Context
Between 1980 and 2003, the potato crop area has gone from 8386 ha to 22428 ha in Wallonia. The importance of this production linked to the development of the transformation industry and increases from 3 to 5 % each year.The potato production is a chain of excellence which is also true for the exportation.
However, we must keep in mind that potato is a speculative market whose qualitative constraints (PSE, coloration indication when frying, sugar content, aspect, calibres, …) are important, even determining.
The interval between the production and the consumption period make it necessary to store potatoes during a more or less long period.
Economic constraints linked to potato storage depend on the structure of the building (insulation, materials, ventilation, …) and of its management (time of ventilation, utilisation of an air-cooled system, …). The price proposed on the free market depends on the supply and demand, but also on the quality of the product. For potatoes sold under contract with an industry, the price fixed when signing the contract can be reduced if the product delivered does not meet the required quality standards (coloration when burning, presence of internal sprouts, …). If the quality is thought to be insufficient, the batch can be refused.
It is therefore essential that farmers take into account the increase of the benefit made after having sold a product of a better quality, directly following from the investment made in the storage hall (improvement of the insulation, installation of a ventilation system, …).
Objectives
This project aims at carrying out a thorough technico-economic study of potato stores. These last years, the FIWAP received many demands of information from the sector, storage being a key factor of the potato production.Results obtained
Situation in WalloniaAn important lack of data concerning the storage capacity and the storage method in Wallonia was noticed. Starting from existing data (FIWAP, CARAH, BELFYT, …) a survey was carry out on a representative sampling of producers, for the different speculations. This survey aimed at making the practical inventory of the advantages and disadvantages of the different storage methods (ventilated hall, unventilated hall, with complete duckboard, external shafts, …) and to make them available by writing sensitization articles. Observations made during storage We often notice an important heterogeneity of the temperatures in the hall (more than 2 to 3° C within the same batch of potatoes). This leads to condensation problems and potential preservation problems. The variations within the batch, as well as their causes, such as a bad working of the ventilation, the presence of earth and humidity in batches, badly located shafts or lack of shafts, insufficient insulation (walls, doors, roof) were studied during two years of storage. Temperature, ventilation, CO2 rate, weight losses as well as the quality evolution of the product were registered. This follow-up allowed to show the main problems for each types of buildings and their impact on the quality of the stored potatoes. All these observations were made in typical halls being representative of each speculation.
Technico-economic studies
Big types of infrastructures listed in the inventory While taking the production costs as well as the incomes into account (very fluctuating free market, contract prices, prices changing during the season), it is important to make an economic and energy assessment considering the insulation (types, materials, …), the air distribution system (duckboards, gutters, …), the ventilation and the different investments (infrastructure, air-cooled system, …). For each buildings type (potatoes for the fresh market, potatoes for industrial transformation and seed) a cost per m² was assessed.
Rehabilitation or improvement of existing halls
This study was made in order to assess the necessary investment costs to the improvement of the performances of an existing storage hall or of its rehabilitation. The costs linked to the change of the structural parameters of the hall (insulation, ventilation, air distribution, …) were connected to the added value of the product, to its profitability improved by these investments.
Partners
Walloon Potatoes Organization , farmersCRAW off coordinator
CRA-WFunding
- DGARNE
