42 



On peaty lands or soils that crack, pumps are useless. In such 

 cases there is no alternative but to apply Tovvgood's system of 

 search for termitai'iums, vide H. C. Pratt's " Observations on Termes 

 Gestroi.'" 



The external application of sundry poisons or forking insecticides 

 into the ground at best only affords temporary relief. 



In the matter of wound protection, my experience is that borers 

 have no regard for tar at all ; while on the other hand " jodelited " 

 wounds are nearly always immune from attack. The most successful 

 covering I have used is a combination of the two, i.e., Jodelite as a 

 first coat and tar as the next. 



Ikcidence of Disease. 



If we could forecast accurately the incidence of development and 

 if we knew exactly Avhen to expect the appearance of certain types of 

 disease, this would go a long way towards solving many planting 

 difficulties. For instance, we should know, the approximate period 

 of time available wherein to complete preventive measures and also 

 up to what point initiating a process of treatment would be valuable. 

 With greater knowledge on this point, each estate would have a 

 better chance of working out its own salvation. At present, 

 unfortunately, we have little to guide us other than individual 

 observation, which, of course, is unsatisfactory to base any woi'king- 

 rule on. As a beginning I record below my own ideas on their 

 sequence and incidence. 



(1) Hymenochate — 



Generally occurs during 1st year. Occasionally also in 3rd 

 year, but not often. 



(2) Fomes and Diplodia — 



Commence end of 2nd year and seldom seen after 4th year 

 (if treated). Greatest activity immediately after rainy 

 season. Fomes development is rapid. 



(3) Pink disease — 



Appears early 3rd year. There is a pink and black variety. 

 Both are inimical and are always constant. Activity is most 

 noticeable during rains immediately following di"y weather. 



(4) Ustulina and Porta — 



Rubber fatalities do not often occur under eight to ten years 

 old and, as a rule, trees are older. Both diseases are slow 

 in development. Attacked rubber yields well for several 

 years until the trees " snuff out." 



(5) Black line canker or black thread disease — 



May be looked for in the first year of tapping and is more 

 serious when tapping on renewed bark. Most active in 

 damp weather. 



