Competition for Nutrients between Cold-Tolerant Maize and Weeds

Maize is a significant crop in Hungary, cultivated on about 1.3-1.5 million ha, approximately 25% of the total arable land. Dense weed infestation of maize can result in significant yield reduction because of the competition for water and nutrients. Adequate fertilization is an important factor for the development of maize but it also enhances weeds growth. Therefore, strong competition for nutrients can occur between the crop and weeds. Recently, hybrid maize, which is tolerant to the cold weather, has been introduced in Hungary. In a field experiment, we assessed the weed cover, development of the weeds, and the rate of the infestation of weeds in competition with this cold-tolerant hybrid. The field trial was conducted in 2010 in Hungary, Zala County, close to the town of Keszthely in field conditions with plot size of 0.1 ha in four replicates. Plant samples were taken from crop and weeds at different intervals of growth. The fresh weight, dry biomass, and nutrient content of maize and weeds were measured. The early development of weeds was very dynamic and strong in the cold-tolerant maize cultures. On the 12th week after sowing, the maize biomass was 64% less than the weed-free maize as a result of the competition. Threefold difference was found in the biomass production of maize between the weedy and the weed-free experimental plots. The difference in potassium (P) content was also similar to that of the biomass production. The P content of maize was 3.17 times greater and the calcium (Ca) content was 3.24 times greater in samples collected from weed-free areas. The biggest difference was observed in the case of nitrogen (N) content. It was 4.73 times greater in the weed-free maize than in the weedy plots. This result shows that the competition for N was very strong between the maize and the weeds.