| Information sheets | | | Elsenburg infopaks | | | Crops, vegetables: 10 |
Production of dry bean seed in the Little Karoo
Afrikaans | Xhosa
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Because of its short growing cycle of four months and the possibilities of a good profit the production of
dry bean seed and more specifically red mottled sugar-bean seed has a lot of potential, provided quality seed is produced. To produce a good quality, disease-free seed with a germination of at least 85% and a high yield, the following guidelines and management should apply.
Soil requirements Beans perform best in deep, well-drained soil that will stimulate germination and the emergence of seedlings. Sandy loam, sandy clay loam and clay loam soils are suitable. Sandy soils could cause problems, like low fertility or eelworm damage. The plants are also intolerant of brackish soil. In general dry beans are planted in soils that had been well-fertilised beforehand. The application of especially nitrogen during the planting season is recommended. Take care not to apply too much nitrogen, especially in the case of topdressing or foliar nutrition. An application of 30 to 45 kg nitrogen per hectare is recommended. Phosphate is normally not a yield-limiting factor. The application could vary from 10 to 25 kg per hectare. Potassium hunger will most likely occur in sandy soils. An application of 20 to 30 kg potassium per hectare is recommended. Trace elements can usually be supplemented with foliar nutrition should symptoms of deficiency be noticed. |
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Methods of cultivation
The production cycle of red mottled sugar-beans is about 100 to 115 days and planting to flowering takes 45 to 55 days. Planting could take place from the end of September until the end of January. The best planting season is the end of September when the danger of frost has passed. Fewer problems with diseases are also usually experienced with early plantings. A plant population of about 140,000 to 160,000 plants/ha (75 kg seed/ha) is recommended. Planting rows of 7 to 9 cm are recommended with the spacing between plants in the rows 8 to 10 cm. A planting depth of 3 to 5 cm is ideal. Water requirements Irrigation should be adapted to the requirements of the plants. From week one to week six not too much irrigation should take place. Plants should dry well between irrigations. From week six to week twelve water consumption increases and plants could use up to 60 mm water per week. From week thirteen until harvesting less irrigation should take place until 25% of the pods had yellowed and then irrigation should be discontinued altogether. Weed control Weeds compete directly with the plants and should therefore be controlled. Weed control could be done mechanically as long as plants are not damaged and could be continued until shortly before the blossom stage. Tilling with hoes is also advantageous in that it will aerate the soil better. |
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Pest control
Insects that cause problems in the Little Karoo are mainly bollworm, CMR beetles and red spider and should be controlled chemically. As far as control of diseases is concerned, certified seed plantings should be free from common blight, halo blight and bacterial brown spot. |
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Harvesting
Harvest time is the most important time of seed production. Commence harvesting when 70% of the pods have changed colour from green to straw. The plants are then pulled up and thrown in bundles or windrows. If it rains at this stage, the seeds will become stained, which is not acceptable. If there is a possibility of rain, the plants should rather be brought indoors. The harvesting process takes place when the seed contains about 16% moisture. If the seed is drier, damaging during the harvesting process is more likely and that will affect germination adversely. If very dry conditions prevail during the harvesting process, it is better to harvest in the morning only when there is more moist in the air. In the Little Karoo where bean threshers are not common, the same thresher is often used by various bean growers. In order to prevent the spreading of diseases and of seed becoming mixed, the thresher should be cleaned properly and the parts that come into contact with the seed, should be disinfected when it is moved from one bean field to another. The bag should be closed only after the moisture content of the beans is lower than 14%, and after that it should be handled with care because rough handling will damage the seeds. A yield of 2 tons and more is possible with a gross income of R10,000/ha that could mean a nett income of R7,500/ha. |
BFA Visser
ELSENBURG / LITTLE KAROO ADC
