Course Overview

Sweet potato is the quickest route from empty field to income in African farming: 3–5 months, planted from vines you multiply yourself, on ordinary soil. This course is built around the two lessons most training under-teaches. First, the weevil war: the Cylas weevil ruins more sweet potato than every other problem combined, and it is beaten not with chemicals but with clean tips, high sealed ridges, early harvest, sanitation and rotation. Second, curing: four warm humid days after harvest that heal the skin and stretch storage from weeks to 3–5 months — the machine that moves your crop from glut prices to lean-season prices. Add the orange-fleshed (OFSP) vitamin A story and its premium channels, and one ridge feeds the family, the pigs, the market and the plan.

What You Will Learn

Match variety to market: high-dry-matter whites vs OFSP and its nutrition premium
Run a vine multiplication bed — clean planting material forever, and a product to sell
Build 30 cm ridges, plant tips 2/3 buried, and gap-fill to a full stand
Two timed weedings with earthing-up, modest K-led feeding, and vines as 16–20% protein fodder
Defeat the sweet potato weevil with the five-part cultural defence — no insecticide required
Recognise and rogue SPVD; refresh material every 2–3 seasons
Harvest without wounds, cure 4–7 days warm and humid, store 3–5 months
Sell across five income streams and into OFSP programme channels; plan the full business

Duration: 6 months, one module per month

Level: Beginner → Job-ready

Units: Metric with imperial where useful

Final project: Your own business plan

Month 1: The Crop, OFSP & Choosing Varieties

Start

Lesson 1.1 — The three-month money crop

Sweet potato is the fastest serious food crop in African farming: 3–5 months from planting to harvest, from vines you multiply yourself for free, on ordinary soils, with modest rain. It fits into gaps — after maize, before the next rains, on the plot too small for anything else — and everything is sellable: roots for food, vines for planting material and livestock fodder, leaves as a vegetable in many regions.

Yields: African average ~5–6 t/ha; good management with clean vines reaches 15–30 t/ha. Same story as cassava — the gap is management.
Drought-tolerant once established, but the first 4–6 weeks need reliable moisture.
Sensitive to waterlogging (roots rot) and to too much shade or nitrogen (all vines, no roots).

Lesson 1.2 — Orange-fleshed sweet potato: the vitamin A crop

The most important sweet potato story of our generation is OFSP — orange-fleshed sweet potato. Its orange colour is beta-carotene, which the body turns into vitamin A. Vitamin A deficiency blinds and kills African children at scale; just 100–125 g of boiled OFSP a day covers a young child's full vitamin A need. Varieties bred and released across Africa (many through the International Potato Center, CIP) combine the orange flesh with good yields and disease resistance.

Business angle: OFSP carries a nutrition premium in urban markets, school-feeding programmes and NGO procurement, plus growing demand for OFSP puree in bakeries (bread, buns) replacing wheat flour and colourants.
Market caution: many rural markets still prefer the drier, starchier white/cream types they grew up with. OFSP tends to be moister and sweeter. As always: check what your target market eats before you plant a hectare of anything.

Lesson 1.3 — Choosing varieties

Type	Character	Market
White/cream-fleshed, high dry matter	Firm, starchy, 'mealy' — the traditional preference in much of East/Southern Africa	Rural and staple markets, home consumption
Orange-fleshed (OFSP)	Beta-carotene rich; often moister	Urban, nutrition programmes, bakery puree, weaning foods
Yellow/purple types	Intermediate; purple = anthocyanins	Niche urban and processing markets

Ask your extension office which released varieties — white and orange — are recommended for your district, and specifically which resist sweet potato virus disease (SPVD) and perform under local weevil pressure. Those two enemies own Modules 2 and 4.

📺 Watch it done: White vs orange — dry matter, taste, and the vitamin A story. Open curated video search → The written lesson above is complete on its own — the video is optional reinforcement.

Practical Assignment — Month 1: Survey your market: record the sweet potato types on sale (flesh colour, size), prices now, and ask two traders how prices move across the year — write their month-by-month sketch down. Then get your extension office's list of released varieties for your district, noting which are OFSP and which resist SPVD and weevils. Choose your candidate variety (or two) and state your reason in one paragraph.

Month 1 Quiz — 10 Questions

Answer every question. Aim for at least 7/10 before marking this month complete. Each answer comes with an explanation — read them even when you are right.

1. Sweet potato typically reaches harvest in:

Why: Three to five months makes it the quickest substantial root crop available — fast enough to fit season gaps and to give a new farmer income within one school term.

2. The orange colour of OFSP flesh comes from:

Why: Beta-carotene is the whole point of OFSP: a small daily serving covers a child's full vitamin A requirement, attacking a deficiency that blinds and kills children across the continent.

3. How much boiled OFSP covers a young child's daily vitamin A need?

Why: Roughly half a small root a day. This is why OFSP anchors school feeding and nutrition programmes — and why it carries a real market premium in those channels.

4. Many rural African markets still prefer white/cream sweet potato because:

Why: OFSP is typically moister and sweeter, which some staple-market consumers dislike. Grow OFSP for the channels that want it; grow high-dry-matter whites for markets that pay for tradition.

5. Too much nitrogen or shade on sweet potato produces:

Why: Sweet potato partitions between vines and roots. Excess N or shade tips the balance to foliage — beautiful field, empty ridge. Moderate fertility and full sun grow the crop you actually sell.

6. A realistic managed yield for sweet potato with clean vines is:

Why: Against a continental average of ~5–6 t/ha, well-managed fields of released varieties routinely triple or quintuple it. As with cassava, the yield gap is management, starting with planting material.

7. The two enemies that should shape your variety choice are:

Why: SPVD degenerates yields through infected vines; the weevil ruins roots in the ground. Released varieties are screened against both — one more reason the extension list beats the neighbour's field.

8. Sweet potato's establishment phase (first 4–6 weeks) requires:

Why: Vine cuttings have no roots when planted; they must grow them in moist soil. Once rooted, sweet potato is genuinely drought-hardy — but a dry first month kills the stand.

9. Besides roots, sweet potato's saleable products include:

Why: Vine bundles sell to other farmers every planting season, vines are excellent pig and dairy fodder, and the leaves are a common vegetable — a three-income plant.

10. Growing OFSP puree demand comes mainly from:

Why: OFSP puree replaces part of the wheat flour, colour and sugar in baked goods while adding vitamin A — a growing processing channel that buys tonnage on contract in several countries.

Month 2: Vines, Multiplication Beds & Planting

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Lesson 2.1 — A crop planted from vines

Like cassava, sweet potato is planted vegetatively — from vine cuttings, not seed. And the same law applies: whatever the mother vine carries, your field inherits. The main degenerator is sweet potato virus disease (SPVD, spread by whiteflies and aphids); fields planted for years from their own recycled vines slowly run down to the sad continental average.

Best cuttings: tip (apical) cuttings 25–30 cm long from healthy, vigorous, symptom-free plants — the tips are usually freest of weevil eggs and virus.
Where available, buy from certified/clean vine multipliers (many countries now have decentralised vine seed systems, especially for OFSP). Refreshing your planting material every 2–3 seasons is one of the highest-return purchases in this crop.
Optional but useful: strip lower leaves and wilt cuttings in shade for 1–2 days before planting — they root faster and any weevil eggs desiccate.

Lesson 2.2 — Your own vine nursery: the multiplication secret

One small irrigated or wet-spot bed turns a handful of clean vines into a field's worth. This is the skill that makes you independent — and can make you a vine seller:

Prepare a fine, fertile, watered bed (e.g. 1 m × 5 m) near the house or water source.
Plant clean cuttings close together (20 cm × 10–20 cm). Water regularly.
Every 4–6 weeks, harvest 25–30 cm tips for planting or sale; the bed regrows. Cut, don't uproot.
One well-run 10 m² bed yields several thousand cuttings per season — enough for half an acre and more.
Replace the bed with fresh clean material every few cycles; rogue any mosaic-stunted plants instantly.

Lesson 2.3 — Ridges, mounds and planting

Element	Standard	Why
Land form	Ridges ~30 cm high, 75–100 cm apart (or traditional mounds)	Loose soil for root bulking, drainage, easier harvest — and the ridge is your anti-weevil wall (Module 4)
Spacing on ridge	Cuttings every 30 cm along the ridge (~33,000–44,000/ha)	Dense enough for tonnage and quick ground cover
Planting	Bury 2/3 of the cutting (3–4 nodes underground) at a slant, tip out	Buried nodes are where storage roots form — shallow planting = few roots
Timing	Early rains, into moist ridges; irrigate the first weeks if erratic	Rooting needs 4–6 moist weeks; early crops also dodge peak weevil season at harvest

Gap-fill at 2 weeks: walk the ridges and replant every failed station from nursery tips. Full stands are free yield; gaps grow weeds.

📺 Watch it done: Building a vine multiplication bed and taking tip cuttings correctly. Open curated video search → The written lesson above is complete on its own — the video is optional reinforcement.

Practical Assignment — Month 2: Establish a vine multiplication bed of at least 1 m × 3 m from the cleanest material you can obtain, close-planted and watered. Separately, prepare and plant a practice plot of at least two 5-metre ridges (30 cm high, cuttings every 30 cm, 2/3 buried, wilted tips). Record planting dates for both, and gap-fill the ridges at two weeks from the bed.

Month 2 Quiz — 10 Questions

Answer every question. Aim for at least 7/10 before marking this month complete. Each answer comes with an explanation — read them even when you are right.

1. The best planting material for sweet potato is:

Why: Apical tips are the youngest tissue — least virus, least weevil eggs — and root fastest. Roots can propagate the crop but carry weevils and disease straight into the new field.

2. Recycling your own vines season after season leads to:

Why: SPVD builds up silently in recycled material — the main reason average yields sit at a third of potential. Refreshing with clean/certified vines every 2–3 seasons resets the field.

3. Wilting cuttings in shade for 1–2 days before planting:

Why: Slightly wilted cuttings throw roots faster when they meet moist soil, and the drying period kills weevil eggs riding on the vine — two benefits for zero cost.

4. A 10 m² vine multiplication bed can supply per season roughly:

Why: Close-planted, watered and tip-harvested every 4–6 weeks, a tiny bed becomes a cutting factory. This is also a business: vine bundles sell readily every planting season.

5. Cuttings are planted with:

Why: Storage roots form at buried nodes. Shallow planting gives a leafy plant with almost nothing under it; three to four nodes in moist ridge soil is the standard.

6. The standard field layout is:

Why: High ridges give loose soil, drainage, easy harvest — and, critically, a thick soil barrier weevils must cross to reach roots. The ridge is agronomy and pest control in one.

7. Vine nursery beds should be harvested by:

Why: Cut-and-regrow keeps the bed producing for multiple cycles. Uprooting ends production and risks moving soil pests with the material.

8. Any plant in the nursery showing mosaic or stunting should be:

Why: A virused nursery multiplies virus by the thousand. The nursery is where hygiene pays most — one minute of roguing there saves a field later.

9. Full moisture is most critical for sweet potato during:

Why: Unrooted cuttings die in dry ridges. Plant into moisture at the start of rains, or hand-water establishment — after rooting, the crop shrugs off dry spells.

10. Gap-filling at two weeks matters because:

Why: With ~35,000+ plants per hectare, a 10% failure rate is thousands of missing plants. A quick replant walk from the nursery restores the stand for almost nothing.

Month 3: Weeding, Feeding & the Fodder Harvest

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Lesson 3.1 — Six weeks of weeding, then the crop takes over

Sweet potato is the rare crop that becomes its own weed control. Vines cover the ground within 5–7 weeks and smother almost everything under them. Your job is the gap before that:

Weed 1: 2–3 weeks after planting, shallow hoeing between ridges.
Weed 2 + earthing up: 5–6 weeks after planting — the important one. Pull soil from the furrow up onto the ridge, covering weeds and, crucially, sealing soil cracks (this is weevil defence — Module 4 explains why cracks are the enemy).
After canopy closure, hand-pull only the tall escapes. Do not hoe under closed vines — you will wound shallow storage roots.

Lesson 3.2 — Feeding: less is more, except potassium

Nutrient	Role	Practice
Nitrogen	Leaf growth — easily overdone	Modest: manure worked into ridges at making, or a light NPK dose at 2–3 weeks. Heavy N = vines, not roots
Potassium	Root bulking and starch — the star, as in all root crops	K-strong compound or wood ash into the ridge; deficiency shows as bronzed older leaves and thin roots
Organic matter	Loose ridge structure roots can swell in	Compost/manure at ridging; avoid fresh manure at planting (forks and scabs roots)

Sweet potato follows a well-fertilised crop beautifully — planted after maize or vegetables, it often needs little more than the residues and ash you give the ridge. Rotation position is fertiliser strategy.

Lesson 3.3 — The vine-lifting question, answered honestly

In humid areas, vines root at nodes wherever they touch wet soil, forming many pencil-thin secondary roots. Some traditions "lift" (gently disturb) vines to break these roots and force energy back to the main ridge roots. The honest evidence: routine vine lifting mostly reduces yield by wounding the plant and disrupting the canopy, and is only worth considering in very wet conditions with long-duration varieties where node-rooting is visibly severe. Default: leave the canopy alone and let it work.

Lesson 3.4 — Vines as fodder: the second harvest

Sweet potato foliage is a genuinely valuable livestock feed — 16–20% protein in dry matter, relished by pigs, dairy cattle, goats and rabbits. Managed cutting of surplus vine growth late in the season (never more than the top third, never before root bulking is well advanced) gives fodder or silage without meaningful root loss, and at final harvest the entire vine mass is feed. For a mixed farmer, this alone can pay the field's costs — a direct link to the Piggery and Rabbit courses.

📺 Watch it done: Earthing up demonstrated — burying weeds and sealing the ridge. Open curated video search → The written lesson above is complete on its own — the video is optional reinforcement.

Practical Assignment — Month 3: Carry out weeding 1 (weeks 2–3) and weeding 2 with full earthing-up (weeks 5–6) on your ridges, recording dates and hours. Work wood ash into the ridge at earthing-up and note the amount. If you or a neighbour keep pigs, goats or rabbits, cut a small sample of surplus vine tips, feed them, and record the animals' response — your first fodder data.

Month 3 Quiz — 10 Questions

Answer every question. Aim for at least 7/10 before marking this month complete. Each answer comes with an explanation — read them even when you are right.

1. Sweet potato needs intensive weeding for roughly:

Why: Ground-covering vines are built-in weed control. Two timed weedings before closure do the whole job — one of the reasons sweet potato's labour bill is so low.

2. The second weeding is combined with earthing up in order to:

Why: Pulling furrow soil onto the ridge kills in-row weeds, deepens the loose root zone, and closes the cracks weevils use as highways down to the roots — three jobs, one hoe pass.

3. Heavy nitrogen fertiliser on sweet potato results in:

Why: N drives the vine–root balance toward foliage. Modest N, strong K and good ridge structure is the root-crop formula — the same lesson as cassava.

4. Bronzed older leaves and thin roots signal:

Why: K is the bulking nutrient; the plant strips it from old leaves first. Wood ash into the ridge is the affordable answer where compound fertiliser is out of reach.

5. Fresh (unrotted) manure applied at planting tends to:

Why: Hot fresh manure damages developing storage roots and encourages forking and scab. Compost it first, or apply it to the previous crop and let sweet potato enjoy the residue.

6. On routine vine lifting, the evidence says:

Why: Lifting wounds vines and disrupts the working canopy. Except where waterlogged conditions cause heavy secondary rooting, the profitable default is to leave the canopy alone.

7. Hoeing under a closed sweet potato canopy is avoided because:

Why: Bulking roots sit just under the ridge surface, wider than you expect. Post-closure weed escapes are hand-pulled; the hoe stays out.

8. Sweet potato foliage as livestock feed contains roughly:

Why: Vine protein rivals many purchased feeds, which is why pigs, dairy animals and rabbits do so well on it. The final-harvest vine mass is a genuine second crop.

9. In-season fodder cutting from a root field should:

Why: Moderate late cutting sacrifices little root yield; aggressive or early cutting starves the roots you are actually growing. At final harvest, everything goes to the animals.

10. Planting sweet potato after well-fertilised maize or vegetables means:

Why: Sweet potato scavenges residual nutrients efficiently and its modest N needs match what previous crops leave behind. Smart rotation placement replaces purchased fertiliser.

Month 4: The Weevil War & Plant Health

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Lesson 4.1 — Meet the enemy: Cylas, the sweet potato weevil

If bruchids are the bean farmer's war, the sweet potato weevil (Cylas species) is yours. This ant-like little beetle is the most destructive sweet potato pest on earth. The adult lays eggs in vines and in any root it can reach; larvae tunnel through the roots, and the plant responds by producing bitter, foul-smelling terpenes. The result: roots riddled with dark tunnels that taste so bitter that even livestock refuse them. Damage of 60–100% in late-harvested dry-season fields is common. There is no rescue spray once larvae are inside the roots — the entire strategy is denial of access.

Lesson 4.2 — How the weevil reaches your roots

On planting material — eggs and larvae in vine bases and in root pieces.
Through soil cracks — the adult cannot dig, but as soil dries and cracks in the late season, cracks become open corridors straight down to the roots.
From reservoirs — old sweet potato fields, volunteer plants, discarded infested roots, and wild relatives keep populations alive between seasons.

Lesson 4.3 — The integrated defence (each step attacks one route)

Weapon	What you do	Which route it blocks
Clean tips	Plant apical tip cuttings, wilted 1–2 days; never plant root pieces or vine bases from infested fields	Arrival on material
Crack sealing / earthing up	Earth up at weeks 5–6 and again if cracks appear; keep ridges high and unbroken; mulch in dry spells to slow cracking; irrigate if you can	The soil-crack corridor — the single most powerful cultural control
Timely (early) harvest	Harvest as soon as roots reach market size; every extra dry-season week in the ground multiplies damage	Exposure time
Field sanitation	After harvest, remove or feed ALL roots and vines promptly (deep-bury infested culls — never leave them lying); uproot volunteer plants	Between-season reservoirs
Rotation & distance	Never follow sweet potato with sweet potato; plant new fields as far as practical (ideally a few hundred metres) from old ones	Reservoir spillover — the weevil flies poorly
Barrier & extras	Where available: sex-pheromone traps for monitoring/mass trapping; some released varieties tolerate weevils better — ask extension	Population knockdown

The one-line weevil strategy: clean tips in, high sealed ridges through the season, harvest early, leave nothing behind, and don't plant next to last season's field. Farmers doing all five routinely hold weevil damage under 10% with zero insecticide.

Lesson 4.4 — SPVD and the rest

Sweet potato virus disease (SPVD): the whitefly/aphid-borne virus complex behind yield run-down — stunted plants with narrow, twisted, pale mosaic leaves. No cure: rogue affected plants, refresh with clean vines every 2–3 seasons, and use resistant released varieties. (This is the same defence triangle you learned in Cassava Module 4.)
Alternaria blight & leaf spots: dark stem/leaf lesions in wet highlands — resistant varieties and rotation.
Rodents (mole rats etc.): serious in some areas — early harvest, clean field edges, traps; damage clusters near bushy margins.
Erwinia/soft rots in store: a curing and handling issue — Module 5 solves it.

📺 Watch it done: Cylas up close — cracks, tunnels, and the five-part defence in the field. Open curated video search → The written lesson above is complete on its own — the video is optional reinforcement.

Practical Assignment — Month 4: Write your five-part weevil plan for your own plot: material source, earthing-up dates, target harvest week, sanitation steps, and next season's field location relative to this one. Then inspect any older sweet potato field nearby: look for soil cracks over ridges, dig one plant, and cut roots open — record whether you find tunnels and estimate damage percentage. Rogue any SPVD-symptomatic plants from your own plot and nursery.

Month 4 Quiz — 10 Questions

Answer every question. Aim for at least 7/10 before marking this month complete. Each answer comes with an explanation — read them even when you are right.

1. Weevil-damaged sweet potato roots are worthless because:

Why: The weevil's tunnels trigger a chemical defence that ruins taste and smell throughout the root — a small larval population destroys the whole root's value, which is why prevention is everything.

2. Once weevil larvae are inside roots, the effective treatment is:

Why: Larvae feed protected inside the root where no economic spray reaches. Every control in this crop is preventive: clean material, sealed soil, early harvest, sanitation, rotation.

3. The weevil's main route to roots late in the season is:

Why: Adults cannot dig, but drying soil cracks into open corridors leading straight to the roots. This single fact explains why earthing up, mulching and early harvest are the core defences.

4. Earthing up defends against weevils by:

Why: A high, unbroken ridge is a physical wall the adult weevil cannot cross. Re-earthing whenever cracks appear keeps the wall intact through the dangerous dry weeks.

5. Delaying harvest into the dry season typically:

Why: Exposure time is the multiplier: cracked dry soil plus mature roots is the weevil's feast. Harvesting as soon as roots reach market size is yield protection, not impatience.

6. After harvest, leftover roots and vines should be:

Why: Crop remains and volunteer plants are the weevil's off-season hotel, breeding the population that attacks your next field. Sanitation breaks the cycle.

7. New sweet potato fields should be located:

Why: Cylas disperses mainly by walking and weak flight. Distance plus rotation starves the emerging population before it finds your new crop — free control through planning.

8. SPVD in the field looks like:

Why: The virus complex dwarfs and distorts plants, and infected plants yield almost nothing. Rogue them out and refresh planting material — the cassava defence triangle, applied here.

9. The reason vine TIPS are the safest planting material against weevils is:

Why: Egg-laying concentrates in vine bases and exposed roots near the soil. Tips, plus 1–2 days of wilting, arrive essentially weevil-free — the clean start every other measure builds on.

10. Farmers applying all five cultural weevil controls typically hold damage:

Why: Clean tips, sealed ridges, early harvest, sanitation and rotation stack multiplicatively. None is perfect alone; together they beat any spray programme this pest allows — cheaply.

Month 5: Harvest, Curing & Storage

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Lesson 5.1 — Reading harvest time

Most varieties are ready at 3–5 months. Field signs: leaves yellowing and thinning, and the test dig — open one plant per corner of the field and check root size and skin set. Milky sap from a cut root that dries quickly (rather than staying watery) also signals maturity in many varieties. Then remember Module 4: when roots are ready, weevils are hungrier every week — dig.

Lesson 5.2 — Harvesting without wounds

Sweet potato skin at harvest is tissue-paper delicate, and every scrape becomes a rot doorway in storage. The discipline:

Cut and remove vines first (they are fodder), then loosen the ridge from the side with a fork, stick or careful hoe, lifting roots by hand — never levering against the roots themselves.
Harvest in dry weather; wet-dug roots rot faster. Keep roots shaded — an hour of tropical sun scalds skin.
Sort in the field: market grade (clean, unwounded, uniform), home grade (minor damage — eat first), and weevil-tunnelled culls (livestock if lightly damaged and palatable, otherwise deep-bury; never leave in the field).

Lesson 5.3 — Curing: the four-day trick that adds four months

This is the lesson most sweet potato training in Africa skips, and it changes everything about storage. Freshly dug roots held for 4–7 days at around 27–30°C (81–86°F) with high humidity (~85–90%) perform a small miracle: wounds heal over with new corky skin ('wound periderm'), the whole skin toughens, and flavour actually improves as some starch converts to sugar. Cured roots store 3–5 months; uncured roots start rotting in weeks.

No equipment needed in the tropics: stack roots in a warm shaded, ventilated spot — under a grass roof, in a well-aired room — loosely covered (e.g. grass or sacking to hold humidity, never airtight plastic), for 4–7 days. Ambient warm-season conditions in most of Africa are close to ideal.
After curing, move to storage: cool as available, dry, dark, ventilated — a raised slatted store, a cool room, or the traditional pit store (lined with dry grass, roots layered with ash or sand, capped against rain and rodents) which works well where done carefully.
Handle cured roots gently still; check stores fortnightly and remove any rotting root immediately.

Why curing is money: the price difference between harvest-glut and lean-season sweet potato is commonly 50–150%. Curing + a decent store is the machine that moves your crop from the cheap month to the expensive one — the same lean-season logic as hermetic grain storage, applied to a root.

Lesson 5.4 — Processing options

Dried chips/flour: wash, peel (optional), slice thin, dry on racks to snap-dry, mill — composite flour for porridge and baking. OFSP flour keeps meaningful beta-carotene if dried fast and stored dark.
OFSP puree: steam, mash, pack — the bakery ingredient; needs hygiene and either cold chain or same-day sale/preservative-free contracts, so start with a confirmed buyer.
Crisps and snacks: fried or solar-dried sweet slices for urban retail — small equipment, good margins, competitive market.
Boiled-and-mashed for weaning porridges blended with legume flour — a home-market product with genuine nutritional weight.

📺 Watch it done: The curing stack — four days that add four months. Open curated video search → The written lesson above is complete on its own — the video is optional reinforcement.

Practical Assignment — Month 5: At harvest (your plot or a cooperating farmer's), practise the full chain: vines off to fodder, side-lifting without wounds, field sorting into three grades, and weighing total yield with a weevil-damage count. Cure at least a basket of sound roots for 4–7 days in a warm shaded ventilated stack under grass or sacking, then move them to your chosen store. Inspect after two weeks and record losses.

Month 5 Quiz — 10 Questions

Answer every question. Aim for at least 7/10 before marking this month complete. Each answer comes with an explanation — read them even when you are right.

1. Sweet potato harvest readiness is confirmed by:

Why: Varieties and seasons shift timing, so the field itself is the calendar: leaf decline plus corner test-digs showing sized, skin-set roots. Then dig promptly — the weevil clock is running.

2. Freshly dug sweet potato skin is:

Why: At digging, the skin slips and scrapes at a touch. Loosening from the side, lifting by hand, shading roots and dry-weather harvest are all protections for that fragile surface.

3. Curing means holding fresh roots for 4–7 days at approximately:

Why: Warm and humid is the healing recipe: wounds seal with new corky skin and the whole surface toughens. In the warm season, a shaded ventilated stack under grass or sacking achieves it with no equipment.

4. Properly cured roots store for about:

Why: Curing plus a cool, dry, dark, ventilated store turns a weeks-perishable root into a months-stable one — the gateway to lean-season prices.

5. Covering curing roots with airtight plastic sheeting is:

Why: Roots are alive and respiring; sealed plastic traps condensation and CO2 and rots them. Loose breathable cover holds humidity while letting the stack breathe.

6. Curing also improves eating quality because:

Why: The same days that heal the skin sweeten the root — cured sweet potato genuinely tastes better, which markets notice.

7. The commercial point of curing + storage is that lean-season prices are commonly:

Why: Everyone sells at harvest; few can sell three months later. Curing and a good store are the machine that moves your tonnage from the cheap month to the expensive one.

8. A traditional pit store works well when:

Why: Done carefully, the pit gives the cool, dark, stable conditions cured roots want — a proven zero-cash storage technology. Fortnightly checks and instant removal of any rotting root keep it healthy.

9. OFSP flour keeps its vitamin A value best when:

Why: Beta-carotene is destroyed by prolonged heat and light. Fast drying and dark storage preserve the nutrition that justifies OFSP's premium.

10. OFSP puree for bakeries should only be started with:

Why: Puree is perishable and specification-driven. The successful sequence is contract first, production second — the opposite order bankrupts small processors.

Month 6: Markets, Streams & the Sweet Potato Business

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Lesson 6.1 — Five income streams from one ridge

Stream	Buyer	Notes
Fresh roots, harvest season	Local and urban markets, traders	The base business — volume at glut prices
Stored roots, lean season	Same markets, 2–4 months later	Curing + storage premium of 50–150%; the margin maker
OFSP channels	Schools, nutrition programmes, bakeries (puree), weaning-food makers	Premium and contract-friendly; documentation and reliability required
Vine bundles	Neighbouring farmers each planting season	From your multiplication beds — clean material sells itself once your fields prove it
Fodder / processed products	Pig and dairy farmers; snack retail	Vines and culls become feed; chips/crisps/flour capture urban margins

Lesson 6.2 — An honest acre budget

Item	Assumption	Amount
Yield	Clean vines, ridges, 2 weedings, early harvest	~6 t/acre (15 t/ha)
Gross — sold at harvest @ $150/t	varies $80–$300/t by market/season	~$900
Gross — 2/3 sold cured in lean season @ $250/t	curing + store, 10% storage loss	~$1,200–1,350 total
Cash costs	Vines (first season), labour, modest inputs, sacks, transport	~$250–400
Indicative margin	with storage strategy	~$800–1,000/acre in 4–6 months

Note what drives the upside: not more hectares — curing/storage timing, clean vines, and early harvest ahead of the weevil. All three are knowledge, not capital.

Lesson 6.3 — Selling OFSP into programmes

School feeding, hospital and NGO procurement are real OFSP buyers across Africa, and they buy on paperwork as much as product: consistent variety, agreed volumes and delivery days, basic records. Your five-line notebook plus your extension office's variety certification are usually the entry ticket. Groups again beat individuals — five OFSP growers with staggered plantings can hold a school contract no single acre can.

Lesson 6.4 — Records and the rotation engine

Notebook lines for this crop: planting date and vine source per block; weeding/earthing dates; harvest date, tonnage and weevil-damage percentage per block; curing dates and storage losses; sales by month, form and price. The weevil-damage column is your management report card — watch it fall as your hygiene tightens. Grow by running sweet potato as the fast module inside a rotation (maize/legume/sweet potato), never back-to-back on the same land, with your vine nursery as the constant clean-material engine — and one processing or programme channel added per year.

📺 Watch it done: Five income streams from one ridge — sequencing them across the year. Open curated video search → The written lesson above is complete on its own — the video is optional reinforcement.

Practical Assignment — Month 6: Using your trader price-calendar from Month 1 and your own harvest data, build your version of the acre budget two ways: all sold at harvest, and 2/3 stored for lean-season sale. Interview one potential premium buyer (school, programme, bakery, or vine customer) about requirements. Conclude with one paragraph naming the two income streams you will run in year one.

Month 6 Quiz — 10 Questions

Answer every question. Aim for at least 7/10 before marking this month complete. Each answer comes with an explanation — read them even when you are right.

1. The margin-making income stream in sweet potato is usually:

Why: Production gets you to average; storage timing gets you to profit. Curing knowledge converts the glut-month crop into lean-month revenue — the crop's single biggest lever.

2. The three upside drivers in the acre budget are notable because they are:

Why: None of the big levers requires money so much as discipline: a shaded curing stack, refreshed planting material, and digging on time. This is why sweet potato is such a strong first enterprise.

3. Institutional OFSP buyers (schools, programmes) purchase largely on:

Why: Programme procurement needs predictability. Your notebook, a certified variety and delivery discipline are the entry ticket — and grower groups with staggered plantings hold contracts individuals cannot.

4. Selling vine bundles is a genuine business because:

Why: A multiplication bed plus visibly healthy fields turns you into the district's seed supplier. As with cassava cuttings, reputation for cleanliness IS the product.

5. The weevil-damage percentage column in your records serves as:

Why: Weevil damage integrates every Module 4 practice into one number per block. Tracking it turns an invisible enemy into a measured, managed one.

6. Sweet potato's correct place in rotation is:

Why: Continuous sweet potato breeds weevils and SPVD; rotation starves both and lets the crop scavenge residual fertility. The vine nursery, not the old field, carries material between seasons.

7. A ~10% storage loss assumption in the budget reflects:

Why: Even good stores lose some roots to rot, sprouting and shrinkage. Budgeting the loss honestly — and inspecting fortnightly — keeps the storage strategy profitable rather than theoretical.

8. Culled, weevil-tunnelled roots at harvest should be:

Why: Culls in market sacks destroy your buyer's trust; culls left in the field breed next season's weevils. Feed or bury — the sorting decision protects both reputation and rotation.

9. For a farmer with pigs or dairy animals, the sweet potato field additionally provides:

Why: At 16–20% protein, final-harvest vines are a serious feed resource. Mixed farmers effectively grow roots at a discount — a direct bridge to the Piggery course.

10. Sensible growth for a sweet potato enterprise is:

Why: The base rotation plus curing generates cash; each year that cash funds one new channel — vines, OFSP contract, chips — each with its own learning curve. Stepwise, recorded, compounding.

🏆 Final Project: Your Sweet Potato Business Plan

The final project assembles everything into a plan for a sweet potato enterprise you could start with the next rains — small in cash, precise in knowledge.

Market and variety: chosen variety (or white + OFSP pair) with your price calendar and buyer evidence.
Material plan: clean vine source, your multiplication bed layout and refresh schedule, and nursery hygiene rules.
Field plan and calendar: ridge layout, planting date, both weeding/earthing dates, target harvest week, and next season's rotation and field location.
Weevil defence page: your five-part plan, written as commitments with dates, plus the damage-percentage target you will record against.
Curing and storage plan: where and how you will cure, your store type, inspection schedule, and the share of crop held for lean-season sale.
Budget and cash-flow: adapt the startup table with local prices; show the two sales scenarios (harvest-sale vs storage strategy) side by side.
Risk page and year-3 vision: three risks with mitigations, and which income streams you add in years two and three.

Submission standard: A plan you could hand to a savings group, a bank officer, or a family investor without embarrassment. Real local prices, real named buyers, honest risks.

💰 Startup Budget — 1 Acre (0.4 ha) + Vine Nursery + Curing/Storage Setup

Sweet potato is among the cheapest serious crops to start — the vine nursery makes planting material a one-time purchase, and curing needs shade and grass, not machinery. Budget assumes family labour for routine work.

Item	Details	Typical cost (USD)
Land preparation & ridging	Ploughing/digging, making ~30 cm ridges	$40–100
Planting material (first season only)	Clean/certified vines for 1 acre + nursery stock	$30–90
Vine nursery bed	Bed preparation, watering cans/drum, shade	$15–40
Planting labour	Cutting tips, planting, gap-filling	$20–50
Weeding × 2 + earthing up	Hired or family labour equivalent	$40–100
Manure/compost + wood ash/K	Modest K-led programme	$25–80
Tools	Hoes, fork or digging sticks, knife, baskets	$25–50
Curing & store setup	Shaded rack/stack area, grass/sacking, slatted store or lined pit, sacks	$30–80
Harvest & transport, first sales	Sacks, transport to market	$30–80
Contingency (10%)		$25–65
Total indicative startup	First income in 3–5 months; vines self-supplied thereafter	$280–735

Prices vary widely by country. Before spending anything, price every line in your own town and rebuild this table — that exercise is part of your final project.

📚 Glossary

OFSP: Orange-fleshed sweet potato — beta-carotene-rich varieties bred against vitamin A deficiency; premium in nutrition and bakery channels.
Beta-carotene: The orange pigment the body converts to vitamin A; destroyed by prolonged heat and light, hence fast drying and dark storage.
Dry matter: The non-water fraction of the root; high dry matter gives the firm 'mealy' texture traditional markets prefer.
Tip (apical) cutting: A 25–30 cm vine tip — the standard planting material, carrying the least virus and fewest weevil eggs.
Vine multiplication bed: A small watered bed producing thousands of clean tip cuttings per season by cut-and-regrow harvesting.
SPVD: Sweet potato virus disease — the whitefly/aphid-borne complex behind yield run-down in recycled vines; managed by roguing, resistant varieties and material refresh.
Cylas / sweet potato weevil: The crop's most destructive pest; larvae tunnel roots, triggering bitter terpenes that ruin them. Controlled culturally, not chemically.
Earthing up: Pulling furrow soil onto the ridge to bury weeds, deepen the root zone and seal the soil cracks weevils enter through.
Crack sealing: Keeping ridge soil unbroken (earthing, mulch, moisture) so adult weevils cannot reach the roots.
Roguing: Uprooting and destroying virus-symptomatic plants in field and nursery.
Curing: Holding fresh roots 4–7 days warm (27–30°C) and humid so wounds heal and skin toughens — the step that extends storage to 3–5 months.
Wound periderm: The new corky skin that forms over harvest wounds during curing, sealing out rot organisms.
Pit store: A traditional grass-lined, capped storage pit; effective for cured roots when protected from rain and rodents and checked regularly.
Lean season: The months after the harvest glut when supplies shrink and prices rise 50–150% — the target of the curing-and-storage strategy.
Puree: Steamed, mashed OFSP sold as a bakery and weaning-food ingredient; perishable, so produced against confirmed contracts.
Volunteer plants: Self-grown plants from leftover roots/vines that harbour weevils and virus between seasons; removed during sanitation.

🔗 Further Resources

International Potato Center (CIP) — the global sweet potato research body; free OFSP variety information, vine multiplication ('Triple S' and rapid multiplication) guides and curing/storage manuals for Africa.
Your national root-crops programme and extension office — released varieties for your district, SPVD/weevil resistance ratings, and certified vine multiplier contacts.
FAO and HarvestPlus materials on OFSP and biofortification — the nutrition evidence and programme-market landscape behind the OFSP premium.
National school-feeding and nutrition programme offices — the actual buyers for OFSP contracts; ask for supplier requirements early.
Rise Africa Skills companion courses: Piggery and Rabbit Farming (vine fodder link), Solar Drying (chips and OFSP flour), Beans & Legumes (rotation partners and the lean-season storage logic).

🎓 Course Completion

Complete all 6 months and pass the quizzes to unlock your Business Seed Record.

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