September, 1909.] 



231 



Edible Products, 



ridges. Many growers run the plough 

 between the rows for a third time, 

 first turning over the vines on to their 

 respective ridges. The half of the soil 

 between the ridges is then turned on 

 to the right-hand ridge and the other 

 half upon the left hand. The vines are 

 then brought to their natural position, 

 and the crop henceforth needs no more 

 attention. 



Harvesting. 



When the roots a*e ready for harvest- 

 ing, which should be before the first 

 frosts set in, the digging should only be 

 done during dry weather. The first 

 thing to do is cut away the vines with 

 a sickle or scythe, when the roots may 

 be lifted either with a digging fork or 

 with a specially adapted plough, which 

 is so constructed as to prevent the roots 

 falling back into the furrows. The roots, 

 which are usually free from adhering 

 soil, are then gathered up and carted to 

 the barn. 



Keeping. 



If it is intended to keep them for any 

 length of time to await a favourable 

 market or for winter use, they should be 

 pitted with sand. Put down a thick 

 layer of sand either in the barn or in a 

 well-drained spot outside. On this place 

 a layer of tubers, then run in sand until 

 all the crevices are filled up, and the 

 layer is covered. Now lay down another 

 layer of tubers, run in more sand, and 

 repeat the process until as many as may 

 be required are pitted. Then cover with 

 straw or bush hay. 



TO ASCERTAIN THE RlPENEsS. 



When the sweet potato is ripe, the sap 

 has reached what may, with some pro- 

 priety, be termed thecrystalisable stage, 

 i.e., when the root is cut or broken 

 and exposed to the air, a white crust or 

 artificial skin is formed over the cut 

 part, and protects it from the air and 

 from the agencies of decay. If it is 

 not ripe, the cut part turns black, and 

 no such artificial skin is formed. If, 

 therefore, proper judgment is exercised 

 as to the time and manner of digging, 

 handling, and storing, there is little 

 danger of loss. • 



Change of Plants. 

 Owing to the constant planting of cut- 

 tings from the same stock, sweet potato 

 tubers will deteriorate and become 

 diseased. The grower will, therefore, 

 do well to obtain cuttings or young 

 tubers from another district. Another 

 certain plan of obtaining a clean crop, 

 free from disease, is to grow the plants 

 from seed as has sometimes been done 

 at the Penal Establishment at St. 

 Helena. When the tubers are about to 



form, a good plan is to twist the vines 

 up in a heap on top of the main stems. It 

 will then be found that the potatoes will 

 at once begin to increase in number and 

 size. One grower says that it does not 

 matter how rich the soil is, providing 

 the tops are twisted. 



NON-SETTIFG OP TUBERS. 



It not unfrequently occurs that no 

 tubers, or at any rate only a few, will 

 form. This non-setting may be brought 

 about through various influences ; but 

 the most common one is the want of 

 care in selecting cuttings from the most 

 fruitful vines. It is a well-known fact 

 that a cutting will, in almost any case, 

 reproduce the peculiarities of the 

 parent plant ; therefore, a crop of tubers 

 cannot be expected from vines taken 

 from an unfruitful parent. 



The class of soil has also much to do 

 with the non-tubering trouble. Many 

 soils will produce a good crop of sweec 

 potatoes when newly broken-up, and in 

 a loose, friable condition; but having 

 been under crop for a few years, and 

 becoming, consequently, closer in 

 texture, the results obtained will usually 

 be — plenty of vines and strings, but no 

 tubers. 



The best remedy is to obtain some 

 good tubers from a reliable source, pre- 

 ferably from another district. By plant- 

 ing these in a hot-bed, and giving a 

 plentiful supply of water, a number of 

 cuttings _ would be obtained from the 

 same eye in a very short space of time. 



Liability to Disease— The Weevil. 



Like most plants the sweet potato is 

 liable to disease and the attacks of insect 

 pests, which affect both vines and tubeis. 



Of insect pests the worst in Queens- 

 land is the sweet potato weevil, which 

 was first noted in Austi alia in 1886, but 

 whence it arrived here is not known. 

 It was discovered in that year on Mr. 

 A. Miles' farm at Hemmant, near Bris- 

 bane. The only remedies which could 

 be suggested by the Government Ento- 

 mologist were destruction of all affected 

 tubers and a change of crop ; but these 

 extreme measures were not adopted. 

 Accordingly, the weevil within the next 

 two years made its way to Woolloon- 

 gabba, a part of Brisbane itself, and 

 shortly afterwards spread to all the 

 farming districts in the South-eastern 

 part of the State, eventually reaching 

 Bundaberg, Mackay, and all the other 

 Northern sugar-growing districts, ut- 

 terly destroying the crops. 



The damage is noticeable in vines and 

 tubers. The former possess much less 

 foliage than they otherwise should ; they 

 are thicker, shorter, and more irregular 



