Selection of maize hybrids with risk-examination method

By examining the data of our polyfactorial long-term experiment carried out on chernozem soil with lime deposits at the Experimental Farm of Debrecen University of Agricultural Sciences we wanted to find out that out of the t hree given hybrids (AB,C) which and in what percentage we should grow in or der to achieve a certain yield with the possibly lowest yield-risk. The fac tors were the following: three types of fertilisation (no fertilisation, 12 0 kg N+90 kg P2O5 +106 kg K2O/ ha, 240 kg N + 180 kg P2O5 + 212 kg K2O/ha), three soil cultivation methods (without ploughing, with spring ploughing, with autumn ploughing), four types of plant density (60, 70, 80, 90 thousan d plants per ha) and two types of irrigation (irrigated and non-irrigated). The randomly arranged experiment was carried out for four years (1990-1993 ) and was repeated four times each year. It is a well known fact that the majority of growers try to reduce the risk of agricultural production. By using mean - variance criterion applicable for the decision-makers who are risk-averse, we have made plans which sugge st that at the lower parts of the possible yield range the cultivation of h ybrid B, while at higher yield levels hybrid C is recommended on a larger p roportion of land (both with irrigated and non-irrigated soil cultivation m ethods). We are going to prove that if the decision -maker chooses the plan which pr omises a lower yield, instead of the one with the highest yield perspective , then with a few percentage of yield loss he can achieve a higher percenta ge of yield-risk decrease.