Effects of a cropping system on weed association and yield parameters of maize

Abstract

Information on the effects of a certain cropping system on weed control and crop yields is necessary for an appropriate choice, adequate integration and timely application of various cropping practices into the system, which would provide the economic and ecologically safe production. Weediness can be controlled by growing maize hybrids in different densities, with the application of herbicides and irrigation as cropping practices. The combined employment of these practices is a part of the integrated weed management to whose successful application we have been aspiring for years. During the growing season in the period from 1996 to 1999, effects of irrigation and applied herbicides on the level of weed infestation and yield parameters of maize were studied. weed infestation was expressed through the number and the weight of weeds m-2. The plant height, leaf area, leaf area index and grain yield were observed in maize. weed infestation of maize differed depending on the application of both, irrigation and herbicides. The lowest, i.e. highest weed fresh weight was recorded under rainfed conditions and the application of herbicides (546.0 g m-2), i.e. on the untreated area under irrigation conditions (2573.1 g m-2), respectively. All investigated parameters of competitiveness and yielding of maize had statistically very significantly higher values under conditions of irrigation and the application of herbicides than under rainfed conditions without application of herbicides in all years of investigation.

Saznanja o stepenu delovanja određenog sistema gajenja na nivo zakorovljenosti i prinos useva neophodna su za pravilan izbor, adekvatno integrisanje i blagovremenu primenu agrotehničkih mera u sistem koji bi obezbedio ekonomičnu i ekološki bezbednu proizvodnju. Zakorovljenost se može kontrolisati gajenjem hibrida kukuruza u različitim gustinama, uz primenu herbicida i navodnjavanja kao agroekoloških mera gajenja. Kombinovana primena ovih mera čini deo integralnog sistema kontrole korova čijoj se uspešnoj primeni teži već duži niz godina. U periodu od 1996. do 1999. godine ispitivano je delovanje dva sistema gajenja kukuruza na nivo zakorovljenosti i parametre rodnosti kukuruza. Pored klasične obrade zemljišta i đubrenja mineralnim đubrivima koji su bili isti za oba sistema, prvi sistem gajenja su činili faktori prirodni vodni režim i primena herbicida a drugi sistem gajenja navodnjavanje i primena herbicida. Nivo zakorovljenosti je određivan na osnovu brojnosti i mase korova po m2 a kod kukuruza su praćeni visina biljke do vrha metlice, lisna površina, indeks lisne površine i prinos zrna. Zakorovljenost kukuruza se razlikovala zavisno od primene navodnjavanja i herbicida. Najmanja sveža masa korova utvrđena je u uslovima prirodnog vodnog režima i primene herbicida (546,0 gm-2) a najveća na netretiranoj površini u navodnjavanju (2573,1 g m-2). U svim godinama ispitivanja u uslovima navodnjavanja i primene herbicida uglavnom su svi ispitivani parametri kompetitivnosti i rodnosti kukuruza imali statistički vrlo značajno veće vrednosti u odnosu na uslove prirodnog vodnog režima bez primene herbicida,.