Variation in Normalized Difference Vegetative Index (NDVI) in canola germplasm

We aim to select canola (Brassica napus) traits that are related to crop performance under water limited conditions. Rapid fractional ground cover (FGC) is a trait that may minimize evaporation loss early in the season which could lead to more water being available for later use by the plant. In addition, the association of FGC to vigour may result in plants with rapidly-growing and deeper roots with greater access to moisture.A GreenSeeker was used to estimate normalised difference vegetation index (NDVI) as a surrogate for FGC. Twenty-nine B. napus genotypes and one B. juncea genotype were sown in a three-replicate plot trial at the Wagga Wagga Agricultural Institute. The 8-row plots were 10 m long and 1.5 m wide, arranged in a three-range x 31-row grid. Before flowering, four estimates of FGC were done on each plot.Differences for FGC were identified among the genotypes under study and these differences were correlated with yield. All tested genotypes showed a FGC that followed a sigmoidal shape but did not reach total ground coverage at early flowering. The differences between genotypes were characterised by non-parallel curves. Normalised difference vegetation index (NDVI), as measured by the GreenSeeker, is a rapid and robust method of estimating FGC which can be used under different field lighting conditions. The genotypes tested here are the subject of further studies particularly with regard to root architecture.