Diseases and pests 545 Agriculture 402 Control 336 Forests and forestry 295 Forest management 251 Research 203 Pinus ponderosa 186 more ... Ponderosa pine 168 Varieties 155 Economic aspects 146 Measurement 145 Trees 137 Environmental aspects 128 Food 114 Forest fires 111 Nutrition 111 Timber 101 Feeding and feeds 96 Storage 95 Soils 94 Soil conservation 93 Watershed management 85 Prevention and control 81 Seeds 81 Forest inventory 80 Fruit 79 Marketing 76 Logging 74 Range management 74 Equipment and supplies 71 less ...