Effects of different cropping systems and weed management methods on free energy and content of pigments in maize

Abstract

Rotation is a cropping system that has many advantages and ensures better crop growth and yielding. Its combination with other cropping measures can ensure optimal crop density for maximal growth and photosynthesis efficiency. The aim of this study was to investigate the influence of different cropping systems: monoculture and two rotations, including maize, wheat and soybean (MSW and MWS), and different weed management methods (weed removal by hoeing, application of a full recommended herbicide dose (RD) and half that dose (0.5 RD), and weedy check) on weed biomass and maize growth parameters - leaf area index (LAI), free energy, contents of chlorophyll and carotenoids, grain yield, and their possible relationships in two fields of the maize hybrids ZP 677 (H1) and ZP 606 (H2). The lowest LAI and grain yield were found in monoculture, particularly in weedy check, which had relatively high weed infestation. Higher weed biomass was also observed in herbicide treated plots in monoculture. Such high competition pressure indicates a stress reflected on reduced LAI and chlorophyll content, and increased free energy and content of carotenoids. On the other hand, rotation, particularly if it is combined with the application of herbicides or hoeing, had a positive impact on yielding potential by increasing LAI and the contents of chlorophyll and carotenoids, and decreasing free energy.

Plodored, kao sistem gajenja ima brojne prednosti koje se ogledaju u boljem rastu i prinosu useva. Njegovom kombinacijom sa drugim merama gajenja moguće je obezbediti optimalnu gustinu za maksimalan rast i efikasnost fotosinteze. Cilj ovog rada je da se ispita uticaj različitih sistema gajenja: monokulture i dva tipa rotacija koja uključuju kukuruz, pšenicu i soju (MSW i MWS), zajedno sa različitim merama kontrole zakorovljenosti (okopavanje, upotreba preporučene (RD), polovine preporučene (0,5 RD) doze herbicida i kontrola bez uklanjanja korova) na biomasu korova, parametre rasta kukuruza - indeks lisne površine (LAI), slobodnu energiju, sadržaj hlorofila i karotenoida, prinos zrna, kao i njihove međusobne odnose kod dva hibrida kukuruza: ZP 677 (H1) i ZP 606 (H2)). Najniži LAI i prinos zrna bili su ostvareni u monokulturi, posebno u kontroli, zajedno sa relativno visokom zakorovljenošću. Veća biomasa korova je bila u tretmanima sa herbicidima u monokulturi. Ovakva situacija bi mogla da ukaže na prisustvo stresa koji se odražava na smanjenje LAI i sadržaja hlorofila, kao i povećanje vrednosti slobodne energije i karotenoida. Sa druge strane, plodored, posebno u kombinaciji sa herbicidima ili okopavanjem ispoljio je pozitivan uticaj na prinos preko povećanja LAI, sadržaja hlorofila i karotenoida i smanjenja slobodne energije.