DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 9-10/2006 str. 27 <-- 27 --> PDF |
M. Idžojtić, M. Glavaš, M. Zebec, R. Pernar, P. Beuk & I. Prgić: INTENZITET ZARAZE ŽUTOM I BIJELOM ... In the area of the Forest Administration Vinkovci from the total number of examined pedunculate oak trees 7.6 % were infected with yellow mistletoe. On the average on each of the infected trees there were 2.5 mistletoe plants, and the largest number on one tree was 17. The largest infection was noted in the Management Unit Vrapčana, of the Forest Office Vinkovci (20.1 %). In the area of the Forest Administration Nova Gradiška 10.5 % of the examined pedunculate oak trees were infected with yellow mistletoe. On the infected trees there were 2 mistletoe plants on the average, and the largest number of plants on one tree was 9. In the Management Unit Glovac-Renovica, of the Forest Office Trnjani, there was considerably more infestation than in other management units (35.5 %). For the Forest Administration Vinkovci the spacial distribution of mistletoe infestation intensity of the pedunculate oak in six most infested management units was presented. Compared with previous research, the intensity of mistletoe infestation of the pedunculate oak is greater in the area of the Forest Administration Vinkovci and Nova Gradiška than in the Forest Administration Bjelovar, and smaller than in the Forest Administration Požega. On the sessile oak yellow mistletoe was investigated in the area of the Forest Administration Nova Gradiška, where mistletoe was observed on 4.6 % of the examined trees. On the infected trees there were 2 mistletoe plants on the average, and the highest number of plants on one tree was 5. The largest infestation was found in the Management Unit Južni Dilj, of the Forest Office Slavonski Brod, where 9.3 % of the examined trees were infected. Previous researches show that the intensity of mistletoe infestation of the sessile oak in the area of the Forest Administration Nova Gradiška is greater than in the Forest Administration Bjelovar, and smaller than in the Forest Administration Požega. Out of the total number of examined narrow–leaved ash trees in the area of Forest Administration Vinkovci, 2.7 %, were infected with white-berried mistletoe, with an average of 2 mistletoe plants per infected tree; the largest number of plants per tree was 5. In the area of the Forest Administration Nova Gradiška 7.3 % of the examined narrow-leaved ash trees was infected with mistletoe, with an average of 4 mistletoe plants per tree; the largest number of mistletoe plants on one tree was 60. f Mistletoes are a constituent part of ff forest eco-systems and they do not ret i present a special threat t tto oo thei theitheir rr hosts hostshosts, ,, if ff the infection intensity is not high. Although the percentage of infested trees varied in individual compartments, i.e. management units, the important fact was that the number of yellow mistletoe plants on infested sessile and pedunculate oak trees was not high (averaging 2 mistletoe plants per tree). The state of infection of the narrow-leaved ash was partly different in individual management units in the Forest Administration Nova Gradiška, where on the average a higher number of white-berried mistletoe plants on the infested trees was observed, and a relatively large oe number o oof ff plants on some trees. Šumarski list br. 9–10, CXXX (2006), 399-409 |