THE PARA RUBBER TREE 119 



deep is then made round the affected area, and the soil 

 within is carefully dug over and all roots removed and 

 bm-nt. The area is again turned over, after an interval 

 of about one month, and it is advisable to dig in lime, if 

 available, at the rate of 2| lb. for every squa.re yard of 

 surface. If these operations are carefully performed, the 

 soil will be free from the fungus after a few weeks' interval 

 and fresh trees may be planted. 



White Ants. — These pests are now decreasing in ]\Ialaya. 

 The usual treatment is to discover and destroy their 

 nests, and to inject arsenic and sulphur fumes into their 

 runs. 



General Sanitation of Rubber Estates. — There are 

 several points connected with the general sanitation of 

 rubber estates which deserve attention by planters, as 

 they have considerable influence on the health of the 

 trees. The part which the decaying jungle stumps play 

 in disseminating fungoid diseases and in harbouring pests 

 has been referred to ah-eady, and their complete removal 

 would be very beneficial to the health of the plantations. 

 The distance at which the trees are planted is also an 

 important point, as close planting tends to produce a 

 humid atmosphere which is very favoiu-able to the growth 

 of fungi, whereas wide planting admits light and air to 

 the plantation and thus diminishes the risk of disease. 

 When catch-crops or cover-crops are grown, care should 

 be taken that the plants selected are not attacked by 

 the same diseases as Hevea brasiliensis (as is the cas6 

 with cocoa) and that their, growth does not give rise to 

 conditions which are detrimental to the general sanita- 

 tion of the estate. In principle it would be desirable to 

 break up the large areas planted with Hevea trees into 

 distinct blocks by means of protective belts of other 

 trees so as to check the spread of any disease which may 

 occiu", but there seems little chance of this plan being 

 adopted at present. 



Tapping. — Cultivated Para trees are considered to be 

 ready for tapping when they have attained a circum- 

 ference of 18 to 20 in. at 3 ft. from the ground. In 

 jMalaya this girth is usually reached in about four years 

 and in other countries in from five to seven years, accord- 

 ing to the climatic conditions and the nature of the 

 soil. Rubber can be obtained from trees less than 18 in. 



