Značaj veličine vegetacionog prostora za zakorovljenost i prinos kukuruza

The arrangement pattern, i.e. shape and size of vegetative space available to growing plants influences crop-weed competitive interaction and weed abundance. Most researches show that growing row crops such as maize, soybean, sunflower etc., with narrow row space, has as a result lower weed infestation and better yield parameters. In this study the effects of the maize vegetative space, which are achieved with combination of different row spaces and spaces between plants in the row, on the weed distribution and fresh matter and some morphological and productive parameters of maize were investigated. The crop density was the same for all arrangement patterns and herbicide application was included with three levels: full and half of the recommended dose and control without herbicide application. In all three years of investigation, the weed fresh matter declined with decreasing row spaces and was, on average, the lowest for the narrower row space and herbicide application at recommended doses (38,6; 12,8 and 351,1 g m-2). In such arrangement pattern of maize plants, significant influence on the fresh matter of D. stramonium, S. nigrum and A. retroflexus, was achieved. Herbicide application at half of the recommended dose also significantly influenced level of weediness compared to untreated control. The size of maize vegetation space significantly influenced grain yield in 2005 and 2006, otherwise, the herbicide application had a significant influence on maize yield in all years. Grain yield did not differ significantly according to LSD-test between treatments with full and half rate of herbicides.Prostorni raspored odnosno oblik i veličina vegetacionog prostora kojim raspolažu gajene biljke značajno utiče na kompeticijske interakcije između useva i korova a time i na zastupljenost korova. Rezultati većine istraživanja su pokazali da gajenje širokoredih useva kao što su kukuruz, soja, suncokret i dr. sa smanjenim međurednim rastojanjem, utiče na smanjenje zakorovljenosti ali i na parametre rodnosti. U radu je ispitivan uticaj veličine vegetacionog prostora koji je ostvaren kombinovanjem međurednog razmaka i razmaka između biljaka u redu u okviru iste gustine, u uslovima primene herbicida u preporučenim i smanjenim količinama, na zastupljenost pojedinih vrsta korova i njihovu biomasu kao i na neke morfološke i produktivne osobine kukuruza. Najmanja ukupna sveža masa korova je u sve tri godine, utvrđena na varijanti sa najmanjim međurednim rastojanjem i primenjenom kombinacijom herbicida izoksaflutol+acetohlor u preporučenoj količini (38,6; 12,8 i 351,1 g m-2). U takvom obliku vegetacionog prostora, značajno je smanjenja sveža masa vrsta D. stramonium, S. nigrum i A. retroflexus. Primena herbicida u polovini preporučene količine takođe je značajno smanjila nivo zakorovljenosti u poređenju sa netretiranom kontrolom. Veličina vegetacionog prostora značajno je uticala na prinos zrna kukuruza u 2005. i 2006. godini, dok je količina primenjenih herbicida vrlo značajno uticala na visinu prinosa u svim godinama. Međusobna poređenja visine prinosa između varijanti sa primenom herbicida u preporučenoj i polovini preporučene količine, na osnovu LSD-testa, nisu pokazale značajne razlike