Cucumber
The cucumber may be grown in any conditions, outdoors or in a greenhouse. There are regular varieties with seeds, as well as parthenocarpic types.
The plant is an annual and excels in rapid growth. The first fruit appears after 5 weeks and fruit production continues for another 4–8 weeks, according to the variety and the season. The growing season is generally 3–4 months.
For proper germination, soil temperature should be at a minimum of 15 degrees. The optimum growing temperature is around 20–22˚during the day and 19–20˚ at night, but the cucumber also grows under hot conditions. High temperatures induce quicker growth but over a longer period, temperatures above 35˚ cause the flowers to degenerate. The cucumber is sensitive to low temperatures, and also to changes in the length of the day. During short days, there are more female blossoms and more fruit.
In greenhouses, it is possible to have three growing cycles with a potential yield of 300 tons/ha/year. The plant is sensitive to leaf diseases, mainly to mildew which develops in humid conditions.
SOIL
The cucumber is not sensitive to soil type and can grow in any kind of soil. In the winter, well-drained soil is naturally preferable, but this is mainly for technical reasons. The cucumber is sensitive to soil diseases, and therefore disinfecting the soil prior to cultivation is recommended. Optimal pH: 6.0–6.5.
Water consumption per season is 400–700 mm. Although the root system is characterized by a tap root, which may reach a depth of 1 m, the overall root system is rather shallow— 30 cm at the top. Therefore, frequent irrigation is recommended. In greenhouses, it is customary to irrigate regularly during sowing.
After sowing, in a moderate climate, 3 mm should be provided daily until harvesting, followed by 5 mm daily for the duration of the harvest. More precise irrigation management should follow the daily
ET and plant stage of growth. The pH of the water is also critical and may need to be adjusted.
The target pH of the nutrient solution supplied to the plants should be between 5.5 and 6.0. Nitric, sulfuric, or phosphoric acid are recommended for reducing the pH if it is above 7. If the water source is alkaline due to high bicarbonate concentrations, the pH should be adjusted before the fertilizer salts are added in order to prevent precipitation.
FERTILIZATION AND FERTIGATION
The given information should be considered only as a guideline. The amount of fertilizer depends on the variety, soil minerals and the expected yield. The nutrient uptake rate by greenhouse cucumbers is very high. One study indicates that cucumbers may require in the range of 28 kg/
ha of nitrogen, 5 kg/ha of phosphorus, and 40 kg/ha of potassium per week during peak fruit production.
The phosphorous fertilizer can be applied prior to sowing, according to soil test.
Recommended pre-season compost application is 50-60 ton/ ha.
SPACING
In Greenhouses
The distance between rows can vary from 1.3 cm to 1.5 cm. Plants spacing in the row is 30–50 cm.
In summer crops grown in high structure greenhouses, the double row concept can be used:
Distance between center to center: 180–200 cm
Distance between the couple rows: 50–60 cm
Distance between plants: 40–50 cm.
A dripline is provided for each row, as well as a dripper for each plant.
DRIP IRRIGATION RECOMMENDATION
Single dripline per row with 0.3–0.5 m between the drippers. One dripper for each plant.
Dripper flow rate: 1–2 l/hr
Tif Drip
16 mm non-regulated drippers Traditionally used in greenhouses
PC Drippers
In large greenhouses the simple design of the 16 mm PC dripper is ideal, ensuring maximal
uniformity.
GRAVITY SYSTEM – DripKit
For small greenhouses (250–500 m2) with flat surfaces, a gravity system with a water tank can
be an economical solution.
AmnonDrip
16 mm 1.0 l/hr every 30 cm, Single row, 140 ton/ha
