28 PHYTOPHTHORA MEADII n. Sp. ON HEVEA BRASIUENSIS 



for some time, or the leaf may come oli as a whole. The lowest two or three 

 centimetres of a shoot become discoloured, and it ultimately dies back to its 

 parent branch. 



(5) During the heaviest part of the monsoon when trmiks of trees are 

 continually wet, a slight rot appears on or near the tapping cut. Dark spots 

 appear here and there, and extend upwards for an inch or two in dark streaks 

 on the recently tapped surface, the miderlying tissue being soft and sodden, 

 and exudations of latex appear on the surface and in cracks in the tissue, 

 sometimes forming pads of coagulated latex between the bark and the wood. If 

 the rain is long continued, the bark splits vertically along the streaks exposing 

 the wood, and, if tapping is persisted in, the bark also splits laterally, and the 

 wood becomes exposed throughout the length of the tapping cut. The rotting 

 of the tapped bark gradually extends upwards, more quickly along the cracks 

 and more slowly in the intervening places, till it is stopped by the advent of 

 dry weather. The disease extends downwards more slowly into the mitapped 

 bark. Areas of wood 17 inches in length and from 1 to 3 or 4 inches in height 

 may be exposed, the lower edge bounded by the hne of the tapping cut, the 

 upper edge ragged and irregular. If, however, there are spells of drier weather, 

 or if the attack comes late in the season, the bark-rot penetrates only a short 

 distance into the cortex, and may not expose the wood or may expose it only 

 very slightly, so that it is healed over quickly after the monsoon rains have 

 ceased. 



Second leaf-fall usually occurs first on Hevea trees when they come into 

 the fruiting stage, which, in South India, is usually about the 5th year. Then 

 however, it is the fruit-rot that is most in evidence, while in succeeding years 

 the second leaf-fall becomes more noticeable. Younger Hevea does not have 

 this second leaf-fall, though it has been seen occasionally on individual trees and 

 oroups of trees before they reach the fruiting stage. In one instance it occurred 

 on a few trees that had been planted only two years ; they were in a very small 

 field surrounded by much older trees that had both fruit-rot and second leaf- 

 fall rather severely, and in another case it was observed on supplies about 

 10 feet high 9 months from planting among 10-year old trees which were also 

 badly afEected by fruit-rot and second leaf-fall. 



Bark-rot generally appears well on in the monsoon, and may occur in the 

 first season in which the fruit-rot appears or in a subsequent season, but it 

 has not been found on trees that have not had fruit-rot. To take a particular 

 example, fruit-rot and second leaf-fall were noticed first in 1914 during the 

 latter part of the monsoon in a small valley at one end of an estate. Next 



