74 Srđan Šeremešić, Ivica Đalović and Dragiša Milošev
At the same time, the real yield potential of wheat was not fulfilled, most
probably due to the poor adaptation to unfavorable climatic conditions
(Šeremešić et al., 2015), absence of fertilization (MW and MSW) or
insufficient weed management. In recent years weed control represent a
important issue in the winter wheat cropping. Nikolich et al., (2012) examine
the weed flora on the long-term field trial to determine weed role in yield
manifestation. The total of 49 weed species from 44 genera, classified in 23
families was determined. The most numerous representatives were from the
family Asteraceae with 6 species and Lamiaceae, Fabaceae and Poaceae with 4
species each. With regard to floristic diversity, significant differences can be
determined between certain variants of crop rotation and fertilisation, as well
as between the studied periods (Kovačević, 2008). In the first research (1990)
there were 16 differential species which were not found in 2010. However, in
the second period (2010) there were 13 new weed species that had not been
determined in the 1990. However, after twenty years, there was a considerable
reduction in the number of weed species in all the studied variants of the
experiment, and in certain variants the number of species decreased almost by
half (Nikolić et al., 2008). After twenty years, the dominance of therophytes
was observed which derived from the anthropogenic effects i.e., instability of
weed synusia.
CONCLUSION
Grain yield of winter wheat showed stagnating trend in the recent decade
compared to period 1980/90 when yield and yield stability was higher. Its
production in the Southern Pannonian Chernozem soil depends on the soil
properties influenced by different crops that rotate with winter wheat, tillage
practices and climatic conditions. Higher yield could be obtained only with the
multiyear rotation that include legume and with balanced fertilization. To
improve winter wheat production soil management must be focused on winter
wheat requirement. Our study suggested that winter wheat has a positive
influence on the soil physical and chemical properties that must be considered
in the designing the cropping systems to alleviate future challenges of the
global warming.