Horticultural practices — A/L Biology

What must I remember about Horticultural practices?

• Horticulture is the intensive branch of agriculture focused on the art, science, technology, and commercial cultivation of fruits, vegetables, flowers, spices, and ornamental landscapes.
• Plant propagation techniques: Sexual propagation by seeds (genetic diversity, rootstocks) versus Asexual vegetative propagation producing true-to-type clonal progeny identical to high-yielding disease-resistant mother plants.
• Vegetative propagation methods: Stem cuttings (softwood, semi-hardwood, hardwood treated with rooting auxin IBA), Layering (simple layering, air layering / marcotting where bark ring is stripped and packed with moist coir dust), Grafting (joining Scion branch onto established Rootstock via cleft, whip, or splice grafting), and Budding (T-budding, patch budding inserting single bud eye under rootstock bark).
• Micropropagation / Plant Tissue Culture: Totipotency of plant cells allows regeneration of thousands of pathogen-free uniform plantlets from tiny explants (shoot apical meristems) on sterile agar medium enriched with Murashige and Skoog (MS) salts, auxins, and cytokinins under controlled light and temperature.
• Protected cultivation technologies: Greenhouses, polytunnels, shade nets, hydroponics (soil-less liquid nutrient culture), and aeroponics maximizing resource efficiency, water conservation, and year-round premium crop yields unaffected by weather extremes.

Test yourself (1 minute)

1. Cell Totipotency concept

   The inherent genetic capacity of any living nucleated plant cell to differentiate and regenerate into a complete, fertile adult organism when supplied with appropriate nutrient and hormonal stimuli (discovered by Gottlieb Haberlandt).

2. Auxin-to-Cytokinin ratio in tissue culture

   High auxin : low cytokinin ratio induces root formation (rhizogenesis); Low auxin : high cytokinin ratio induces shoot bud regeneration (caulogenesis); Balanced intermediate ratio produces undifferentiated callus tissue.

3. Cambium alignment requirement in grafting

   Success of grafting strictly depends on intimate vascular cambium contact between rootstock and scion to permit cell division and continuous xylem/phloem bridge regeneration.

Practise Horticultural practices questions today

Source: NIE G.C.E. (A/L) Biology Syllabus & Resource Book, Unit 10

What should I study first?

What comes next?

Next in the syllabus

Where does Horticultural practices fit in the syllabus?

Year 2 · Term 3