Study: Poor planting materials hurting potato production in Kenya
A farmer planting potatoes on his farm in Njoro sub-county, Nakuru County on March 25, 2022.
Poor planting material is to blame for the dwindling potato production in Kenya, a new study has revealed.
The research was done by the Centre for Agriculture and Bioscience International (CABI).
The report compiled by CABI’s regional centre for Africa based in Nairobi also attributed the low potato yields, which is averaging at 8.6 tonnes, to bad management practices used by farmers in the country.
Potato is one of the most widely grown crops in Kenya with the sector contributing nearly Sh3 billion a year and employing over three million people.
However, the report reveals that over the years, the yields have been declining. In the last 10 years, the yield has hit a low of 12.4 tonnes per hectare, which is far below the global average of 21 tonnes per hectare.
Pests and diseases
“This has been attributed to several problems with the most important being the high incidence of pests and diseases, some of which are seed- and soil-borne,” states the report.
CABI conducted a surveillance exercise to identify and map the distribution of pests such as Pectobacterium and Dickeya species which cause blackleg and soft rots in Kenya.
The research also extended to other pests like Clavibacter michiganensis subsp. sepedonicus which causes ring rot in the country.
The two diseases decimate yield and also affect the quality making it unfit for market.
Potato is grown by about 800,000 farmers spread across several counties which including, Bomet, Bungoma, Elgeyo Marakwet, Kericho, Kiambu, Kirinyaga, Meru, Muranga, Nakuru, Narok, Nyandarua, Nyeri, Trans Nzoia, Uasin Gishu and West Pokot.
The surveillance exercise was conducted during the short rains season of 2019. It preceded a report which had just been written as part of the project ‘Surveillance of potato diseases in Kenya’ funded by the Wageningen Centre for Development Innovation in the Netherlands.
The study involved the collection of over 1,000 samples from farms across the six counties in Kenya.
Despite occupying the biggest acreage, potatoes came third after maize and cabbage. A similar trend was observed across the target counties.
The surveillance team from CABI worked closely with the Kenya Agricultural and Livestock Research Organization (KALRO).
The scientists believe that the spread of the diseases detected was a result of seed- and soil-borne transfer which underscores the role of using potato planting materials from the informal sector in spreading blackleg and soft rots and probably other pests.
Dr Joseph Mulema, Senior Scientist, Research, has been managing the surveillance of potato diseases in the Kenya project.
“Although low yields have been observed in Kenya, these low yields cannot only be attributed to management practices used by potato farmers. Some of these practices were aimed at managing some pests which did not include C. sepedonicus and the genera Dickeya and Pectobacterium. This demonstrated a poor understanding of these problems, especially blackleg and soft rots,” said Dr Mulema.
“The low yields could partly be attributed to the poor quality of potato planting materials where there is over-dependence on the informal sector. This has resulted in planting materials infested with pests resulting in soil contaminated with soil-borne pests,” he added.
Dr Mulema and the project team suggest that pest free areas can be delineated – especially for the production of potato seed.
“There is a need to address the issue of over-dependence on seed from the informal sector probably through supporting interventions that increase the availability of certified seed or clean seed where farmers use home-saved seed,” said the report.
Positive seed selection
Some of these interventions include positive seed selection and seed plot technique both of which improve the quality of farmer-saved seed.
“It is important that fit-for-purpose information and communication materials are developed and used in raising awareness amongst various stakeholders especially farmers, extension and agro-input suppliers. Evaluation of potato varieties against SRP-associated diseases will also improve extension advisory,” Dr Mulema added.
The researchers concluded that Pest-initiated risk analysis (PRA) needs to be conducted for pests like P. atrosepticum, D. solani, and D. dianticola to assist in deciding the most appropriate actions that will reduce the risk of damage these pests may have on plants and plant products.
