New method to determine FAO number of maize, Zea mays L.

Abstract

FAO numbers are generally calculated from the grain moisture at harvest, which has decreased substantially in recent decades. In many countries maize is now harvested with a grain moisture of around 20 %. However, the lower the grain moisture at harvest, the smaller the difference in grain moisture between the maturity groups and/or individual hybrids. The reliability of grain moisture measurements has not improved parallel to the decline in the differences between hybrids, making it difficult to determine the maturity dates of the hybrids reliably. A new method has been elaborated to solve this problem and has been successfully used for the last two years in official trials in Hungary. The new method has several advantages: (a) more maturity parameters are taken into consideration, so the evaluation of more data improves reliability, (b) regression between the maturity parameters and the FAO number is calculated using several standards, thus reducing the effect of the G x E interaction and the experimental error. As a result, the annual fluctuation in the FAO number for each 1 % grain moisture is reduced.FAO brojevi, koji oznacavaju grupu zrenja kod kukuruza , generalno se izracunavaju na osnovu sadrzaja vlage pri berbi, koja se znacajno smanjila u poslednjim dekadama. U mnogim zemljama kukuruz se bere sa sadrzajem vlage u zrnu oko 20%. Smanjenjem sadrzaja vlage u zrnu pri berbi smanjuje se razlika u sadrzaju vlage izmedju grupa zrenja i/ili izmedju pojedinih hibrida. Pouzdanost merenja sadrzaja vlage u zrnu nije poboljsavana paralelno sa smanjenjem razlika izmedju hibrida sto otezava odredjivanja datuma sazrevanja hibrida. Novi metod za resenje ovoga problema je testiran i uspesno koriscen poslednje dve godine u oficijelnim eksperimentima u Madjarskoj. Novi metod ima nekoliko prednosti: (a) Koriscenje veceg broja parametara zrelosti sto daje pouzdanije rezultate ocenjivanja; (b) Regresija izmedju parametara zrelosti i FAO brojeva se izracunava koriscenjem nekoliko standarda tako da se smanjuje efekat G x E interakcije i eksperimentalna greska. Kao rezultat se javlja godisnje smanjenje fluktuacija FAO brojeva i za 1 % vlage.