Investigation of the possibility to determine salt stress in brocoli (Brassica oleracea L. var. italica) using multispectral cameras

In this study, it was aimed to determine evapotranspiration, plant growth and yield parameters, and usability of multispectral cameras under different salinity concentrations and salt sources of broccoli plants. The study was carried out in lysimeter-type pots in a plastic greenhouse located in the experimental area of the Faculty of Agriculture at the Akdeniz University in the fall growing season of 2021. In the study, there were 39 pots, including 4 different salt sources (CaCl2, MgCl2, NaCl and Na2SO4), 3 different salinity levels (3.0, 6.0 and 9.0 dS/m) and 3 replications, together with the control treatments. During the growing period, plant height, stomatal conductivity, leaf chlorophyll content index, and multispectral camera measurements were performed. While the highest yield was determined for control treatment (C0), increasing salt concentrations caused a decrease in the chlorophyll content index, stomatal conductivity, plant height, and some yield parameters. Research results showed that different salt sources affect fruit fresh and dry weights, and fruit diameters differently. The highest values for these plant parameters occurred in the Na2SO4 (TK4) treatment containing SO4. In addition, this research showed that increased salinity stress caused a decrease in the NDVI (Normalized Difference Vegetation Index) values obtained using multispectral cameras that the NDVI values yield parameters could be estimated with acceptable accuracy.