PGR - Plant growth regulators, Kohlrabi, Mildew

pH - The effect of pH on crop results, Kale, Mealybugs

PK - Phosphorus, Lettuce, Physiological disorders of plants

Plant physiology - Basic plant structure, Garlic chives, Fungus gnats

Ventilation - Principles & Practices, Carrots, Green Lacewings

Watering - Watering plants, Rhubarb, Integrated Pest Management

Propagation - Biological Control (IPM), Peas, Cuttings

Enzymes - Ghost peppers, Minute pirate bug, Mini vegetables

Coir - Field peas, Parasitic wasps, re-using coco

Plant environment - Brussels sprouts, Parasitic wasps