If you rarely get rain, this fruit won't disappoint

Temperature in one of the numerous greenhouses at Jomo Kenyatta Univeristy of Agriculture and Technology is attuned to that of perched areas that barely support farming.

And because of the immense heat, clear beads of sweat start forming on our faces immediately we step into the greenhouse where hundreds of banana plants are neatly arranged in sisal planting bags.

There are other peculiar seedlings too, their single leaf shooting out of rich mixtures of soil, sand and manure, cocopeat and other tinned nutritious growth media.

The seedlings are odd to anyone who has never seen the initial stages of doum palm, a plant of the coconut family found exclusively in dry areas.

Dr Cecilia Mweu, the lead researcher in a project dubbed ‘Doum Palm Production and Utilisation in Kenya’ at JKUAT explains that conditions in the greenhouses, set for mass production of seedlings, are attuned to those of harsh environmental conditions which don’t support farming, save for the doum palm and such other hardy plants.

These, according to the researchers are dry areas including Tharaka Nithi, Tana River, Kwale, West Pokot, and Turkana.

“The heat is set to mimic that of places where doum palm is grown. The immense heat hardens the seedlings from our labs so that they do not succumb to the drastic change in conditions when they are eventually taken to the farmers,” says Dr Mweu.

Sprouts and seedlings developed in the high end research labs at the university are brought in the greenhouse for hardening after culturing them in the lab.

It is a project funded by the National Research Fund (NRF) in which the university researchers come up with methods of mass production of quality plantlets as well as shorten germination time of the doum palm.

Normally, one doum palm nut is equivalent to one plantlet. But with tissue culture, up to 20 plantlets can be obtained from one nut. In the case of a banana, one cultured piece is equivalent to up to 200 plantlets.

But the project isn’t just about mass production of plantlets; the whole process is the secret behind shortening the germination period of the doum palm nut.

Normally, the nut takes up to three years from the time it falls on the ground to germinate.

Dr Mweu attributes the long duration to the harsh conditions where the plant grows.

“Places where the plant grows are either very hot or very salty. Tana River for instance is very salty and when the seed falls on the ground, its root goes deep looking for favourable conditions before it sprouts. This takes years,” explains Dr Mweu.

With tissue culture, however, germination takes place in just three weeks.

She says the doum palm grows in highly marginalised areas that survive below a dollar, sometimes relying solely on the plant’s fruits during drought seasons. Its leaves are also fodder for livestock in these communities, she says.

For their richness in nutritive vitamins A, B and C, as well zinc, calcium, iron, protein, fibre and glucose, the fruits help in digestion and are good for diabetics and people with kidney related complications.

Communities with doum palm also rely on the plant’s ‘makuti’ for roofing.

Its seeds and husks are used for making doum peat which is rich in nitrogen, phosphorus and potassium, while its sap is used industrially to make wine and juices.

Dr Mweu’s concern is that the doum plant, which is still regarded as a wild plant in most places where it grows, may become extinct in coming years.

“I have visited many places and discovered that there are only two age groups of the doum palm. There are very old trees that may die soon and stunted shrubs that are continually fed on by goats. In most places, the middle age of the doum palm is missing,” the lead researcher says of the plant which has up to a 100-year lifespan.

“And since it traditionally takes long to get off the ground, there is need that we come up with ways that will shorten this germination period. We also need to produce doum palm plantlets in huge masses and sensitise communities to domesticate it,” says Dr Mweu.

The Science

At the project disposal, the university has a fully equipped molecular lab where plant samples from different places are tested for their genes. Genes responsible for, say, resistance to harsh climatic conditions are tested and established.

Alternatively, stress-induced plants are grown in a greenhouse and their progress measured against a control experiment that is usually subjected to all possible conditions necessary for normal growth.

If genes present in, say, samples of doum palm coming from Tharaka Nithi are absent in samples from other places, the plantlets developed during the project are taken only to Tharaka Nithi because that is the only place they can grow.

“But if the genes in samples drawn from different places are similar, the plantlets developed can be taken to all those places. It could be that they have evolved and can survive in any environment,” says Dr Mweu.

Adjacent to the molecular lab is a tissue culture facility that is partitioned into a preparation room, a culture room and a growth room. It is the facility responsible for mass production of plantlets.

Sterilisation and preparation of materials used in the culture room and the growth room happens in the preparation room. The aim is to rid all the specimen of dangerous bacteria and fungi. Culturing involves breaking of the roots and shoots into smaller pieces that are re-planted.