Pine 19 Norway spruce 8 Diseases and pests 6 Forest genetics 6 Forests and forestry 6 Seeds 6 Trees 6 more ... Scots pine 5 Wood 5 Coniferae 4 Fungi 4 Lodge-pole pine 4 Pine seed 4 Scotch pine 4 Seed 4 Spruce 4 Wood-decaying fungi 4 Cellulose 3 Conifer seed 3 Microbiology 3 Physiological effect 3 Plants, Flowering of 3 Research 3 Beetles 2 Botany 2 Cloning 2 Economic aspects 2 Embryology 2 Fertilization of plants 2 Fertilizers and manures 2 less ...