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TECTONA 723 



tion being insufficient, but the planted seedlings showed markedly poorer 

 growth in that area than they did in the open. On the edge of the clearing 

 the drip from the overhanging trees in the adjoining plantations certainly 

 affected the young plants ; but in the shaded areas the breadth affected and 

 devoid of all natural reproduction was in places as much as 130 ft., and it is 

 therefore beyond question that the absence of natural reproduction and the 

 inferior growth of the planted seedHngs were the direct result of the lateral shade. 



(ii) 8oil-aeration is a term which may for the present be applied, for want 

 of a better one, to certain conditions which have a marked effect on the 

 establishment or failure of natural reproduction. Under this head may be 

 included the tendency of teak seedlings to rot in excessively moist or water- a 

 logged situations, and where damp weed-growth exists ; the mortality from 

 this cause during the rainy season may be very high. The wholesale death 

 of seedlings during the rainy season owing to the drip from overhead trees 

 may possibly be attributable, in part at least, to the same cause. It has 

 sometimes been attributed to some toxic effect in rain water falling from teak 

 leaves, but this is mere conjecture. Whatever the precise nature of the adverse 

 influence may be, it is a well-known fact that seedlings are killed off in large 

 quantities by the drip from overhanging trees, and that anything short of 

 complete clearance of the overhead canopy is liable to result in high mortality 

 among teak seedlings in forest at all approaching a moist type. The aeration 

 of the soil by loosening has a marked effect on the development of young 

 plants, and in dry localities it is a useful means of stimulating a strong and 

 healthy growth which enables seedlings to survive drought. In the experiment 

 alluded to above, Mr. Hole found that an admixture of dead teak leaves in 

 fairly heavy loam was beneficial to the growth of teak seedlings when the soil 

 was kept well aerated and fully exposed to light and air, but was injurious 

 when kept constantly wet. The vigorous growth of teak seedlings on the sites 

 of old charcoal kilns and on patches of burnt debris is probably attributable 

 to the aeration of the soil in such places. Soil-aeration pla3^s an important 

 part in the establishment of seedlings under the system of mulching described 

 in the next paragraph. 



(iii) Soil-moisture. Deficiency of soil-moisture is one of the greatest obstacles 

 to the establishment of natural reproduction in many parts of the Indian 

 Peninsula, particularly in forests of a dry type. Seedlings often appear in 

 quantity at the beginning of the monsoon, but have to contend against weedsv 

 during the rainy season, with the result that those which survive the struggle 

 are weakly plants, which succumb to drought during the ensuing dry season. 

 Any measures which will tend to promote vigorous growth during the early 

 life of the seedling are likely to aid it in surviving the effects of drought, and 

 the measures first tried with success by IVIr. W. E. Copleston in the Hahyal 

 teak pole forests in the drier parts of the Kanara district and now 

 adopted in other parts of Bombay, have proved to be an effective 

 method of securing the survival of natural seedlings in localities where under 

 ordinary circumstances they are liable to perish from drought. The survival 

 of the seedlings is secured by a system of surface mulching. The mulch 

 consists of a small armful of green twigs with leaves, grass, or even dead 

 material, the refuse of the fellings, spread in a ring round the plant ; on this 



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