~ 614 ~ Journal of Pharmacognosy and Phytochemistry 2019; 8(6): 614-616 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2019; 8(6): 614-616 Received: 25-09-2019 Accepted: 27-10-2019 Kathari Lakshmaiah Department of Floriculture and Landscape Architecture, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India S Subramanian Department of Floriculture and Landscape Architecture, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India M Ganga Department of Floriculture and Landscape Architecture, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India P Jeyakumar Department of Crop physiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India Corresponding Author: S Subramanian Department of Floriculture and Landscape Architecture, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India Optimization of pinching and GA 3 application to improve growth and flowering of lisianthus ( Eustoma grandiflorum ) Kathari Lakshmaiah, S Subramanian, M Ganga and P Jeyakumar Abstract An experiment was conducted at the Horticultural Research Station of the Tamil Nadu Agricultural University at Ooty in the Nilgiris District of Tamil Nadu to optimize pinching coupled with GA3 application to improve the growth, yield and quality characters of lisianthus (Eustoma grandiflorum [Raf.] Shinn.) for cut flower production under polyhouse. The study was taken up in the variety ‘Mariachi Blue’. The experiment was laid out in Factorial Randomized Block Design with 9 treatments in three replications. The treatments consisted of two levels of pinching (single and double) and spraying of gibberellic acid (GA3 @ 50, 100 and 150 ppm). GA3 was applied as a foliar spray at 30 days after pinching before formation of flower buds. The results revealed that the vegetative growth characters namely, plant height (66.33 cm) and internodal length (9.41cm) and quality character namely, flower stem length (63.33cm) were highest in the treatment T5 ( Single pinching + GA3 @ 150 ppm). The highest number of side shoots (7.32) and number of leaves (41.79) per plant were recorded with T9 (Double pinching + GA3 @ 150 ppm). Considering the overall performance, it was noticed that the plants subjected to single pinching and foliar spraying with GA3 @ 150 ppm recorded superior performance in lisianthus. Keywords: Lisianthus, Eustoma grandiflorum, single pinching, double pinching, growth regulator Introduction Lisianthus is a relatively new cut flower crop when compared with other commercial floricultural crops like cut roses, carnations and chrysanthemums that have been grown as commercial cut flowers for many decades. Yet, lisianthus has made a tremendous impact on the global cut flower trade. It was first available in Japan during 1933 and became the number one cut flower with over 129 million stems sold during 2001. In Europe, it is ranked as one of the top 10 cut flowers and in the United States, the popularity of this flower crop continues to grow not only as a cut flower but also as a bedding plant and pot plant. As far as India is concerned, Lisianthus is a relatively new cut flower. In Tamil Nadu, production of lisianthus is concentrated in limited area in the hill stations namely, Ooty and Kodaikanal. Lisianthus is a crop which has immense potential as cut flower and pot plant. However, the research reports available on lisianthus is meagre. The present research work was undertaken to study the influence of pinching practices and growth regulator application on the growth and flowering of lisianthus. Materials and Methods The experiment was conducted under polyhouse condition in the farm of the Horticultural Research Station of Tamil Nadu Agricultural University, in The Nilgiris during 2018-19. The variety Mariachi Blue was involved in the study. The experiment was carried out in a Factorial Randomized Block Design (FRBD) with three replications. The treatments consisted of two levels of pinching (single and double) and spraying of gibberellic acid (GA 3 @ 50, 100 and 150 ppm). Single and double pinching was done at 30 and 45 days after transplanting respectively. GA 3 was applied as foliar spray at 30 days after pinching before formation of flower buds. Data were collected on plant height (cm), internodal length, flower stem length, number of side shoots per plant, number of leaves/plant, number of flowers/plant. The datawere statistically analyzed using SPSS program. Mean values for all the treatments were calculated and the analysis of variance for each of the character was performed by F test. Difference between treatments was evaluated by DMRT at 5% level of significance.