Courgette cultivation.

» Courgette planting

Courgettes can be grown in seedbeds or directly in the field.

• Seed sowing: around March in protected cultivation. Transplanting should be done when the seedlings have about 3 true leaves, normally after 15-20 days.
• Direct sowing: between April and May. The optimum soil temperature for germination is between 20-25^o

·Soil

Courgettes generally adapt well to any type of soil, but prefer loamy, deep, well-drained soils rich in organic matter. Furthermore, courgettes tolerate soil and irrigation water salinity well and the pH of the soil should be between 5 and 7.

·Climate

Courgette is a vegetable that requires warm-temperate climates, as it is not very tolerant to low temperatures and frosts. It also needs about 10-12 hours of light.

Below 10^oC their development starts to stall while temperatures above 40^oC cause imbalances in the plants.

• Crop rotation

Crop rotation should be practised in courgette cultivation, as it consumes a large amount of nutrients and could deplete the soil. It is advisableto allow at least 3 years of rest before replanting courgettes in the same place and to alternate with leguminous plants.

» Care requirements for courgettes

·Soil preparation for courgette cultivation

Before growing courgettes, the soil must be prepared. To do this,weeds and residues from previous crops are removed, as well as all types of residues to ensure that the courgettes receive the right amount of nutrients. In addition, the soil will be turned with the help of specialised machinery to improve aeration. On the other hand, the soil is moistened just before sowing, as this helps the root system of the plants. Finally, it is very important to apply a good base fertiliser as courgettes are very demanding plants in terms of nutrients.

·Watering courgettes

Watering of courgette crops must be frequent and regular, being even more frequent when the first fruits start to appear.

Waterlogging can encourage the development of diseases or cause root asphyxia. Conversely, a shortage of moisture can lead to dehydration of tissues, lack of fertilisation and reduced production.

The most commonly used irrigation systems for courgettes are drip irrigation and furrow irrigation.

• Trellising

The courgette plant is a creeping plant, so it is at risk of disease and rotting if it stays in contact with damp soil. Therefore, it is best to stake the plants.

• Thinning

Thinning is carried out in cases where more than one seed has been planted and more than one plant is growing at the same point. The most vigorous one is left and the others are removed.

• Ridging

Mulching consists of covering part of the stem of the plants with soil in order to strengthen their base and encourage root development. This practice is carried out 15-20 days after nascence and favours fruit development.

• Shredded and stripped

Courgette thinning is based on the removal of the secondary shoots. Leaf plucking is carried out if the lower leaves are very old or overgrown and hinder aeration and light.

• Flower cleaning

When the courgette flowers have done their work, they fall off and fall on the ground or on the plants themselves. As they rot, they can be a source of disease and their removal is recommended.

• Fruit cleaning

Fruit cleaning is based on the harvesting of courgettes that show damage, malformations or excessive growth. This is done in order to eliminate possible sources of disease and to avoid plant exhaustion.

» Fertilisers for courgette cultivation

As we have already mentioned, courgettes are a very demanding vegetable in terms of nutrients.

Nitrogenis an essential element for plant growth, as it is involved in the process of chlorophyll formation.

Phosphorus helps plants carry out photosynthetic processes and is involved in the formation of oils and sugars that plants use for energy. In addition, this element promotes flowering and root growth.

Potassium is directly involved in plant growth, controlling water and energy within the plant and intervening in metabolic processes. It is also necessary for the creation of plant proteins, photosynthesis and fruit production.

Calcium promotes the uptake of other nutrients and improves the plants’ resistance to the disease “blossom-end rot”. It is caused by a calcium deficiency in the soil.

For the organic cultivation of courgettes, organic fertilisers, such as manure, compost or worm hummus, as well as those formulated with seaweed, minerals or other natural elements, shall be applied.

» Harvesting courgettes

The courgettes are harvested by hand about one and a half months after sowing.

Courgettes are consumed at various stages of physiological maturity. It is recommended to harvest them before the seeds start to grow and harden. Therefore, they are usually harvested at the desired size even in very immature stages.