Potato Blight Advice
Potato Blight Advice

FAQ

 

Potato Blight

 

 Unfortunately for the past few years we have been troubled by potato blight.  Here are some suggestions that would perhaps help avoid or keep at bay this unwanted disease.

 

  More advice and pictures of the symptoms can be found here.

 

What is it?  It is an airborne fungal disease. How does it start?  It starts with last years potatoes being left and rotting in the beds overwinter. 

What can I do?  Make sure all potatoes are removed from your bed before winter.  If you see any surviving potatoes from last year appearing remove them as they may well be infected.. Preferably destroy any potatoes left in the bed before spring.

The spores from the disease spread in warm wet conditions and the disease doesn’t normally appear until late June /early July with warm wet conditions.

Planting early potatoes and lifting them early is one way of beating it before it has a chance to start.

 

Signs of Blight; The leaves have dark blotches mainly on the tips and edges.  They become watery. The plant will collapse and die quickly. The leaves shrivel and turn brown.

The tubers have black sunken bits or go mushy and foul with bacterial soft rot. There is a reddish brown  decay below the skin. Sometimes they look okay but they rot in storage.

 

What can be done?  To escape infection we can earth up the potatoes  or put mulch around them.  We should smooth out any cracks in the earth so the spores don’t get in.

Earthing up prevents the spores washing down into the tubers.

 

All infected leaves should be removed immediately. When 25% of the plants leaves are infected the stem should be cut down right to the ground.  The plant should be deposited for  burning. This will stop the disease spreading down the stem into the ground and potatoes.   The potatoes should be left in the bed for three weeks.  This will allow the skins to harden.  If they are left longer they will be on the menu for slugs. Mainly they should be left this long to avoid infecting the tubers with spores when lifting.

 

Potatoes  Buy good quality seed potatoes.  Potatoes will long leggy shoots will not give such a good crop of potatoes.  Scotland traditionally produced seed potatoes because the colder climate didn’t allow viruses to develop.

 

Potatoes to avoid as they are prone to blight are  king Edward and Ulster Chieftan

 

BLIGHT RESISTANT POTATOES

 

Firsr Early   Orla      Rocket  good disease resistant for use in bags

 

Second Early   Melody

 

Maincrop  (these are lifted later and more prone to blight)

 

Recommended   

All the Sarpo potatoes are the most blight resistant   Mira, Gwyn, Shona, Axona, and Una

 

CARA   SETANTA  LADY BALFOUR  SANTE  VALOR  DRUID PENTLAND CROWN    PENTLAND SQUIRE  PENTLAND DELL   KESTRAL ROMANO  BLUE DANUBE KIFI  DRUID

 

Many potatoes are resistant to other diseases.  Online sellers will give full details.

 

 


Potato Blight Advice
©Organic Growers of Fairlie 2012