Genetic abnormalities Viruses, viroids Air pollutants Other chemicals Bacteria Soil acidity/alkalinity Fungi, oomycetes Nutrient imbalance Disease (broad sense) Parasitic plants Low oxygen Drought Nematodes Insects, mites Heat or frost Mechanical impact Other herbivores Non-living, abiotic Living, biotic
Genetic abnormalities Viruses, viroids Air pollutants Other chemicals Bacteria Soil acidity/alkalinity Fungi, oomycetes Nutrient imbalance Disease (broad sense) Parasitic plants Low oxygen Drought Nematodes Insects, mites Heat or frost Mechanical impact Other herbivores Non-living, abiotic Living, biotic