Onions require frequent/ regular applications of fertilizer in order to produce the highest yields and the largest, best quality onions.
The crop requires different nutrient rates and ratios at different growth stages and in order for the nutrients to be available when the plant needs them, fertilizers should be applied at the right timing.
Fertilization of onion plants is vital for a successful production.
Early growth stage
This is the period between seed sowing, germination, transplanting and about 2-3 weeks after transplanting the seedlings.
The nursery should be drenched with OPTIMIZER 20ml/20l. This helps in breaking seed dormancy, ensuring uniform germination as well as providing nutrients to the emerging seedlings.
To promote strong early growth, maximise root development, ensure good shoot growth and supply food reserves to the seedlings after transplanting, the crop should be sprayed with GOLDCHANCE SUPER START 50g/20l or LAVENDER 20ml/20l or VITABOR GOLD 30ml/20l or PLANT SOUL 20ml/20l
To avoid/ prevent transpiration shock, seedlings are sprayed with OPTIMIZER 10ml/20l.
When transplanting, the main field should be applied with DAP or manure, depending on the fertility of the soil.
It is during this stage when the crop is actively growing and making food in order to accumulate enough resources for utilization during bulbing.
In order to ensure continued growth and development, maintain vigorous, healthy leaf growth and to ensure that photosynthetic growth is not limited, GOLDCHANCE SUPER GROWTH 50g/20l or LEGENDARY 40ml/20l or LAVENDER 20ml/20l should be applied to the crop.
The size of the onion bulb is dependent upon the number and size of the green leaves or tops at the time of bulb maturity. For each leaf there is a ring of onion and the larger the leaf, the larger the ring.
Top dressing should be done using CAN. Other basal fertilizers like NPK 23:23:0 could also be applied during this stage.
Bulb formation & development
The crop should be supplied with adequate nutrients during this stage in order to achieve the best.
Spraying GOLDCHANCE SUPER FLOWERS & FRUITS 50g/20l or LEGENDARY 40ml/20l or DIMIPHITE 20ml/20l or GREENPHITE 50ml/20l or VITABOR GOLD helps in;
- Maintaining early growth and bulb development
- Maintaining leaf growth
- Maximizing dry matter and general quality of the bulbs
- Improving the storage quality of the bulbs
- Maintaining bulb firmness and size
- Enhancing the bulb colour
- Ensuring ripening and early maturity
- OPTIMIZER 10ml/20l should be sprayed at all stages in order to boost crop’s immunity, manage stress, and improve the general performance of the crop. It supplies both macro and micro nutrient elements and growth hormones.
- All basal fertilizers (e.g. DAP, CAN, etc.) and manure should be mixed with HUMIPOWER at the rate of 1kg Humipower into 50kg fertilizer or 1 ton of manure. Humipower helps to improve on the nutrient uptake by the crop, stimulates growth, improves soil structure, and adds organic matter to the soil among other benefits.
- Whenever doing foliar sprays of the fertilizers, it is advisable to always mix the foliar feed with INTEGRA 3ml/20l. This is a sticker, spreader and penetrant which improves the absorption level of the fertilizer by the foliage of the crop.
- Fertilizer application timing has a significant effect on crop yields. Proper timing of the fertilizer application increases yields, reduces nutrient losses, increases nutrient use efficiency and prevents damage to the environment.
- Foliar sprays should be repeated on weekly basis while still monitoring the general performance of the crop.
- Once the neck starts feeling soft do not apply any more fertilizer. This should occur approximately 4 weeks prior to harvest.