Effect of Photoperiod and Temperature on the Development of Sorghum¹

Abstract

Three varieties of Sorghum bicolor (L.) Moench, (i.e., 'Early Hegari,' '80-Day 2Vlilo,' and 'Wheatland') were grown in controlled environment chambers and subjected to all combinations of 10-, 12-, and 14-hour photoperiods, 27 and 32 C day temperatures, and 16 and 21 C night temperatures. Days to floral initiation were determined for each variety under each treatment combination. In addition, days to anthesis and days in the floral period (from initiation to anthesis) were determined for the treatment combinations involving 21 C night temperatures. Ten-hour days hastened floral initiation and anthesis of each variety at all temperature combinations. ~'ourteenhour days delayed development, but with some temperature regimes the delay was not significant, compared to the shorter days. The rate of development for the varieties under 12-hour days was highly dependent upon day and night temperatures, since floral initiation ranged from as early as that obtained with 10-hour days to later than that obtained with 14-hour days. The response to day temperature during the floral period was small, but statistically significant. The time to anthesis followed a pattern similar to that for the time to floral initiation.

Climate and the Growth of Sorghum at Kabba, Nigeria

“…In general panicle initiation is largely determined by temperature, and temperature -photoperiod interactions (Caddell and Weibel, 1971;Downes, 1972;Quinby et al, 1973;Kassam and Andrews, 1975). These results therefore suggest that the time of head initiation of sorghum crop at Kabba might be considerably earlier than the 94 days after sowing assumed for the station every year.…”

Flowering induction in the bioenergy grass Miscanthus sacchariflorus is a quantitative short-day response, whilst delayed flowering under long days increases biomass accumulation

“…Floral initiation in quantitative, as opposed to qualitative, SD plants is promoted by SDs but is not necessarily dependent on them. The actual critical daylength for flowering varies between species and geographical origin, and between different cultivars of Sorghum can vary by as much as 4h (Caddel and Weibel, 1971). Within the Miscanthus genus, M. sacchariflorus flower less readily than M. sinensis , both in North European (Clifton-Brown et al ., 2001; Jensen et al ., 2011 a ) and in diverse Chinese (Yan et al ., 2011) field conditions, and reports have indicated that some, particularly thick-stemmed, M. sacchariflorus require SD treatments for floral induction (Deuter, 2000).…”

Trait physiology and crop modelling as a framework to link phenotypic complexity to underlying genetic systems

“…For example, the photothermal model predicts that thermal time to anthesis and final leaf number of a hybrid are independent of temperature under a given photoperiod, yet temperature effects, independent of photoperiod, have been reported (Caddel and Weibel 1971;Major et al 1990;Morgan et al 2002). Consistent with this, phenology is accelerated under natural asynchrony between thermoperiod and photoperiod (i.e.…”