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...
Greenhouse white fly
Description Greenhouse white fly, also known as Trialeurodes vaporariorum is a sap feeder. The easiest way to find white flies is to brush or shake...
Pythium and Phytophthora root rot in closed hydroponic systems
Diseases of crops grown and closed hydroponic systems can be a problem and occasionally catastrophic. However, the presence of a pathogen does not necessarily mean...
Understanding tomato taste and flavour
Tomatoes (Solanum lycopersicum) is the world’s most valuable fruit and essential greenhouse crop. They deliver vital nutrients to our diets and serve as a pivotal...
The relationship between temperature and growth in greenhouses.
Factors determining plant temperature in a greenhouse. Radiation or heat energy can be reflected, transmitted, absorbed, conducted, re-radiated or used to evaporate water. Evaporation requires...
Spread of viruses in greenhouses
There are various ways viruses can spread throughout the greenhouse. Transmission or method of spreading depends on the virus genes. A virus cannot move from...
The relationship between acid and sugar content in the taste of fruit.
The intricate relationship between the fruit’s acidity and sugar content affects how it tastes. A modest role is also played by other substances such as...
Source of viruses in a greenhouse
Everyone has become more knowledgeable about the spread of viruses and the diseases they cause. Just like the COVID virus, we have to understand the...
Nutrient content of water soluble hydroponic fertilizers
The nutrient content of water soluble hydroponic fertilizers is not always clearly indicated on packaging. It is fine that fertilizer companies take control out of...
The basic principles of a good spray program
Well planned spray programs are more effective than unplanned, random chemical applications. Have you ever considered spraying when there is no pests or diseases? Poorly...
Angular leaf spot
The disease is found in conditions if high humidity, especially in poor ventilated greenhouses or where the ventilation is not controlled properly. Optimum temperature for...
The effect of low intensity radiation on flowering
Changing the length of the dark and light periods is another way of growth control. It is an important aspect of greenhouse culture, especially flowers....
The effect of high intensity radiation on plant growth in greenhouses.
High intensity radiation is more common in equatorial regions than cold weather climates. This is because of the angle the sun rays hit the soil...
The effect of radiation on growth and yield
Understanding the effect of radiation on plants will help identify weaknesses in your greenhouse. The effect of radiation can be divided into three parts; its...
Basic pest and disease resistance management strategies in greenhouses
Resistance to chemicals is due to the intense selection pressure exerted on the population that is controlled. There is only a limited number of chemicals...
Understanding the greenhouse environment
The protected greenhouse environment The greenhouse environment is designed to allow plants to perform close to their genetic optimum so that the grower achieves maximum...
