By Saintly Ngwenya
Sweet potatoes are one of the easiest crops to grow, both in terms of agronomic and economic requirements. However, most farmers miss out on the profitability of the crop due to some simple blunders they make along the production cycle of the crop. As VaMudhumeni we have noted some of the mistakes that farmers make and thereby fail to enjoy the sweet returns from sweet potatoes. Here are 5 top mistakes that sweet potatoes farmers make:
- Soil requirements – as we always encourage, farmers should regularly test their soils to determine its pH and nutritional composition. Sweet potatoes require sandy loam soils for easier root growth and tuber development.
- Fertiliser application – many farmers usually neglect supplying their sweet potatoes with proper nutrients. This greatly affect the yield and quality of the tubers. In the absence of soil analysis recommendations, sweet potatoes require 300 kg/Ha of Compound C or L which has to be incorporated at mound-making. Top dressing with AN should be applied at 4 weeks after transplanting.
- Time of planting – generally farmers put sweet potatoes last on their planting calendar. This results in farmers missing out on the most important growth phase of sweet potatoes. The ideal time to plant sweet potatoes in Zimbabwe is mid-November to mid-December. However, this is the period when most farmer will be concentrating on other major crops. Late planted sweet potatoes are generally affected by light frosts which retard growth.
- Pest control – just like any crop, sweet potatoes are also affected by pests and diseases. However, it is rare to see farmers putting some control measures to their crops. Sweet potatoes are affected by vine borers, crickets, white flies, fusarium wilt, black rot, root-knot nematodes, but the most menacing insect is sweet potato weevil. Farmers need to have preventative measures and regularly scout their crops for any pests.
- Post-harvest management – during the time of sweet potatoes harvesting (usually April to May) most farmers will be concentrating on harvesting other field crops and preparing to plant winter crops. Proper curing of tubers for storage is often neglected resulting in huge post-harvest losses. Uncured tubers deteriorate faster and are lesser appealing in quality. Well cured tubers are sweet and have a storage life of close to 6 months.
There is sweet money in sweet potatoes. On average a hectare of sweet potatoes yields up to 20 tonnes which is double the yield of maize. The selling price for sweet potatoes is $0.90/kg which is thrice that of maize. Return per dollar invested in sweet potatoes is around $3.9 whereas that of maize is at $2.11. The crop is not only sweet in taste but is also sweet in its returns.