Cropping systems affect photosynthetic pigments and grain yield in maize

Abstract

Maize is still widely growing in monoculture, due to its domination in sowing structure. Nevertheless, rotation, as cropping system has many advantages in regard to monoculture, revealing through better crop growth and yielding. The aim of this experiment was to evaluate different cropping systems, which include maize monoculture (M), maize-winter wheat-soybean (MWS) and maize-soybean-winter wheat (MSW) rotations, with different weed control measures: full and half of herbicide doses, weed removal by hoeing and control – without weed removal, on dry mass (DM), concentration of chlorophyll a, chlorophyll b and carotenoids in aboveground maize biomass, as well as grain yield during three seasons. Obtained results referred that DM accumulation in above ground biomass highly correlated with carotenoids concentration in maize leaves and that full dose of herbicides is an important strategy for greater DM accumulation. MSW is the most promising cropping system to achieve high grain yield of maize, what is possible tied to low variations in all three photosynthetic pigments, indicating that this system enables better conditions for assimilation and crop growth. Higher values of chlorophyll a, as found in treatment with weed removal, are important for maize productivity. What is more, carotenoids role is emphasized again, having primary role in chlorophyll a protection against oxidative stress, thus contributing to optimal assimilation and increased grain yielding potential.

Najšire rasprostranjen način gajenja kukuruza je monokultura zahvaljujući njegovoj dominantnosti u setvenoj strukturi. Međutim, plodored ima brojne prednosti u odnosu na monokulturu koje se ogledaju u boljem rastu i prinosu useva. Cilj eksperimenta je da se uporede različiti sistemi gajenja koji uključuju monokulturu kukuruza (M), kao i rotacije kukuruz-ozima pšenica-soja (MWS) i kukuruz-soja-ozima pšenica (MSW), u kombinaciji sa različitim merama kontrole zakorovljenosti: puna i polovina doze herbicida, uklanjanje korova okopavanjem i kontrola – bez kontrole zakorovljenosti, na suvu masu (DM), koncentraciju hlorofila a i b i karotenoida u nadzemnoj biomasi kukuruza, kao i prinos zrna, na kraju vegetacije tokom tri sezone. Dobijeni rezultati ukazuju da akumulacija suve mase nadzemnih delova u visokom stepenu korelira sa promenama koncentracije karotenoida u listovima kukuruza i da je puna doza herbicida važna strategijacza veće nakupljanje suve mase. MSW se pokazao kao najperspektivniji sistem za povećanje prinosa zrna kukuruza, što je najverovatnije povezano sa smanjenjem u variranu fotosintetskih pigmenata, što upućuje da upravo ovaj sistem gajenja omogućava bolje uslove za asimilaciju i rast useva. Povećanje vrednosti hlorofila a, posebno u tretmanu gde su korovi ručno uklanjani su vrlo važne za produktivnost kukuruza. Važna uloga karotenoida je iznova istaknuta, preko zaštite hlorofila a od oksidativnog stresa, što doprinosi optimalnoj asimilaciji i povećanju potencijala rodnosti kukuruza.