Propagation - Biological Control (IPM), Peas, Cuttings
Plant physiology - Basic plant structure, Garlic chives, Fungus gnats
Oxygen & Roots - Root zone temperature, Parsnip, Pythium
Micro-organisms - Soil life rhizobacterias, Asparagus, Viruses
Nutrients - Interaction between nutrients, Spinach, Broad mites
Roots - Water types & treatments, Root hairs