Subject
- Range plants -- Oregon79
- Forage plants31
- Forage plants -- Oregon31
- Plant-water relationships26
- U.S. International Biological Program. Coniferous Forest Biome24
- Growth (Plants)22
- Plant competition22
- Virus diseases of plants21
- Plant communities -- Oregon18
- Plant-soil relationships18
- Plants, Effect of herbicides on18
- Douglas fir17
- Plants -- Nutrition17
- Plants, Effect of nitrogen on16
- Plant breeding15
- Plant ecology15
- Plant communities14
- Plant hormones13
- Plants -- Metabolism12
- Vegetable gardening -- Oregon12