R.O Awodoyin, Sola Ogunyemi

Germination of seeds of sicklepod as affected by pre-germination treatments, fruit maturity and depth of sowing: Implication in sown fallow management

Introduction

Germination of seeds of sicklepod as affected by pre-germination treatments, fruit maturity and depth of sowing: implication in sown fallow management. Optimize sicklepod seed germination using pre-germination treatments (acid, hot water, scarification). Understand fruit maturity and sowing depth impacts for effective sown fallow management strategies.

Abstract

Sicklepod (Senna obtusifolia) is a multipurpose plant with potentials in improved bush fallow management. Studies were carried out in 1997 and 1998 in the laboratory, nursery and on the field in Ibadan, Nigeria to understand its germination ecology. Studies included germination as affected by: a) pre-germination treatments - sulphuric acid, boiling water and physical scarification, b) fruit maturity, and c) depth of seed burial. Seed coat dormancy was evident in the seeds of sicklepod, especially at dark brown pod maturity stage. Acid-scarification for 2-15 minutes, steeping in boiling water for 10-60 seconds and physical wounding of seed coat resulted in. about 100% germination within four days compared to 20% germination obtained in non-scarified seeds at seven days after sowing. Seeds were not physiologically mature enough until the light brown pod stage. At seven days after sowing, seed germination was 100%, 50% and 0% at 0-4 cm, 8 cm and 16 cm soil depth respectively. Results showed that pre-germination treatments will induce early and uniform germination in sicklepod. The latest stage to remove sicklepod for mulching or green manuring to prevent multiplication of seeds in the soil seed bank is yellow pod stage when the embryo is still immature.

Review

This study investigates the germination ecology of sicklepod (Senna obtusifolia), a plant with recognized potential for improved bush fallow management. Conducted in Ibadan, Nigeria, over two years (1997-1998), the research comprehensively examined the impact of various factors on seed germination, including pre-germination treatments, fruit maturity stages, and depth of sowing. The paper successfully highlights the critical role of these ecological factors, providing valuable insights for optimizing the establishment and control of sicklepod within agricultural systems, particularly for its use in sown fallows. The experimental findings reveal significant insights into sicklepod's germination behavior. Seed coat dormancy was clearly identified, being particularly pronounced in seeds from dark brown pods. The research demonstrated that mechanical and chemical scarification methods—specifically acid scarification (2-15 minutes), steeping in boiling water (10-60 seconds), or physical wounding—effectively broke this dormancy, leading to a remarkable ~100% germination within four days, a stark contrast to the mere 20% germination observed in non-scarified seeds after seven days. Furthermore, the study established that seeds achieve physiological maturity at the light brown pod stage and that sowing depth critically influences germination, with optimal rates (100%) occurring at 0-4 cm, decreasing to 50% at 8 cm, and becoming nil at 16 cm depth. The implications of these findings are highly relevant for practical agricultural management. The efficacy of pre-germination treatments in achieving rapid and uniform germination is a key takeaway, suggesting methods to enhance the establishment of sicklepod in sown fallows. Equally important is the recommendation to remove sicklepod for mulching or green manuring at the yellow pod stage, before the embryo matures, to prevent the replenishment of the soil seed bank and potential weed proliferation. This research offers robust, data-driven strategies for both promoting and controlling sicklepod, making a significant contribution to sustainable fallow management practices in tropical agroecosystems.

Full Text

Comments

You need to be logged in to post a comment.