4 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 1, 



FOO D CR OPS. 



EXPERIMENTS ON YAM CULTIVATION, 



St. Clair Experiment Station, 1918-19. 



By R. 0. Williams, 



Acting Supt., Royal Botanic Gardens and St. Clair Experiment Station. 



As reported in Bulletin XVII, 1918, p. 69 a planting distance 

 experiment for yams has been carried out. 



Ten trenches each 200 feet long and 4 feet apart were dug 

 2 feet in breadth and about 18 inches in depth. These were filled 

 partly with trash and partly with cow manure, then covered and banked 

 up with soil in the usual way. 



The plants used weighed approximately \ lb. each and two of the 

 trenches were planted at 1 foot apart, two at 15 inches, two at 18 inches^ 

 two at 21 inches and two at 2 feet. The planting was done during the 

 month of April, 1918 and the crop reaped during January, 1919. 



The labour was performed by a prison gang, but to enable one 

 interested in cultivation of this kind to get an idea of the cost of 

 labour, &c., and the profits to be derived from it, I will take the cost of 

 cultivation in trenches four feet apart and of the same dimensions as 

 worked out at St. Augustine under estate conditions in 1917-18. 

 These were published in an article by the Superintendent of Field 

 Experiments in Bulletin XVII, 1918, 66. 



It will be noticed that in this experiment the only difference in the 

 cost of cultivation between wide and close planting is due to more plants 

 being required and a little more labour iji planting, as all trenches are 

 four feet apart and cost the same to prepare. 



The cost of cultivation and of yams used for planting if calculated 

 on this basis would be for the ten trenches $44.51, and the value of the 

 crop reaped at two cents per lb. $122.42, making a profit on the whole 

 experiment of $77.91. 



As will be noted from the table given below, this experiment has 

 shown that planting 15 inches apart in the rows has given the best return 

 as whereas the 4 ft. by 2 ft. gave a profit of $9.93 per 1,600 square feet of 

 land, 4 ft. by 1ft. 9 in. $10.05, 4 ft. by 1ft. 6 in. $16.61, 4 ft. by 

 1 ft. 3 in. gave $21.37 and 4 ft. by 1 ft. $19.95. 



