VIENID Start practicing

Home › Lessons › Agriculture (SSW 2)

Cultivation Management of Greenhouse Horticulture, Fruit Trees, Flowers, and Tea

Agriculture (SSW 2) · 農業(2号) · Written by Tokutei Pass based on the official study texts; not copied verbatim.

Greenhouse Environmental Control and Hydroponic Culture

Greenhouse covering films include agricultural PVC film (Nobi: high heat retention but heavy and tear-prone) and polyolefin film (No-PO: lightweight, tear-resistant, and non-sticky).

On sunny winter days in a closed greenhouse, crop photosynthesis depletes indoor CO2 below ambient levels (~400 ppm), so ventilation or a CO2 generator is used to replenish it.

Soilless culture (hydroponics) grows crops with nutrient solution in solid media such as rockwool or in water, monitoring total nutrient concentration via an EC meter. Simultaneously supplying water and liquid fertilizer through drip tubes in soil is called fertigation (youeki-dokou).

Greenhouse Environmental Control and Hydroponic Culture

Key points


  • Agricultural polyolefin (No-PO) film is lighter, stronger, and more durable than PVC (Nobi) film.

  • Closed winter greenhouses become CO2-depleted during daytime photosynthesis, making morning CO2 enrichment highly effective.

  • In hydroponics, monitor nutrient concentration daily with an EC meter and acidity with a pH meter.
WordMeaning
greenhouse covering materials
CO2 enrichment
hydroponics / soilless culture
fertigation (soil drip fertigation)

Training, Fruit-Set Management, and Precooling in Fruiting Vegetables & Strawberries

In single-stem tomato training, only the main stem is kept while lateral shoots (suckers) are snapped off while small on sunny mornings so wounds dry quickly. Removing old lower leaves and pinching the growing tip improve airflow and nutrient allocation.

Greenhouse tomatoes and strawberries use pollinating insects (bumblebees for tomatoes, honeybees for strawberries) or plant growth regulators to ensure uniform fruit set. Strawberries are propagated vegetatively using runners (stolons) from mother plants.

Harvested produce loses freshness from respiration heat, so precooling is performed before shipping. Vacuum precooling—evaporating moisture under reduced pressure—rapidly cools leafy vegetables like lettuce to their core.

Key points


  • Remove tomato lateral shoots (suckers) while small on sunny mornings so wounds dry rapidly.

  • Use bumblebees (tomatoes) or honeybees (strawberries) for greenhouse pollination, and propagate strawberries via runners.

  • Precool harvested produce to suppress respiration; vacuum precooling is ideal for leafy vegetables like lettuce.
WordMeaning
side-shoot removal (suckering) and pinching
pollinating insects (bumblebees, honeybees)
runner (stolon)
vacuum precooling

Fruit Tree Characteristics, Pruning, Fruit Thinning, and Bagging

Fruit trees are classified into deciduous fruit trees that shed leaves in winter and require winter chilling to break dormancy (apple, pear, peach, grape, persimmon) and evergreen fruit trees (Satsuma mandarin, loquat).

Self-incompatible fruit trees (apple, Japanese pear, sweet cherry) cannot set fruit with their own cultivar's pollen and require cross-compatible pollinizer trees or artificial pollination. Early bud, flower, and fruit thinning prevents alternate bearing and produces large fruit.

In apples, keep the earliest-blooming central 'king flower/fruit' and remove lateral flowers/fruits. Gibberellin treatment in grapes induces seedlessness and berry enlargement, while fruit bagging protects against pests, diseases, and skin blemishes.

Key points


  • Apple, pear, peach, grape, and persimmon are deciduous; Satsuma mandarin and loquat are evergreen.

  • Self-incompatible apples and pears require pollinizer cultivars; apple fruit thinning retains the central 'king fruit'.

  • Thinning prevents alternate bearing and enlarges fruit; gibberellin treatment produces seedless, larger grapes.
WordMeaning
deciduous and evergreen fruit trees
self-incompatibility
alternate bearing (biennial bearing)
king fruit (central fruit) and fruit thinning

Flowering Control in Cut Flowers (Lighted Chrysanthemums) and Tea Cultivation

Autumn chrysanthemum is a short-day plant. Applying night-break lighting in autumn and winter creates long-day conditions that inhibit flower bud initiation, allowing stems to reach marketable length and delaying flowering on schedule (retarded culture).

For standard single-bloom chrysanthemums, keep the terminal bud and disbud lateral shoots; for spray chrysanthemums, remove the central terminal bud. Cut flowers are pretreated with preservatives (such as STS) to improve water uptake and block ethylene senescence.

Tea thrives in strongly acidic soil (pH 4.0–5.0). Frost protection fans blow warmer air from the inversion layer down onto tea canopies to prevent spring frost damage on first-flush shoots, while shading nets for Gyokuro and Tencha preserve savory theanine.

Key points


  • Night lighting on short-day chrysanthemums inhibits flower bud differentiation, ensuring stem length and scheduled delayed blooming.

  • Standard chrysanthemums retain only the terminal bud, and cut flowers use anti-ethylene preservatives to prolong vase life.

  • Frost fans mix warmer upper air down to protect young tea shoots from frost, and shading prevents theanine from converting into bitter catechin.
WordMeaning
night-lighting cultivation (photoperiodic lighting)
cut-flower preservative (anti-ethylene agent)
frost protection fan (wind machine)
shaded tea and theanine (umami amino acid)

Greenhouse, Fruit Trees and Flowers

Practice this chapter in the app

Official references