Dr Jonathan Richetti1, Dr Victor Sadras2, Dr Di He3, Dr Brenton Leske4, Dr Bangyou Zheng5, Dr David Deery3, Dr Yacob Beletse3, Dr Mariano Cossani2, Dr Ha Nguyen3, Dr Fernanda Dreccer5, Dr Jeremy Wish5, Dr Julianne Lilley3
1CSIRO, 147 Underwood Av, Floreat, Australia, 2South Australian R&D Institute, The University of Adelaide, Australia, 3CSIRO, 2-40 Clunies Ross Street, Acton, Australia, 4The Department of Primary Industries and Regional Development, 3 Baron Hay Court, South Perth, Australia, 5CSIRO, 306 Carmody Road, Sta Lucia, Australia
Biography:
Jonathan Richetti is a research scientist with the Spatial Temporal Decisions team in CSIRO Agriculture & Food. His research interests are crop modelling, deep learning and machine learning, earth observation, and remote sensing applied to agricultural decision-making.
Abstract:
Frost and heat events affect plant development, growth, and yield, add pressure to global food security and lead to considerable economic loss. Quantifying the yield damages from frost and heat events is critical to improve farm resilience. We reviewed the scope and limitations in yield response functions that simulate the impact of heat and frost within processed-based crop models. We review the current knowledge of the physiological impact of timing, intensity, and duration of heat and frost events on the yield of major annual grain crops and the opportunities to improve damage functions for crop modelling. A summary of model analytical functions and threshold temperatures is provided, modelling assumptions are made explicit, and future requirements are discussed. In section 1, we outline the problem and current situation. In section 2, we briefly explore the physiological effects of frost and heat stress and summarise experimental studies on temperature effects on various crops at different developmental stages. In section 3, we present different modelling assumptions. Models do not account for acclimation, compensation, and pathogen-induced freezing and psychrophiles. Interactions of extreme temperatures with radiation, water supply and demand, and nitrogen availability are not explicit in models, but some of these might emerge depending on model structure. In section 4, the various approaches are explored. We conclude with the immediate, medium, and long-term research opportunities to improve the modelling of heat and frost on annual grain crop yield.