Chlorophyll Fluorescence-Spectral Characteristics of Vegetables Under Different Fertilizer Treatments

The reflectance spectra and chlorophyll fluorescence parameters of Brassica campestris L. and Brassica pekinensis Rupr. under different fertilization conditions were measured in order to further analyze the growth physiology of vegetables under different fertilization conditions and the response relationship between the spectra and chlorophyll fluorescence. The results show that, (1) In the visible light range, the reflectance spectrum of Brassica pekinensis Rupr. increased with the growth and development of vegetables. The reflection spectrum of the Brassica campestris L. increased first and then decreased with the growth of vegetables; in the near-infrared range, the reflection of Brassica campestris L. and yellow cabbage The spectrum increases with the growth and development of vegetables. (2) Under different fertilization conditions, the spectrum of vegetables was significantly different, and it showed significant performance in the near-infrared band. During the growth period, the reflectance of Brassica pekinensis Rupr. was higher at the C3 and C5 levels, and the reflectance of the Brassica campestris L. at the C2 and C3 levels was high. At the maturity stage, the spectral reflectance of the Brassica pekinensis Rupr. had a higher reflectance at the C5 and C6 levels; the Brassica campestris L. was higher at the C3 and C5 levels. (3) The chlorophyll fluorescence parameters Fv/Fm of Bra ssica campestris L. and Brassica pekinensis Rupr. increased with the development of the growth period. Fv/Fm of Brassica campestris L. was the highest at C6 level, and Fv/Fm of Brassica pekinensis Rupr. was the highest at C2 and C6 level. (4) Under different fertilization conditions, the characteristic spectral parameters and chlorophyll fluorescence showed a significant positive and negative correlation. The relationship between chlorophyll fluorescence and spectral characteristics can provide a reference for monitoring the growth physiology and health status of vegetables.