Maize competitivenes and productivity under different crop densities

Abstract

Two or more integrated management practices can improve crop competitiveness and lower weed infestation. The crop density is one of factors which can improve crop competitiveness and may suppress weed at a relatively low cost. Its application in maize, as a broad-cast, spring crop, in the combination with a herbicide application, can, to a great extent, contribute to weed suppression and yield increase. Field studies were conducted during the 1996-1999 period at the Maize Research Institute, Zemun Polje. The 4-replicate trial was set up according to the RCBD. Effects of three different maize densities on fresh weight of weeds (g m-2) and the leaf area index and grain yield (t ha-1) of two maize hybrids were studied under conditions with and without herbicide applications. Data were processed by ANOVA. The increased maize density significantly reduced (P lt 0.05) the fresh weight of weeds and increased the leaf area index and grain yield (P lt 0.01). At the same time, the higher crop density (D1 to D3) was the significantly higher (P lt 0.01) leaf area index and grain yield were. The weed fresh weight leaf area index and grain yield of maize significantly differed over variants with and without herbicide applications. The crop density x herbicide application interaction resulted in very significant differences in the weed fresh weight. The lowest weed fresh weight (117.4 g m-2) was determined in the highest crop density on the area treated with herbicides. Obtained results point to the fact that weed infestation can be successfully controlled by the application of both higher densities of maize together with herbicide applications.

Kombinovanom primenom dve i više mera gajenja može se uticati na povećanje kompetitivnosti i smanjenje zakorovljenosti useva. Jedna od mera koja se, po relativno niskoj ceni, uspešno može primeniti u tu svrhu, je gustina useva. Njena primena u kukuruzu kao širokoredom, jarom usevu, u kombinaciji sa primenom herbicida, može dosta da doprinese smanjenju zakorovljenosti i povećanju prinosa. Istraživanja su sprovedena tokom 1996, 1997, 1998. i 1999. godine u Institutu za kukuruz "Zemun Polje". Ogled je bio postavljen po RCB dizajnu u četiri ponavljanja. Proučavan je uticaj tri različite gustine kukuruza na svežu masu korova (g m-2), indeks lisne površine i prinos zrna dva hibrida kukuruza (t ha-1) u uslovima sa i bez primene herbicida. Podaci su statistički obrađeni metodom analize varijanse (ANOVA). Povećanje gustine kukuruza uticalo je na značajno smanjenje (P lt 0,05) sveže mase korova. Istovremeno, indeks lisne površine i prinos zrna kukuruza su se vrlo signifikantno (P lt 0,01) povećavali sa povećanjem gustine od A1 do A3. Interakcija faktora gustina useva x primena herbicida, je uticala na vrlo značajne razlike u svežoj masi korova, tako da je najmanja sveža masa utvrđena na površini sa primenom herbicida u najvećoj gustini (117,4 g m-2). Sveža masa korova, indeks lisne površine i prinos zrna kukuruza su se vrlo značajno razlikovali između varijanti sa i bez primene herbicida. Prinos zrna kukuruza bio je vrlo značajno viši na tretiranoj površini, u gustini A2 u odnosu na A1, a kod hibrida C2, i u gustini A3. Dobijeni rezultati pokazuju da se gajenjem hibrida kukuruza u povećanim gustinama uz primenu herbicida, može uspešno kontrolisati nivo zakorovljenosti.