Decreasing water availability for rice based systems resulted in the introduction of water saving production systems such as aerobic rice and alternate wetting-drying technology. To further improve resource use efficiency in these systems, water management should be attuned to critical growth stages, requiring accurate prediction of crop phenology. Photoperiod-sensitivity of aerobic rice genotypes complicates the estimation of the parameters characterizing phenological development and hence impairs predictions. To overcome this complication, we followed a two-step approach: 1) the photoperiod response was determined in growth chambers, through a reciprocal transfer experiment with variable day length, conducted at a fixed temperature, and consecutively, 2) the temperature response was studied by combining the obtained photoperiod parameters with data from field experiments. All four aerobic rice genotypes tested exhibited strong photoperiod-sensitivity. Durations of basic vegetative phase (BVP) i.e. when plants are still insensitive to photoperiod, photoperiod-sensitive phase (PSP), and post-PSP (PPP) varied among genotypes. The temperature response of the genotypes was explored by combining phenological observations in the reciprocal transfer experiment with observations in two field experiments. The temperature range in the field experiments was too narrow to obtain convergence to a unique set of temperature response parameters, regardless whether a bilinear or a beta model was used. Sensitivity analysis however provided clear arguments in support of the recent doubts on the validity of a commonly used set of cardinal temperatures for rice phenology. Using standard cardinal temperatures overestimated the rate of development at temperatures below 31 °C. This finding stresses the need for experiments on rice phenology under a wider range of temperatures.

Item Type:	Refereed Article
Keywords:	aerobic rice, photothermal response, flowering, phenology parameterisation, reciprocal transfer experiment
Research Division:	Agricultural, Veterinary and Food Sciences
Research Group:	Agriculture, land and farm management
Research Field:	Agricultural systems analysis and modelling
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Grains and seeds
Objective Field:	Rice
UTAS Author:	Meinke, H (Professor Holger Meinke)
ID Code:	85878
Year Published:	2014
Web of Science® Times Cited:	7
Deposited By:	Tasmanian Institute of Agriculture
Deposited On:	2013-08-13
Last Modified:	2017-11-06
Downloads:	0