INSTITUTE, PUSA, FOR 1917-18 95 



and outgrew the attack of pests and diseases. This per- 

 centage in the case of the different thick varieties enume- 

 rated in last year's Report was : — 



Purple Mauritius (treated) .... 82 per cent. 



Sathi No. 131 (untreated) 

 Sathi No. 15 (untreated) 

 Kaludai Budhan (untreated) 

 D. 09 American (untreated) 



16T „ 



161 „ 



101 „ 

 129 



From the half-acre under Purple Mauritius, 14,277 affected 

 shoots had been cut out, whilst the other plots were left 

 undisturbed. The harvested canes in the case of these other 

 plots therefore contained an unknown quantity of canes 

 which, though classed as non-stunted and harvestable, had 

 been presumably bored more or less, and the outturn of 

 sugar from such bored canes would be poorer in quality 

 and quantity than from unbored canes. The above percent- 

 ages therefore fail to give an exact estimation of borer dam- 

 age. It was unfortunate that no check plot of Purple Mauri- 

 tius was available last year for observation and comparison 

 of results, but in February, 1918, two half-acre plots of Sathi 

 No. 131 were planted, one for treatment by cutting out and 

 removing plants and shoots which were dry or showed 

 " dead-heart " together with the insects found in them, and 

 the other to be left untreated as a check. These two plots 

 are practically similar as regards. soil, are not contiguous 

 (having a crop of indigo separating them), and are situated 

 at a considerable distance from the main sugarcane crop of 

 the Farm. The results so far obtained (up to July, 1918) go 

 far to corroborate those obtained in the Purple Mauritius 

 plot and to show that the cutting-out treatment retards the 

 proper growth of the canes to a great extent. 



The foregoing trials have been made with thick canes 

 because these are more liable to borer attack, the thin 

 varieties being damaged to a much smaller extent. With 

 one exception the yield of canes in the seventeen thin 

 varieties ranged from 122 to 746 per cent, of setts planted. 



The two experimental plots of Sathi No. 131 referred 

 to above are situated in a piece of land which was brought 



