Proper farming practices will check low yields

Banana is a perennial crop that grows well in areas with high rainfall or areas which receive moderate rainfall all year round, have fertile deep and well-aerated soils with temperatures ranging between 20-30 degrees Centigrade.

Uganda which produces nine million tonnes of banana annually has for long been the world’s second largest producer of banana. The crop is a staple food and cash crop for many communities especially in the central and western parts of the country.

According to Dr Andrew Kiggundu, a banana researcher at the National Agricultural Research Institute, Kawanda, in the past, banana was a highly sustainable crop with a long plantation life and stable yields but due to a complex web of issues, the crop is threatened and the yields are on the decline.

Dr Kiggundu says the increasing incidence of banana pests and diseases is responsible for a significant reduction in banana yields.

Management of banana pests
Pests like the banana weevils infest the base of the banana plant where they bore into the pseudostem and the suckers and into roots.

Infested plants have dull yellow green and soft foliage, the suckers often wither and fail to develop. The plants are easily brought down by mild or strong winds and the fruit is small.

Mr Timothy Njakasi, a r=etired agricultural extension worker and an organic farming trainer in Mukono district, says since banana weevils thrive in cool conditions, a farmer is advised not to create the condusive breeding and living conditions. The farmer can achieve this by putting any of form of manure at the base of the banana plant.

After cultivation, the pseudostem should be completely cut down and the sheath leaves disengaged before they are arranged in the banana plantation for easy drying.

Also, a farmer can apply pesticides like Furan and Dursban dust which he or she can scatter at the base of the banana plant. For good results, it is suitable to apply them during the rainy season.

Another banana pest is the nematode, which attacks roots and causes root rot. Mr Njakasi says root rot caused by nematode results into lower bunch weight.

He says that replenishing soil fertility through mulching with organic waste could suppress nematode damage by stimulating and improving root growth.

Alternatively, before planting the banana suckers, they should be treated in water for between 24 and 48 hours. This will suffocate the nematodes and weevils and ensure that a farmer plants disease- and pest-free suckers.
Pesticides like Furan, Furadan or Dursban dust can also be spread at the base of the plant.

Management of banana diseases
The Banana Wilt Disease is a devastating bacterial disease that leads to yellowing of the leaves of the infected plant. Even though the leaves may remain upright for a week or so, some of the leaves may then collapse at the leaf stalk and hang down at pseudostem.

A lengthwise cut on the pseudostem will show numerous brown and black lines running in all directions, and it emits a strong smell.

Banana Wilt Disease can be controlled by immediately cutting down the affected plant and burying them in a hole.

Black Sigatoka, also known as black leaf streak, is a fungal banana disease that starts as small yellow dots on the underside of the banana leaf which eventually become black and leads to drying of the leaf. The disease the spreads quickly to other leaves.

Mr Njakasi says that to reduce the effect of Black Sigatoka, all affected leaves must be removed from the plant to reduce fungal spread and impact. Then the cut leaves should be placed upside down to further reduce spread of fungi spores by wind.

Decline of soil fertility
But apart from pests and diseases, Dr Kiggundu explained that banana yields are declining due to reduced soil fertility, since banana are heavy feeders and require fertile soils in order to flourish.

He says that many farmers have grown bananas on the same piece of land for a long time without replenishing the soil fertility of their lands, thus leading to poor yields. Many farmers don’t mulch their soil, apply organic manure or control soil erosion, which would have helped the soil to maintain its fertility.

This has disappointed farmers who have resorted to growing other crops like sweet potatoes and cassava, which are not labour- intensive and costly to grow.

Dr Kiggundu advises that farmers should mulch their banana plantations with plant materials or banana leaves which are placed between the rows. Mulching conserves moisture in the soil, prevents soil erosion, controls weeds and most importantly adds manure to the soil when the mulching material decomposes.

Mr Njakasi says mulching material should be six inches thick, and a space of two feet from the banana plant should be left because if the mulch is placed on the base of the plant, this would create a conducive environment for pests and diseases.
He strongly advises against the practice of weeding in a banana plantation because by doing so, roots of the plant are cut since bananas are shallow rooters.

To increase the size of the banana bunch, Mr Njakasi says only three banana plants should be maintained per hole. Maintaining three plants lessens competition for soil nutrients.

He also says that while digging in a banana plantation, a farmer should avoid heaping soil at the base of the banana plant as this encourages upward growth of roots. When the roots are exposed, the plant will easily be felled down by wind.
Dr Kiggundu reveals that to increase banana yields, researchers have come up with improved banana varieties which are resistant or non-susceptible to pests and diseases and drought.

Resistant breeds
An improved banana variety like Kiwanguzi which is resistant to Black Sigatoka has been bred.

Also, the kabana banana variety (Fhia), which is high yielding, resistant to pests and diseases and drought, has been developed and is now being grown in semi-arid areas like parts of northern Uganda.

A prominent banana farmer in Lubongo village, Ngogwe sub-county, Buikwe district, Ms Nalongo Kyeswa says she had five acres of banana in 1980s but says almost her banana plantation has been wiped away by the Banana Wilt Disease, Black Sigatoka and other leaf diseases.

She, however, says that because banana is her staple food and cash crop, she is trying to revive her banana plantation by employing appropriate practices like mulching, adding organic fertiliser and pruning the plants regularly.
Mr James Rwebikire, an agricultural extension worker in Kayunga district, however says that a farmer who wants to grow bananas should also look after animals or birds so that the cow dung or chicken droppings are used as fertilisers in the banana plantation.

He says with the declining soil fertility, there is need to replenish the land with fertilisers for better yields.