J. Humphreys et al., EFFECTS OF SEED-BORNE MICRODOCHIUM-NIVALE ON ESTABLISHMENT AND POPULATION-DENSITY AT HARVEST OF WINTER-SOWN OATS, Plant varieties & seeds, 11(2), 1998, pp. 83-90
The relationship between seed-borne levels of Microdochium nivale and
establishment, development and subsequent population density at harves
t of winter-sown oats under field conditions was examined. Six varieti
es of oats were sown in a field trial at three seeding rates (400 seed
s, 480 seeds, and 560 seeds m(-2)) using untreated seed in October 199
1. Plant establishment in November 1991 was variable between varieties
and ranged from 40% to 82%. Samples of seed from each variety were te
sted on potato dextrose agar and found to have levels of M. nivale ran
ging from 5% to 61% significantly correlated with plant establishment.
Laboratory work showed seedbone M. nivale was effectively transmitted
to seedlings. At harvest, plant population density ranged from 360 to
470 ears m(-2) and was significantly correlated with establishment. G
rain yield ranged between 6.9 t to 8.2 t ha(-1) and was related to est
ablishment but was also influenced by a number of variety-specific fac
tors including susceptibility to Erysiphe graminis. observed reduction
s in emergence, ears m(-2) and grain yield indicate the importance of
effective control of seed-borne M. nivale infection in winter-sown oat
s.