54 



Experiments on Sugar Estates. — Small scale experiments on es- 

 tates are not considered of any value, but experiments have been 

 established under which only results obtained on not less than 

 areas of one acre and repeated on not less than 6 estates are re- 

 quired. 



Some results of these field trials showing yield and proportions 

 of yields compared with those of Bourbon and of white Transpa- 

 rent taken as lOO : — 



Out of a total area of 78,468 acres under cane in 1903-1904, 

 about 12,000 acres are under new seedling varieties. Of these the 

 favourites are D. 1 09, B. 147, D. 145, D. 625, and B. 208. 



In the selection of seedling varieties, more attention should be 

 given to the size of the cane, number of shoots to the stool, and 

 its ratooning power, rather than to its higher saccharine content. 



The advantage of the seedlings most appreciated is that several 

 yield remunerative crops where Bourbon will not now thrive. 



Manurial Experiments. — Lime, 5 tons to acre, increases fertility 

 of heavy clay-land in British Guiana. The excess yield upon 

 limed plots in 9 crops amounted to 33 tons of canes on un-manured 

 plots, and 35 tons on manured land. 



Phosphates have as a rule exerted some effect when applied to 

 plant canes, applying slag-phosphate at the rate of 900lb. per 

 acre. Potash is not required. 



Nitrogen — Results obtained over ten crops in 13 years indicate 

 that every 10 lbs. of nitrogen in the form of sulphate of ammonia 

 when added in proportions up to 300 lbs. per acre, give approxi- 

 mately 1 . 3 tons of canes, or say 2\ cwts. of commercial (96 ^) 

 sugar. It is an easy matter to estimate knowing the prices of 

 sulphate of ammonia and of sugar respectively, if manurings on 

 land in good heart with sulphate of ammonia are likely or not to 

 prove profitable. Similarly with nitrate of soda up to 250 lbs. 

 each 10 lbs. of nitrogen gives 1.4 tons of canes, or 2\ cwts. of 

 sugar. 



Experiments prove that all new varieties require manuring with 

 nitrogen to give satisfactory results. 



The nitrogen which accumulates in the upper layers of the soil 



