How to prepare and manage seedling nursery

In this blog, we will look at the two main methods of setting up a nursery namely:

Normal ground method
Seedling trays method

In either of the two, there are several measures that should be put into account to ensure you end up with but not limited to:

Good germination
Healthy seedlings free from pests & diseases
Strong seedlings with proper root development
Minimal root disturbance during transplanting to minimize shocks.

Seeds could also be presoaked with water preferably adding HB 101 hormone (Click on the link to view) https://www.agropests.co.ke/products?s=hb%20101 before sowing. Let's have a look at each of the two methods:

Normal ground method:

The following procedure can be followed in this method;

The sowing should be done in a well-controlled and protected nursery, preferably under a shade
The nursery bed should be raised with a width of 1m to give room for normal operations without stepping on the beds. A distance of at least a foot should be left in between beds.
Prepare the soil into a fine tilth. Evergrow https://www.agropests.co.ke/products?s=evergrow is an organic fertilizer which can be incorporated in the top soil to improve the soil structure and also provide nutrients to your seedlings. Aternatively, well-decomposed cow or goat manure can also be used. Note that you should avoid manure with high ammonium levels such as that of chicken waste as this would only lead to poor germination due to scorching. Raw manure should also be avoided.
Make sowing lines of about an inch in depth, 10cm apart. The lines need not reach at the edges of the nursery beds.
Place your seeds in the lines. Avoid congestion of seeds as it will only lead to non-uniformity of your seedlings due to competition and may also favour the development of fungal infections.
Slightly cover your seeds with light soil, then use dry grass or gunny (sisal) bags to cover the nursery bed. Note that covering may attract pests such as termites, crickets and cutworms, which may harm your seed/seedling therefore, precaution must be taken. It's recommended that u follow up with an insecticide drench on and around the seedbed and the covering materials.
Water gently to avoid splashes and displacing the seeds. Watering should preferably be done in the morning and frequently. Avoid doing it in the evening to reduce exposure to moisture for longer night hours which could lead to soil-born diseases such as dumping off.
The nurseries should be uncovered immediately after the majority of the seeds have just emerged after germination to allow the seedlings access to light.
Use an appropriate combination of fungicide+insecticide to protect your seedlings against pests and diseases at an interval of about 7-10days.

Insecticides may include:

Confidor https://www.agropests.co.ke/products?s=confidor

Actara https://www.agropests.co.ke/products?s=actara

Twiga Ace https://www.agropests.co.ke/products?s=twiga%20ace

Fungicides may include:

Ridomil https://www.agropests.co.ke/products?s=ridomil

Milraz https://www.agropests.co.ke/products?s=milraz

Twigalaxyl https://www.agropests.co.ke/products?s=twigalaxyl

Pearl https://www.agropests.co.ke/products?s=pearl

Foliar sprays with high phosphorus may be used to provide nutrients. e.g Mazao Plenty Starter Plus https://www.agropests.co.ke/products?s=mazao%20plenty%20starter%20plus
Water the nursery adequately before transplanting to make it easier to uproot the seedings so as to minimize root disturbance.
Keep weeds at the minimum levels. If kept uncontrolled, weeds will not only bring about unnecessary competition to your seedlings but may also act as a harbour to pests and diseases. Due to the delicate nature of the seedlings, we advice that you weed manually, but carefully not to harm your seedling.

In this method, one can achieve upto about 70-78% success rate of your seedlings

Seedling trays method:

Note: Planting media does not contain nutrients. It is therefore recommended that we use foliar fertilizers with high phosphorus regularly and/or mixing the media with an organic fertilizer such as Evergrow https://www.agropests.co.ke/products?s=evergrow before putting it in trays.

The following procedure can be followed in this method;

Fill the holes of seedling trays with the planting media in loose form while slightly compressing until almost full. You can use cocopeat blocks, an ideal growing medium https://www.agropests.co.ke/products?s=cocopeat%20blocks
Place a single seed per hole at the center of the sowing holes
Fill the holes with the media. Note that the seeds should not be placed too deep for better and faster germination. The recommended depth of the seed is about twice the diameter of the seed in question.
The trays should not be placed on the ground or mulch to prevent the tap root of the seedlings from protruding through the holes at the base of the trays. They can be placed on a raised ‘table’ in a warm environment.
Avoid over or underwatering. Water gently and frequently, preferably in the mornings.
Use an appropriate combination of fungicide+insecticide to protect your seedlings against pests and diseases at an interval of about 7-10 days. Foliar fertilizer sprays could come in between the fungicide+insecticide sprays (refer to ground method above to find out some of the pesticides that can be used)

In this method, one can achieve up to about 85-99% success rate, hence the most preferred method of raising your seedlings. For onions, however, ground nursery would be more ideal. Some of the advantages of the seedling tray method over the conventional ground methods may include:

Reduced incidences of damping-off caused by overcrowding and non-treated soil
Higher germination rate
There is much-improved root development and reduced incidences of transplanting shock.
Crops grown from germination trays mature faster as they quickly establish once transplanted. This is so because there is a significant reduction/no root disturbance during transplanting
Uniform harvesting as compared to those raised directly in the soil
Ease of transportation.