POTATO CULTURE

Sun (Auckland), Volume I, Issue 246, 7 January 1928, Page 23

POTATO CULTURE

! TESTING VARIETIES FANCY PRICES PAID FIVE HUNDRED A TON In a. list of prices of home-grown agricultural produce issued by the National Farmers’ Union of Scotland, seed of Arran Banner, one of the varieties of potatoes in the third year’s test for registration by the Board of Agriculture for Scotland, is quoted at £SOO a ton; £3OO a half-ton; £SO a hundred-weight; £S a stone. This seedling, Arran Banner, which was awarded the Lord Derby medal at Ormaskirk in October, is one of three that remained of 3,000 seedlings planted out in 1922 by Mr. Donald MacKelvie, Lamlash, Arran, who is one of the leading and most successful potato raisers in the world. Another of his seedlings, Arran Consul, was the first potato to be registered by the Board of Agriculture for Scotland. Remarkable Yields

In an address to the Agricultural Discussion Society of Edinburgh University in November, Mr. MacKelvie referred to the remarkable yields obtained from Arran Banner, and said that a few small lots of seed were sold last year at £SO a stone, a price he was a little ashamed of at the time, but now that the results were to hand, he thought he had not charged enough, a remark that evoked loud laughter. He uses not only British, but German and American, parent plants for breeding new varieties. He endeavoured to use parents that had between them all the characteristics desired in the offspring, but whether all these characteristics would appear in any one seedling was a problem that there was no means of solving beforehand. Among the most successful parent varieties were Flourball, Abundance, and Epicure, the first-named being the pollen parent that gave the best results. Sutton’s Abundance was the most satisfactory mother plant, being both healthy and vigorous, although it had been introduced as long ago as 1886. Methods of Propagation

During the course of his address Mr. MacKelvie gave some interesting particulars regarding the different methods adopted in propagating Arran Banner. In the County of Dublin one stone of uncut seed planted 70yds of a drill and yielded scwt 2qr 201 b, equal to 26 tons an acre. In the County of Donegal one stone of uncut seed yielded scwt lqr 191 b, over 20 tons an acre. In another centre in County Donegal 10Jib of seed gave a return of 17cwt lqr 211 b, or one hundred and eighty-six times the weight of the seed planted. These potatoes were cut to angle eyes and set one yards apart. Plenty of room, careful tillage, and liberal manuring were responsible for this result, which was equal to nearly 48 i tons an acre. Other two stones sent to Northern Ireland yielded 21ewt and 20cwt respectively. Well-Sprouted Seed The seed potatoes, Mr. MacKelvie explained, were sent out well sprouted. One Scots grower who bought a stone of seed took off the sprouts and planted them in pots in a greenhouse, and his yield was 13cwt 621 b. Mr. MacKelvie did not approve of this method of propagation, as cultivation under cover exposed the plants to virus diseases, especially if there were tomatoes in the greenhouse. Another Scots grower cut his seed to single eyes, and wherever two stems came up together one was carefully removed and transplanted. This gave a return of 18cwt from ' one stone of seed. Another grower waited till the plants were fairly well grown, then gently removed the original sets and planted them again; and his return was 15cwt. In another case one stone planted in 28in drills in a turnip field, and given no artificiials until setting up, yielded 16cwt. Farmers* Results The best result was obtained by a farmer who grew his potatoes under field conditions. He cut the tubers to single eyes and planted the sets 18in apart in alternate drills (drills 28in wide). The ground got from 15 to 20 tons an acre of cow manure ploughed in, and straw off the top of the manure heap was spread at the bottom of the

drills and the sets planted on it. The crop received lewt an acre sulphate of ammonia at the time of setting up. The potatoes were weighed two months after lifting, and the results were: Marketable tubers, 18cwt 91b; seed, 3cwt 361 b; chats, 291 b; blight, 101 b; total, 21|cwt. Rejection Difficulty In potato breeding the difficulty was which of the seedlings to reject, and if science could devise a test for blight which would allow susceptible varieties to be discarded in the earliest stages, it would be very helpful. No selection was made in the first year except to throw out seedlings that were obviously of bad shape or with badly coloured flesh. All the produce of other seedlings was kept. In coming to a final decision the qualities taken into account were:—(l) Proportion of marketable tubers; (2) shape of tubers; (3) resistance to blight in the tuber; (4) early blight formation; (5) resistance to blight in the foliage of late varieties. The incidence of blight was very irregular, and the results of one year could not be depended upon as a test for the disease. It was not expected, said Mr. MacKelvie, that new varieties would be produced that would b© much heavier yielders than the best of the existing varieties in the full vigour of youth; but the combination of desirable qualities would be greatly improved.