Indian Journal of Entomology
Open Access
SCOPUSWeb of Science
  • Year: 2017
  • Volume: 79
  • Issue: 1

Effect of leaf morphology and phytochemistry of okra on development and survival of two spotted spider mite, Tetranychus urticae Koch

Department of Entomology, CCS Haryana Agricultural University, Hisar-125004, Haryana

*Corresponding Author Email: jitender12121984nain@gmail.com

Online published on 3 March, 2017.

Abstract

Studies on cultivars of okra [Abelmoschus esculentus (L.) Moench] revealed that the genotype HRB-107-4-1 has a maximum leaf area (443.23 cm2) while in BB1 it was minimum (294.76 cm2); length of trichomes varied from 18.95 in HBT-6-15-3-7 to 42.12 in HB-02-14-1-1. Lowest number of trichomes was recorded in genotype HBT-6-15-3-7 and it was highly susceptible to mite Tetranychus urticae Koch. Genotype HB-02-14-1-1 with highest number of trichomes was the least susceptible. Thickness of leaf lamina varied significantly, from 0.05 mm (HTB-1-17-5) to 0.08 mm (HB-02-14-1-1). There was significant positive relationship between length of trichomes and number of eggs laid.

Phosphorus content was found to be high in the least susceptible genotype HB-02-17-1 (1.20%) compared to the highly susceptible BB1 (1.06%). Potassium content ranged from (1.80%) in HB-02-14-1-1 to (1.20%) in HBT-6-15-3-7 and it differed significantly (p<0.05). Nitrogen and protein contents were low (nitrogen 1.94%; protein 12.66%) in HRB-107-4-1 and high (nitrogen 2.18%) in HB-02-14-1-1 and (protein 13.78%) in HB-02-17-1. Total phenols content ranged from 0.40% in HBT-6-15-3-7 to 0.62% in HB-02-14-1-1. Tannin content varied from 0.40% in HBT-6-15-3-7 to 0.60% in HB-02-14-1-1. Total sugar content was significantly positively (p<0.05) correlated with larval (r = 0.71*) and nymphal periods (r = 0.74*), and negatively with larval and nymphal survival (r = -0.81**).

Anti-nutritional compounds like phenol showed a positive and significant (p<0.05) correlation with larval (r = 0.81*) and nymphal periods (r = 0.78*); and negative relationship with larval and nymphal survival (r = - 0.79**); whereas, tannin content showed a positive and significant (p<0.01) correlation with larval (r = 0.88**) and nymphal periods (r = 0.76*), and it was showing a negative and significant (p<0.05) correlation with larval and nymphal survival (r = - 0.78*).

Keywords

Tetranychus urticae, okra, leaf trichomes, thickness of leaf lamina, phosphorus, potassium, nitrogen, protein, tannin, phenol contents, development, survival