DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 11-12/1961 str. 36 <-- 36 --> PDF |
NEW MEASURES FOR THE IMPROVEMENT OF SEED HUSBANDRY AND OF NURSERIES SUMMARY The author first discusses the stimulation of seed yields in seed-producing stands by means of the trace element boron which is largely applied in agriculture, especially in horticulture and fruit-growing. Foreign experiences ought to be applied in this country; therefore the author recommends spraying of the upper part of tree crowns with 0.3*/o solution of borax (sodium tetraborate) by means of an atomizer. Boron not only induces a good seed crop but also strengthens the physiological resistance of crown and the whole tree. This foliar nutrition is especially recommendable for application in seed-sources. To this purpose treatments by helicopters are practised. In the second part of the article the author discusses the foliar nutrition in nurseries and plantations, and reports on his own experiences as to the successful application of boron in protection of plants against frosts and diseases. Borax is dissolved in water in 1 : 200 ratio. When endangered by frost the leaves are sprayed by this solution (FONTAN). The rain after the treatment does no harm. The effect of boron is the strongest at the beginning and during the full growth (spring). There is no success in summer and it is no use to treat unopened buds. The wind and the sunlight increase the evaporation and bring about a higher concentration of the solution thus giving rise to the scorching of leaves! The lowest temperatures of frost in successful experiments were —9° and —6° C. There was no more any success at —8° C. For the purpose of protection against diseases it suffices to apply spraying in the beginning of the growing season when the newgrown needles and leaves are already normally developed, and to repeat spraying 3—4 weeks later. The author discusses further the problem of charcoal as a seed and soil disinfectant. After 1950 in Slovenia and Croatia charcoal is successfully applied in nurseries. Excessive dosages bring a negative effect. Charcoal dust is used in nurseries in doses of 0.5 kg per one sq. m. or 5 t./ha. to be mixed with the 6´—8 cm.-thick layer of topsoil (duration of effect is at least 10 years). When transplanting the seedlings their roots are filled up with earth containing an admixture of Š^/o charcoal dust. The author mentions also the experiences in this country in the extraction of Spruce and Larch seeds. At the same time the author reports on the soaking of seeds in rainwater in order to obtain a high percentage of germination also without stratification. / |