Addressing the yield by density interaction is a prerequisite to bridge the yield gap of rain-fed wheat


  • I.S. Tokatlidis

    Corresponding author
    1. Department of Agricultural Development, Democritus University of Thrace, Orestiada, Greece
    • Correspondence

      I.S. Tokatlidis, Department of Agricultural Development, Democritus University of Thrace, Pantazidou 193, Orestiada 68200, Greece. Email:

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Environmental variability induced by climate change is connected with inter-annual variation in grain yield of rain-fed wheat. Density-dependent cultivars, relying on high populations, usually vary in optimum population. The optimum population is primarily affected by the water regime, while sowing date, heat, terminal drought, frost and type of soil are also indicators. These forces make it difficult to estimate optimum population on the basis of the expected yield level. Furthermore, accounting for the difficulty in foreseeing long-term weather by variation in the planting versus seeding ratio, an appropriate population might be hard to establish and thus, harvested yield lags behind the highest possible yield. The greater the reliance on high populations, the larger the potential level of this gap and poor yield performance of individual plants is the root cause. Thus, while for drought-prone environments cultivation at lower populations is prudent, cultivars that fall short of efficient resource capture at the single-plant level demand much higher populations for seasons with adequate rainfalls. Therefore, flexible density-independent cultivars performing well at wide range of populations are imperative to meet the future demands in the matter of sustainability and food adequacy. The goal appears attainable through improvement of the single-plant performance, and the implementation of breeding for yield compensation components offers such a possibility.