What leads the Loss of Banana Production?

Similar to other crops, bananas are exposed to many diseases caused by microorganisms, such as fungus, bacteria and viruses, as well as pests caused by nematodes, aphids, spider mites and physiological diseases.

• Poor drainage soils with high salinity and poor unbalanced nutrients that are crucial for plants could lead to weak growth and reduced production. Therefore, the cultivation would become economically useless.
• Water scarcity and irregular irrigation could lead to a delay in the growth and wilting of plants, exposing them to diseases.
• Despite being resistant to normal winds, bananas could suffer from leaf blades, trunk cracking, and consequently huge losses in production when exposed to storms and heavy winds.
• If bananas are not covered in special plastic bags, they could become dry due to direct sunburns. Their color could also turn pale green and they could get cracked, making them lose their market value.
• A fertile soil that comprises all necessary macro and micro nutrients, as well as fermented organic fertilizers is highly important for successful banana cultivation.

The most important fungal disease that banana plants are exposed to is Fusarium Oxysporium (Cubenese), also known as “Panama disease or TR4”.

The Cavandish banana variety, which is the most widespread variety in agriculture, is resistant to fungal wilt disease. However, a new fungal strain appeared in the 1990’s, known as FOC-TRH -TROPICAL RACE 4. It is one of the most dangerous diseases that Banana seedlings are exposed to, and is capable of destroying all banana crops wherever they are located. This strain spread first in East Asian countries and then moved to Africa and some countries of the Middle East, such as Jordan in particular, before reaching Latin American countries.

This fungal disease kills banana crops and leaves a devastating impact. It is transmitted through both soil and water and can remain dormant for over 30 years. Therefore, it is usually impossible for farmers to know if their crops are infected without careful testing (which is not available). When this fungus finds a suitable host, it targets the root system and goes up towards the xylem vessels, which are responsible for transporting water within the plant. It settles in the roots, causing many symptoms, such as yellowing of leaves that extend to the center, leading to wilts, and causing the leaves to die after turning brown. This weakens the affected plant and greatly affects its production.

International research centers and laboratories are working on finding solutions to combat this dangerous epidemic. FAO has also been providing technical assistance to affected countries in order to limit the spread of the disease and contain newly discovered cases in other countries.

In addition to the fungal wilt disease, some fungal diseases spread in banana fields and cause spots on the leaves that range from brown to black. This spotting could destroy the leaves as a result to being infected by Mycosphaerella musicola and Cercospora musae.

How to Treat Fungal Diseases?

• Cultivation of disease-free varieties.
• Dipping the plant in Novotreat followed by irrigation using Novotreat for two months (6 months after cultivation)

Banana bunchy top virus is one of the most important and dangerous viral diseases that affect bananas.

An aphid known as Pentalonia nigronervosa is the transmitter of this virus. Symptoms include green spots that appear on the lower surface of the leaves, which then connect to form dark lines that can be clearly noticed. The affected plant and leaves then shrink in size and resemble the shape of a flower.

Pseudomonas is a bacterial disease that affects bananas. Its symptoms include discoloration of the lower leaves, whereby their color turns to greenish-yellow and then gray, before they become dry. By cutting the affected leg, one can notice that the vessels are black, and the affected plants often fail to produce fruits.

Banana seedlings are exposed to different types of nematodes, including the ones that affect the inside of the plant and grasp its roots, as well as the type that appears on the outside in the form of knots or tubers.

Nemaotdes that usually affect banana roots:

• Meloidogyne
• Pratylenchus
• longidoridae xiphinema
• Radopholus similis

When nematode grasp the plant roots, it hinders the plant’s physiological process entirely, including its absorption of water and nutrients from the soil, leading to a slow growth, and thus a decrease in productivity and a market value.

Moreover, this virus could cause a number of complex diseases and hinder the resistance of some varieties to other parasites, such as Fusarium wilt and other soil diseases.

Nematodes treatment

Today, it is possible to treat nematodes thanks to the effective pesticide called Velum, invented by the German company Bayer to combat this dangerous pest. This pesticide is safe for humans and the environment, and can be used by adding 125 grams per dunum during irrigation and fertilization.

Banana Disease Treatment With Debbane Freres

The Technical and Crop Protection department at Debbane Freres has worked alongside with Banana experts to provide the best solution for Banana farmers in order to reduce the damages of this disease and increase their profits. Below is a table that includes a preventive and curative program to combat fungal diseases and nematodes found in the soil.

by Eng. I. Younes

Previous Articles in The Banana Series

Banana cultivation – Part One