Seedlings

Conventional Seedbeds

Normally 10 to 15 days are needed for seed germination if temperatures are over 18°C. In sites where very low temperatures are common, it could take longer. To produce healthy seedlings in conventional plantbeds, requirements are as follows:

- Loose, deep, fertile and well drained soils, free from pests, diseases and weeds; 
- Availability of a water source near the plantbed for chemical/phytosanitary treatments and irrigation;
- Exposure of the plantbed to the sun in the morning, avoiding wet and shady sites. Areas affected by strong winds should also be avoided in order not to damage the germination and the development of the seedlings; 
- Easy Plantbed access is recommended, and so is level ground to facilitate cultural practices, and total protection against animals is required, so as to prevent any possible damage to the seedlings; 
- Previously planted areas and areas close to solanaceous crops (potatoes, tomatoes, eggplant, red pepper) should be avoided; 
- Preventive chemical treatments are required for weed and disease control.

The production of seedlings in conventional plantbeds requires thinning operations to produce strong, uniform and healthy seedlings. The recommendation is for no more than 300 seedlings per square meter for good development.

The first clipping is recommended when the seedlings are approximately 7 cm high, or with 6 to 7 leaves. In this process, it is important not to cut the apex (main bud) of the seedling. Clipping should be repeated as many times as necessary, so as to allow the smaller seedlings to develop, resulting in a more uniform batch of seedlings. After clipping, there is a need to apply preventive agrochemicals to prevent outbreaks of bacterial and fungal diseases. It is also recommended to disinfect all the clipping tools before and after use, in order to prevent the seedling from being infected by virus diseases.

Clipping can increase the number of usable seedlings by improving the stem diameter uniformity, making the seedlings harder and stronger. If these precautions are not taken, weak seedlings might end up in the field, jeopardizing the crop. Disease control in plantbed is easier and less costly.

Float System

This method consists in producing transplants in styrofoam trays that float on water in waterbeds in a tunnel covered with a plastic tarpaulin. The purpose of the system is to provide a protected environment for better seed germination and seedling development.

The basic material for the production of seedlings by this system consists of a wood or brick structure 10 to 20 cm high, covered with a black plastic tarpaulin to form a water bed, another transparent plastic canvas  supported by arches forming the tunnel, trays that float, growing medium and seed.

The size of the float bed, as well as the number of trays, is defined in accordance with the number of seedlings to be produced in each tunnel. 
The bed should have a minimum volume of water to keep the seedlings hydrated, as well as to avoid excessive concentrations of fertilizers and agrochemicals used to control diseases and pests. To keep the water at the maximum level also has the purpose to prevent the water from freezing in cold regions.

The trays are filled with growing medium and then seeding takes place. Right after seeding, the trays are placed in the float bed.

There are several types of fertilizers and chemical products available for the production of seedlings by this system. The safest manner to start a float system is to follow the technical recommendations given by the leaf company’s field staff.

In the “Float System”, effective control of pests and diseases is essential for the production of healthy seedlings. If care is not taken, weak seedlings will be transplanted, jeopardizing the success of the field.

The system has several advantages over traditional plantbeds.

These advantages include:

• Elimination of thinning operations;
• No need to control weeds;
• More uniform seedlings;
• Transport to field made easier;
• Less need for replantings;
• More uniform fields;
• Bigger yields.