Influence of Apical Cutting on Growth Parameters of Roselle (Hibiscus sabdariffa L.) in Two Agro-climatic Zones of Niger

Improving roselle yield and production, particularly in light of climate change and variability, remains challenging and constantly urges for the modification of agro-techniques. One such modification that has proven successful in boosting yield of many vegetable crops in recent years is the adaptation of the apex cutting technique, especially in unfavorable agro-climatic circumstances where traditional methods are not plausible. This study was to assess the effect of cutting the main stem apical bud on roselle growth parameters and determine the optimal stage of apex cutting. The experiment was conducted in a split plot experimental device in randomized blocks with four (4) repetitions at Tara/Gaya and Tarna/Maradi. Two factors were studied, six (6) roselle ecotypes and four (4) levels of apex cuttings viz. C0 (uncunt plants as a control); C1 (20 days after sowing (DAS)); C2 (30 DAS); and C3 (40 DAS). The findings showed that apex cutting significantly affected all the morphological parameters evaluated. Apex cutting significantly reduced the total plant height and the number of primary branches per plant. Furthermore, significant increases were observed in the diameter and the number of secondary branches per plant for the six ecotypes. Moreover, the optimal time-point for obtaining the best collar diameter and secondary branches per plant was found to be between cut 1 (20 DAS) and cut 2 (30 DAS).