Influence of plant growth regulators on yield attributes and induction of dormancy in bunch groundnut (Arachis hypogaea L.)

Seed dormancy plays a crucial role in preventing in situ sprouting of groundnut pods, especially in non-dormant bunch types grown during the Kharif season. Variety TG-37A are widely cultivated in Gujarat state. Due to changing climatic conditions, varieties like TG-37A are increasingly affected by end-season rains, leading to yield loss and deterioration in seed and oil quality. Therefore, the present study aims to develop effective strategies for inducing seed dormancy through the use of plant growth regulators. A field experiment entitled “Effect of plant growth regulators on yield attributes and induction of dormancy in bunch groundnut (Arachis hypogaea L.) was conducted using a Randomized Block Design (RBD) with three replications in the variety TG-37A. The experiment consisted of ten treatments of different plant growth regulators with control. Results revealed that foliar application of all growth regulators improved pod yield, harvest index, sound mature kernels, filled and mature pods per plant, and seed dormancy as compared to control. The highest pod yield (1818.06 kg/ha) and sound mature kernel (SMK) percentage (96.33%) were recorded with foliar application of Cycocel (CCC) at the rate of 10,000 ppm at 90 DAS (T8). Significantly the lowest In situ sprouting or viviparous germination percentage upto 20 days after maturity was also observed in treatment T8 (CCC @ 10,000 ppm at 90 DAS) as compared to control, indicating its superiority for inducing seed dormancy in bunch groundnut. In addition to this, seed dormancy in groundnut showed a positive correlation with total phenol content, with the highest phenol level (3.53 mg g⁻¹ fr. wt.) at 100 DAS recorded under treatment T8, which was statistically at par with T7 (Cycocel @ 5000 ppm at 90 DAS).