Impact of Phytophthora Spp. on Morphological, Physical, and Biochemical Parameters of Citrus reticulata

Abstract

Citrus gummosis, caused by Phytophthora spp., is one of the economically critical fungal diseases prevailing in the major citrus-growing areas of the country. The fungus induces alterations in morphological and physiological parameters (leaf area, fruit weight, fruit volume, fruit length, fruit diameter, peel thickness, peel weight, rag weight, and juice weight). Therefore, the study was conducted to analyze the physical and biochemical parameters of citrus plants of various Citrus reticulata infected with phytophthora gummosis. Citrus leaves and fruits were collected to determine different morphological, physical, and biochemical parameters to compare the diseased and healthy citrus samples. There was a significant difference (P > 0.05) in physical parameters between infected and healthy citrus samples. The fruit size was significantly lower within the range of 29.1-35.4 cm2 in the diseased plants as compared to healthy ones (37.3-43.6 cm2). The fruit volume of infected samples, with a maximum difference of 37.1 cm3, was also recorded in infected and healthy samples. The infected citrus samples had lower fruit weights of 111.3–145.2 g than the healthy samples (147.8–175.9 g). The leaf area was significantly less for diseased plants (11.8–20.0 cm2) compared to 17.1-29.5 cm2 for healthy samples. Other physical parameters were also altered, but not significantly. Similarly, biochemical parameters such as TSS to Acid ratio 77.9–86.8, Total Soluble Solids 11.3–11.6%, Vitamin C 55.4–77.9 mg/100 mL, total phenolic contents 288.8–341.9, total flavonoids 210.1–240.2, antioxidant activity 655.7–749.5, and pH 3.13–3.32 were found to be significantly lowered at P > 0.05 in diseased citrus samples as compared to those in healthy citrus samples with the mean values of 101.3–109.5, 12.2–12.4%, 91.5–123.5 mg/100 mL, 3636.1-421.2, 249.7–285.6, 749.6–867.7, and 3.52–3.81, respectively. The findings of the research revealed the devastating impact of Phytophthora spp. on C. reticulata, resulting in low yield and fruit quality.