A method of using larch wood extracts as natural compounds to give superior resistance to plants, plant parts, fruits and/or flowers against pathogens as bacteria and fungi. The method includes using larch wood extracts as natural compounds that naturally protect plant tissues against ultraviolet radiation and temperature, thus giving protection against sunburn to plants, plant parts, fruits and/or flowers during their development. Additionally, the method includes using larch wood extracts as natural compounds to naturally increase adaptive potential of the seedlings, increase the root growth of seedlings, and to maximize the ability of plants to grow vigorously in response to changing environmental conditions. The above natural compounds are derived from a plant material and are antioxidant Dihydroquercetin (taxifolin), polysaccharide Arabinogalactan, a combination of Arabinogalactan with Dihydroquercetin (taxifolin) and wood oleoresin including oil and resin, wherein all these natural compounds are extracted from larch wood and\or by-products of logging industry.
