The widest proportional margin in this week's Lagos data sits on a single yam tuber, and it is a margin with a date on it. The Ministry of Agriculture and Food Systems market survey for the week of 17 July 2026 records Medium Sized Yam at ₦2,300 at Epe Main Market and ₦5,000 at Ile-Epo Market, a difference of ₦2,700 or 117% on the same tuber in the same week.
Ile-Epo Sits Alone at the Top
The Lagos average is ₦3,380 across ten markets, which puts Ile-Epo 47.9% above the citywide figure and Epe 32.0% below it. Mushin Market, Sabo Market Yaba and Agege Market all quote ₦2,800, Agbalata Market ₦3,200, and Oyingbo Market and Fresh Food Hub Mushin ₦3,500. Mile 12 Market sits at ₦3,900 and Ajah Market at ₦4,000, so the second dearest quote is ₦1,000 below the ceiling.
The Margin Has Been Widening
Yam is the fastest rising staple in the survey. The Lagos average climbed 5.3% from ₦3,210 in the prior week, 13.4% from ₦2,980 four weeks ago and 31.3% from ₦2,575 on 9 January. A rising market widens spreads because the markets that reprice fastest pull away from those that do not, and the reporting from other states matches the direction. A News Agency of Nigeria survey carried by Premium Times found medium tubers of old yam in Enugu at ₦3,000 to ₦5,000 in early July against ₦2,000 to ₦3,500 in May, and Blueprint reported the same range.
New Harvest Is the Deadline
The current window exists because old-crop stock has thinned ahead of a harvest that has not yet fully released. Festivals that formally open new yam consumption were under way through late July, with AgricNews Digest listing the Odi Ogori Ba Uge festival in Bayelsa running from 27 July to 2 August and Ekiti communities opening their harvest earlier in the month. A buyer quoted by Premium Times expected prices to stabilise during peak harvest. Anyone treating the ₦2,700 gap as a durable feature is betting against that.
Freight and Spoilage Against the Spread
Two costs sit between the quote and the margin. Transport has moved sharply, with Politics Nigeria reporting petrol at ₦1,400 per litre in parts of the country in late July and fares rising in several states, and Legit.ng noting that diesel powers the trucks moving food between regions. Supply risk is the other. Tribune reported NiMet flood warnings across 27 states alongside World Food Programme concerns, and traders in Enugu told Peoples Gazette that insecurity was keeping farmers from fields and buyers from northern supply points.
Where Households Sit in the Trade
Ajah Market is the only market on the Ajah and Lekki axis reporting a yam price, and its ₦4,000 sits 21% above the mainland average of ₦3,311. Nigeria's minimum wage is ₦70,000 a month, so the ₦2,700 gap is 3.9% of a month's wage on one tuber. A household buying four tubers a month at Epe rather than Ile-Epo keeps ₦10,800, which is 15.4% of the minimum wage.
Traders reading the same numbers should note what the spread is not. A 117% gap on a perishable tuber is not 117% of margin once haulage, loading, spoilage and the risk of arriving after the harvest has landed are subtracted. Six of the ten markets surveyed price between ₦2,800 and ₦3,500, so the realistic trade is not Epe to Ile-Epo but Epe into the middle of the market, where the gap is ₦500 to ₦1,200 and the buyer base is larger.
For households the calculation runs the other way. Anyone buying yam at Ile-Epo this week is paying the top of a market that has risen on every timeframe measured, and the alternatives are not distant. Three markets quote ₦2,800, ₦1,200 below the ceiling and ₦580 below the citywide average, which puts a meaningful saving inside the mainland cluster rather than only at the Epe extreme.
FoodPrices Nigeria will track whether the new harvest closes the gap. Live prices: foodprices.ng/real-time-prices