Effects of Soil Moisture Content Variations on Fruit Quality and Tree Stress in Satsuma Mandarin ‘Miyagawa Wase’ during Porous Sheet Mulching Cultivation

• Published in: Weon'ye gwahag gi'sulji Vol. 42; no. 2; pp. 200 - 213
• Main Authors: Kang, Nam-Ho, Lee, Jung-A, Park, Sook-Young, Kang, Seok-Beom, Han, Sang-Heon
• Format: Journal Article
• Language: English
• Published: 한국원예학회HST 01.01.2024; 한국원예학회
• Subjects: 농학; abscisic acid; soil moisture content; drip irrigation; potential; chlorophyll fluorescence; jasmonic acid
• ISSN: 1226-8763; 2465-8588
• DOI: 10.7235/HORT.20240017

This study, focusing on porous sheet mulching cultivation for high-quality and annual steady production of Satsuma mandarin, investigated trees photosynthetic oxidation stress according to the soil moisture in the porous mulching cultivation. Leaf, vesicle tissue water status, chlorophyll fluorescence, plant hormone abscisic acid (ABA) and jasmonic acid (JA) activity were measured using a phychrometer sample chamber, potable fluorescene meter and UHPLC and MS/MS were measured. Leaf water potential fluctuated according to the change in soil moisture content between the non-sheet mulching (control) and restoring the porous sheet (mulching) groups throughout this experiment period, and about 2 weeks intervals drip irrigation after the mulching (Mul. + Drip). In September, the leaf water potential of the control (‒0.9 ~ ‒1.3 MPa) was higher than that of the mulching (‒2.5 ~ ‒2.7 MPa), and Mul. + Drip (‒2.2 ~ ‒2.3 MPa) groups. In October, due to continuous dry weather, the results of control and mulching were ‒3.0 MPa and ‒4.0 MPa or below respectively, which were lower than Mul. + Drip (‒2.64 MPa). The water potential of vesicle tissue also fluctuated similarly to that of the leaf water potential. The osmotic potential was tendentially higher in the control than that in mulching and Mul. + Drip group. The turgor pressure remained constant at 0.5 MPa in October and November except for the time in September. The soluble solids content (SSC) of fruit at harvest was higher at 14.55°Brix in the mulching and 13.96°Brix in the Mul. + Drip, which were both higher than 11.05°Brix in the control, showing a significant difference and confirming a rise in the SCC caused by osmotic control. The degree of oxidative damage according to water stress level caused by drought stress was investigated by the comparison of the maximum quantum efficiency value of (Fv/Fm), the initial fluorescence value (Fo) value, and the change in photosynthetic rate. The concentration of ABA in the leaf, fruit peel, and flesh was relevant to the leaf moisture stress and fruit sugar content. The concentration of JA varied as the concentration of ABA changed. In conclusion, Fv/Fm and Fo of chlorophyll PSII and ABA regarding photosynthetic oxidative damage were found to be indicators of the degree of damage according to tree water stress levels. KCI Citation Count: 0