WE are already in the winter farming season. And as expected, a lot of farmers have gone for onion farming. However, it is important at this stage that farmers must worry about growing their fruit.
During cold temperatures, tubers like onions go through a process called vernalisation.
A scientist, Neru Streck writes in the Nature Magazine that vernalisation is a process required for certain plant species, among these onions, to enter the reproductive stage, through exposure to low, non-freezing temperatures.
Ideally, it is known that autumn-sown onions become thick-necked in the following summer. Farmers are expected to have planted their seeds in February. Temperatures around this time are usually around 23°C and this is good for germination.
For those who are well equipped, the seed should be in seed trays and must have been kept in a greenhouse until mid-March and the end of April, respectively. They are all transplanted by May 7.
Of course with research and technological advancements there are varieties that will do well all year round but we are talking about general onion farming.
Around this time, when night temperatures drop, this is when vernalisation takes place.
The reason for writing this article is that in many instances farmers tend to enjoy the onion crops’ vegetative growth and then forget that what they are supposed to take to the market is underground.
Remember we are not farming for the pocket. Good onion leaves do not necessarily mean that you are going to get good onions. It just means that there is sufficient nitrogen for the plant to survive.
For one to get a good fruit, you need good vegetation to support the fruit. It is almost the same as saying a healthy mother will give birth to a healthy baby.
As vernalisation begins, onion bulbs begin to form. This is the most critical stage of the crop and it is advised that farmers must do all they can to induce bulb formation.
One way of doing it is applying top dressing fertiliser. For those who are into organic farming, must re-apply manure four weeks after transplanting.
Those who use chemical fertilisers are encouraged to apply potassium. It enhances fruit growth. But if by any chance, farmers use potassium nitrate, it works wonders.
The advantage of potassium nitrate is that while the potassium content is used for fruit development, nitrogen is for vegetative growth.
In four weeks’ time, it is important that farmers must start talking to the market about the expected bulb size. Not every retailer wants big onions, some like them small for various reasons.
It is against this background that farmers are encouraged to engage the market as soon as possible because after bulb formation, the amount of water put in the crop, determines the size of the onion bulb.
Pests and diseases
As the onions grow, they have two major threats; thrips and fungi. Farmers are encouraged to be on the lookout for such.
The greatest mistake that any farmer can make is to start an onion farming project without a proper storage plan.
Onions are heavy when still fresh. They need proper structures for drying. Trying to do that using dilapidated structures only leads to destruction.
Onions need proper ventilation to dry, otherwise they will easily rot. Gifted farmers have settled for onion dryers after noticing the cumbersome post-harvest process.
Otherwise, despite its huge financial outlay, onion farming is a good venture. It hardly fails.