Shahid Chamran University of Ahvaz, Ahvaz, Iran & Shahid Chamran University of Ahvaz, Ahvaz, Iran
Abstract: (99 Views)
Introduction: Roselle (Hibiscus sabdariffa L.) is used as food, hot and cold drinks, flavoring, and medicine. During the critical stages of development when plants require optimum moisture and temperature during planting, germination, flowering, and fruit formaion, choosing the suitable sowing date can affect growth and yield of medicinal plants (Mir et al., 2011). The purpose of this study was to evaluate the effect of sowing date and plant density on some growth characteristics and yield components of roselle (sour tea) under the climatic conditions of Ahvaz, Iran. Material and Methods: In order to evaluate the effect of sowing date and plant density on the growth and yield of roselle (sour tea), an experiment was carried out as split plot arrangements in randomized complete blocks design with three replications in the research farm of the Agricultural and Natural Resources Research and Education Center of Khuzestan province in Ahvaz, Iran, in 2022. Sowing dates at five levels (April 11, April 21, April 31, May 10, and May 22) were assigned to the main plots, and plant densities at three levels (4, 8, and 12 plant m-2) were randomized in sub-polts. After emergence, seedlings were thinned to reach the defined plant density (4, 8, and 12 plant.m-2) at three to four leaf stages. The growth characteristics were measured during five growth stages from 30 days after sowing dates and at intervals of 30 days. Roselle plants were harvested at the stage of boll ripening. After harvesting roselle plants, some characteristics related to yield componentsinclude plant dry weight, boll dry weight, number of boll.plant-1, number of seed.boll-1, 1000 seed weight, sepal weight.plant-1, biological yield, dry sepal yield and seed yield were measured and recorded. Results: Analysis of variance showed that the interaction of sowing date and plant density was significant on plant height, number of boll.plant-1, number of seed.boll-1, seed weight, sepal weight.boll-1, biological yield, sepal dry weight, seed yield and seed harvest index. Also, the effect of sowing date was significant on leaf area index, plant dry weight, boll dry weight, sepal anthocyanin content and sepal harvest index. Mean comparison showed that the highest plant height was measured in Aprill 21 with 12, 4, and 8 plant.m-2 (198.2, 197.9, and 194.6 cm, respectively). The highest number of seed.boll-1 was recorded in April 30 with 4 and 8 plant.m-2 (24 and 22.7, respectively). The heaviest single seed weight obtained in April 21 and April 30 with 8 plant.m-2 (19 g). The highest of sepal weight.plant-1 was obtained in April 31 with 12 plant.m-2 (43.9 g.plant-1). The highest biological yield was harvested in April 21 with 8 plant m-2 (44707.2 kg.ha-1). Also, the highest leaf area index (9), boll dry weight (0.893 g), number of boll.plant-1 (209.9) and sepal anthocyanin content (0.329 µmol g-1) were measured in sowing date of April 30. Conclusion: The results of this experiment showed that most of the growth characteristics and yield components of roselle (sour tea) plants sown on April 30 with 8 plant.m-2 were higher compared to other treatments. Delay in sowing date caused decreases in the growth characteristics and yield components, which is probably due to the increase in temperature and its effect on the growth and production of roselle plants. Considering the results of this experiment, the planting date of April 30 with plant density of 8 plant.m-2 was identified suitable packge for the growing of roselle under the environmental conditions of Ahvaz in Iran.
Hasani Nasab M, Fateh E, Aynehband A, Monsefi A, Behnamfar K. Effect of sowing date and plant density on growth and yield of roselle (Hibiscus sabdariffa L.) plant under climatic conditions of Ahvaz, Iran. علوم زراعی 2024; 26 (2) :170-186 URL: http://agrobreedjournal.ir/article-1-1355-en.html