Effect of gibberellic acid (GA3) and organic substances on root growth and seedling vigour of Custard Apple (Annona squamosa L.) seedlings under shade net condition

Abstract

The current study, entitled “Effect of gibberellic acid (GA3) and organic substances on root growth and seedling vigour of Custard Apple (Annona squamosa L.) seedlings under shade net condition”, was carried out during 2024-2025 at the Horticulture Nursery, Department of Fruit Science, College of Agriculture, IGKV, Raipur (C.G.). The experiment was laid out in a Completely Randomized Design (CRD) with 13 treatments, in three replications. The pre-soaking treatments consisted of GA₃ and various organic substances, detailed as follows:T0: Control, T1: Distilled water + 72 hours soaking, T2: GA3 @ 400 ppm + 24 hours soaking, T3: GA3 @ 500 ppm + 24 hours soaking T4: Azospirillum @ 5% + 24 hours soaking,T5: Azospirillum @ 10% + 24 hours soaking, T6: PSB @ 5% + 24 hours soaking, T7: PSB @ 10% + 24 hours soaking, T8: Cow urine @ 5% + 24 hours soaking, T9: Cow urine @ 10% + 24 hours soaking, T10: Custard Apple Leaf Extract @ 5% + 24 hours soaking, T11: Custard Apple Leaf Extract @ 10% + 24 hours soaking and T12: Cow dung slurry @ 10% + 24 hours soaking. In conclusion, results of the present investigation showed that among the various pre-soaking treatments, T2 (GA3 @ 400 ppm + 24 hours soaking) was the most effective in enhancing root growth and seedling vigour parameters, followed by T3 (GA3 @ 500 ppm + 24 hours soaking). Control (T0) showed the lowest performance across all evaluated parameters. Among the organic treatments, T9 (Cow urine @ 10% + 24 hours soaking) gave the most favourable results, followed by T12 (Cow dung slurry @ 10% + 24 hours soaking). Hence, T9 may serve as a viable alternative to chemical treatments in organic or low-input production systems.