Phenotyping Flowering in Canola (Brassica napus L.) and Estimating Seed Yield Using an Unmanned Aerial Vehicle-Based Imagery

Phenotyping crop performance is critical for line selection and variety development in plant breeding. Canola (Brassica napus L.) flowers, the bright yellow flowers, indeterminately increase over a protracted period. Flower production of canola plays an important role in yield determination. Yellowness of canola petals may be a critical reflectance signal and a good predictor of pod number and, therefore, seed yield. However, quantifying flowering based on traditional visual scales is subjective, time-consuming, and labor-consuming. Recent developments in phenotyping technologies using Unmanned Aerial Vehicles (UAVs) make it possible to effectively capture crop information and to predict crop yield via imagery. Our objectives were to investigate the application of vegetation indices in estimating canola flower numbers and to develop a descriptive model of canola seed yield. Fifty-six diverse Brassica genotypes, including 53 B. napus lines, two Brassica carinata lines, and a Brassica juncea variety, were grown near Saskatoon, SK, Canada from 2016 to 2018 and near Melfort and Scott, SK, Canada in 2017. Aerial imagery with geometric and radiometric corrections was collected through the flowering stage using a UAV mounted with a multispectral camera. We found that the normalized difference yellowness index (NDYI) was a useful vegetation index for representing canola yellowness, which is related to canola flowering intensity during the full flowering stage. However, the flowering pixel number estimated by the thresholding method improved the ability of NDYI to detect yellow flowers with coefficient of determination (R2) ranging from 0.54 to 0.95. Moreover, compared with using a single image date, the NDYI-based flowering pixel numbers integrated over time covers more growth information and can be a good predictor of pod number and thus, canola yield with R2 up to 0.42. These results indicate that NDYI-based flowering pixel numbers can perform well in estimating flowering intensity. Integrated flowering intensity extracted from imagery over time can be a potential phenotype associated with canola seed yield.

Partial Removal of Phenolics Coupled with Alkaline pH Shift Improves Canola Protein Interfacial Properties and Emulsion in In Vitro Digestibility

The effect of polyphenol removal (“dephenol”) combined with an alkaline pH shift treatment on the O/W interfacial and emulsifying properties of canola seed protein isolate (CPI) was investigated. Canola seed flour was subjected to solvent extraction to remove phenolic compounds, from which prepared CPI was exposed to a pH12 shift to modify the protein structure. Dephenoled CPI had a light color when compared with an intense dark color for the control CPI. Up to 53% of phenolics were removed from the CPI after the extraction with 70% ethanol. Dephenoled CPI showed a partially unfolded structure and increased surface hydrophobicity and solubility. The particle size increased slightly, indicating that soluble protein aggregates formed after the phenol removal. The pH12 shift induced further unfolding and decreased protein particle size. Dephenoled CPI had a reduced β subunit content but an enrichment of disulfide-linked oligopeptides. Dephenol improved the interfacial rheology and emulsifying properties of CPI. Although phenol removal did not promote peptic digestion and lipolysis, it facilitated tryptic disruption of the emulsion particles due to enhanced proteolysis. In summary, dephenol accentuated the effect of the pH shift to improve the overall emulsifying properties of CPI and emulsion in in vitro digestion.

Evaluation of a sprayable elemental sulphur fertilizer under field conditions in Alberta

Elemental sulphur (ES) fertilizers have high S content, but may not be effective in the year of application due to the time required to oxidize. Rapid oxidation may be possible if the ES has a large surface area in contact with the soil. We evaluated the efficacy of Sulgro 70, a micronized ES fertilizer that is sprayed onto the soil surface, in eight field trials in southern and central Alberta over a two-year period. Under dry conditions in southern Alberta, the relative efficacy of Sulgro 70 to increase S supply to ion-exchange membranes was 22% during the first four-week period after seeding and 53% during the second four-week period after seeding, compared to ammonium sulphate (AS) sprayed on the soil surface. Under wetter conditions in central Alberta, the relative efficacy of Sulgro 70 to increase S supply was variable (51 to 201%) during the first four-week period after seeding and 56% during the second four-week period after seeding. Based on increases in biomass S concentration in three trials where the unfertilized control had low S concentration (<3 g S kg 1), the relative efficacy of Sulgro 70 was 34%. Canola seed yield was not increased by application of AS nor Sulgro 70 in any of the trials. Sulgro 70 sprayed on the soil surface oxidized appreciably during the first eight weeks after seeding and, with suitable management, has the potential to meet canola S requirements in the year of application.

PSVII-35 Late-Breaking Abstract: Microwave heat treatment feed effect on ruminal degradability and intestinal protein digestibility - a brief review

Rumen degradability of crude protein (CP) of feed is a major factor that determines the utilization of CP in ruminant production. This study briefly reviewed the findings from six international studies of microwave (MW) heat treatment effect on feed CP rumen degradability and intestinal CP digestibility. Six in vitro studies of concentrate feed (canola seed, canola meal, soya bean meal, cottonseed meal, corn, and barley) showed a decrease in effective rumen degradability of dry matter and protein by 4–40% and 17–40%, respectively compared to control group (untreated concentrate feed). Among the six studies, four studies identified the MW heat treatment effect on intestinal protein digestibility. Due to MW heat treatment, canola seed, canola meal, soya bean meal, and cottonseed meal showed an increase in intestinal CP digestibility by 17%, 20%, 21%, and 19%, respectively. Overall the briefly reviewed studies showed that, MW heat treatment substantially reduced feed CP ruminal degradability and increased in vitro CP digestibility of ruminally undegraded CP.