THE POTATO GRUB

Taranaki Daily News, Volume LIII, Issue 277, 13 April 1911, Page 3

THE POTATO GRUB

SOSIE NOTIONS ABOUT IT. > Tim specially destructive operations of the potato grub this year in. North Otago, and its greater frequency than Usual in Canterbury, is, no doubt, properly attributed to the dryness of the season, as dry weather must be more favorable to the increase and activity of the moth tribe, and it is'from the eggs of a moth that the potato grubs are hatched. It is a little curious that authorities at Christchurch differ about tlia manner ill n'hivji the grubs get into the potatoes. Ml", J. 0. Blackmore, who was Government pomologist for many years, thinks the moth lays her eggs on the potatoes themselves; therefore when growing they should be well ridged up, and when dug should he picked, bagged, "and sewn lipwithout a moment's unnecessary delay/' the hags carted to the place of storage, dusted with slaked lime, and covered with a thick coat of straw to keep the moth's away. The potato haulms should not be used for this .covering, as there is always a grave danger of these being affected. Mr. A. E. Lowe, a well-known gardener, also writes as if he supposes that the moth lays its eggs directly on the tuber, and therefore recommends careful earth-ing-lip so that none are showing above ground. That is not unlikely, so far as opportunity offers, hut the serious damage done to whole crops 'cannot be' explained in that way. Mr. Lotfe found some bagged potatoes affected, he had them sorted, and the sound ones dusted with lime and re-bagged, "and there has been no return of the pest." A sackful taken up later, and not treated, was. found to contain many riddled tubers and a good few moths, but the limed potatoes were not re-infected. Sir. Lowe does not' explain how he supposed the lime-dusted potatoes, that had been selected as clean, could be infected through the .sacks; oJ does he mention that he ever saw moths loitering about the sacks with mischievous intent. Sir. J. Sltifley, of Redcliffs (Sumner), says he has been growing, potatoes for twenty years, and has had a good dea> of experience of the pest; in fact, he has see more or less of them every season, and they are worse in extraordinarily dry seasons. 'Sir. Slaffey has quite a different idea of the manner of infection from the others quoted. He says; "They start in the joints of the haulms lirst and work down, attacking the tubers near the surface, especially those that are exposed." He proceeds: "Slv advise to growers is that as soon as they notice the.haulms turning dark, prematurely to examine them, and if they found the grubs ther<> to start and got them out of the ground and put them in the coldest and darkest place they can, taking care not to put in, the tubers that are already spoilt." Sir. Slaffey adds some suggestions about killing the grubs that have obtained a lodgment in the tubers, as the others have done. One suggests a bath of Jeyes' fluid, another carbolic acid, or tar water! In view of the unusual habits of the moth tribe, there can be 110 doubt that, as Sir. Slaffey says, the grubs work down the tubers. If, as he .says also, the infected haulms turn brown prematurely, this seems to indicate that the gruhs live in the haulms as long as they can, and if that is the case tile tubers would perraps be saved from infection if haulms "going off" were promptly removed, and the soil dosed with something to kill any grubs shaken off. It may be, however, that the grub does not stay long 011 the haulms, but works (town to' the' tubers early in life—they are very active wrigglers when small—in which ease early digging and treatment of the tubers to kill the grubs before they have done much mischief seems the only available palliative.—Timaru Herald.