BLIND SEED DISEASE

Press, Volume LXXXVI, Issue 26123, 27 May 1950, Page 5

BLIND SEED DISEASE

BURNING OFF STUBBLES ADVOCATED

Control of blind seed disease in ryegrass by burning over paddocks from which seed crops have been taken is advocated by the authorities- in the United States. A recent issue o’f the “Seed World,” a leading American publication, states:—

Preliminary germination tests made from the 1949 perennial ryegrass crop show the blind-seed disease control programme is effectively curbing the disease, reports Dr. John R. Hardison, U.S. Department of Agriculture plant pathologist working at the Oregon State College experiment station. Judging from approximately 150 seed samples, 80 per cent, of this year’s crop is showing up with 90 per cent, germination or better. Last, year, the worst year on record for blind-seed disease, only 64 per cent, of the seed lots rated 90 per cent, germination or above.

Yet findings made thus far show at least 42 per cent, of the fields need to be burned over again as a disease control measure. Linn county is the primary district involved, since most of Oregon’s perennial ryegrass seed crop is grown in that county. Last

year, however. 80 per cent, of the fields needed to bo burned, according to Dr. Hardison’s findings. Fearing that growers will become complacent again about the perennial ryegrass disease which affects seed germination adversely, Hardison is urging all growers in Oregon’s Linn county to burn over their perennial ryegrass fields again this fall. While germination percentages are up. he points out that the disease itseif is still present. A year of lax control measures would be a decided set-back, he believes.

To those growers replanting perennial ryegrass, the pathologist recommends seeding disease-free seed or seed that is at least 24 months old. Fields which are badly infested with blind-seed disease are not safe for replanting perennial ryegrass for at least two years, during which they are devoted to other crops. To prevent emergence of spore cups and discharge of disease spores. Hardison recommends that ploughing of such infested fields be done before May 15.