PROSOPIS . 397 



commonly adopted is thirty years. In Sind the treatment followed, which is 

 based primarily on the requirements of the principal species, Acacia arahica, 

 is that of clear-felling with natural reproduction on the riverain alluvium, 

 supplemented where necessary by artificial sowing, often with the aid of field 

 crops ; these sowings, as applied to Prosopis spicigera, have been described 

 above. At one time a rotation of fifteen years was adopted, but as this was 

 found to be too short it was raised subsequently to thirty years, which is 

 the rotation prescribed in the more recent working plans. In the Sind 

 coupes, reproduction of Prosopis is secured also by root-suckers and coppice- 

 shoots. 



It is many years since the stimulation of reproduction by root-suckers 

 became the subject of observation and experiment in the Punjab. In 1881 

 ' Punjabi ' } recording his observations in the case of land cleared for cultiva- 

 tion where the stumps were respectively left in the ground and grubbed out, 

 notes that in the latter case the resulting root-suckers were stronger and more 

 numerous than in the former, and ascribes this in part to the fact that water 

 lodges in the holes left after grubbing out the stumps and tends to keep the 

 surrounding soil moist : these observations were subsequently confirmed by 

 experiments made on forest land. The grubbing out of the stump and upper 

 portion of the taproot, apart from its effect in stimulating the production of 

 root-suckers, has the advantage of providing a considerable quantity of fuel 

 and thus increasing the yield. The question of sucker reproduction is again 

 alluded to in 1892 by Mr. C. F. Elliot,- who writes : ' It is some years since 

 in the Punjab we recognized that the regeneration of Prosopis spicigera in the 

 bar forests depends chiefly on root-suckers ; at all events, that any improvement 

 in the way of filling up blanks will be accomplished in this way and not by 

 seed. ... It is well known that these shoots from the roots of trees of which 

 the stumps and main roots even have been dug out on the compartment lines 

 are almost impossible to kill : year after year they have to be cleared away to 

 keep the lines open.' 



Rate of growth. Seedling trees. The growth of the seedling for the first 

 few years is slow, but subsequent growth up to an age of about forty to fifty 

 years is fairly rapid, particularly on land which is subject to periodical floods. 

 In the original working plan of the Jerruck division, Sind, it is estimated that 

 an average diameter oi 10 in. is attained in 30 years. ^ In the Naushahro 

 division, Sind,^ countings of annual rings on stumps of seedling stems in 

 fiverain forest gave 3-1 in. diameter in six years, 5-1 in. diameter in eleven 

 years, and 6-6 in. diameter in fourteen years. In partially inundated areas 

 the growth was faster, namely 6 in. diameter in nine years, and 7-5 in. diameter 

 in fourteen years. 



Coppice-shoots. Mr. B. 0. Coventry ^ estimates that coppice-shoots in the 

 Punjab attain a height of about 30 ft. in fifteen years, with a girth of 2 to 3 ft. 

 in good localities, and that the out-turn of fuel per acre varies from 100 to 

 1,000 cubic ft. and averages 300 cubic ft. stacked. The following measure- 



1 Ind. Forester, vi (1880-1), p. 327. ^ /jj^^,^ xviii (1892), p. 305. 



3 Working Plan for the Jerruck Division, Sind, A. C. Robinson, 1899. 



* Working Plan for the Forests of the Naushahro Division, Sind, A. C. Robinson, 1900. 



s Ind. Forester, xli (1915), pp. 310-11. 



