72 THE DATE PALM. 



cold north and east winds in southern Tunis a are said to hinder the 

 pollination of the date palm. When they occur in summer they retard 

 the maturing of the fruit and may even cause it to drop. In Seistan, in 

 the plain of southern Persia, at an altitude of 1,300 feet above the sea 

 level, in the same latitude and altitude as flourishing date oases in the 

 Sahara, date culture is entirely prevented and all other fruit cultures 

 rendered impossible except in the shelter of high walls by the " Badi 

 sado biat," or "120-day wind,"- a violent, bitterly cold northwest 

 wind which blows from the spring equinox until about July 20. b This 

 wind would destroy the flowers of the date palm if they were exposed 

 to it, and as the date palm can not easily be protected by walls, its 

 culture is not attempted in this region, though it is followed in oases 

 lying at higher altitudes far to the north which by their position in the 

 shelter of mountain ranges are protected from such winds. It is pos- 

 sible that in spring cold winds may occur in the Salton Basin, but they 

 are probably less violent than in the Sahara, and are of course not to be 

 compared to the u badi sado biat" of Seistan. 



RESISTANCE OF THE DATE PALM TO ALKALI. 



The date palm has long been known to withstand large quantities of 

 alkali/ and some have even claimed that a certain amount of salt in the 

 soil is beneficial to its growth. ^ As to how much alkali the date palm 

 can resist and still grow and bear fruit in profitable quantities practi- 

 cally nothing definite is on record, notwithstanding the fact that hun- 

 dreds of thousands of dollars have been invested by the French com- 

 panies in plantations of date palms in the oases of the Algerian Sahara 

 where alkali abounds. Apparently the date palm is so enormously 

 resistant that it has not been necessary to pay much attention to the 

 amount of alkali in the soil where it is grown. It has been planted on 

 soil of practically all degrees of alkalinity and irrigated with all sorts 



Masselot, Les dattiers des oasis du Djerid. In Bui. Direct, de 1' Agriculture et du 

 Commerce, Regence de Tunis, vol. 6 (1901), No. 19, p. 121. 



& Bellew, H. W. From the Indus to the Tigris, London, 1874, p. 239. 



c The term alkali is applied rather loosely to the more readily soluble saline matters 

 which accumulate in the soils or in the water of desert regions. In spite of the name 

 such salts are mostly neutral in reaction, consisting chiefly of chlorids, sulphates, 

 and nitrates of the bases sodium, potassium, and magnesium. Only the carbonates 

 of sodium and potassium, constituting the much-dreaded " black alkali," are strongly 

 alkaline in reaction, and because of their caustic nature much more deleterious to 

 most plants than are the neutral salts or "white alkali," which latter are injurious 

 chiefly indirectly by rendering the soil water too concentrated a solution and thereby 

 unfitted to nourish the roots. 



^ Ibn-el-Fasel, an" Andalusian Moor, whose book, written in the twelfth century, 

 unfortunately has been lost, is said to have given the exact amounts of salt which 

 should be mixed with the manure for date palms. (See Cusa, Salvatore, in Archive 

 storico siciliano, I, 1873, p. 356. ) 



