This was presented by one of the group of students to our Asst. professors Mr. and Mrs. Poudel (Pathology) in 2017. By B.Sc.Ag Paklihawa IAAS campus, Full phase 6th batch

1. Black heart of potato

2. INTRODUCTION
 Important physiological disorder, storage, transit and
market disease caused by poor oxygen relation
leading to dark necrotic cavities.
 Also occur when the temperature goes above 320C
during growth and maturation of tuber and also during
transit.

3. SYMPTOMS
 Symptoms first visible at the center of the
tuber.
 Center of the affected tissue is dark grey to
black in an irregular pattern indicating
necrosis.
 Darkened areas are firm but on exposure to
room become soft .
 Advance stage, affected tissue dry out,
shrinks with the formation of cavity in the
center.
 Symptoms on reaching the surface appear as
dark sunken patches.

6. CAUSES
1. Asphyxiation
 Storage at low temperature at and below 00C
high temperature (8-10) 0C.
 Compact soil which restricts air movement.
 Prolonged hot or drought period
 when soils are flooded or stay saturated for longer
period oxygen diffusion into potato tuber is restricted.
Lack of O2 to tuber interior causes interior tissue to die
and ultimately turn brown purple or black.
2. Low calcium mineral content in the soil.

7. MANAGEMENT
 Timely and proper irrigation and flooding.
 Application of calcium rich fertilizer like gypsum and
limestone.
 Maintain moderate temperature during cold storage.
 Maintain adequate ventilation during transport,
storage to avoid asphyxiation.

8. MANAGEMENT
 Avoid harvesting at extremely heat around 30 c and
excessively low temperature around 0 c.
 Do not delay harvest i.e. timely harvest.
 Plant variety resistant to heat stress e.g.. Atlantic
variety is must susceptible while Harley Blackwell is
most resistant.