Current issue: 58(5)
In Finland the mite Nalepella is found in Norway spruce (Picea abies (L.) H. Karst.) in forests practically in every tree, and even in the nurseries. The paper reports on the occurrence of Nalepella Haarlovi var. picea-abietis Löyttyniemi in Finland in tree nurseries in Finland. The study is based on a large material, collected in connection with an investigation into spruce spider mites.
Nalepella lives vagrantly on the needles. Due to the sucking of the mites, the needles turn yellow, become dry an die. Single patches from sucking cannot be seen by the naked eye. They occur on all sides of the needles. The worst damage to spruce seedlings in nurseries is caused to the needles located in the top of the seedling. Sometimes the terminal bud dryes and the whole terminal shoot can die. However, the whole seedlings seldom die in consequence of the Nalepella mite alone. Subsequent damage to the injured needles is often caused by fungus Cladosporium herbarum.
The study shows that the mite causes economically significant damages only in the nurseries. In forests no such damages were observed in seedlings or in older trees. In 1965–68, significant damages occurred in 16 nurseries in Finland. About 600,000 four-year-old seedlings were destroyed in 1967. The damages were economically important only in the 4-year-old seedlings.
According to the study, seedlings damaged by Nalepella can be used for planting as they recover rather well after planting in the forest. Moreover, the damages end after planting, and density of the mite population decreases during the first summer.
The mite overwinters as egg on needles. The eggs hatch in Southern Finland in the end of April and in the beginning of May.
The PDF includes a summary in English.
The paper outlines the information about forest tree nurseries in the Roman Empire, found in ancient writings. According to the author, it cannot be stated that actual forest cultivation was practiced in the times of the Roman Empire, even if tree seedlings were used for a variety of purposes, such as embellishment of cities, parks and gardens, and raising supporting trees in forest vineyards. Nurseries were usually established on farms to fill the owner’s needs. For instance, Gato, Varro, Virgil, Pliny and Colulmella have given instructions about establishment and management of nurseries, and methods to sowing seeds of different tree species. Except for seeds, both root- and branch-cuttings were used in cultivation of trees. Also, grafting was known.
The PDF includes a summary in English.
Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.
This presentation describes production of forest tree seedlings.
The aim of the study was to investigate effect of growth conditions on germination and growth of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings in greenhouse conditions. Germination of seeds becomes markedly slower as the soil temperature decreases. It seems that low temperatures affect more Norway spruce than Scots pine. When temperature rises, the fresh weight of the seedlings increases more in pine seedlings than in spruce seedlings. Accordingly, lower temperatures affect less the weight growth of spruce seedling than that of pine seedlings.
An experiment testing how root competition affect germination showed that adjacent seedlings decrease germination of seeds more than shading with branches. The effect was strongest on pine and spruce seedlings when the shading tree species was fast growing birch (Betula sp.). On the other hand, shading affected most height growth of birch seedlings. Growing space can vary in relatively large range without it affecting greatly tree growth.
The PDF includes a summary in German.
The aim of this study was to find out the planting vigour of Scots pine (Pinus sylvestris L.) stored over the winter either in winter storage mainly in the temperature of 4 – -6 °C or in nursery beds. The experimental planting included about 4,500 of 2+1 transplants in Northern Finland. In spring 1965 the control plants were lifted in the spring before budbreak and stored in closed bags in a cold store, in the following year the control plants were lifted in June when the growth had started.
Winter storage of pine transplants in a cold store, tightly closed into bags for the major period, did not, according to the results, increase plant mortality as compared to lifting in the spring. Soaking the stored-plant roots did not affect plant mortality. Mortality was rather small in all treated lots and probably more dependent on planting site and other local factors.
No consistent difference on the leader growth, needle length, bud number and plant grade was found between the plants stored over winter and those lifted in the spring. Sealing the plants into tight bags for winter proved to be suitable method, efficiently preventing water shortage in the plants. No moulds or fungal diseases were found in the plants. In the exceptionally cold 1965–1966 winter, temperature in the cold store sank to -15 °C, but in spite of the temperatures below the recommended storing temperature, the plants survived well. The reason was that the plants froze slowly in the fall and thawed out slowly in the spring.
The value of vigour grade in predicting plant-characteristic development proved to be good, and predicted plant development also in the following year fairly well.
The PDF includes a summary in English.