Standardisation of seed biopriming for seedling establishment, growth, yield and nutritional characters in tomato (Solanum lycopersicum L.)

Abstract

The present study entitled “Standardisation of seed biopriming for seedling establishment, growth, yield and nutritional characters in tomato Solanum lycopersicum L.). was conducted in the Department of Seed Science and Technology, College of Agriculture, Vellayani, Kerala during 2020-21. The objective of this study was to standardize the biopriming methods in tomato for germination, seedling vigour, yield and nutritional characteristics using three biopriming agents Trichoderma asperellum 106 spores mL-1and 108 spores mL-1), Pseudomonas flourescens 106 CFU mL-1 and 108 CFU mL-1) and Piriformospora indica 106 spores mL-1 and 108 spores mL-1) for one and two hours. The study was divided in to two experiments. Experiment I was conducted in Completely andomized Design C D) with fourteen treatments and three replications. During experiment I germination studies were conducted using roll towel method. Best three treatments were selected from experiment 1 based on the germination parameters. Experiment II was also conducted in Completely andomized Design with five treatments and four replications. The pot culture experiment was conducted to evaluate the effect of these best three treatments on phenological, physiological, growth, quality, biomass and yield parameters. During experiment I, among various treatments employing T. asperellum, T2 T. asperellum 106 CFU mL-1 for two hours) recorded the highest germination percentage 88.67 ), shoot length 7.60 cm), root length 6.39 cm), shoot dry weight 0.92 mg), root dry weight 0.45 mg), seedling vigour index 1 1240.09), seedling vigour index II 121.30) and speed of germination 7.28). On biopriming with P. flourescens T8 P. flourescens 108 CFU mL-1 for two hours) reported the maximum germination percentage 86.67 ), shoot length 7.56 cm), root length 7.63 cm), shoot dry weight 0.91 mg), root dry weight 0.45 mg), seedling vigour index 1 1316.26), seedling vigour index II 117.54) and speed of germination 7.23). On biopriming with P. indica maximum germination percentage 91.33 ), shoot length 7.67 cm), root length 7.82 cm), shoot dry weight 0.97 mg), root dry weight 0.54 mg), seedling vigour index 1 1414.73), seedling vigour index II 137.46) and speed of germination 7.68) was obtained from seeds bioprimed with P. indica 106 CFU mL-1 for one hour. Based on the above results the best three treatments selected were T. asperellum 106 CFU mL-1 for two hours T1), P. flourescens 108 CFU mL-1 for two hours T2) and P. indica 106 CFU mL-1 for one hour T3) along with appropriate control. Then pot culture experiment was conducted to evaluate the effect of these three biopriming treatments on phenological, physiological, growth, quality, yield and biomass parameters. Among the phenological parameters days to first flowering and days to first fruiting was minimum in T3 P. indica 106 CFU mL-1 for one hour) 51.92 and 78.75 days respectively). Biopriming with P. indica 106 CFU mL-1 for one hour T3) recorded the maximum physiological and growth parameters including chlorophyll content 2.82 mg g-1 fresh weight), specific leaf area 3.96 m² g-1), crop growth rate 0.912 g m-2 day-1) and net assimilation rate 0.027 g m-2 day-1). Among the various quality parameters analyzed, there was no significant difference observed for TSS and soluble sugar content. Highest Lycopene content 2.81 mg g-1) and vitamin C 35.56 mg g-1) content was noted in T3 P. indica 106 CFU mL-1 for one hour). Highest titrable acidity 0.68 ) was recorded in T1 T. asperellum 106 CFU mL-1 for two hours). Plant height was also maximum in T3 P. indica 106 CFU mL-1 for one hour) during vegetative 80.20 cm) and flowering stages 127.37 cm). Biopriming with P. indica 106 CFU mL-1 for one hour recorded the maximum shoot dry weight 8.31g), root dry weight 0.97 g) and total dry weight 9.28 g). There was no significant difference observed in root shoot ratio. The yield parameters including number of fruits per plant 7.25 ), fruit set percentage 56.78 ), average fruit weight 36.60 g) and yield per plant 263.56 g) was maximum in T3 P. indica 106 CFU mL-1 for one hour).The intensity of fruit drop 4.96 ) was minimum in T3 P. indica 106 CFU mL-1 for one hour). Biopriming is reported to have exerted significant influence on the growth, yield and nutritional characters of tomato. Among various biopriming agents P. indica 106 CFU mL-1 for one hour outperformed T. asperellum and P. flourescens in improving phenological, physiological, growth, quality, biomass and yield parameters. Thus being an eco-friendly technique, the farmers can adopt biopriming with P. indica as a great alternative for conventional chemical seed treatments.