Understanding the deadly Fusarium Wilt disease on tomatoes

Fusarium wilt is a disease that can wipe out the entire tomato crop if not controlled in time. It has been reported in over 40 countries around the world. It also affects other plants within the solanaceous family, bananas sweet potatoes and tobacco.

In this article we have used the simplest and easiest words to try and educate our dear farmers and other people on the causes, spread and control measures of the disease.

Causes.

Fusarium wilt is caused by a fungus-Fusarium oxysporum sub species Lycopersici for the tomatoes. This is a soil borne pathogen and can survive in soil for a long period of time, Whether cultivated or non-cultivated. The fungus survives in most soil types.

Environment.

The fungus thrives in high temperatures and warm moist soils. The ideal temperature for it to thrive is 25-300c.For root infection is 300c.

Mode of infection.

F. oxysporum infects a healthy plant by means of mycelia or by germinating spores penetrating the plant root tips, root wounds, or lateral roots. Once the mycelium is in the plant, it penetrates and gets into the xylem vessels, clogging it, thus this stops transportation of water and mineral salts to other parts f the plant, this leads to wilting and eventual death of the plant.

Dispersal means.

The pathogen is dispersed by many means from one field to the next. For short distances it can be spread by use of infected farm implements or splash of water. It can also  be carried over from previous infected tomato debris.

Signs and symptoms.

·        Yellowing on the bottom of the leaves.

·        Stunted growth.

·        When you split open the stem, the xylem vessels are dry, soft and brownish in color.

·        In case the crop fruits, It will have inferior fruits, but eventually the plants die.

Preventive measures. 

Farmers ought to be enlighten on how to avoid and prevent fusarium wilt, rather than to wait for it to ravage their crops and then look for control of curative measures.

These are some of the preventive measure of the pathogen,

·        Carry out a soil test before planting, this will enable you to know the pathological status of your soil.(If there is any disease causing agent in the soil.)

·        Clean your implements after using, Implements used on infected soil if not thoroughly cleaned, will spread the disease to other parts of the farm where it is used.

·        When irrigating, check the quality of water and avoid careless splashing. The pathogen is also transmitted through water splash.

·        Carry out crop rotation to avoid continuous diseases spread from a previous plant debris that was affected.

·        Maintain high hygiene levels on your farm to avoid creating environments for the pathogen to thrive.

·        In case a soil test indicates your soil is infected, then treat it with copper fungicides before planting.

Control measures.

In case your crop is infected, carry out the following control measures,

·        Uproot and destroy the affected plants.

·        After harvesting, destroy the debris of the infected crop and burn.

·        Chemical control can be used with copper fungicides such as SULCOP 50DF from Osho Chemicals.