442 XXIII. LEGUMINOSAE 



usually commence at an age of about ten years, and are repeated at intervals 

 of five or six years ; they are carried out with sufficient intensity to free the 

 crowns of the trees from contact with each other. In the Bombay Deccan 

 regular thinnings are also the rule. 



Grazing. The question of closure to grazing has been carefully studied 

 in Berar, and it is now recognized to be most beneficial to admit light grazing 

 of cows and bullocks, one animal per 2 acres or sometimes up to one head per 

 acre, as soon as the field crops are off the ground : this continues until the 

 young crop is well established, that is for about five to seven years, after which 

 the limit as to number is removed and buffaloes may al^o be admitted, but 

 camels, goats, and sheep are excluded. In the Bombay Deccan closure to all 

 kinds of grazing is prescribed for varying periods up to fifteen years or even 

 more. In Sind the coupes are closed to all grazing for five years from^ the 

 date of sowing, though in view of the rank growth of grass which springs up 

 it would probably be beneficial to admit light grazing of cows and bullocks at 

 an earlier stage : this is recognized, and actually closure is enforced for the 

 first six to twelve months only. Browsers are not admitted until ten years 

 after sowing, though it would be advantageous to exclude them for a longer 

 period, if not permanently. 



Rate of growth. The annual rings in Acacia arahica are indistinct, 

 and much reliance cannot therefore be placed on the results of ring- 

 countings. The rate of growth varies considerably, but under favourable 

 conditions it is rapid. The following recorded measurements refer to various 

 localities : 



Punjab. Brandis ^ says that in the Punjab the tree attains a girth of 

 2| ft. in about twelve years, and 5 ft. in about thirty years. Mr. Minniken 

 reported that in the Delhi Bela plantation a girth of 2 ft. was attained in 

 1^ years. 



Sind. Brandis ^ states that in lower and middle Sind the average girth 

 at 4 ft. from ground-level has been ascertained to be 4 ft. in 35 years, and 

 6 ft. in 55 years. He also mentions that trees planted in 1844 at Jacobabad 

 reached in less than 30 years a girth of 6-8 ft. and a height of 50-60 ft. More 

 recent measurements in the Jerruck forest division - in annually inundated 

 coupes of known age from 5 to 18 years old showed a mean annual girth 

 increment of 1-73 in. : on alluvial land the age of which was approximately 

 known the mean annual girth increment up to 40 years was estimated to be 

 1-67 in. 



In the Hyderabad forest division measurements of trees of known age 

 gave the following results : ^ 



1 For. Flora N.-W. and Central India, p. 182. 



'^ Revised Working Plan for the Jerruck Forest Division, D. J. Navani, 1915. 



^ Working Plan for the Hj^derabad Forest Division, H. Mitra, 1900. 



