Optimization of pinching and GA3 application to improve growth and flowering of lisianthus (Eustoma grandiflorum)

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.