Fundamentals of Horticulture and Plant Science
Domain 1 tests how well you connect basic plant science with horticultural practice: naming branches, classifying crops, explaining growth and reproduction, and choosing a propagation method. Questions usually apply a definition to a crop rather than ask for an isolated definition.
Core map
- Horticulture is the science and art of cultivating fruits, vegetables, flowers, spices, plantation crops and ornamentals. Its main branches are pomology (fruits), olericulture (vegetables), floriculture (flowers), arboriculture (trees) and landscape horticulture.
- Life cycles: an annual completes its life in one season (tomato, marigold); a biennial needs two seasons (onion, cabbage); a perennial persists for years (mango, coconut).
- Photosynthesis makes carbohydrate in chloroplasts; respiration releases energy; transpiration pulls water through stomata. Stomata also regulate gas exchange.
- Growth and development respond to light, temperature, water, nutrients and hormones. Auxin, gibberellin, cytokinin, ethylene and abscisic acid have distinct roles.
- Photoperiodism controls flowering in short-day, long-day and day-neutral plants. Vernalization is low-temperature promotion of flowering.
- Sexual propagation uses seed and creates variation; asexual propagation by cuttings, layering, grafting, budding or tissue culture preserves genotype.
Worked example
A farmer wants uniform guava fruit and a quick ornamental hedge. Guava is a fruit crop, so the relevant branch is pomology. Because seed-grown guava is variable, use grafting or budding onto a seedling rootstock to preserve the cultivar. For the hedge, choose a species that roots from cuttings and propagate it vegetatively; this avoids seedling variation and gives uniform height.
Traps that cost marks
Horticulture is not synonymous with agriculture. Botanical classification differs from market classification. Respiration consumes oxygen; photosynthesis releases it. Not every flowering plant is a cut flower, and not every fruit is a horticultural fruit.