SPAD index and leaf pigments in cauliflower in different water conditions and silicon fertilization

Abstract

The measurement of leaf pigments using non-destructive methods can be influenced by water management conditions and the use of nutrients in cauliflower, not showing adequate correlations with chlorophyll contents. The objective of this study was to evaluate the correlation between the SPAD index and the pigment content in cauliflower leaves managed with different water conditions and the application of silicon (Si). The cultivation was carried out in a protected environment in the city of Maringá, Paraná State from October 2019 to March 2020. It was adopted a randomized block design, with treatments in a 3 x 4 factorial scheme, with three levels of water recharge (40; 70 and 100% of crop evapotranspiration (ETc)) and four doses of Si (0; 50; 100 and 150 kg ha-1), with four replications. Once plants showed developed inflorescence, the SPAD index was determined in the field and the levels of chlorophyll a, chlorophyll b, and carotenoids in the laboratory using leaves from the upper third. The correlation between water recharge and Si fertilization on the SPAD index was determined. The proportion of carotenoids in relation to total pigments was compared under different conditions. Correlation analysis was performed considering silicon fertilization, water recharge, leaf pigments, and the SPAD index. Silicon fertilization reduced the levels of carotenoids in addition to being related to chlorophyll a (100% of ETc) and chlorophyll b (70% of ETc). The correlation of the SPAD index with pigments is variable with the water condition of the crop, in a condition without water deficit, it is related to chlorophyll a and in a condition of 70% replacement of ETc, it is correlated with chlorophyll b.

Resíduos orgânicos e composto fermentado bokashi no desenvolvimento de mudas de couve-flor

“…The proportion of chlorophyll a, chlorophyll b, and carotenoids is associated with the environment and crop management (Moura Neto et al, 2021). There is an increase in carotenoid levels during the development of cauliflower under stress conditions (Wenneck et al, 2021).…”

“…In the production of seedlings, characteristics related to the cultivation medium and substrate directly interfere with the availability of water and nutrients, impacting morphological development, health, standardization, and commercial quality (Kumi et al, 2020;Antunes et al, 2021;Wenneck et al, 2021).…”

Pigmentos Foliares Na Cultura Da Ervilha: Relação Entre Índice Spad E Conteúdo De Clorofila

“…Os pigmentos foliares, principalmente clorofila e carotenoides, são reflexo da atividade fotossintética e das condições de desenvolvimento da planta, envolvendo nutrição, disponibilidade hídrica e sombreamento (JIANG et al, 2017;SHAH et al, 2017;SILVA, 2020). A quantificação do conteúdo de clorofila pode envolver métodos diretos, com a extração dos pigmentos, e métodos indiretos, com a determinação pelo índice SPAD (SHIBAEVA et al, 2020;WENNECK et al, 2021).…”

“…diferentes para uma mesma espécie, a análise pode ser adotada para avaliar o impacto da condição sobre as variáveis Wenneck et al (2021). obtiveram variações na interação do y = 0,1x2 -6,7082x + 129,42 R² =…”