Chlorophyll dynamics of field-planted Harumanis Mango (Mangifera indica L.) at flowering and fruiting stages using SPAD-502 measurements

Abstract

Chlorophyll plays a fundamental role in photosynthesis and contributes significantly to plant growth and yield. However, limited information is available on chlorophyll dynamics in tropical fruit crops, particularly mango. This study evaluated chlorophyll dynamics of field-planted Harumanis mango at two different growth stages (flowering and fruiting). The chlorophyll status of Harumanis mango leaves was measured using the Soil Plant Analysis Development (SPAD-502) chlorophyll meter. The SPAD chlorophyll index of Harumanis mango trees at both stages was described and compared using statistical analysis. During the flowering stage, the SPAD chlorophyll index ranged from 43.10 to 124.00 with a mean of 67.59. Meanwhile, during the fruiting stage, SPAD values ranged from 35.60 to 95.60, with a mean of 62.46. The variability in SPAD index could be related to dynamic changes in chlorophyll allocation during both growth stages. The frequency distributions of SPAD chlorophyll index analysis indicated that SPAD values did not follow a normal distribution, possibly due to physiological differences between the two stages. The SPAD chlorophyll index differed significantly across flowering intensity stages but not across crop load stages. A decreasing trend in chlorophyll content was observed with increasing flowering intensity and crop load, suggesting possible effects of nutrient resources and availability. Overall, this study enhances the understanding of chlorophyll dynamics in Harumanis mango and offers insights for improving sustainable orchard management of this economically important tropical fruit.