Occurrence of ash dieback in stands and plantings

Abstract

The results of forest pathology investigation carried out in 2014 in ash stands of the republic are analyzed. Incidence of damaged branches is 100%. Occurrence of the disease on the first and second stand stories are 89.9% and 73.3% consequently, and on underbrush is 14.8%. Less disease stability have young plants in forest nurseries, occurrence of the necrosis is 91.6%. The development of ash dieback in forest sites differes insignificantly and increases weakly in South-North line. Average category of tree state 3.3 refers the stands to weakened hard. Ash decline is continued in forests, the number of wind-fallen trees in eight years is up 15.6 to 96.8%. On grows plots of some forestries ash trees fully died in this period. Branch necrosis develops together with Armillaria root rot (correlation coefficient is 0.81). Crone declining is faster than root rot formation, some water sprouts form even on weakened trees. This gives evidence of increasing the intensity of pathogen Hymenoscyphus fraxineus development in Belarus and decreasing the disease stand stability in last 6 years.