Tips to have a Good Germination

Steps and Tips to have a Good Germination in the Float System:

• Quality Seed;
• growing medium;
• water level in the float bed and fertilization;
• plantbed management;
• quality and sanitation of trays;
   

Seeds:

When opting for seeds, things to consider include their origin and quality, the desired cultivar, reputation and guarantees of the supplier. ProfiGen has certified seed of several hybrids and cultivars with high standards of quality and germination. 

Growing Medium:

There are several brands of growing medium available in the market. Besides their physical characteristics, the growing mediums also vary in their chemical characteristics. Normally, growing medium contains fertilizers in its formulation, and these fertilizers can vary greatly in quantity and type. Check with your supplier for the recommendations for each type and brand and if it is recommended to add fertilizers to the water in the bed at seeding time, or if they should be added after the germination of the seeds.

In cases where the growing medium contains high contents of fertilizers in the original formula, the addition of fertilizers to the waterbed might cause fertilizer salt injuries, impairing seed germination or the development of the seedlings.

Should information or recommendations not be available for a specific brand of medium, it is suggested that no fertilizer should be added to the waterbed before germination is complete. After germination, fertilizers can be added, after taking into consideration the visual aspect and development of the seedlings. 

Water level in the float bed and fertilization:

It is recommended to level the plantbed and keep the level of water in the float bed at its maximum level to avoid salinity and fertilizer salts injuries. With the reduction of the level of water in the bed, the salts from the fertilizers tend to concentrate. With water evaporation fertilizer salts will concentrate on the top of the medium, surface of the bed, causing germination problems and damage to the seedlings.   

In the same float bed, if there are variations in the germination of the different trays, variations caused by bed location, it might indicate a salinity problem. In many cases, better germination at the borders of the bed suggests a salinity problem, lower incidence of sunlight caused by lateral shading, reducing the evaporation, makes that less salts accumulate on the surface, whilst the bigger evaporation increases the accumulation of these salts at  the center of the bed.

When these symptoms show up, fine jet irrigation is recommended to leach these salts away, preventing them from concentrating on the surface and from causing damage to the root system of the seedlings.

There are several types of fertilizer formulas available in the market. Companies have their own formulas and recommendations as to the right moment to apply. Hydrosoluble fertilizer formulas are the ones most recommended for float beds. This is due to the saline content of some field fertilizers, frequently used by the growers. Any excessive application may cause salinity problems. It is recommended to dilute the fertilizer in a can or bucket and then apply uniformly over the water of the entire bed, so as to prevent fertilizer concentrations in specific parts of the bed. Care must be taken, as excessive fertilizer applications might delay the development of the seedlings, instead of triggering their growth, causing damage to the root system, or even killing the seedlings. 

Plantbed management:

The plantbeds should be managed so as to provide appropriate temperature, luminosity and moisture for every phase. Openings on the side of the plantbeds are fundamental for aeration and the removal of excessive moisture levels, thus preventing disease outbreaks. In warmer days, it is also important to prevent the temperature from rising above ideal limits, in order to prevent seedling disturbance. On the other hand, on cold days it is important to keep the beds closed, thus conserving heat and reducing cold stress effects. On cold days, it is also important to protect the seedlings against winds, so as to avoid damages. Such stresses are likely to interfere with the development of the seedlings in the field, causing growth delay or even early flowering. When production occurs outside the normal time, in warm periods, with high temperatures and excessive luminosity, germination difficulties might occur, and some kind of shading is needed. 

Tray quality and sanitation:

It is recommended that used trays are sanitized and cleaned right after the seedling production or before the next use to remove plant materials and possible diseases. Ask your technician or farm agent about the best method to make this cleaning. New trays might have dry cell problems, repealing the water and so making that growing media has water absorption problems. Dry cells may also originate from gaps in the growing medium due to its granular structure, or tray filling problems. Exerting a light pressure on the medium might solve the problem of dry cells, but a light irrigation could be carried out in order to accommodate the medium within the tray, just taking the care to avoid that medium and seeds are not splashed out of the tray.

For further information or doubts, go to your farm technician or to a specialist in tobacco seedling production.