Are you a potatoes farmer, or an aspiring farmer? Here is how to control Late Blight


Potatoe blights can spread best in wet condition. 

What is a potato blight?

This fungal disease led to the Irish potato famine, late blight, is a widespread disease of the Solanaceae family. It is often called potato or tomato blight because it particularly affects these crops, it can destroy your entire farm of potatoes or tomoes in less than 7 days.

Blight is a fungal disease caused by spores of Phytophthora infestants which are spread on the wind and which can also contaminate potato tubers in the soil.

When does blight strike?

Warm ,humid weather, especially during the long rain season around December in areas around Mount Kenya regions. Or any other parts suitable for potato farming experiencing high rainfalls.

How can you spot a potato blight?

When you see brown blotches around leaf tips and edges, spreading towards the middle, shrivelling and rotting the leaf, further brown lesions spread to stems. The leaves and stems rapidly become sort of black and the plant collapses.

How is Late blight spread.

Spores are released on the wind and quickly spread to infect neighboring plants. They can also washed by water into the soil where they can infect potato tubers.

Heavy rain washes the fungal spores of late blight into the soil. The disease also persist in infected potato tubers in the ground or on the compost heap. Sometimes these tubers grow the following season to produce infected plants which release fungal spores onto the wind to infect new crops.

How can you prevent the spread of Late blight?

The best way to prevent or reduce the possibility of late blight is simply to choose blight resistant potato varieties. Details on blight resistant potatoes will be here.

Read: Nigeria’s Agriculture potential besides oil reliance. 

How can you effectively control Late Blight?

There is little you can do to save an infected crop, so the best thing you can do is to prevent and take precautions to reduce the chances of disease becoming on loose. Here are the tips:

  1. Plant healthy, disease free seed potatoes from certified suppliers. Early crops, harvested before the worst of the blight season, have less chance of being infected.
  2. Always choose an open planting site with good airflow and leave a sufficient space between crops. Better airflow allows crops to dry quickly after the rain.
  3. During dry weather, water plants in the morning so that any moisture can dry during the day. If possible, water at the base of the plant.
  4.  Crop rotation helps prevent a build up of disease spores in the ground, and avoids infected plants growing from potato tubers that were missed during last year’s harvest.
  5. Spray potato crops with a protective fungicide before signs of blight appear.

If you spot Late Blight into your potatoes, what can you do to prevent further spread? Sometimes even if you work your best, you can still spot some blights in extreme wet weather, this is what you can do;

  1. Walk to the nearest Agro-Chemicals dealers and ask for triazole fungicides which are very effective in getting rid of Late Blight, examples in East Africa you can get Score and many more.
  2. Reduce the the intervals of spraying for example, let’s say from seven days to five or even four days.
  3. Remove and destroy all affected plants. If your potatoes have already developed tubers, you might be able to save them by cutting away the foliage and stems. Leave the soil undisturbed for 2–3 weeks to kill off any lingering spores so that they don’t infect the crop when it is lifted.

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