54 



JOURNAL OF THE ROYAL. HORTICULTURAL SOCIETY. 



under live inches, the Punjaub area (with the exception of Hissar, of 

 which the rainfall is 1(5 inches) a fall of under 10 inches, Jhind a fall of 

 practically 20 inches, while in the Ganges-valley area the fall lies between 

 20 inches and 80 inches. This statement holds good when we consider 

 the rainfall of the rains only (Map 11.). The dry-weather rainfall, as this 

 map shows, is insignificant, being less than four inches during the seven 

 months over the entire area under consideration. It is a period, also, 

 when little or no indigo is cultivated. 



Maps III. and IV. indicate the direction of the isothermal lines ; 

 Map III. the normal annual maximum temperature ; Map IV. the normal 



Fxo. 10. Raiiwalpir Plant. 



mean temperature for three of the four seasons (cold weather, December 

 to February; hot weather, March to May; rains, June to August). Of 

 these periods the cold weather may be neglected, since the cultivation of 

 indigo during this period is very limited. 



During the hot weather — also a period of little importance * — it will be 

 noticed that all districts lie on, or slightly south of, the 80° F. isotherm. 



* Throughout the parts under consideration indigo is sown on irrigated land only. 

 It cannot, therefore, be sown before the rise of the rivers admits of the opening of the 

 canals. The usual, though not invariable, custom is to sow annually. Occasionally, 

 however, the plant is left for a second year, in which case it is cut for dye the first, 

 and for seed the second, year. 



