In my daily field encounters, one of the things I have realised is confusing to both farmers and consumers is the differences between broccoli and cauliflower.
They both belong to brassica family hence show similar growth patterns and appearance. Some of plants which also belong to this family are kales and cabbages.
Broccoli is usually green while cauliflower is white although there is green cauliflower. Both vegetables have light-bunched florets growing from a central point.
Broccoli florets are spread out while the cauliflowers are tightly bunched.
Both crops are rich in vitamin C and fibres. However, broccoli contains vitamins while cauliflower has calories. Currently, however, there is low demand for both crops thus they are grown for the high-end market.
However, due to the health benefits of the crops, most people are eating the vegetables creating a progressive increase in demand.
The two crops are affected by the same pests and diseases and require cool temperatures. When choosing the variety to grow, one should consider the colour, size and heat-tolerance.
In most cases, the compact size does not require much space to grow hence the best choice where the land is scarce. High temperatures may become a hindrance to a proper head formation and result in immature flowering.
To be a successful cauliflower or broccoli farmer, one should ensure that the crop grows in full sun where the temperatures do not exceed 280c to avoid quality loss. In hot areas, one should grow them in partial shade since broccoli turns yellow and flowers rapidly in hot weather conditions.
Cool weather conditions during maturity make broccoli to have a sweet taste. The two crops will grow in a wide range of soils that are fertile, well-drained, and moist and rich in organic matter soils. The pH should be slightly acidic, that is between 6-6.8.
CONSISTENT SUPPLY OF MOISTURE
The seeds are sowed in the nursery for 4-6 weeks after which they are transplanted. This can be done either in the greenhouse or in the open field. The seedlings should be transplanted when they have two to three true leaves.
The spacing depends on the variety, soil fertility and water availability. However, a spacing of 45cm by 60cm would be ideal for large headed variety while 30cm by 60cm for small heads.
Depending on the nutrients available in the soil, DAP can be used during planting and top dressing done in week four using CAN or urea to enhance the vegetative growth. Deficiency in nitrogen results to yellowing of the leaves usually termed as leaf chlorosis, which results in reduced yields.
Consistent supply of moisture is important and can be achieved by regular watering, especially in dry conditions. On the other side, too much watering, especially on the heads, may result to head rot. Mulching helps in keeping the soil moist hence maintaining the soil temperatures.
Field hygiene should be maintained by keeping weeds under control at all times. Pull out and properly dispose infected plants.
Broccoli and cauliflower are likely to be affected by pests such as caterpillar, which can be controlled by use of Bacillus thuringiensis, aphids and leaf miners
Diseases that affect the crops include black rot and downy mildew, and this is prevented by cultural methods such as crop rotation, field hygiene and use of chemicals where necessary.
When the temperatures are too high after head formation, blanching should be done which is a practice of tying the outer leaves together with a rubber band or string to protect it from the direct sunlight. Both crops mature after 2-3 months depending on the variety. The florets should be dark green.
Yellow colour indicates a start of blooming or bloating hence harvesting should be done before yellowing. The broccoli head should be harvested at a slant by cutting the stalk about 2-3cm below the head. This encourages side shoots production for continued growth for some varieties.
Cauliflower should be harvested when the head is mature, firm and compact with a sharp knife and some leaves left around the head to keep it protected.