Figure 5. Traits difference between different nitrogen and
water treatments of Wedelia trilobata and Wedelia
chinensis based on Pearson Correlation under monoculture. For each cell
green, orange and red square respectively, indicate Positive, zero and
negative percentage difference in the traits value between Wedelia
trilobata and Wedelia chinensis under each treatment.
RGRB, relative growth rate of total dry weight,
RGRSl, relative growth rate of stem length, SWR, stem
weight ratio, RWR, root weight ratio respectively.
WT could increase its growth and physiological
performance under nitrogen and flooding treatments, particularly in the
competition (Fig. 2), because Water and nitrogen are the most important
factors for growth and development (Liu et
al., 2018c, Tulloss and Cadenasso,
2016). Generally, the role of nitrogen along with water promotes plant
growth with increasing plant height, DW, and RGRB(Čuda et al., 2017,
Wang et al., 2016b);
that trend was also found in this
study (Table 2, Fig. 2 and Fig. 5). DW of WT was higher
under mixed culture because of taller plant height and higher leaf area,
that was plant strategy to cope with flooding conditions because higher
plant height makes the plant able to get connect with sun light for
photosynthesis process (Zhao et al.,
2015) and reduce the effect of oxygen deficiency that was created by
flooding conditions (Strange et al.,
2018). Higher leaf area enhances its photosynthesis and transpiration
capacity under flooding and nitrogen enrichment conditions
(Wang et al., 2016a,
Parepa et al., 2019). Therefore,
WT has higher ability for resource absorption than
WC and also has higher relative growth rate along with
reduced resource investment per unit area under combination of nitrogen
and flooding (Dalmolin et al., 2012),