engleski

Some causes of damage to the seeds of peduncled oak (Quercus robur L.) and field elm (Ulmus minor Rich.) in ecological-managerial forest type II-G-10

Peduncled oak (Quercus robur L.) is the most important economic species in Croatia, which in the last two centuries has been significantly cleared by cutting, so that today it is found in the Pannonian region (II) on approximately 200.000 ha. Once, apart from Peduncled Oak, Field elm, the second economically important species, comprised more than 25 % participation in these forests. However, fifty years ago it almost completely vanished. Determination of parameters of the seed quality of Peduncled Oak and Filed Elm has been carried out continuously for more than four decades, according to ISTA standards. Seed samples of both species come from acknowledged seed stands. The results of the investigation of the seed crop for 2000 are as follows: average absolute weight is 5.479 g. The number of acorns in 1000 g was on average 186. Average germination capacity was 80, 09 %. With regard to the categorization of acorn, healthy acorn participated with 63, 68 %, and decayed / rotten and unusable acorn, attacked by insects and fungous diseases , with 36, 32 %. Furthermore, of the healthy acorn only 40, 42 % was usable for seed husbandry requirements , almost 60 % of the acorn was unusable. Clearly there was an absence of adequate protection, both of the stands and fructification. Field Elm seed has very low germination capacity, which on average is 15, 99 %, and is caused by the empty seed average of 39, 1 %, and diseased and decayed seed of 44, 91 %. The empty Field Elm seed is caused by the Elm Weevil (Anthonomus ulmi Deg.), which bites of the top of the pestle during fructification in February, thereby preventing fecundation. The above results indicate extremely irrational management of acknowledged seed stands and production of forest seed acorn , the demand for which is several times greater than the realistic possibilities of seed production.

ecogical-managerial forest types II-G-10 seed production; seed

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