Chlormequat chloride and ethephon affect growth and yield formation of conventional, naked and dwarf oat

Abstract

Department of Plant Production, PO Box 27, FIN-00014 University of Helsinki, Finland. Current address: MTT Agrifood Research Finland, Plant Production Research, FIN-31600 Jokioinen, Finland. e-mail: pirjo.peltonen-sainio@mtt.fi Plant growth regulators (PGRs) are not usually applied to oat (Avena sativa L.) crops. This study was designed to test whether the antigibberellin chlormequat chloride (CCC) and ethylene-releasing ethephon sprayed on to oat foliage represent potential agents for manipulation of yield formation under northern growing conditions. Effects of these PGRs on yield components and tiller growth and productivity were examined in detail. This study included a long-strawed landrace, a modern standard height cultivar, two naked (A. sativa ssp. nuda L.) and two dwarf oats. Field experiments were conducted at Viikki Experimental Farm, University of Helsinki, in 1995 and 1996. Chlormequat chloride was sprayed at the two-node stage and ethephon when the flag leaf ligule was just visible on the main shoot. Various traits characterizing growth and yield formation were assessed. Chlormequat chloride increased grain yield by 0% to 13% depending on cultivar and year, while ethephon most often decreased it by up to 17%. No lodging occurred and the recorded increase in grain yield of CCC treated plants was not therefore due to prevention of lodging. However, CCC treatment resulted in more panicles per square meter and in 1995 tillers contributed more to grain yield. Ethephon treated plants had less grains per main shoot panicle, lower panicle filling rate (PFR) and parallel decreased harvest index (HI). Stem elongation of dwarf oat was enhanced by CCC, in contrast to that of conventional and naked cultivars.;

Effects of method of harvest of Triticum aestivum L. on straw biomass and estimated accumulation of soil carbon

“…With lower plant heights one would expect reduced MOG yields. However, in this research we disregarded the effect of growth regulation on SGR because the reported effects of growth regulators on SGR are moderate or inconsistent (Hay, ; Peltonen‐Sainio & Rajala, ). Toyota et al .…”

Response of Hulled and Hull-Le Ss Oats to the Action of Growth Regulators

“…Wyniki te nie są zgodne z danymi uzyskanymi przez Peltonen-Sainio [12] i Peltonen-Sainio i wsp. [11], którzy stwierdzili, że przy braku wylegania zastosowanie CCC w fazie 2 kolanka nieznacznie zwiększa plon ziarna ze względu na wyższą obsadę i większy transport asymilatów do ziarna. Również Maciorowski i wsp.…”

Plant Growth Regulator and Daylength Effects on Preanthesis Main Shoot and Tiller Growth in Conventional and Dwarf Oat

“…P lant growth regulator effects on growth and yield formation of oat ( Avena sativa L.) have not often been studied (Rajala and Peltonen‐Sainio, 2000), but some results have shown that oat responds to PGRs when grown at high latitudes (Peltonen and Peltonen‐Sainio, 1997; Pietola et al, 1999; Peltonen‐Sainio and Rajala, 2001). For example, when plants did not lodge, CCC applied at the two‐node stage [Zadock's Growth Stage (ZGS) 32, Zadoks et al, 1974] resulted in slightly increased grain yield.…”

“…For example, when plants did not lodge, CCC applied at the two‐node stage [Zadock's Growth Stage (ZGS) 32, Zadoks et al, 1974] resulted in slightly increased grain yield. This was due to more panicles per square meter and higher tiller contribution to grain yield (Peltonen‐Sainio and Rajala, 2001). Similarly, CCC and ethephon applications have resulted in enhanced tiller growth in barley ( Hordeum vulgare L.) and wheat ( Triticum aestivum L., Naylor et al, 1987; Woodward and Marshall, 1987; Craufurd and Cartwright, 1989).…”

“…Earlier studies unexpectedly showed that stem elongation of dwarf oat with Dw6 gene was enhanced, rather than inhibited, following CCC applications (Peltonen‐Sainio and Rajala, 2001). Therefore, when studying the effects of DL in Finland (18 h) and Minnesota (14 h), standard HE oat cultivars Virma and Milton were compared with dwarf cultivar Pal, which was developed and released in Minnesota.…”