BGCSE Horticulture 1257 flashcards
BGCSE Horticulture 1257 · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Photosynthesis equation
- The process by which green plants use light energy to convert carbon dioxide and water into glucose and oxygen, catalysed by chlorophyll in chloroplasts.
- Apical dominance
- Suppression of lateral bud growth by auxin produced in the terminal bud; removing the shoot tip releases lateral buds and encourages branching.
- Cation exchange capacity
- The soil's capacity to hold positively charged nutrient ions on clay and organic matter surfaces; higher CEC means greater nutrient retention.
- Field capacity
- The water content remaining in soil after excess water has drained away by gravity; it represents the upper limit of plant-available water.
- Loam soil
- A balanced soil texture of roughly 40% sand, 40% silt and 20% clay, giving good drainage, aeration and water retention for most crops.
- Nitrogen deficiency symptom
- General yellowing (chlorosis) of older leaves first, because nitrogen is mobile and the plant moves it to new growth.
- Iron deficiency symptom
- Interveinal chlorosis of young leaves, with veins remaining green, because iron is immobile and often unavailable in high-pH soils.
- Fertiliser analysis N-P-K
- The percentage by weight of nitrogen, phosphorus (as P2O5) and potassium (as K2O) in a fertiliser, e.g. 10-10-10.
- Integrated pest management
- A tiered approach combining prevention, cultural, physical and biological controls, using chemicals only as a last resort.
- Damping-off
- A fungal disease of seedlings causing collapse at the soil line, favoured by wet, crowded, poorly ventilated conditions.
- Viral plant disease
- A disease caused by viruses, spread by vectors such as aphids and by contaminated tools; there is no chemical cure.
- Bypass pruner
- A pruning tool with a blade that passes beside a hook, making clean cuts on living wood without crushing the stem.
- Hardening off
- Gradually acclimatising plants raised under protection to outdoor conditions over about one to two weeks before planting out.
- Crop rotation
- The practice of growing different plant families in sequence on the same ground to reduce soil-borne pests and diseases.
- Gross margin
- Gross output (yield multiplied by price) minus variable costs; fixed costs are excluded from this measure of enterprise performance.
- Break-even output
- The quantity of produce that must be sold to cover costs, calculated as fixed costs divided by price minus variable cost per unit.
- Ethylene gas
- A plant hormone that promotes ripening; it is produced by ripe fruit and can accelerate spoilage of sensitive produce in storage.
- Chilling injury
- Damage to tropical or subtropical produce stored below its recommended temperature, causing pitting, discolouration and poor ripening.
- Composting balance
- Successful composting requires a mix of carbon-rich browns and nitrogen-rich greens, adequate moisture and aeration.
- Pesticide harvest interval
- The minimum time between the last pesticide application and harvest, stated on the label to ensure residues are within safe limits.
- Fair test
- An investigation in which one variable is changed while all others are kept constant, with a control and repeated measurements.
- Percentage germination
- The number of seeds that germinate divided by the number sown, multiplied by one hundred; used to compare seed lots.
- Pricking out
- Transferring seedlings from a seed tray to individual pots when the first true leaves appear, handling them by the leaf.
- Soil pH
- A measure of soil acidity or alkalinity on a scale of 0 to 14; most nutrients are most available between pH 6 and 7.
- Transpiration
- The loss of water vapour from leaves through stomata, creating the pull that draws water and dissolved nutrients up the xylem.
- Rooting cutting medium
- A material such as perlite or coarse sand mixed for cuttings, providing good aeration and drainage while holding some moisture.
- Thinning fruit
- Removing some developing fruits to improve the size and quality of those remaining and to reduce alternate bearing.
- Mulching
- Covering the soil surface with organic or other material to conserve moisture, suppress weeds and moderate soil temperature.
- Green manure
- A crop grown and then incorporated into the soil to add organic matter and nutrients; legumes also fix atmospheric nitrogen.
- Risk assessment
- A process that identifies hazards in a horticultural task, evaluates their likelihood and severity, and sets controls before work begins.
- Grafting
- Joining a scion to a rootstock so their cambium layers align and form vascular connections, producing a combined plant.
- Soluble solids (Brix)
- A measure of dissolved sugars in fruit juice used as a maturity and quality index, commonly expressed in degrees Brix.