Secrets to cabbage production (Part 2)
CABBAGE is one of those healthy vegetables! Nutritionally, cabbage is an important source of Calcium with moderate amounts of Potassium and Sodium. Cabbages are a good source of vitamin A and C and therefore protect the body against cancer attacks. It is also a very good source of roughage which prevents hypertension and constipation.
Planting of cabbage can be done on beds during the rainy season which helps to aid drainage and on the flat during the winter period since water is controlled. If beds are made, they should be 1,5 metres-centre to centre. We recommend 2 rows on the top of the bed between 50 to 60cm apart and planting stations 45 to 50cm in row. Planting on the flat rows can be 50 to 60cm apart and planting stations 45 to 60cm in row.
Plant populations should be between 27,000 – 35,000 depending on market requirements and variety. Higher plant populations generally tend to give smaller sized heads.
Fertilization
Cupping with fertilizer cups by hand into the planting hole can be done but the fertilizer must be well mixed and incorporated in the hole to prevent root burn. We recommend farmers to do a full soil analysis to determine the nutrient status of the soil and to determine the fertilizer types and rates to be applied.
Based on soil analysis results and soil types, rates of basal fertilizer that can be applied ranges from 800kg – 1,000kg compound C per hectare. These are general recommendations. There are also other basal options, which can be used. Cabbages will require around 400kg per hectare of AN split into 3 applications between week 2 and week 8 after transplanting, but still the quantities can vary with several soil status factors.
Seedlings and crop establishment Planting with seedlings is the most practical method as seedlings which are strong and healthy at transplanting forms a good basis for a uniform crop, helping to aid efficiency at harvesting. We generally recommend farmers to plant around 10% more plugs per hectare of a selected plant population density to ensure an optimum population density after factoring in field conditions.
When using seedlings at transplanting, a farmer should make sure to attain a good ‘plug to soil contact’. This will aid the quick mobility of the root system from the plug set to the surrounding fertilizer enriched soil to a quick ‘new’ root setting and root development. We recommend the farmers to plant the seedlings as quickly as possible after pulling them from the trays to avoid drying out of the tiny hair roots.
Plant into pre-irrigated soils in which the soil has been irrigated to field capacity.
After transplanting a light settling in irrigation is required to remove air pockets between the plug and the soil and ensure a firm contact to enhance the plug-soil contact. It is recommended that seedlings are dipped in a solution of Actara before planting to give the crop a 6 week protection against economically important pests such Aphids and Whitefly.
Irrigation
During the dry winter months irrigation is essential and key for a good cabbage crop. Overhead (sprinkler or centre pivot irrigation) is the most commonly used option. Other options include flooding as well as “drip” irrigation-a recent ‘clean’ technology. During summer production, the farmer’s ability to supplement irrigation during long dry spells will ensure a good, even and viable productive crop.
Approximately 600mm – 750mm of irrigation is generally required to achieve a good cabbage crop. Irrigation is key, hence it is imperative for the farmer to schedule irrigation, so that water is applied as and when it is needed by the crop from establishment up to maturity. Always avoid over and under-applying water as both scenarios have detrimental effects to yield and returns.
Crop protection
Watch out for and address these potential problems:
◆ Pest problems-Cutworms, Diamond Back Moth (DBM), Caterpillars and Aphids are of economic importance.
◆ Disease problems-Damping off, Black Leg, Bacterial Black, Rot Downy Mildew, Club Root, Black Rot and Alternaria. Choosing resistant varieties is the smartest and first port of disease control.
◆ Weed problems-grasses (annual and perennial) and broad leaved weeds. There are several herbicide options available for use in cabbage production.
Contact the Seed Co Agronomist or your nearest Agritex Extension worker for chemical spraying guides.
Harvesting
Cabbages are ready for harvest when the head is firm to the touch-when pressed and when the veins on the outside leaves just begin to crack. Ideally about 60% - 70% of the heads should be cut at first harvest, ensuring maximum yield potential. Depending on variety and time of the year, a cabbage crop takes about 65 – 115 days to harvesting after transplanting.
Parting shots
A farmer must be a Crop Doctor, who takes time to investigate his/her fields in order to prevent problems and improve productivity. He/She walks his/her fields regularly, observing, inspecting, evaluating and interpreting the possible effect of the observations on crop growth. He/She diagnoses problems, seeks and proffers solutions. Quote of the week by John Basera “Once you have missed the first buttonhole, you’ll never manage to button up. Once you fail on the fundamentals of crop establishment; right seed variety, optimum soil condition (pH), basal fertilizer dressing, optimum crop stand and a good crop head start, then nothing else will come right for the crop and this can result in a heavy yield penalty and affect the enterprise bottom line”. About the authors
◆ John Basera is Seed Co Agronomy and Extension Services Manager. He can be contacted on +263 772 413 184/ john.basera@seedcogroup.com ◆ Silas Mutota is Seed Co Regional Sales Manager. He can be contacted on +263 773 473 948/silas. mutota@seedcogroup,com