26 THE DATE PALM. 



abundantly four or five years after being transplanted (see PL XXII). 

 However, in the large plantations made in Algeria by the French col- 

 onists it is not considered advisable to allow the palms grown from 

 offshoots to bear fruit until five or six years after they are -set out, 

 and the trees are not in full bearing until eight or ten years after 

 they are planted. They continue bearing, if well cared for, until they 

 are a hundred years or more old, a good tree producing an average 

 of from 60 to 200 pounds of fruit a year," although some trees have 

 been known to produce as much as 400 or 600 pounds 6 when grown in 

 rich soil and abundantly irrigated. The tree shown in a previous 

 paper (Yearbook, 1900, PI. LVII, fig. 1) is a demonstration of the 

 capabilities of Arizona as a date-producing country. It was only 8 

 years old from the seed when photographed, and yet bore some 400 

 pounds of dates. Again, an Amreeyah palm, grown from an offshoot 

 imported by the Department of Agriculture from Egypt in 1889, 

 yielded in 1900 over 300 pounds of dates (see Yearbook, 1900, PL 

 LXII, fig. 1). A little palm growing on the grounds of the University 

 of Arizona, at Tucson, where the winters are often cold, bore, never- 

 theless, when it had been transplanted five years, two bunches of fruit 

 weighing together some 30 pounds (see Yearbook, 1900, PL LVH, fig. 

 2). The large Deglet Noor palm growing at Biskra, Algeria, shown 

 in the foreground of Plate LX, Yearbook, 1900, bore over 15 bunches 

 of fruit, and the young Deglet Noor palm shown in Plate XXII, 

 grown from a sucker set out only three years before, bore 3 bunches 

 of fruit. 



POLLINATION OF THE DATE PALM. 



In a wild state the date palm is undoubtedly pollinated by the wind, 

 and about one-half of the trees are males. It is probable that pollina- 

 tion would be incomplete unless the proportion of male trees was 

 something like one-half, for, although enormous quantities of pollen 

 are produced, only a very small part of wind-blown pollen ever reaches 

 the female flowers. The artificial pollination of the date palm was 

 doubtless discovered by the ancient Ass}^rians, and has been practiced 

 probably for three or four thousand years at least. Because of the 

 great economy of pollen brought about by this practice, one male 

 tree suffices to pollinate from fifty to a hundred females. 



The male flower cluster of the date palm consists of a stalk bearing 



M. Masselot has published a list of all the important varieties of dates grown in 

 the Tunisian Sahara (Bui. Direc. Agric. et Comm., Tunis, Vol. 6, No. 19, Apr., 1901), 

 and gives the average yield per tree of 92 sorts. The Loozee variety has the lowest 

 average yield, 55 pounds, and the Areshtee and Hamraya the highest, 220 pounds; 

 the average yield of all the 92 varieties is 116.5 pounds per tree. 



ft ln the oasis of Tebbes, the northernmost in Persia, it is reported that a full-grown 

 tree may yield 200 man (of 3 pounds). Bunge, Petermann's Mittheilungen, 1860, 

 p. 214. 



