Resistance to insect pests and growth of scotch pine pinus sylvestris accessions outside of its natural area in the region of the village rabisha belogradchik forest farm bulgaria
Tsankov, G.; Kostov, K.D.
Gorskostopanska Nauka 22(1): 23-30
Studies were carried out aiming to assess the extent of insect pest infestation, the resistance to insect pests and the growth and productivity seedlings of various provenans of Scotch pine. The trial, using the block method design included seedlings of the following provenance: 1. Bunderitsa, 2 and 3. Bansko, 4. Belitsa, 5. Smolyan, 6. Devlin, 7. Youndola, 8. Beslet, 9. Govedartsi, 10. Borovets, 11. Malyovitsa, 12. Sandanski, 13, 14 and 15. Rumania. It was found that on the third year of Scotch pine plantations the winter pine shoot moth appears. Its numbers increase and reach a maximum at the 5-6 year age of the trees. Along with this insect pest leaf aphids and Pineus pini Koch. are observed. The numbers of this group of insect pests during the time of crown closure are reduced, but then the pine yellow saw fly appears. Seedlings growing more slowly which have small buds, are more resistant to insects. Evidently their ability to produce resin is higher.