Online Reporter
Engineer Tapuwa Justice Mashangwa
Every agricultural season comes with its own characteristics that are necessary for the optimum growth and adaption of plants and animals. The acknowledgement of these trends allows agribusiness participants to better understand their projects in light of that agronomic success depends on understanding the biological and environmental needs of each crop. Proper land preparation, seed selection, planting techniques, nutrient management, irrigation, pest control and harvesting practices all influence yield and profitability. This month of May is the best time for planting wheat, canola, garlic, pumpkin and tomatoes.
Wheat is a major cereal crop grown for food, feed and industrial uses. It thrives in cool temperatures and well-drained fertile soils. It performs best in loamy soils with a pH of 6.0–7.5. Before planting, soil testing is recommended to determine nutrient levels and lime requirements. Land should be ploughed and harrowed to create a fine, firm seedbed for uniform germination.
Certified seed varieties adapted to local climatic conditions should be used. Winter wheat is planted between May and June under irrigation. Seed rates typically range from 100–140 kg per hectare depending on variety and planting method.
Planting depth should be 3–5 cm, with row spacing of 18–25 cm. Wheat requires adequate nitrogen, phosphorus, and potassium. Basal fertiliser such as Compound D or MAP should be applied at planting, while nitrogen top dressing using ammonium nitrate or urea is applied during tilling and stem elongation.
Consistent irrigation is critical, especially at germination, tilling, flowering, and grain filling stages. Weed management should begin early using pre- and post-emergence herbicides or manual weeding. Common pests include aphids and armyworms, while diseases such as rust, powdery mildew and leaf blight should be managed using resistant varieties and fungicides.
Harvesting occurs when grains reach physiological maturity and moisture content drops below 14 percent.
Canola is an oilseed crop valued for edible oil and livestock feed. It grows well under cool conditions and requires fertile, well-drained soils. Canola prefers loamy soils with pH 5.5–7.0. Avoid waterlogged or highly acidic soils. Deep ploughing followed by fine seedbed preparation is ideal due to the crop’s small seed size.
Planting should occur during cool months, generally from April to June in subtropical climates. Seed rates range from 3–5 kg per hectare, planted shallowly at 1–2 cm depth. Row spacing of 25–30 cm promotes airflow and ease of management.
Canola has high sulphur and nitrogen requirements. Basal fertiliser rich in phosphorus and sulphur should be incorporated before planting. Nitrogen is applied in split doses, with the first at planting and the second before flowering.
Moisture is essential during germination, flowering and pod filling. Irrigation should be scheduled carefully to avoid drought stress. Weed competition is severe during early growth stages, requiring pre-emergence herbicides and timely cultivation.
Major pests include aphids, diamondback moth and flea beetles. Diseases such as blackleg, sclerotinia stem rot and alternaria can be minimised through crop rotation, resistant varieties and fungicide use.
Harvest when pods turn yellow-brown and seeds are black and firm.
Garlic is a high-value bulb crop used in culinary and medicinal applications. It requires cool growing conditions and loose, fertile soil. Garlic grows best in sandy loam or loamy soils rich in organic matter, with pH 6.0–7.0. Heavy clay soils restrict bulb expansion and should be avoided. Fields should be deeply cultivated and enriched with compost or well-rotted manure.
Garlic is planted using healthy cloves separated from disease-free bulbs. Large cloves produce larger bulbs and higher yields. Planting is typically done in autumn or winter.
Cloves are planted 3–5 cm deep, pointed end facing upward. Recommended spacing is 10 cm between plants and 20–30 cm between rows. Basal fertiliser containing phosphorus and potassium is applied before planting. Nitrogen is applied in split applications during vegetative growth but should be reduced as bulbs begin forming.
Garlic requires regular moisture but not waterlogging. Drip irrigation is preferred to reduce disease incidence. Weed control is critical because garlic competes poorly with weeds. Common pests include onion thrips, nematodes and bulb mites. Diseases such as white rot, downy mildew and purple blotch require crop rotation, proper spacing and fungicide management.
Harvest when 50–70 percent of leaves turn yellow and begin drying.
Pumpkin is a warm-season cucurbit crop grown for fruit, seeds and leaves. It requires fertile soil, adequate moisture and sunlight. Pumpkins grow well in sandy loam soils with good drainage and pH 6.0–6.8. Land should be deeply ploughed and mixed with organic manure before planting.
Seeds are planted directly in the field after frost risk has passed. Planting holes or mounds are recommended to improve drainage and root development. Seeds are sown 2–3 cm deep, with 1–2 seeds per station. Spacing varies by variety but commonly ranges from 1–2 meters between plants and rows due to vine spread.
Pumpkins respond well to manure and balanced NPK fertilisers. Nitrogen supports vine growth, while phosphorus and potassium enhance flowering and fruiting.
Regular watering is essential during flowering and fruit development. Mulching helps conserve moisture and suppress weeds. Key pests include fruit flies, aphids, and red spider mites. Diseases such as powdery mildew, downy mildew and bacterial wilt require sanitation, crop rotation and fungicide application.
Harvest when fruits develop hard rinds and mature colouration.
Tomatoes are one of the most commercially important vegetable crops. They require careful nursery and field management. Tomatoes prefer well-drained fertile soils with pH 5.5–7.0. Nursery beds should be raised and sterilised before sowing.
Seeds are first raised in trays or nursery beds and transplanted after 4–6 weeks when seedlings have 4–6 true leaves. Transplanting should be done during cool periods or late afternoon. Spacing is typically 30–50 cm between plants and 75–120 cm between rows, depending on growth habit.
Tomatoes require high nutrient levels, especially phosphorus at transplanting and potassium during fruiting. Fertigation through drip irrigation is highly effective. Consistent watering prevents blossom end rot and fruit cracking. Staking, pruning, and trellising improve airflow and fruit quality.
Major pests include whiteflies, aphids, tomato leaf miner, and cutworms. Diseases such as early blight, late blight, bacterial wilt, and fusarium wilt require integrated pest management.
Harvest begins 70 – 100 days after transplanting depending on variety and market requirements.
In conclusion, successful production of wheat, canola, garlic, pumpkin and tomatoes requires crop-specific management tailored to soil conditions, climate, and market goals. Farmers who follow sound agronomic practices improve productivity, quality and profitability.
The writer is Engineer Tapuwa Justice Mashangwa, GCEO Emerald Investments, CEO DataFarm, CEO Emerald Agribusiness and CEO TranslateZW. He can be contacted on +263771641714 and email: [email protected] or [email protected].
