Augmentation of Dry Matter Production, Photosynthetic Enzymes, Yield Attributes and Quality Parameters of Sunflower through Seed Priming Effect of Gibberellic Acid—A Multifaceted Hormone

Abstract

The aim of this experiment is to search best concentration of GA and appropriate duration (soaking hour) as well as to find out best interaction between best concentration and best soaking duration. Soaking the seeds with 10 −5 M GA for 8 h is best for growth and development of sunflower cv. PAC 3776. Surface sterilized seeds sunflowers (Helianthus annus L.) were soaked in 0, 10 −7 , 10 −5 and 10 −3 M aqueous solution of gibberellic acid (GA) for 4, 8, 12 and 16 h and sown in pots filled with 4 kg homogenous mixture of soil and farmyard manure in the ratio of 4:1. The plants were sampled at 50 and 70 days after sowing (DAS), for analysis of shoot and root dry weight, leaf area index (LAI), carbonic anhydrase activity (CA) and nitrate reductase (NR) activity, nitrogen (N), phosphorus (P) and potassium (K) content at 50 and 70 DAS and seeds per head, seed yield, and harvest index, acid value, iodine value and saponification value at harvest (90 DAS). All parameters were found to be significantly enhanced by the GA seed priming effect, with maximum stimulation being noted following an 8 h soaking treatment with 10 −5 M GA. Moreover, the most of the mentioned parameters were enhanced by 132.98%, 170.59%, 33.82%, 25.86% and 86.14% over the control at the 50 DAS except the CA, N, and P found to be non-significant at this stage. N content was found to be non-significant also at 70 DAS. Similarly, yield parameters were enhanced also by 123.49%, 44.76%, 41.38%, 111.76% and 1.64% respectively at harvest over control except iodine value. The objective of this experiment is to enhance the quality of sunflower constituents through application of best concentration and soaking time of GA.