



ALKALI RESISTANCE OF DATE PALMS. 



The alkali resistance of the date is very remarkable, it ranking as 

 the most resistant plant in cultivation, even exceeding the Australian 

 salt bush. Old well-established trees are able to endure a much greater 

 strength of alkali than young seedlings. The old trees may seem to be 

 much more resistant than they really are from the fact that alkali 

 ticcumulations on the upper layer of soil, which is usually turned by the 

 plow, may become very heavy with little injury if the roots can pene- 

 trate to subsoils having a comparatively small percentage of the poison- 

 ous salts. This is very noticeable in the Tempe garden at the present 

 time. The plantation was made in 1900 on land where alfalfa had been 

 killed out, and similar to lands which Thomas H. Means, of the Bureau 

 of Soils, had found to contain about 2i/2 per cent by weight of harmful 

 soluble salts in the upper 12 inches. At the present time there is a 

 marked alkali crust over the whole area, and the problem of keeping- 

 down weeds is practically eliminated, for few attempt to grow. Young 

 plants from seed sprouting under the trees turn brown at the surface 

 of the soil and die before the end of their first summer. The caretaker 

 has been unable to surround his house with any shade trees, a single 

 pomegranate bush being the only woody plant besides the dates able to 

 survive in the enclosure. The fact that the ground water rises very 

 quickly when the surrounding alfalfa fields are irrigated show^s that 

 there is a free movement of water in the substrata, probably a part 

 of the great Salt River subfiow, and the date roots are doubtless grow- 



