Tipburn in lettuce
Tipburn in lettuce has been a problem since the first farmer planted lettuce. Any grower will at some stage have the problem occur to some...
Category Archives: Physiological disorders
Physiological disorders are caused by non-pathological factors such as lighting, irrigation, nutrients, climate. These factors affect the functioning of the plant metabolism and expresses itself in either the fruit, leaves, stem or roots. The part affected are usually malformed and easily identified.
Lettuce deficiency and toxicity symptoms of macro and micro elements
It is often quite difficult to identify a deficiency or toxicity symptom in the field because they never really occur as a single element deficiency...
Common physiological disorders in cucumbers
Physiological disorders caused by low temperatures Low temperatures injury only occurs with fruit that are in storage (either in transit or in storage rooms). Small...
Growth cracks in greenhouse vegetable fruit
Growth cracks symptoms There are two types of cracking found on tomato fruit. Concentric cracking are cracks that vary in depth and size found in...
Cat-face tomato fruit – genetic physiological disorder
Cat-face tomato fruit Symptoms Fruits have a long scar at the blossom end that extends inwards and renders the fruit unmarketable and disfigured (abnormal). There are...
Hollow fruit disorder in hydroponic greenhouse systems
Hollow fruit description Hollow fruit, also called puffy fruit or boxy fruit are angular in shape instead of round, however one should be careful since some...
Zippering – Physiological disorder of tomato and pepper fruit
Zippering symptoms Zippering are thin scars running from the top of the shoulder of the fruit down the length to the blossom end. These longitudinal...
Blossom drop – A sure sign of stress in hydroponic greenhouses
Blossom drop Symptoms Blossom drop (flower buds abscise) occurs prior to anthesis under stress conditions. The early indications of blossom drop are the yellowing of the...
Blossom-end-rot – most common physiological disorder in vegetable fruit
Blossom-end-rot (BER) Symptoms This physiological disorder looks like a typical fruit disease. The symptoms generally occur at the blossom-end of the fruit and begins with...
Sunscald or sun burn on vegetable fruit – sun damage that can be prevented
Sunscald or sunburn causes Sunscald may appear on foliage and fruits. The disorder is caused when the temperature of the fruit exceeds 40°C. An imbalance...
Thin spindly sick pale plants – it’s causes and solutions
At some stage a grower will see thin spindly pale plants growing somewhere in the greenhouse. Although not a physiological disorder of fruit, it is...
Small fruit in crops grown in greenhouses is a sign of stress
Getting small fruit (peppers or tomatoes) is better than getting no fruit at all. However it can be frustrating when growing to achieve 140 g...