THE BUD-ROT OF PALMS IN INDIA. 237 



between the paddy fields, and the seedHngs grow up beneath the 

 older pahns which line these bunds. In such cases it is probable 

 that the vertical drip of water during rain carries down the spores 

 to the young plants below. This would only occur in the cases 

 in which the living fungus grows exposed to the rain. Further, 

 successful infection would only occur if the spores reach a suitable 

 part of the palm, such as an exposed inner leaf-sheath. Hence 

 there is usually far less disease amongst the seedlings and young 

 trees than in those which are large enough to be regularly climbed 

 for leaves. Isolated young palms not gro^ving near larger ones are 

 seldom attacked ; isolated mature ones almost as often as those in 

 clumps. 



The intensity of the disease varies enormously in different 

 places. Four hundred palmyras were found dead or dying in a 

 single acre in one of the lankas close to where the disease is beheved 

 to have first appeared in the district. It was calculated that from 

 '50 to 75 per cent, of all the palms within a mile of the village of Ko- 

 lanka had succumbed by the end of 1907. In one place along the 

 bank of the canal near this village the mortality increased from 

 between 5 and 10 per cent, in August 1905, to between 60 and 70 

 per cent, in March 1907. In some fields of Ainavilli three-quarters 

 of the palmyras were infected in June 1907. In one clump in this 

 village 180 out of 236, in another 107 out of 140 had died. Of 

 course, these are extreme cases, but there are many villages where 

 it appears probable that not a fourth of the palms will soon be left 

 unless the disease is checked. 



The length of time taken to kill a tree can only be determined 

 if the moment of first attack is known, and requires also the fixing 

 of an arbitrary moment of death. In so large an organism as a 

 mature palm, death does not occur all at once, excepting possiblv 

 under such circumstances as when a tree is struck by lightning 

 Ordinarily, death occurs "by inches,'' and when the apical bud 

 and even all the leaves are killed, the stem and roots may still main- 

 tain their vitality for some time. Two periods may be selected 

 as indicating the "death" of the palm in bud-rot. The first is 



