Grain yield and kernel setting of multiple-shoot and/or multiple-ear maize hybrids

ROTILI, D.H.; ABELEDO, L. G.; MARTINEZ LARREA, S.; MADDONNI, G. A.

FIELD CROPS RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2022

0378-4290

Rainfed maize ( Zea mays L.) crops in low-rainfall regions are cultivated at very lowplant population densities that favor the production of fertile tillers or multiple ears inthe main shoot. Little information exists regarding the functional processes governinggrain yield and kernel setting on ears of different order of shoots of maize crops. Tostudy these functional processes, field experiments were conducted cultivating twocommercial maize hybrids (AX7784 and DM2738) under supplementary irrigation usingdifferent plant densities, N rates at sowing, shading around female flowering (silking)and tiller removal treatments. Hybrids differed in the number of tillers per plant at R 1(AX7784 > DM2738). Early tiller removal increased main shoot growth rate aroundsilking, suggesting competition for light among shoots. Kernel number per plant waspositively and curvilinearly related with plant growth rate around silking, i.e. criticalperiod (PGR CP ), in tillered and non-tillered plants of both hybrids. Tillered plants sethigher kernel numbers than non-tillered plants at PGR CP > 9 g pl -1 d -1 (AX7784)or 11 g pl -1 d -1 (DM2738), while the opposite trend occurred at PGR CP values AX7784) and tillers(AX7784 > DM2738). The different pattern of kernel setting between hybrids wasexplained by differences in the biomass partitioning to tiller ears and the reproductiveefficiency of ears of tillers (AX7784 > DM2738), and both the biomass partitioning toand the reproductive efficiency of second and third order ears of main shoots (DM2738> AX7784). Kernel number per plant was higher for DM2738 due to a higher kernelsetting on multiple ears of main shoot plus tillers (more prolific and with lower tillerfertility) than for AX7784 (less prolific and with higher tiller fertility). However, grain yielddid not differ between hybrids, because of the highest kernel weight of AX7784.Therefore, this work opens avenues for exploiting higher grain yields in maize cropswith low plant population densities through the combination of prolificacy and tillering.Further studies should analyze the impact of reproductive plasticity on kernel weightdetermination in low-density maize crops.