Subject
- Agricultural pests -- Control -- Congresses10
- Fruit -- Diseases and pests -- Control -- Columbia River Valley7
- Pesticides -- Application -- Columbia River Valley7
- Spraying and dusting in agriculture -- Columbia River Valley7
- Apples -- Diseases and pests -- Control -- Columbia River Valley5
- Cherry -- Diseases and pests -- Control -- Columbia River Valley5
- Pear -- Diseases and pests -- Control -- Columbia River Valley5
- Barred owl -- Reproduction3
- Northern spotted owl -- Reproduction3
- Vegetable gardening -- Oregon3
- Cherry -- Pruning2
- Chinook salmon -- Effect of water pollution on2
- Chinook salmon -- Growth2
- Clam fisheries -- Oregon2
- Lignin2
- Wood-pulp industry -- Environmental aspects2
- Airplanes -- Materials -- Testing1
- Apple -- Anatomy1
- Apple -- Pollination1
- Apples -- Anatomy1