Weediness and grain yield of specialty maize hybrids cultivated with the application of ecological fertilisers

Abstract

Maize hybrids (Zea mays L.) with specific traits, such as those with red pericarp, high-protein flints or white kernel hybrids, have increased utility value as they contain some vitamins and minerals beneficial to human and animal nutrition. Furthermore, their cultivation with the application of specific fertilisers could further increase the grain quality through increased participation of macro- and micro-elements that are lacking in the diet. Agronomic biofortification encompasses the application of different production technology that enables better absorption and effective accumulation of essential elements such as iron, zinc, manganese, copper in the edible parts of cultivated plants. On the other hand, fertilisation influences the weed infestation levels and especially the presence of nitrophilic weed species in maize crop. The fertiliser application changes the balance in competition between crops and weeds, not only for nutrients but also for other resources. The effects of different fertilisers were compared within developmental research in the field of ecological agriculture to point up the advantages of microbiological and organic fertilisers, since these fertilisers can contribute to higher yields, but unlike mineral fertilisers, they positively affect the soil and agro-ecosystem. The studies were carried out to determine to what extent agronomic biofortification contributed to the increase of yielding potential and grain quality of maize genotypes with specific traits, as well as how it affected the occurrence and distribution of weeds. The red kernel maize hybrid ZP5048C, high-protein flint maize hybrid ZP737 and white kernel maize hybrid ZP552b, were grown in variants with mineral fertiliser urea, microbiological fertiliser Team Micorriza Plus and organic fertiliser Fertor, that contained essential elements necessary for the nutrition of cultivated plants. No fertiliser was applied to the control treatment. The fertilisation mainly contributed to the increase of weed mass in comparison with the non-fertilised control variant in extremely dry 2017. The highest weed mass was recorded in the hybrid ZP737 in the variant with organic fertiliser, while the lowest weed mass was recorded in all hybrids when microbiological fertiliser had been applied. The highest, i.e. lowest grain yield was recorded in the hybrid ZP5048C (5.83 t ha-1), i.e. ZP737 (3.36 t ha-1), respectively. The protein content was increased at the highest extent in the kernel of ZP737 hybrid after the application of urea, while oil and starch contents were the highest in the grain of white kernel hybrid ZP552b treated with microbiological fertiliser. Due to the specificities and importance of meteorological conditions, the studies will be continued during the next few seasons.

Hibridi kukuruza (Zea mays L.) specifičnih svojstava, poput onih sa crvenim perikarpom, tvrdunci sa povećanim udelom proteinske komponente ili hibridi belog zrna, imaju povećanu upotrebnu vrednost jer sadrže određene vitamine i minerale korisne za ishranu ljudi i životinja. Njihovim gajenjem, uz primenu određenih đubriva, moguće je dodatno povećati kvalitet zrna unošenjem makro i mikorelemenata koji inače nedostaju u ishrani. Agronomska biofortifikacija obuhvata različite mere gajenja kojima se omogućava bolja apsorpcija i povećana akumulacija esencijalnih mikroelemenata, kao što su gvožđe, cink, mangan, bakar i dr. u jestivim delovima gajenih biljaka. Primena đubriva značajno utiče i na nivo zakorovljenosti useva, posebno nitrofilnim vrstama korova. Unošenjem đubriva menja se balans u kompeticiji između useva i korova, ne samo za hraniva nego i za ostale resurse. U okviru razvojnih istraživanja iz oblasti ekološke poljoprivrede upoređivani su efekti primene različitih đubriva i ukazane su prednosti mikrobioloških i organskih đubriva. Ova đubriva takođe mogu doprineti većem prinosu, ali za razliku od mineralnih đubriva, pozitivnije utiču na zemljište i agroekosistem. Data ispitivanja su sprovedena kako bi se utvrdilo u kolikoj meri agronomska biofortifikacija utiče na pojavu i zastupljenost korova i doprinosi povećanju rodnog potencijala i kvaliteta zrna specifičnih genotipova kukuruza. Hibrid kukuruza crvenog perikarpa ZP5048C, hibrid tvrdunac sa povećanim procentom proteina ZP737 i hibrid belog zrna ZP552b gajeni su uz primenu mineralnog đubriva Urea, mikrobiološkog đubriva Team Micorriza Plus i organskog đubriva Fertor, koja sadrže neophodne elemente za ishranu gajenih biljaka. Na kontrolnoj površini đubrenje nije primenjeno. Rezultati su pokazali da u 2017. godini, koja je bila ekstremno sušna, ima značajnih razlika u nivou zakorovljenosti i nešto manjih razlika u prinosu zrna gajenih genotipova zavisno od vrste primenjenog đubriva. Najveća masa korova utvrđena je kod hibrida ZP737 nakon primene organskog đubriva, dok je najmanja masa korova kod svih hibrida zabeležena nakon primene mikrobiološkog đubriva. Đubrenje je uglavnom doprinelo povećanju mase korova u poređenju sa neđubrenom, kontrolnom varijantom. Najveći prinos zrna je imao ZP5048C (5,83 t ha-1), a najmanji ZP 737 (3,36 t ha-1). Sadržaj proteina najviše je povećan u zrnu hirbida ZP737 nakon primene uree, dok su sadžaj ulja i skroba bili najveći u varijanti sa mikrobiološkim đubrivom u zrnu ZP552b. Zbog specifičnosti i značaja meteoroloških uslova za delovanje đubriva na hibride kukuruza, ispitivanja će se nastaviti.