By Olivia Chipeta Nkolokosa
Vegetables come in different forms in terms of their forms (morphology), biological (botany), seasons amongst others. We should be able to know that any part of a plant that is fresh, herbaceous, edible, has high moisture content is classified as a vegetable. Vegetables can be described based on the part that is edible.
For example in peas we eat seeds, Tomato we consume fruits while in carrots we consume a root. So based on the part that is eaten, we have fruit vegetables like tomatoes, root vegetables like carrots, seed vegetables like garden pea, leafy vegetables like cabbage, lettuce. As a result of this, it is important to know how to treat and manage each crop based on its edible part. Vegetable crops that are consumed directly are different with those that have covers like peas. Therefore, one should put into mind these factors.
Another way of describing vegetables is upon their common characteristics they share based on their biological factors. As a result, we have families of vegetables just as we have families of people in real life. Just as I may not resemble with my siblings’ 100% percent, there are some features that are common amongst us all such that whenever a stranger becomes aware of one of us, they easily relate that we belong to the same family. As a result, vegetables also share similar characteristics.
For example, Irish Potato, Tomato, Pepper belongs to the same family which is called Solanaceae (Night shade) whilst Rape, Mustard, Chinese Cabbage, Cabbage, Kale belongs to the Brassicae family. There are s many groups of the vegetable families. Why am I mentioning this? Knowing the family of the vegetable crop assists in crop rotation, you do not need repeat the same family crop on the same plot just after harvesting as these harbor same pests and diseases.
The use of the soil nutrients is also the same as a result continuous use of the same crops on the same piece of land leads to increase incidences of pests and diseases and same nutrients removal. However, interchanging the plants from one season to another helps in minimising these and balance nutrients use. There is therefore a need of putting deliberate efforts in minimising these risks as they affect yield quality and quantity.
One of the most important factors in vegetable production is consideration of climate/weather. Vegetables are either warm season or cool season with some vegetables being in the mild conditions adapting mild temperatures. Most fruit vegetables are warm season crops whilst most leafy vegetables belong to the cool season. There are other varieties that can produce economic yield under mild conditions.
Therefore, growers should be able to differentiate the seasons of their vegetable crops. This is important because seasons are directly related to length of days. Each crop requires certain amount of heat (heat units) per day so as it should be able to produce effectively. This is why some crops slow down when grown in a wrong season and don’t produce to the expected yield. Growers should be able to put this into consideration as it affects costs of production but increases chances of high profits. Let’s stop here for this week.
Olivia Chipeta Nkolokosa holds a BSc in Horticulture from Malawi, MSc Plant Breeding from South Africa. She writes in her personal capacity as an Agronomist.