Introduction of the science of tissue culture has made it easier to grow fast-maturing and healthy bananas locally.
Until a few years ago, farmers relied on banana suckers harvested from growing plants for planting materials. Some farmers still uproot and re-plant the suckers, but this practice has cost many dearly due to diseases such as banana wilt, banana streak and sigatoka.
Such plants are also easy prey for weevils and nematodes with production remaining low if the banana suckers survive to maturity.
Every shoot must be planted in its own sterilised bottle in a special soil containing essential nutrients.they should stay there for about five weeks before they are ready for sale to farmers at Sh100 each.
Enter science, and the birth of tissue-culture seedlings. Done in a laboratory, the technique involves multiplication of high quality banana plants that inherit the genetic properties of the parent plant.
The seedlings grow in sterile conditions in the laboratory for weeks and then hardened in a greenhouse for at least six weeks, before they are ready for planting. There are several tissue culture laboratories in the country and one of them is run by three friends – a professor and two agronomists in Nakuru. Named China Kenya Hort Technology Centre Ltd, the facility which was started seven years ago, produces thousands of tissue culture seedlings every year.
The work involves planting tiny shoots in a mixture of nutrients that include calcium, potassium and phosphorous and hormones for multiplication. This takes about four weeks before shoots are separated and multiplied further in a process that takes another four weeks, explained Duncan Mwangi, the laboratory manager. One original shoot, which is known as meristem, can produce 1,000 plants making the technology highly effective and beneficial.
After the shoots have been produced and multiplied, they are then taken to another room named ‘growers’ where they are supplied with hormones to facilitate growing of roots. They will remain here for another four weeks.
“Every shoot must be planted in its own sterilised bottle in a special soil containing essential nutrients,” said Mwangi, adding that the lab is certified by the Kenya Plant Health Inspectorate Service. From the lab, the shoots are taken for hardening inside a greenhouse. There, they are first planted in trays filled with coconut husks, which are preferred to soil because they can be sterilised easily to remain pathogen-free.
The shoots will grow in the trays for one month before being transplanted in soil-filled polythene pots, still inside a greenhouse.
“They should stay there for about five weeks before they are ready for sale to farmers at Sh100 each,” he said.
A similar lab in Kisii, run by Cyrus Nyakundi, sells up to 600,000 seedlings at peak times during the rainy season and has employed more than 20 people. Operating under the business name Agro Tech Ltd, Nyakundi’s lab, like China Kenya Hort Technology Centre Ltd in Nakuru, breeds various varieties such as Williams, Grand Nain and Ngombe. Inside the tissue culture laboratory are hundreds of glass jars, cleaned and placed upside down to dry. The bottles are well-sanitised to reduce risk of contamination.
One of the major challenges in the banana sector is limited access to quality planting materials and low yields occasioned by prevalence of pests and diseases and poor agronomic practices
Everyone entering the facility must sanitise themselves in a footbath, wash their hands and wear protective clothing first.
“These are mandatory measures that each person must take to avoid contaminating anything within the laboratory, especially the minute tissue culture banana seedlings that are in the process of formation,” Nyakundi explained. The entire process begins with sterilising clones acquired from mother plants. After washing them with soap and later with bleaching agent (jik) and ethanol, they are taken to the septic room.
From this stage onwards, they are handled using sterilised equipment. The clones are split into two, and each one put in a class jar, which contains necessary nutrients and hormones to enhance growth and multiplication. The clones are bisected every four to five weeks to produce multiple plants. Local banana varieties can produce up to 80 seedlings while the hybrid ones can produce up to 1,000.
Later, the seedlings are taken to a greenhouse for primary hardening where they are nurtured for three months. They are later transferred outside to the nurseries for secondary hardening where they stay for two months and are ready for re-planting in orchards. Nyakundi, a graduate of Bachelor of Agricultural Education and Extension from Egerton University, said his journey into tissue culture banana seedlings production started in early 2009, when he was a participant at a horticultural workshop organised by Fresh Produce Exporters Association of Kenya (FPEAK). At that time, he worked for a company in Nairobi which specialised in tissue culture banana seedlings production.
“Some agricultural officers from Kisii asked if the company could supply seedlings in the area,” said Nyakundi, saying he saw it as a business opportunity. He later quit his job and got into business. One of the major challenges in the banana sector is limited access to quality planting materials and low yields occasioned by prevalence of pests and diseases and poor agronomic practices, according to Ann Kitisya, who runs a tissue culture banana laboratory in Kitengela, Kajiado County.
She notes that to grow healthy, productive bananas, the farm should have well-drained soils, plenty of water and organic manure.
She has been in the capital intensive business for over 10 years, producing Grand Nain, William Hybrid, and Chinese Cavendish banana varieties, with each seedling going for an average of Sh150.
Growing tissue culture bananas
- The area should have an altitude of at least 800 metres above sea level and receive minimum rainfall of 1,000mm per annum.
- Irrigation can be used in areas that receive low rainfall.
- Bananas prefer soils that are fertile and well-drained to avoid water logging. Your certified seedlings will require pits measuring 3 feet by 3 feet by 3 feet.
- Dig out the soil and mix the topsoil with well rotten manure, fertiliser and a nematicide.
- Put in the hole the mixture and plant the plantlets 30cm deep within the hole. Firm the soil around the plant and mulch it.
- Harvesting starts at 15-18 months, with the fruits displaying a light-weight shiny look to signal they are ready.