THE POTATO DISEASE.

Otago Witness, Issue 2661, 15 March 1905, Page 21

THE POTATO DISEASE.

OTAGO CROPS AFFECTED. The present season appears to be an unfortunate one for some Otago potato crops owing to the ravages of the potato blight, and Mr T. W. Kirk, Government l>iologisfc, is at present on a visit to Otago to inquire into the effects and spread of the disease. In the 1903-4 season there were 31,778 acres planted in potatoes in Kew Zealand, and for the present season j only 26,331 acres, so that the present season commenced with a shortage of 5447 acres. This fact alone is sufficient to warrant the belief that the crop will be short, but added to it is the alarming intelligence that the potato disease has become pretty generaJ throughout the colony. The blight broke out in several counties in Auckland -where it has destroyed a large portion of the crops, and in some cases whole areas of crop ; it has also made its appearance in Taranaki, the Hutt Valley (Wellington province), South Canterbury, and then down the Otago coast as far as the Taieri. Mr Kirk has visited the Otago Peninsula, and he did not find a potato patch that did not show the disease more or less, and the same may be said of the Taieri Plain. Mr Kirk states that in a whole day on the .Taieri he did not see a crop that did not show the disease in some degree. In South Canterbury— about Geraldine, Temuka, and Timaru — some of the crops, he states, were totally destroyed, and' many others were mothered as though a fire had passed over them. The potatoes b-?ing not more than ihalf-grown, they will nob reach maturity, and would not keep. In Oamaru and North Otago the crops are further ahead, and the ibulk is ready for digging, so that the loss there should only be slight, provided the jpotai/oes are promptly lifted. The blight ihas also been discovered around Christchurch. Slpecimens received from Balclutha prove that the disease exists there, and Mr Hark will inspect that district to-day. Mr Kirk says what growers should understand as that those- crops which are not ready to dig should be promptly sprayed with the Bordeaux rriixture. In the case of the second and third sprayings, and of crops already grown, where the foliage is toughened, the 6.4.4-0 formula (i.e., 61b blueStone, 41b lime, and 40gal water) may bcvaed with advant&ae. SiiovJd rain fall

within three or four hours after spraying it will, of course, be necessary to repeat the dressing as soon as possible. Crops which have been allowed to become badly diseased I should at once be dug up. Before digging is commenced it is essential that all the tops should be carefully removed and burnt. This will destroy millions of the spores, and greatly lessen the danger of infection of healthy crops, and minimise the risk cf spores becoming attached to the tubers. Great care should also be exercised, when picking the potatoes, to place on one side and burn all those which show the slightest sign of the disease, for if diseased tubers are stored with healthy ones they will contaminate the whole pit, and the entire crop will be come rotten and useless Mr Kirk emphatically declares that if these instructions are carefully carried out the spread of the disease can be carefully checked, but if nothing is done the crops will be utterly ruined. Ho leaves for Balclutha to-day, and will then go on to Invercargill, and then to Roxburgh.