Economic assessment of various levels of improved wheat post head-emergence frost (PHEF) tolerance breeding options: final technical report

Frost, during reproductive developmental stages, especially post head emergence frost (PHEF), can result in catastrophic yield loss for wheat producers. Breeding for improved PHEF frost tolerance may allow greater yield to be achieved, by (i) reducing direct frost damage and (ii) sowing crops earlier to reduce risks of late-season drought and or heat stress. This paper provides an economic feasibility analysis of conventional and genetically modified (GM) PHEF tolerant wheat variety breeding options. The APSIM wheat model, with a phenology gene-based module, was employed to simulate direct and indirect yield benefits for various level of improved frost tolerance. The economic model considered optimal profit, based on sowing window and nitrogen use, rather than achieving maximum yield, when calculating the economics of PHEF breeding options. The results reveal that PHEF tolerant varieties, both conventional and GM, would lead to a significant increase in economic benefits through reduction in direct damage and an increase in yield through early sowing. The economic benefits of up to $4,841million and $4,826 could be realised from breeding conventional PHEF tolerant lines and GM PHEF tolerant if useful genetic variation can be found. Sensitivity analyses indicated that the benefits are particularly sensitive to the increase in fixed costs, discount rate, and delay in variety release. However, the investment still remains viable for most tested scenarios. Based on comparative economic benefits, for both conventional and GM PHEF tolerant varieties, if breeders were able to develop PHEF tolerant varieties that could withstand cold temperatures –4 °C below the current damage threshold using conventional methods, instead of breeding fully frost tolerant GM varieties, the investment on the PHEF tolerant breeding program would be highly attractive