INFLUENCE OF DIFFERENT PLANT GROWTH REGULATORS ON GROWTH AND YIELD PERFORMANCE OF SESAME (SESAMUM INDICUM L.)

Abstract

Sesame is an important oilseed crop cultivated in India since ages during kharif season. Due to congenial environment and availability of moisture excessive vegetative growth is observed, which resulted in poor capsule formation and low seed yield due to poor source to sink partitioning of photosynthates.  A field experiment was conducted to evaluate the influence of foliar application of plant growth regulators tested against control with no plant growth regulator application on crop growth, seed and oil yield of sesame (Sesamum indicum L.). The experiment was laid out in a randomized block design (RBD) with three replications and eleven treatments comprising a control, salicylic acid, paclobutrazol, mepiquat chloride, chlormequat chloride and potassium chloride (KCl), applied either as a single spray at 60 days after sowing (DAS) or as split sprays at 45 and 60 DAS. Each foliar treatment was applied at a spray volume of 300 L ha⁻¹. The treatments included salicylic acid at 200 ppm at 60 DAS and 100 ppm at 45 and 60 DAS; paclobutrazol, mepiquat chloride and chlormequat chloride at 200 ppm at 60 DAS and 100 ppm at 45 and 60 DAS; and KCl at 2% at 60 DAS and at 45 and 60 DAS. Observations were recorded on plant growth attributes, physiological parameters, yield attributes and seed yield. The results showed non-significant differences for plant population m² and it varied from 20.00 to 22.67 plants m2, maximum plant height at maturity 115.11 cm in treatment T11. While maximum number of branches per plant (4.44), maximum LAI (3.18), number of capsules plant-1 (68.33), seeds capsule-1(68.83), capsule length (28.52 mm) and capsule girth (8.73 mm) was recorded in treatment T8. Treatment T₂ (1837.03 kg ha-1) recorded maximum straw yield while the harvest index varied between 23.99 in T1 to 32.44% in treatment T8. Among the treatments, chlormequat chloride @ 200 ppm applied at 60 DAS (T8) showed the most consistent superior performance by producing maximum number of capsules plant⁻¹, seeds capsule⁻¹, capsule length and capsule girth with the greater number of branches and leaf area index, together. These improvements in reproductive attributes were reflected in the highest seed yield of 692.03 kg ha⁻¹, along with higher seed test weight and harvest index.