NEW POTATO DISEASE.

New Zealand Herald, Volume XVIII, Issue 5918, 4 November 1880, Page 3

NEW POTATO DISEASE.

Last mail brings intelligence that on a farm in the West of Ireland a diseaseentirely new in its devastating effects—had made its appearance on the potatoes. According to Mr. \V. G. Smith, in the Gardencrs' Chronicle, the infected field is reclaimed bog, first brought into cultivation about eight years ago, when three crops of potatoes manured from the farm-yard were taken consecutively. There was a coat of ;lay spread over and incorporated with the ■oil, the field was then laid down with a crop >f oats, and has been in grass since and ueadowed. The meadow was found light, nd the land was first planted this spring, seaweed was first spread on the grass, and .bout ten days afterwards it was covered with arm-yard manure ; the potato sets were laid in the manure and then covered. Ridge Wanting was adopted. It appears that in iugust last Mr. Balfe, Secretary to the Royal Horticultural Society of Ireland, sent Mt. smith some potato haulms, very badly itl'ected, and in a way that neither of these .'entlemen had ever seen before. Mr. Balfe vrote :—" O:i dividing the afflicted portion >f the stems longitudinally, and seeing them lollowed out, and small black looking masses it intervals, I oft-hand thought it was the ,vork of a larva, and that the little dark jodies were the egesta. A moment's reketion told me they were rather large for ;he larva of an insect to deposit, so I picked some, and dividing them, saw they were in jonuection with a. I»ed of mycelium tliat iushioned them, that the affection was of i fungoid nature, and to me, at all events, iew and strange. These little amorphous jodies are like scleroderma in miniature or ;rgot." Mr. Balfe also referred to the para:ite as "an unfamiliar and very destructive iiiemy." From further particulars sent to Vlr. Smith, the disease had increased a good leal. The potatoes att'eoted had been bought is Champion seed. Another variety was in he field, kuown as Protestants, which were {uite free of disease. On examination of .he diseased haulms, they were found in the nost wretched condition—cracked, blistered :orroded, and utterly exhausted ; the leaves educed to tinder, with mycelium traversing he plant in every direction, withinand withiut. The interior of the stems of the lotato plants were, it seems, quite stuffed up vith dense masses of spawn, and thickly tudded with large sclerotia ; the outside in l similar condition, reaching to where the eaves should be. In answer to the question, iVhafc is a sclerotium ? Mr. Smith answers as bllows : —" A sclerotium is not a perfect ungus, but a densely compacted and com)ressed nodule of fungus spawn in a resting >r hibernating condition; it arises and is omied from mycelium or spawn, and to this :übstance it is usually attached or cushioned, ls in the present instance. Sclerotia fremently occur under the cuticle ii. plants ; it other times they are deeply embedded in ihe substance. They grow in and on living slants, and in decaying vegetable and animal natter. Sclerotia arc a peculiar condition if fungus mycelium, and when the mycelium s in this state the spawn is preserved from lestruction in a dormant state for a period if time, which may be long or short, as in he hibernation of resting-spores in various ungi. An equally important question is, iVhat will become of these innumerable ipeeimens of sclerotia now formed, and being brmed, on the Irish plants ? The unneasant answer is, They will undoubtedly all to the ground with the decaying plants vhere they will at length be ploughed in. This is a condition of things exactly suitable o sclerotia ; they will quietly repose in the ;round till their period of rest has expired ; hey will then burst and produce mycelial breads, some perfect fungus, and countless pores. These spores will probably afflict iext season's potatoes with some destructive ungus, and with sclerotia similar with the iodies here described."

It may be stated that while harvest prospects throughout Ireland were very cheer ing, there was :i considerable amount of blight among some crops of potatoes, as will be seen from the following letter from the Times: —"The magnificent weather with which Providence has blessed us since this day fortnight lias done wonders for the farmers. The blight in the potato crop has been arrested, the corn crop ripened, and the hay saved. We must not, however, be too sanguine. To-day I asked a very trustworthy farmer how he stood with regard to his potato crop. He said that about half was blighted. I remarked that the injured half would be useful for the feeding of pigs but his opinion was that the injury was bo great as to render the blighted potato useless —that it will, after a little time, as he ex" pressed it, ' melt in the ground.' The fact is, that had not the weather providentially cleared up, this year would have been very calamitous for Ireland, more se than last year. The same farmer told me that last year lie had not a quarter of his potato crop, that though he had sown two and a half acres, he had not eaten a potato since last February. The corn crop is nearly all that could be desired."

Writing from Galway on September 1, a correspondent of the Agricultural Gazette says : —" Potatoes, a very large yield, but considerably diseased. Champions yet grow ing sound, and likely to become the general potato for the country. Some people expecting the Champion to be fully grown in the month of August, have felt disappointed at the hitherto small size of the tubers, but an inspection of the vigorous and healthy stalks, together with the sound appearance of the tubers, affords a strong ground for believing that the crop will by the Ist of October be excellent, and a great boon to this poor country." One of the Blue Books lately published at Home is the "Report of the Select Committee on the Potato Crop," ordered to be printed by the House of Commons. It contains a mass of information on the subject of disease amongst potatoes. It seems that a llr. Henry Thompson asserts that he has a specitic for the potato disease, and offers, if £10,000 be staked in the hands of the Lord Mayor, to manage, on two farms, any kinds of potato which might he. given him, so that they should be free from disease, upon these terms : —That if the experiment proved successful the money should be his, but that if it failed the money should be returned to those staking it. One of the persons who gave evidence before the Committee was Mr. May, of Kent, who atated that he grew every year from lf>o 1 to "200 acres of potatoes —that he took an animal trip to Scotland to watch new varieties, or to observe successful methods of cultivating the crops, and also to obtain suitable seed. During last season he had grown [Champions entirely, while his neighbours had stuck to the old sorts, and had them nearly all bad —one having a flO-acre field of Victorias which were not worth £2 an acre. It was a general opinion among those who gave evidence that particular years are suited to special varieties—that there might lie Champion seasons and Regent seasons. One potato merchant was of opinion that the favourite potato in London—the Kegunt—might be vc-invigorateil ; and that two-thirds of potato-growers fail through inattention to certain details necessary to a successful culture of the crop. The report w;is concluded by the Committee recommending that experimental farms for the creation and establishment of new varieties of the potato should be established in England, Ireland, and Scotland. Aukicola.