Pests and diseases(Irish potatoes)

• Pests, diseases and weeds are factors which significantly reduce potato yield.
• It is necessary to fight against pests, diseases and weeds which can reduce the yield up to 100%.

• Diseases are many and vectors differ. We can mention the following pests and diseases.

Ifoto igaragaza indwara y’imvura

• Mildew is caused by a fungus called Phtophtora infestans. It is frequent in rainy seasons.
• The disease attacks leaves, stems and even the tubers.
• Affected plants leaves get brown, and later on, die.

Means of fighting against the disease:

• Plant resistant varieties and non contaminated seeds;
• All potatoes must be removed from the field at the harvest;
• Uproot any potato plant available in the field, since it could constitute a source of the disease,
• Ridge properly the potatoes.

During rainy and wet seasons:

• When the plants are still young, the farmer may applies Ridomili (50 gr for 20 L of water).            

Two weeks later:

• One a week, apply dithane of Mencozeb (50 gr for 20 L of water) on leaves.
• Rotate potatoes with other plants from other plant families.

Potato bacteria wilt

Picture showing potato bacteria wilt

• This disease is transmitted through a bacteria called Pseudomonas solacearum which comes from the soil or poor quality seed;
• The disease attacks leaves and tubers;
• It is characterized by fading of leaves and stems which dry out, the leaves become green and a white liquid comes from the tubers;
•  A cut tuber reveals grey circle inside.

  Means of fighting against the disease:

• Use safe seeds from resistant varieties;
• Rotate potatoes with other plants from other plant families
• Uproot the seedlings attacked by the disease which could be present in the field.

Potato tuberworm moth

• Potato tuberworm moth: This disease is transmitted by one insect of butterflies family called “Phthorimaea operculella”;
• Its larva dig galleries in the veins of leaves that get brown;
• These insects severely damage tubers (potatoes);
• This is remarkable by galleries made by the insects and by blackish excrements of the same insects;
• Insects damages from the fields may continue their harmful action on the production in storage.

Means of fighting against the disease:

• The farmer is recommended to plant clean and disease free potato seeds and use Deltamethrine or Cypemethrine as prevention treatment.