A photogrammetry phenomic approach to quantifying canopy architecture traits in spring wheat

Canopy architecture refers to the arrangement of plant organs, leaves and shoots within a canopy and is an important plant trait which contributes to yield. High-throughput phenotyping has gained attention because of its high efficiency, quantitative and non-destructive method of phenotyping plants, which can be used to estimate canopy architecture traits. The objectives of this study were: (i) compare the use of an inexpensive photogrammetry system to estimate canopy volume, canopy height-to-width ratio (H:W) and leaf angle of wheat plants to a manual visual scoring scale and (ii) assess whether photogrammetry provides reliable canopy architecture measurements by comparing trends observed in field and growth chamber environments. To achieve this, a growth chamber trial was conducted at the University of Winnipeg, Manitoba along with a one-year field trial performed in 2023 at the University of Saskatchewan, Saskatchewan. Canopy volume, H:W ratio and leaf angle were rated using a manual visual scoring scale and digitally imaged at 14 and 35 days after seeding (DAS) to estimate canopy volume, H:W ratio and leaf angle. A significant negative relationship (P< 0.001, R2 =0.61) was observed between the manual canopy rating and canopy H:W ratio at 14 DAS and those estimated from the photogrammetry system. Also, a significant positive relationship was found (P<0.001, R2 = 0.74) between leaf angle at 14 DAS and manual canopy rating. The photogrammetry system was effective to estimate canopy traits H:W ratio and leaf angle compared to the manual visual scoring scale and could be used in high throughput phenotyping.