Characterization of vegetative and grain filling periods of winter wheat by stepwise regression procedure, II: Grain filling period

Abstract

In wheat, rate and duration of dry matter accumulation and remobilization depend on genotype and growing conditions. The objective of this study was to determine the most appropriate polynomial regression of stepwise regression procedure for describing grain filling period in three winter wheat cultivars. The stepwise regression procedure showed that grain filling is a complex biological process and that it is difficult to offer a simple and appropriate polynomial equation that fits the pattern of changes in dry matter accumulation during the grain filling period, i.e., from anthesis to maximum grain weight, in winter wheat. If grain filling is to be represented with a high power polynomial, quartic and quintic equations showed to be most appropriate. In spite of certain disadvantages, a cubic equation of stepwise regression could be used for describing the pattern of winter wheat grain filling.

Stopa i trajanje akumulacije suve materije u zrnu zavisi od genotipa i uslova gajenja. Cilj ovoga istraživanja bio je da se metodom hijerarhijske višestruke regresije odredi matematički model nalivanja zrna kod tri sorte ozime pšenice. Ovaj metod je pokazao da je nalivanje zrna kompleksan biološki proces, i da je teško odrediti jedinstvenu i odgovarajuću matematičku jednačinu koja bi određivala promenu u sadržaju suve materije u zrnu od cvetanja do postizanja maksimalne mase zrna. Primenom navedenog metoda utvrđeno je da se promena u masi zrna tokom njegovog nalivanja može predstaviti polinomom četvrtog ili petog stepena. Pošto se radi o prilično komplikovanim jednačinama predlaže se primena, kubna jednačina, uprkos njenim određenim nedostacima.