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For hints and tips on growing a vegetable garden or subsistence farming visit the Starke Ayres Garden Centre website - www.starkeayresgc.co.za
All the latest news on Starke Ayres’ vegetable seed varieties, and the success that commercial vegetable seed farmers have achieved using them.
This page will also be updated with new seed variety releases and other commercial seed industry news.
Long term storage of onion bulbs can be a complex procedure requiring specialized facilities. In most cases, South African producers use elements of both traditional and modern methods. In Northern Europe particularly the practice of pulling onions and letting them dry in windrows is rare. If bulbs get wet and remain so during this stage, dark stains appear on the scale leaves. This is caused by increased microbial activity and leads to quality loss. In regions where this is a problem, most bulbs are harvested directly. With this method, leaves are removed by a flail 8 – 10cm above the bulb and left for a few hours to allow any sap to dry. The bulbs are then lifted, taken to a store and piled not more than 4 m high (figs.1and2). Any more than this can result in damage to the lower layers. Mechanical damage must be minimized by covering sharp parts of machinery and padding any drops. (Fig 3) Surface moisture is removed by blowing warm, dry air through the heap. Once surfaces are dry, air is re-circulated until necks are closed. Outside air is only introduced when relative humidity exceeds 75%. Once the drying is complete, the store temperature is reduced for long term storage. Relative humidity is maintained at 75-80% to prevent cracking of the outer skins. Any condensation of water on the bulbs at this stage causes staining and a reduction of quality.
In most South African cases, bulbs are dried in windrows or heaps in the field, clipped and then taken to stores. Most of these stores have fans that force ambient air through the piles to prevent moisture build-up. Long-term storage is not common practice in the Northern regions as most varieties produced are short day varieties not suited to this purpose. These bulbs are usually cured in the field and marketed soon after this. Short – term holding in bulk bins is common but only for short periods. Longer- term storage is most common in the Western Cape with central areas a mix between the two.