Horticulture is one of the most lucrative fields in Zimbabwe but can be challenging for most new entrants. In this article we explore some of the most common mistakes which you need to be aware of;
1. Poor site selection: Badly drained soils– soils in the selected site should be free draining to 1.5m depth. Gravelly soils: The more stones /pebbles present the smaller is the water holding capacity of soil. Too close to trees or buildings or too steep a slope with excess run off of irrigation water? This can affect the yield of your crops.
2. Poor choice of variety for the market, time of the year, day length, and area. Lack of proper crop planning.
3. Poor soil preparation: The soil must be porous, aggregated, oxygenated to a depth of 0.5M for top yields. See Charter Seeds soil preparation technique to convert badly compacted soil into an excellent tilth in a matter of weeks.
4. Badly planned rotations: Subsequent crops must not be in the same family or group of plants.
5. Inadequate isolation distances between crops.
6. Temperatures and humidity levels are very important for many crops especially in greenhouses. The most frequent fault seen in greenhouses is lack of temperature control.
7. Poor Irrigation: Too much water in winter – especially March – April in Zimbabwe. Too little water in summer – especially September – October. Affects both the nursery and the field. Often the case with drip irrigation which is not really understood by many farmers. If you have a white efflorescence of salt on the surface of the soil it is likely you will be under watering. Examination of the soil will show the subsoil is dry.
8. Poor seedlings: A good well prepared, well hardened seedling is the foundation of a good crop and vice versa. Not too large or not too small and no excess leaf. Must be of the right size, 12-15cm tall, with strong, sturdy stems to prevent post planting shock, and a good root structure. The plugs must hold enough water to carry the seedling in the time before it starts to use soil water. Seedlings of cucurbits for instance need a larger volume of medium than seedlings with a smaller leaf area like cabbages and tomatoes. Use sleeves for cucurbit seedlings, especially watermelons and cucumbers.
9. Poor fertilization: Fertilize according to soil analysis taking both nutrient intensity and nutrient capacity into account. The fertilizer must be carefully placed in the soil so that it coincides with root development at critical periods of growth like vegetative growth, flowering and fruit development. Know your variety so that in a well prepared soil you know where the roots will be in the soil at a given time.
10. Poor planting. Water plant into a soil at field capacity. Never plant into dry soil. Make sure the seedling is full of water when transplanting. Water the night before pulling. Shade cucurbit seedlings after transplanting to minimize water loss.
11. Badly planned pest and disease control. Before the crop is planted have a spraying program planned based on previous experience. Start spraying before the problem occurs and rotate chemicals to prevent a build- up of resistance and stick to your planned program.
Finally, horticulture is a business: Inputs must be governed by the likely gross return – but the more you put in the more you will get out.In modern horticulture absolute attention to detail is necessary in all aspects of production to make use of the factors incorporated into modern vegetable varieties.
All Credit: Charter seeds, distributors of Stark Ayres in Zimbabwe.
Emmanuel is a qualified Agronomist and development practitionerwith more than a decade’s experience working in the agri-business industry and development sector. You can contact him on edndsep@gmail.com or whatsapp on 0783495396
