Treated Seed Raises Potato Yield

Press, Volume CV, Issue 30953, 8 January 1966, Page 8

Treated Seed Raises Potato Yield

By treating potato seed with granular insecticides to prevent the spread of leaf roll virus, the Plant Diseases Division of the Department of Scientific and Industrial Research, Lincoln, has achieved impressive results in field trials on the property of Mr L. J. Franks, Russley road, Harewood.

Last season the treated area yielded 82} sacks of table potatoes, and 23 sacks of seed, whereas the untreated area yielded 70 sacks of table, and 31 of seed.

“The trial at Harewood with Ham Hardy, has worked particularly well,” said Dr. R. C. Close, of the D.S.I.R, Lincoln, this week. The department, as a result of the trials, has planned a field day at Mr Franks’s property on Monday, January 10, at 2 p.m. Potato growers and others interested in the use of granular insecticides for leaf roll virus control, are invited to attend. Speakers will include Dr. Close and a fellow plant pathologist, Mr C. M. Driver. When converted to yield an acre, last season’s trial at Harewood resulted in 7.1 tons of table and 1.9 tons of seed from the treated area, and 6.1 tons of table and 2.7 tons of

seed from the untreated area. This increase in table yield was due to the aphid and virus control achieved.

The number of aphides (for 100 leaves) during the 1964-65 season at 31 and 46 days after planting was: treated areas, two and 11 aphides respectively; untreated areas, 615 and 940 aphides respectively. Last season, Dr. Close said this week, the amount of leaf roll in the crop was 3 per cent It was expected that seed saved from the treated areas would be of good

quality, whereas the seed from untreated areas would have deteriorated considerably because of the high aphid populations. The seed was replanted at Harewood this season, and there has been marked differences in the plants grown from seed saved from the treated and untreated areas. Counts made this season Show the leaf roll percentages as follows:

Treated seed, loz to 4oz in Size, 6.8 per cent; 2oz to 4oz in size, 4.3 per cent; 6oz in size, 3.5 per cent. Untreated seed, loz to 4oz in size, 53.1 per cent. The difference in percentage of leaf roll virus between treated and untreated seed is very obvious in the field at Lincoln, according to Dr. Close.

Monday’s field day, he said, would give growers the opportunity to see the effectiveness of granular insecticides in preventing the spread of leaf roil virus.