The role of fungal diseases in the accumulation of dead tissue in timothy and meadow fescue swards

摘要

Under Nordic climate conditions the proportion of dead tissue in silage leys can be substantial in the second and third cuts and thus decrease the nutritive value of the yield. The role of plant diseases in this process is insufficiently known. Our aim was to determine the effects of fungal diseases on accumulation of dead tissue and the nutritive value in timothy (Phleurn pratense L.) and meadow fescue (Festuca pratensis Huds.) swards. A field experiment was conducted at Maaninka, Finland during 2011-2014. The factors were: timing of the second harvest and the use of chemical control of fungal diseases. After the first cut in June half of the plots were sprayed with a mixture of fungicides Amistar and Zcnit. The second cuts were taken 4, 6 or 8 weeks after the first cut. The proportion of dead tissue was 0.6-11.2% in timothy and 2.2-27.0% in meadow fescue, increasing with longer cutting interval. In meadow fescue the fungicide treatment decreased the proportion of dead tissue and simultaneously increased digestibility in one year out of three. The effect was strongest at the latest cutting time. In timothy the effects were minor.