Multispectral and chlorophyll fluorescence imaging for detection of nutrient deficiency symptoms in common bean

Crop production might suffer severe economic losses due to insufficient fertiliser availability. Specific signs of nutrient shortage influence plant morphology and physiology. This study pioneers the non-destructive tracking and characterization of nutrient deficiency symptoms in common beans using multispectral and chlorophyll fluorescence imaging, offering novel insights into the dynamic responses of plant morphology and physiology to specific nutrient shortages. Plants were cultivated in nutrient solutions with and without nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), iron (Fe) and control solution. Measurements were taken every three days for 12 days (MT1-MT4) of growth. K and N deficit plants had the earliest symptoms and most noticeable changes, whereas Fe deficiency plants had the slowest and least noticeable symptoms. Except for Fe, the most responsive chlorophyll fluorescence parameter was electron transport rate, which was reduced in plants from all nutrient deprivation treatments compared to control. All nutrient deficit treatments reduced leaf area at MT2, which was the most affected morphological parameter. The green leaf index, reflection in blue, and specific green were the most affected multispectral traits by nutritional deprivation. These findings demonstrate that plant nutrient deficit can be recognized and tracked non-destructively utilizing multispectral and chlorophyll fluorescence analysis. Overall, our work not only sheds light on the dynamics of nutrient deficiency in common bean plants but also offers practical implications for improving crop management strategies using non-destructive digital technology.