Agronomist notebook: First step in growing quality tomatoes

Susan Maina waters tomato seedlings in Nyeri in this past photo. For good growth, tomato seedlings should be watered twice a day.  PHOTO | FILE | NATION MEDIA GROUP

What you need to know:

  • Before starting, consider water availability, type of soil, topography and the irrigation system.
  • The spacing of the plant is mainly determined by the variety and the irrigation method.
  • Manure improves the soil structure and ensures the germination of healthy and strong seedlings.
  • Always ensure the mulching materials are clean to stop the introduction of pests and disease in the nursery bed.

Tomato is one of the most popular plants on our farms, but it is also very delicate, as a simple misstep can make you harvest huge losses.

So, how do you get things right? Starting today, and over the coming weeks,  I will take you through tomato production, from nursery preparation to harvesting the produce.

To start with, tomatoes grow in vast areas, but mostly in places that receive moderate rainfall and irrigation can be easily done.

They do not do well in highlands due to high rainfall, which results in the spread of fungal diseases, affecting production.

Before starting, consider water availability, type of soil, topography and the irrigation system.

These are some of the things I took Moses, a first-time farmer, through to him grow the crop.

Moses is using a drip irrigation system, which is the best because it minimises instances of leaf wetness. Overhead irrigation results in high spread of fungal diseases.

We went for seeds that are well-adapted to the environment. In our case, we are farming in Kajiado County, so we settled on Rambo F1.

While buying the seeds, we ensured the container had the Kenya Plant Health Inspectorate Service (Kephis) logo, scratched the pack to reveal a code that we sent to 1393 to check if the seeds were certified.

Our target was a quarter-acre at a spacing of 40cm by 60cm to end up with four plants per metre square, so we bought a 10g pack.

The spacing of the plant is mainly determined by the variety and the irrigation method.

Avoid deep sowing

Armed with the seed, we prepared a raised nursery bed inside the propagation unit. Since the soil is black cotton, a raised bed ensures proper drainage.

We cleared the land and double-dug to ensure that all the hard pans were broken down.

We then raised the bed to a height of about 15 – 20 cm and applied well-rotten manure as per the soil analysis recommendations. We added 2kg of manure per metre-square.

We ensured the manure is well-incorporated into the soil to avoid scorching the seeds.

Manure improves the soil structure and ensures the germination of healthy and strong seedlings.

We then leveled the nursery to ensure uniform germination of seeds and made small drills or furrows measuring 15-20cm apart at a depth of 2cm.

Since the seeds are smaller, one must avoid deep sowing to allow easy germination.

The seeds must be sowed singly to curb overcrowding in the nursery bed.

After sowing the seeds, we covered lightly with soil and mulched using dry seedless grass to a thickness of about 3cm.

This prevents soil erosion on the nursery bed, which can wash away seeds.

Always ensure the mulching materials are clean to stop the introduction of pests and disease in the nursery bed.

I advised Moses to water the bed twice per day depending on the weather conditions, using a watering can or a hose pipe with a flower head gently to prevent splash erosion.

In the next article, I will focus on nursery management practices.

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