THE PALMS OF BRITISH INDIA AND CEYLON. 689 



month at least above 80°. For the moderately late varieties these 

 temperatures must be above 75° and 85° respectively, and for the 

 best and latest varieties 84° and 94°. The tree must, moreover, be 

 exposed to the direct rays of the sun ; it will not grow under 

 shade even when young. 



The physical character of the soil, whether sand, loam or heavy 

 clay, seems to have little influence on the growth and productive- 

 ness of the tree, except, perhaps, that on light soils flowers and 

 fruits develop earlier than on heavy ones. On the whole sandy 

 loams appear to be best suited for the cultivation of dates. 



The Date Palm is equally indifferent to the quantity of alkali 

 in the soil. The United States Department of Agriculture investi- 

 gating the soils of the Algerian palm-bearing tracts came to the 

 conclusion that this plant, although it can grow in soils contain- 

 ing 3 to 4 per cent, of their weight of alkali, does " not produce 

 fruit, unless its roots reach a stratum of soil where the alkali con- 

 tent is below 1 per cent, and does not yield regular and abundant 

 crops unless there are layers in the soil with less than 0*6 per 

 cent, of alkali." 



Propagation may take place in two ways by seeds and offshoots. 

 Mr. Fletcher describes the method of rearing seedlings as follows : — 

 " The seeds should be sown in a seed-bed that has been specially 

 prepared on sweet soil by ploughing in a mixture of ordinary farm- 

 yard manure and on oil-cake at the rate of about 1 tons of the 

 former and 400 lbs. of the latter per acre. Suitable oil-cakes for 

 India are those obtained from the castor-oil plant (Ricinus com- 

 munis), Eruca sativa or any of the mustard family ; these cakes 

 have the property of more or less preventing the attacks of white 

 ants. Emphasis is laid on the fact that the soil of the seed-bed 

 should be sweet and not impregnated with alkali soils (reh or usar 

 lands), since, though offshoots and adult plants will tolerate large 

 amounts of such salts, a very small percentage of these in the soil 

 will suffice to kill the seedlings soon after germination, if not 

 actually to prevent germination. 



" After this preparation, the seed-beds should be irrigated in 

 March or April and two or three days later the seeds sown in it at a 

 depth of 1 or 2 inches in rows, 3 feet apart with intervals of 3 feet 



