MSc

The present investigation entitled “Enhancing fruit set and yield of tomato (Solanum lycopersicum L.) in poly house using artificial pollination and growth regulators” was conducted at the Department of Vegetable Science, College of Agriculture, Vellayani during 2017-2018. The objective of the study was to enhance the fruit set and yield of tomato under poly house through artificial pollination and application of plant growth regulators.

The tomato variety “Akshaya” was raised in polyhouse and subjected to three artificial pollination methods, seven growth regulator treatments and their combinations along with control. The artificial pollination methods were A0 (Control), A1 (Shaking), A2 (Air Blowing), A3 (Vibratory Pollination) and growth regulator treatments were G0 (control), G1 (PCPA 10 mgL-1), G2 (PCPA 20 mgL-1 ), G3 (PCPA 30 mgL-1), G4 (GA3 20 mgL-1), G5 (PCPA 10 mgL-1 + GA3 20 mgL-1), G6 (PCPA 20 mgL-1 + GA3 20 mgL-1) and G7 (PCPA 30 mgL-1 +GA3 20 mgL-1). Artificial pollination methods were executed daily during morning hours and plant growth regulators were sprayed on to the flower trusses at fortnightly intervals during the entire flowering period.

The artificial pollination methods and its interaction with growth regulators did not significantly influence vegetative characters like plant height, height at flowering, primary branches plant-1, leaf length and leaf width. Combination of Gibberellic acid (GA3) and Parachlorophenoxy acetic acid (PCPA) improved vegetative growth of plant by increasing plant height, leaf length and leaf width against control and application of individual growth regulators. Application of PCPA 30 mgL-1 + GA3 20 mgL-1 resulted in maximum plant height (324.90 cm) which was on par with combination of PCPA 20 mgL-1 + GA3 20 mgL-1. Application of PCPA 30 mgL-1 + GA3 20 mgL-1 produced longer (37.85 cm) and wider (23.65 cm) leaves.

Vibratory pollination significantly improved fruit set (67.35 %) compared to other methods and control. Shaking or blowing air on flower trusses could not improve fruit set significantly. Application of growth regulators did not influence days to first flowering, days to fruit set and flowers cluster-1 but significantly improved inflorescence plant-1, fruit set and pollen viability and reduced number of flowers with exserted stigma. Highest fruit set (66.34 %) and pollen viability (64.20 %) was obtained by application of PCPA 30 mgL-1 which was on par with PCPA (10 mgL-1 and 20 mgL-1) in combination with GA3 20 mgL-1. Maximum inflorescence plant-1(17.27) was obtained for PCPA 30 mgL-1 + GA3 20 mgL-1 which was on par with PCPA 20 mgL-1 + GA3 20 mgL-1 (15.57) and GA3 20 mgL-1 (15.17). PCPA 20 mgL-1+ GA3 20 mgL-1 significantly reduced flowers with exserted stigma (25.72 %). PCPA 30 mgL-1, GA3 20 mgL-1 and PCPA 10 mgL-1 + GA3 20 mgL-1 also were on par.

Pollination with vibrator significantly improved fruits cluster-1 (6.60), fruits plant-1 (45.69) , fruit length (6.63 cm), fruit girth (15.02 cm), yield plant-1(1311.75 g) and yield plot-1 (2.90 kg m-2 ) and number of seeds fruit-1 (131.94) compared to other methods and control. Shaking and air blowing did not significantly influence any of the fruit characters. PCPA 30 mgL-1 + GA3 20 mgL-1 produced maximum fruits plant-1 (45.45) , fruit length (6.90 cm), fruit girth (15.65 cm), yield plant-1 (1487.50 g) and yield plot-1 ( 3.47 kg m-2). PCPA 20 mgL-1 + GA3 20 mgL-1 was also equally effective for all these characters. All growth regulator treatments except PCPA 10 mgL-1 + GA3 20 mgL-1 were equally effective in improving fruit weight. However, all growth regulator treatments except GA3 20 mgL-1 lowered the number of seeds fruit-1. Growth regulator application did not influence fruits cluster-1 and thousand seed weight.

Fruit quality parameters like total soluble solids, titrable acidity, vitamin C and lycopene were not significantly influenced by any of the treatments and their interactions. Application of growth regulators PCPA 30 mgL-1 + GA3 20 mgL-1 and PCPA 30 mgL-1 induced more abnormalities in fruits.

The results indicated that application of PCPA 20 mgL-1 + GA3 20 mgL-1 on flower clusters at fortnightly intervals during the flowering period not only enhanced inflorescence plant-1, pollen viability, fruit set, fruit size and yield of tomato but also reduced the number of flowers with exserted stigma and number of seeds fruit-1 while vibratory pollination improved fruit set, fruit size, yield and number of seeds fruit-1, which can be used selectively for improving fruit production and seed production of tomato under poly houses in Kerala.