RESUME

Thirty-eight year results of European larch (Larix decidua Mill.) provenance trials (IUFRO series 1958/59) in the Czech Republic
Jiří Šindelář, Josef Frýdl (pp. 18-19)

This report contains the results of evaluations and measurements of the four research plots (IUFRO series 1958/59) 38 years after they were established. Elsewhere, evaluations were made according to the methods proposed by the IUFRO co-ordinator, R. Schober. The parameters measured included height growth, DBH and stem form, plus average volume production was calculated. The results were subjected to standard statistical tests. Biomass production was estimated on a per ha basis. The autochthonous and allochthonous Sudetic provenances were shown to be best. In spite of their average stem form they produce a very good level of volume. These results agree with results from previous research in the Czech Republic and elsewhere.

However, it should be mentioned that some Sudetic populations vary enough that it is not possible to characterise all populations of this origin as above average. Very good levels of quantitative and qualitative traits have been recorded for three provenances of European larch of the Slovak ecotype from the Low Tatras (Nízké Tatry) Mountains. Also, it should be stressed that a high level of stem form characteristics was found for Slovak larch from the High Tatras (Vysoké Tatry) Mountains. Average volume production, with very good stem form, was found for populations from the Northern Alpine areas and from Northeast borders of these mountains. An average level of volume production and very bad stem form occurred in Japanese larch as well as in spontaneous hybrids of European and Japanese larch.

Adamov larch
Jiří Truhlář (pp. 20-21)

School Forest Enterprise (SFE) Křtiny located in Southern Moravia is a centre of propagation of larch (Larix decidua Mill.) population, which is for its growth characteristics, considered a unique culture population called Adamov larch. The species in not autochtonous there, it has been introduced there from the 1870s. Both Sudeten and alpine (Austrian) provenances have been systematically introduced and their spatial and time distribution over the area of the SFE has permeated and resulted in crossing by pollination. The author hypothesises a unique cultural population, which gained favourable features of the both provenances, was cultivated through such unintentional hybridisation. The hybrid vigour is extraordinary. However the hypothesis on the genetic fundaments of Adamov larch requires verification. Larch in the SFE has become domesticated and a common productive species. Its average share is 8.6 per cent at present and envisaged at 10 per cent.

Contamination of forest understorey by aerially applied pesticide.
František Bartoníček, Helena Maloňová, Milan Švestka (pp. 36-37)

DIMILIN 48 SC with an effective agent diflubenzuron is one of the most frequently aerially applied insecticides in the CR. Therefore this formulation was chosen to identify the contamination of forest understorey and residua dynamics and to assess the adequacy of imposed protective period (28 days). The experiment was aimed at getting data on contamination of forest plants’ leaves and fruits from stands aerially treated with insecticides. The analyses of samples justified the contamination of forest understorey after aerial treatment. The highest values of insecticide residua were observed immediately after the treatment in the leaves of raspberry 1,71 mg/kg), blackberry (1,32 mg/kg), birch (1,59, 1,33, and 1,09 mg/kg) and fungi (1,32 mg/kg). In low-growing plants like bilberry or strawberry including the berries the highest observed concentrations on the day of application were 0,52 mg/kg at maximum. The contaminant levels dropped gradually in examined materials. They ranked between 0,05-0,33 mg/kg (in bushes) and below the maximum of 0,07 mg/kg in blueberries, strawberries, and fungi after the 28 days of protection period. Most measurements fell bellow the detection threshold (0,05 mg/kg). So, after the expiration of the 28-day protection period the diflubenzuron residua level was mostly below the detection threshold and did not represent any health risk.