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SEEDLING PRODUCTION

 

The following basic items are necessary for the production of good quality seedlings:

Polystyrene or plastic modular (or cell) trays are recommended because, with care, they have a long life and can be easily cleaned and transported. There are several (5) proprietary types. The trays can be re-used, but each time after use they should be surface sterilised with a solution of chlorine bleach, washed off and stored in clean conditions ready for use. Each tray should have 60-80 cells. Provided that there is a satisfactory germination and subsequent plant stand approximately seventy trays or boxes will provide sufficient seedlings to plant out one acre (0.4 hectare). Alternative containers include seedling boxes or flats, but raising the plants in modules is preferable.

Potting soil

Some farmers may prefer to buy ready mixed potting soil from a supplier. If it is known to be reliable then this is the most straightforward source. It is usually locally available by the "bag" and two bags will be sufficient to fill one seedling box. However, it is best to first confirm the actual volume in the unit of sale. Awide range of top soils may be used, but the following points should be taken into account either when purchasing the soil or when making farmers' own seedling mixture. The optimum soil pH for the satisfactory growth of peppers is between 6.0 and 6.5. If in doubt or mixing at the home farm, have a representative soil sample tested to check the pH. If found to be required, mix in the appropriate amount of liming material. However do not mix liming materials with fresh animal manures, otherwise there is a high possibility of ammonia scorch to the plants' roots.

FIGURE 3.
Single seedling in each module




FIGURE 4.
Sowing in tray



FIGURE 5. Home made soil sterilizer

The soil should have good drainage and be free of soil-borne pests, diseases and weed seeds. Farmers who make their own seedling mixture should partially sterilize the soil first. The widely adopted method uses heat. Soil can either be placed on a corrugated iron sheet over a heated grill or in a container made from a metal drum which has been cut lengthways. The clean half drum is safely and firmly fixed over a long grill or burners (see Figure 5).

The soil to be heat treated should be relatively dry and in a fine tilth. Heat will take longer to penetrate any lumps and may therefore leave pockets of unsterilized soil. If the soil is too wet the initial heat will be wasted in heating the soil moisture. The heat moves on a "heat front" generally from the bottom of the container to the top. The optimum temperature for partial soil sterilization is 82 degrees C (approximately 179.6 degrees F). This is the temperature at which all known harmful organisms are killed; the beneficial soil bacteria, such as those responsible for maintaining soil fertility are able to survive up to this temperature.

Local farmers have been advised to heat the soil for approximately thirty minutes and to check the temperature in the top of the soil at this stage by feeling with the hand. While this can be a useful guide if done with care and experience checking with a soil thermometer at several points would be both safer and more accurate. The heat source is turned off when the required temperature has been reached at the top of the soil. After the soil has cooled down it can be removed for use. The treated soil should be handled with clean implements and not allowed to make contact with unclean areas or containers.

When the partial soil sterilization has been completed and the soil cooled down it can be thoroughly mixed with any further materials required for a satisfactory seedling mixture.

Asatisfactory seedling mixture can be made by mixing appropriate proportions of partially sterilized soil, composts, manures and mulches. However, manures and other organic materials must be well decomposed otherwise the subsequent plants may be affected by toxicities. All the materials must be weed free.

Seed sowing and young plant production

The clean boxes are filled with the prepared soil so that each cell is evenly filled, the soil in the box is then levelled off.

The seeds are sown at a depth of 1/4 inch (7 mm), at a sowing rate of 1 or 2 seeds per cell or station. The seeds are covered lightly with additional prepared soil. The sown trays are transferred to their nursery quarters (if not already there) and then carefully watered and allowed to drain. This application of water is best done with a can or suitable method of water application using a fine rose. Care must be taken to avoid flooding or washing out the sown seed or cells.

FIGURE 6.
Taking care of seedlings in the nursery


The seeds will germinate in about seven to twelve days. Alight application of water may be necessary if the soil in the trays shows signs of drying out before seedling emergence. The emerged seedlings should be carefully thinned (or singled out) to give one seedling per cell or station as soon as they are large enough to handle.

This will avoid undue competition within individual cells and provide a uniform plant stand. Subsequent waterings should continue until the transplanting stage is reached.

As the plants develop, a liquid foliar feed can be applied. The three most important nutrients are nitrogen (N), phosphorus (P) and potassium (K). Although other nutrients may be required from time to time these are the three most routinely applied. The ratio of the three is normally described, or stated on bags or containers as ratios of N:P:K. An optimum commercially available soluble fertilizer suitable for peppers is N:P:K 20:20:20. This can be dissolved in the irrigation water and applied to the foliage, usually once a week from the first true leaf stage until planting out. Some of the liquid fertilizer is taken in through the plants' leaves while some is taken up through the roots via the soil. It is important to follow the manufacturer's instructions in order to avoid foliar scorch or over feeding. There are also proprietary starter solutions available for liquid feeding during the early stages. Additional waterings will usually be required between the liquid feed applications, especially as and when the young plants develop more foliage.

The young plants will need to be 'hardened-off' approximately one week before planting out. The stage for planting out is described in the box. The hardening-off process will allow the plants to acclimatize to the environment in their final growing on site, i.e. to become capable of withstanding field conditions after planting. The young plants are gradually given more light by gradually reducing the shade over a week or so. Less water is also given, although obvious wilting should not be allowed to occur.

SUMMARY OF
PROGRAMME TO PRODUCE SATISFACTORY
PEPPER SEEDLINGS

Start with high quality improved seeds.

Identify a suitable nursery site.

Use new or surface disinfected seed trays.

Prepare a suitable potting soil.

Fill the cells in the trays with good quality potting soil.

Sow one or two seeds per cell at 1/4 inch (7 mm) deep and cover with the potting soil.

After seedling emergence (approximately seven to twelve days from sowing) thin to a single seedling per cell.

Apply a suitable liquid feed at weekly intervals, starting from the first true leaf stage.

Start the gradual hardening off process one week from when it is estimated the planting out stage will be reached.


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