Saving Karura's tree seedlings

Some of the tree seedlings in nurseries at Karura forest that have been drenched in biological plant protection solution that protects them from disease attacks. PHOTO: NANJINIA WAMUSWA.

Karura forest, located on the outskirts of Nairobi, has for a long time suffered fungal attack causing major loss of tree seedlings.

“The intensity of fungal attacks varies from tree species to tree species, with some being more susceptible than others. Fungal attacks result in 50-80 per cent loss of seedlings,” said Fredrick Mutisya - Karura Forest Assistant Forester.

To protect the numerous species of tree seedlings in the nurseries, Mutisya and his team have been using mainly cultural control methods to keep the plants healthy. This has, however, not been working well.

“Root and butt rot caused by a species of fungi has been one of the most serious diseases our fruit and forest trees have faced,” he said.

Thankfully, this is set to be a thing of the past after intervention by crop solutions specialists Koppert Biological Systems Kenya, in partnership with forest officials, have turned to biological plant protection solutions to save the seedlings.

The intervention, which started with a pilot project launched in December 2015, saw more than 450,000 tree seedlings at nurseries drenched with Trianum. This was to insulate them from fungal attacks that wipe out up to 80 per cent of seedlings.

“Continued observation of tree seedlings where Trianum was applied revealed that a number of tree species responded quite well,” says Purity Kabuba, Business Development Manager - Koppert Biological Systems Kenya.

Following this process, by early March, two tree species Markhamia and Nandi flame had showed extreme positive response in terms of more vigorous growth and vegetation.

Researchers have found that the active ingredient in Trianum is very effective in inhibiting the growth of fungal diseases.

It protects the trees by establishing itself on the root zones, forming a physical barrier against attack from pathogens while promoting healthy root development, leading to improved uptake of water and nutrients.

John Orwa, a forester at Karura Forest said this has resulted in stronger and healthier trees that are more resistant to stress caused by diseases, sub-optimal feeding or climatic conditions.

“The impressive results we have recorded in our nurseries with this pilot project has motivated us to explore how we can do this with more seedlings. With this biological control method, we are sure we can increase the seedlings population. It is a key ally in helping us meet our 10 per cent forest cover,” he said.