This work deals with the regional characteristics of the supplied irrigation effect on the cereal yield in Tunisia. It underlines the value of the knowledge how scientifically brought to farmers. This study analyses the results of an inquiry carried on over seven consecutive years at the level of two categories for farmers practising irrigated wheat farming. The first category of farmers is taking advantage of a set of the technological support actions which related both to the vulgarization of different forms of technological innovations and the miscellaneous forms of support in kind, while the second category of farmers is granted no form of support. The specification of the different regions studied in Tunisia and the comparison of the two farmers categories studied is brought out by the Principal Components Analysis technique and the PLS regression. The mastering of the irrigation waters use, the rationalization of the fertilization as well as the soil exploitation in the north of the country are better valorised by the supported farmers.
