Current issue: 55(2)
Exposure to phenoxy acids and their effect on worker’s health were studied among 35 exposed forest workers. The control group was 47 non-exposed loggers. The both groups were medically examined before and after their working period including such laboratory analyses as B-differential count, B-thrombocytes. In addition, the exposure to eight ULV sprayers and two clearing saw sprayers were measured in breathing zone.
The mean of phenoxy acid concentrations in urine among all the exposed workers after the working period was 6.5 μmol/l being significantly below the hygienic limit value (14 μmol/l). The mean concentrations of ULV sprayer workers was 7.3 μmol/l and of clearing saw sprayer workers 2.7 μmol/l. The mean of air concentrations among ULV sprayers was 0.23 mg/m3 and among clearing saw sprayers 0.06 mg/m3. No statistically significant differences were noticed in the hematologic parameters and in the enzyme activities of the liver, kidney and muscles between the exposed and control groups before or after the working period. So, it seems that these low exposure levels don’t cause sudden changes in health.
The PDF includes an abstract in English.
The purpose of this study was to measure workers’ exposure to MCPA and glyphosate when sprayers connected to the brush saws was used. A non-pressurized sprayer with a pump and a pressurized sprayer where dosage was regulated with manual control were studied. Exposure was measured from the breathing zone and urine samples.
MCPA collected from the breathing zone gathered into alcohol was 0.05 mg/m3 for the pressurized sprayer, 0.02 mg/m3 for the non-pressurized sprayer, and 0.04 mg/m3 (average) for both types of sprayers together.
MCPA in the breathing zone, collected from splashes and fog into a glass fibre filter, was 0.18 mg/m3 for the pressurized sprayer, 0.09 mg/m3 for the non-pressurized sprayer, and 0.12 mg/m3 for both sprayers used together. Glyphosate in the breathing zone, collected into sodium hydroxide was below 0.05 mg/m3.
In five urine samples taken after the work day there was on the average 0.4 mg/l MCPA, while in 21 samples the MCPA contents were under the definition limit (0.2 mg/l).
The PDF includes a summary in Finnish.
Since 1954 studies have been carried out by the Department of Plant Pathology of Agricultural Research Centre on occurrence of low-temperature parasitic fungi in nurseries in Finland. This paper reports analysis of the damage caused by the fungus to Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seedlings.
In Southern and southwestern Finland, scarcely any damage caused by low-temperature parasitic fungi to coniferous seedlings was found. On the other hand, in Central, Eastern and Northern Finland, considerable injuries were present in the seedlings. The extent of damage varies between different localities and in a same location from year to year. The extent of damage is mostly dependent on snow cover which is heaviest in Central and Northern Finland. Damages are largest in wooded areas and in places where snow accumulates abundantly and remains until late in the spring.
The principal cause of winter damage to spruce seedlings is Hepotricia nigra (Hartig) which causes black snow mould. Depending on the amount of infestation, the damage can be limited to scattered groups or consist of large areas of dead seedlings. The fungus is unable to infect the plants during warm months of the growing season. The most damaging parasitic fungus in Scots pine is Phacidium infestans (Karst.) causing snow blight. The infestation varies from reddish-brown patches of infected seedlings to large areas of infected plants. Also, Botrytis cinerea has been determined from one- and two-year plants of pine and spruce.
In trials of chemical control by PCNB (pentachloronitrobenzene) gave nearly complete control of low-temperature parasitic fungi in one-year spruce seedlings. In addition, a compound of zineb (Dithane Z-78) gave similar results. Chemical control of the fungi is now common in the nurseries.
The PDF includes a summary in English.
The aim of the study was to find out more about pine weevil (Hylobious abietis L.) injuries in Scots pine (Pinus sylvestris L.) seedling stands and their control by means of DDT. For this purpose, inventories were made of seedling stands established earlier. Control experiments were made on burnt areas by planting seedlings dipped in a DDT emulsion.
The results of the inventories show that injuries caused by pine weevils can, in certain circumstances, especially in seedling stands established by planting, cause the complete failure in artificial regeneration. The extent and quality of the injuries vary greatly according to planting method, treatment of the cutting area, age of the seedling stand, environmental factors, and weather conditions. The most extensive injuries occur in regeneration areas of old Norway spruce stands burnt after clear cutting and planted with Scots pine seedlings. Injuries are greater in seedling stands established by planting, especially after broadcast burning, than in seedling stands originating either from artificial or natural seeding. The quality of the patch for sowing or planting has a considerable effect on the quantity and character of the injuries: in a patch from which organic matter has been removed, injuries do not appear or they are slighter. Seedlings can be protected effectively and economically by dipping their tops up to the root collar, in a DDT emulsion before planting.
The PDF includes a summary in English.
In 1953 and 1954 needle cast (Peridermium pinastri (Shrad.) Chev., now Lophodermium) caused much damage at the Leksvall nursery at Tammisaari as well as at some other nurseries in Southern Finland.
Experiments were conducted at the Leksvall nursery with different fungicides. The results showed that with spraying done every second week during the whole growing season beginning on May 20th and ending on 27th September in 1954, the damage caused by needle cast was entirely controlled with 2% Bordeaux mixture and the zineb preparation (Dithane Z-78); nabam preparation (Dithane D-14) being somewhat less effective. Lime sulphur, Burgundy mixture, thiram preparation, captan preparation, and PCNB preparation were rather ineffective, in addition, of these the lime sulphur and the Burgundy mixture caused damage to the needles. Phenylmercury preparation proved useless.
The article includes an abstract in English.
Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. 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 a field experiment on the use of herbicides to prevent growth of ground vegetation in cutting areas before sowing. The study suggests that the chemicals used in the experiment were not effective enough to prevent growth of ground vegetation in the more fertile lands, but were effective in poorer lands. However, the treatment affected also growth of tree seedlings.