Biochemical and Physiological Responses of a Few Mulberry Varieties to Thrips and Yellow Mite Infestation
Jayashree *
Technical Service Centre, Sulibele Hoskote (tq)- 562129, India.
K. C. Narayanaswamy
University of Agricultural Sciences, Mandya – 571405, India.
Manjunath Gowda
Department of Sericulture, UAS, GKVK, Bangalore- 560065, India.
K. G. Banuprakash
Department of Sericulture, UAS, GKVK, Bangalore- 560065, India.
C. Chinnamade Gowda
AINP on Agricultural Acarology, Department of Entomology, UAS, GKVK, Bengaluru- 560065, India.
K. S. Jagadish
Department of Apiculture UAS, GKVK, Bengaluru- 560065, India.
*Author to whom correspondence should be addressed.
Abstract
Background: Mulberry leaf quality is adversely affected by sucking pests such as thrips and yellow mites, which can alter the biochemical and physiological characteristics of the leaves. Understanding the biochemical traits associated with varietal tolerance is important for identifying mulberry varieties with greater resistance to pest infestation and for supporting sustainable pest management strategies.
Aim: This study assessed biochemical changes in mulberry leaves affected by thrips and mites across different stages of pest severity to clarify the underlying mechanisms and support the development of more sustainable pest-management approaches.
Design: The experimental design for this study was a 3X5 completely randomised design.
Place and Duration of the Study: The study took place during 2021-24 in the Department of Sericulture, College of Agriculture, University of Agricultural Sciences, Gandhi Krishi Vigyan Kendra, Bengaluru-560065.
Methodology: Mulberry infestations by thrips and mites were monitored over three crop periods between June 2023 and April 2024. Counts of both pests were obtained separately from the third through seventh leaves from the shoot apex of each of 11 popular mulberry varieties, viz., RFS175, MR2, S13, S34, S36, V1, DD (Vishwa), S54, Mysore Local, TR10 and M5. Qualitative feeding damage was evaluated by comparing the biochemical profiles of pest-infested and healthy leaves from tolerant and susceptible varieties.
Result: Mysore Local and M5 were highly tolerant to thrips, whereas V1 and MR2 were highly susceptible. TR10 and M5 were highly tolerant to yellow mite, while MR2 and V1 were highly susceptible. MR2 recorded lower potassium (1.65%) and phenol (6.11 mg/g) but higher sugar (137.24 mg/g) than Mysore Local, which recorded 2.25% potassium, 6.63 mg/g phenol and 109.39 mg/g sugar. V1 had higher protein (20.25%) and nitrogen (3.24%) but lower potassium (1.55%) and phenol (6.01 mg/g) than TR10, which recorded 2.84% potassium and 6.89 mg/g phenol. Thrips and mite infestation reduced chlorophyll, with larger declines in susceptible varieties.
Conclusion: Higher potassium and phenolic contents may contribute to enhanced resistance/tolerance against thrips and mites and may be considered useful traits for screening and breeding thrips- and mite-tolerant mulberry varieties.
Keywords: Mulberry, thrips, yellow mite, biochemical resistance, potassium, phenolic content, chlorophyll, host-plant tolerance