Non-Destructive Chlorophyll Meters: A Comparison of Three Types of Meters for Grain Yield Estimation of Durum Wheat Under Semi-Arid Environments

Abstract

Optimizing management practices to maximize crop yield and efficiency necessitates real-time monitoring of plant growth throughout the growing season. Utilizing spectral indices, such as normalized difference vegetation index, SPAD chlorophyll meter readings, and the CM-1000 chlorophyll meter, can provide quantitative data to aid in making informed management decisions. This study investigated the relationships between spectral indices (NDVI, SPAD, CM-1000) and grain yield in five durum wheat genotypes under semi-arid conditions. Spectral indices were taken at three growth stages: heading, anthesis, and maturity. Our findings revealed significant variations in spectral reflectance values among the genotypes and across growth stages. NDVI values were highest during the early growth stages and declined towards maturity. SPAD values also exhibited a similar trend, peaking at heading and anthesis. Chlorophyll content, as measured by SPAD readings, varied across growth stages, with different genotypes exhibiting peak chlorophyll content at different times. CM-1000 measurements showed significant differences among genotypes at all stages, with 'Fırat 93' and 'Hasanbey' generally exhibiting higher chlorophyll content. Correlation analysis revealed significant positive relationships between NDVI values at different stages, as well as between CM-1000 measurements and grain yield. Conversely, SPAD values showed a negative correlation with grain yield. These findings suggest that CM-1000 measurements could be a valuable tool for selecting high-yielding durum wheat genotypes under semi-arid conditions.