The distribution of weeds in the maize-soybean intercrop

Abstract

Weeds have been a limiting factor in agriculture since the beginning of its development. With the intensive cultivation of certain corps, weeds, due to their great adaptability, have evolved to be more or less resistant to common systems of suppression. This weed resistance has lead to the increased use of herbicides, which furthermore has increased the total production costs and risks to the environment and human health. Therefore, other, alternative measures for weed suppression should be applied. Weed control measures are one of the natural ways of solving problems related to crop weediness, which can be achieved by special systems of cropping in which intercrops have an important role. The aim of this study was to determine the effects of different maize hybrids and spatial maize-soybean intercrop patterns on the floristic composition of the weed community in spring. The trial was carried out according to the additive intercropping system under rainfed conditions in the experimental filed of the Maize Research Institute, Zemun Polje on chernozem in 2003 and 2004. The weed community in the maize-soybean intercrop consisted of 15 weed species during the two-year studies. Solanum nigrum (L.) and Amaranthus retroflexus (L.) were dominant annual weed species, while Sorghum halepense (L.) Pers. prevailed among perennial weed species. The greatest, i.e. lowest number and weight of weed species were measured in monocrops, i.e. in maize-soybean intercrop sown in alternate rows (29.3 m-2), respectively.

Korovi su oduvek bili ograničavajući faktor poljoprivredne proizvodnje, od samih njenih početaka pa do danas. Intenziviranjem gajenja pojedinih useva korovi su, zahvaljujući velikoj sposobnosti prilagođavanja, postali manje-više, otporni na uobičajene sisteme suzbijanja. Otpornost korova je dovela do povećane upotrebe herbicida, što je, takođe, povećalo ukupne troškove proizvodnje i rizik za životnu sredinu i zdravlje samih ljudi. Zbog toga je potrebno primeniti i druge, alternativne mere suzbijanja korova. Jedan od prirodnih načina rešavanja problema zakorovljenosti useva jesu mere kontrole korova, što se može postići posebnim sistemima zemljoradnje, u kojima združeni usevi zauzimaju važno mesto. Cilj ovog rada bio je da se utvrdi uticaj različitih hibrida kukuruza i prostornog rasporeda kukuruza i soje u združenom usevu na floristički sastav korovske sinuzije u prolećnom aspektu. Ispitivanje je obavljeno na oglednom polju Instituta za kukuruz u Zemun Polju na černozemu u 2003. i 2004. godini. Ogled je izveden po sistemu aditivnog načina združivanja (additive intercropping system) u uslovima prirodnog vodnog režima. Korovsku sinuziju združenih useva kukuruza i soje tokom dvogodišnjih ispitivanja činilo je 15 vrsta korova. Dominantne korovske vrste bile su: Solanum nigrum (L.) i Amaranthus retroflexus (L.) od jednogodišnjih, i Sorghum halepense (L.) Pers. od višegodišnjih. Najveći broj jedinki i najveća masa korova izmereni su u čistim usevima, a najmanji u združenom usevu kukuruza i soje združivanih po principu naizmeničnih redova (29,3 po m2).