The use of cover crops in well-planned crop rotations can help to interrupt the life cycle of many fungal, bacterial, insect or nematode pests.
White Mustard (Sinapis alba)
- White mustard is an annual plant, with an erect stem and numerous branches springing from the main stem. Leaves are alternately arranged, petiolate and serrated, with short, white bristles along the veins. Flowers are pale yellow, forming a shape of a cross. Flowering occurs from June to August.
- Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well- drained soil. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in semi- shade (light woodland) or no shade. It prefers moist soil.
- Farmers are using it as a green manure crop that has been shown to increase aeration, water infiltration rates, and organic matter in a potato-wheat cropping system. It is very fast growing, producing a good bulk in just a few weeks from seed, but it is shallow rooted so does not do so well in dry periods.
- With Brassicaceae like Sinapis alba (white mustard) it’s also possible to reduce and control soil-born diseases and act as a bio fumigant. Plants must be cut at early flower and cultivated back into the soils. Degradation of the plants will start the fumigation process.
- Can also be used as a cover crop in vineyards and orchards
- Sowing time: Autumn (under irrigation or in a winter rainfall area)
- Sowing rate: 4-7kg/ha.
Bladrammenas (Raphanus sativus subsp. oleiferus)
Bladrammenas is an annual plant that has the same growth habit as rammenas, except being more vegetative and with bigger pods. It is widely adapted to most soils and is quick to establish. This aids the plant to reach maturity in a short period of time and to bulk up on material for effective weed suppression. It is more tolerant to frost than white mustard. This tolerance provides a longer growing season and therefore it can be sown later in the season and still produce enough material for effective bio fumigation. In the case of heavy frost the plants will die from where it must be tilled into the soil. The plant is characterised by a taproot system and hairy leaves and stems. Bladrammenas is mainly utilised for its organic matter, the nitrogen it puts back into the soil when decomposed, and for bio fumigation. Should be planted during autumn months at a sowing rate of 6- 10kg per ha.