The application of standard si units and thermodynamics in determination of herbicides’ influence to maize inbreeds: 3. The low temperature effect

Abstract

The five maize inbred lines were subjected to concomitant treatments of herbicides: EPTC, alachlor and S-metolachlor and extended low temperature (22°C during 6 days and 10°C during 15 days). The fresh and dry substance and water content were determined. The calculated parameters fluctuated: concentration between 72 and 219 g L- 1; then, pseudo-specific density between 47 and 51 µmol mg -1. The free energy, spend for 1 mg of dry substance biosynthesis was higher in low temperature conditions and in alachlor treatment at both temperature conditions. Meanwhile, the changes of differential free energy, enthalpy and entropy, as thermodynamical parameters, followed the changes of fresh, dry substance and water volume in root and shoot of examined inbreeds, therefore the inbreeds with lower values of differential free energy, enthalpy and entropy had the higher tolerance to herbicide treatments.

Pet samooplodnih linija kukuruza bilo je izloženo kombiniovanom tretmanu herbicida: EPTC, alachlora i S-metolachlora u kombinaciji sa produženom niskom temperaturom (22°C tokom 6 dana i 10°C tokom 15 dana). Određivan je sadržaj sveže i suve supstence i sadržaj vode. Obračunski parametari su varirali: između 72 i 219 g L-1, zatim, pseudo-specific density između 47 I 51 µmol mg -1. Slobodna energija, utrošena za biosintezu 1 mg suve supstance imala je niže vrednosti pri nižoj temperature i u tretmanu sa alahlorom, u oba temperaturna režima. Takođe, promene diferencijalne slobodne energije, entalpije i entropije, kao termodinamičkih parametara, pratile su promene sveže i suve supstance i sadržaj vode u korenu i izdanku svih ispitivanih linija. Sa druge strane, linije koje su imale niže vrednosti diferencijalne slobodne energije, entalpije i entropije, imale su i veću tolerantnost prema upotrebljenim herbicidima.