By Dr. CM Ayyub, Dr. Mujahid Ali, Saqib Ayyub

Disorders of Potato

Black Heart:


Promote good soil drainage and avoid excessive irrigation.

Do not delay harvest in hot soils.

Avoid a build up of carbon dioxide in excessively sealed stores and any temperature extreme (above 30 C or near freezing).

Be vigilant for any crop stress that might stimulate excessive respiration.

Hollow heart and internal browning:


Cultivar selection as some are more susceptible than others.

Take care to maintain uniform growth.

Plant tubers uniformly as close as possible and minimize problems that lead to uneven plant stands.

Avoid over irrigation.



The aim during growth is to keep the tubers within the ridge profile to avoid contact with light.

Seed potatoes should be planted at the right depth for the seed size and variety and in a wide enough ridge in order to avoid tubers pushing through the side of the ridge during the bulking phase.

Pit Rot:


Prevention of water logging in the field, rapid drying in store and ensuring adequate ventilation.

Some varieties eg. Desiree and Cara are more prone to the defect.

Internal sprouting:


The best control is achieved by fogging before the crop settles or spraying at store loading.

If possible choose longer dormant cultivars or those that can be stored at cooler temperatures.

Disorders of Tomato

Blossom-end rot:


Blossom-end rot can be minimized by maintaining a uniform supply of moisture through regular watering and soil mulches.

Application of fertilizer according to the results of a soil test.

Avoid root injury by not cultivating within 1 foot of the base of the plant.



The best way to avoid sunscald is to maintain a healthy tomato plant through management of insect and disease pests that defoliate tomatoes.

Growth cracks:


Maintaining even moisture by watering regularly.

Mulching the soil around the tomato plant can help reduce growth cracks.

Varieties differ in susceptibility to cracking.

Variety descriptions may be helpful in choosing a plant less likely to crack.



Large fruited tomatoes are more susceptible to catface than small fruited tomatoes.

In addition some varieties are particularly prone to catface and should be avoided if catface has been a problem in the past.

Disorders of Chilies



There are some pepper varieties that are resistant to sunscald.

Planting these will reduce the chance that the peppers get damaged.

Providing optimum pest control is another way to reduce the problem.

Defoliation amplifies the sun’s effects.

Watch for pests and begin a treatment program right away.

Watermelon and squash blossom-end rot


Minimized by mulching to maintain constant soil moisture, applying calcium fertilizers and avoiding high levels of nitrogen. Drip irrigate crop to control water management.

Watermelon with hollow heart

Avoid watermelon varieties with a tendency

to exhibit hollow heart. Implement best

Practices for irrigation and fertilization programs.

Cucumber Light Belly Color


Can be partially controlled by avoiding luxuriant vine growth. Avoid excessive nitrogen

Rind necrosis in watermelon


Genetic tolerance has been identified in watermelon. Avoid drought stress in melon.

Melon sunscald (Courtesy of Gerald Holmes)


Minimize by maintaining strong vine growth to ensure the fruit is covered.

Honeydew Melon with Measles


Control measles by reducing irrigation frequency and duration as fruit approach maturity in fall-harvested crops. Irrigation reduction at the later stages of fruit development has not shown any adverse effects on fruit size and soluble solid content.

Disorders of Garlic

 Waxy Breakdown

 The early symptoms of waxy breakdown appear as light yellow areas in the flesh of the   clove.


High temperature, Low oxygen level

Symptom only seen after removing skins

 Remedies:-   High oxygen level during storage High ventilation.

Rubberification and premature sprouting

 Are main physiological disorders in garlic .

Proper storage ensures bulbs don’t sprout till after they are replanted into the garden bed.

Bolting in Garlic


High tem prevent the bolting

High moisture supply

Long Photoperiod.

Disorders of onion



Serious disorder of onion

Use of over fertilizer should be avoided

Growing non-bolting varieties like early grano

Transplant healthy seedlings for 6 to 7 weeks old.

Supply the recommended dose of nitrogen

Cut the stalk at early stage.



Seedlings should be planted little bit deeper into soil to avoid exposure of bulbs to direct sun during development phase

After harvest the bulb should never be left in the field.

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I am working as Assistant Horticulturist (BS-18) at Water Management Research Farm Renala Khurd, before this served as Assistant Professor (IPFP) in Horticulture at the University of Sargodha. I have completed my Ph.D. in 2018 from the Institute of Horticultural Sciences, UAF previously worked as Visiting Lecturer in Horticulture UOS, worked as Research Fellow in ACIAR project on vegetables, and worked as Teaching Assistant in Horticulture UAF. Moreover, Ph.D. IRSIP did in the NC State University, United States.

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