1'he Sweet Potato and its Oultivation. 



2^9 



lu: nuriiig of one crop may wholly anticipate the rainy season, and 

 that of the other fall well after its close. 



Irrigation of the planted cuttings is not advised by Mr. 

 llohertson, unless absolutely necessary. For open crumbly soils it 

 is best to plant the cuttings in a damp soil, and for stiff soil irriga- 

 tion should not follow but precede planting; sandy soils, however, 

 may be irrigated after the cuttings are in. 



When the young plants have started growing, the important 

 point is the continuous use of the cultivator for getting rid of weeds, 

 ani hand-scuffling must also be practised. This is specially necessary 

 in the early stage of growing, for later on the crop itself, with its 

 interlacing runners and leaves, chokes all further growth of weeds. 



{To he continued in next month'' s issve.) 



Average Yields of Certain Crops. 



The following comparative statement of the average yields per 

 acre of cereals and potatoes has been drawn up from available 

 information. The South African figures have been taken from the 

 Census of Agricultural Production, 1918. The average for oats 

 (given in brackets) has been calculated by assuming that the weight 

 of "oats green in bundles" given in the Census w^ould yield 40 per 

 cent, grain, while the average for barley (given in brackets) is 

 obtained by assuming that the green barley consisted of 25 per cent, 

 dry matter, and that if grown to maturity it would have yielded 50 

 per cent, grain. These figures are. only rough approximations. 



The figures for foreign countries are either the average of the 

 last five years (where obtainable) or for 1917 or 1918. 



The weights per bushel taken are those adopted by the United 

 States, as it is considered they are best suited for comparative 

 purposes for most of the countries enumerated hereunder. 



Weigl't i)cr Kushel. 



Wheat-, 60 1b 



Rye, 5f) lb 



Maize, 56 11; 



Kaffir Corn, 56 lb. 



Oats, 32 lb 



I (S.A.41t71b.Oatsplus6-H)lb. "Green") 

 Barley, 48 lb 



(S.A. 737 lb. Barley plus 371 lb 



"Green") 



Potatoes, 60 lb 



Sweet Potatoes, 60 lb. ... 



Average Yield per Acre in Bushels. 



■J2 -I 



9-9 

 6-4 



7-8 

 7-1 

 23) 



16-5) 



33 

 50 



11-7 

 26-8 



16-8 

 19-5 



103 





15-0 

 14-4 



25-6 



35-3 



26-0 



95 

 95 



15-7 

 32-1 



29-3 

 22-3 



143 



o 

 31-5 



85-1 

 36-0 



160 



