Effect of anti-ethylene and cytokinin biostimulants on flowering and yield of Sweetpotato (Ipomoea batatas L.)
Authors:   Department of Biotechnology, National Root Crop Research Institute (NRCRI), Umudike.P.M.B 7006, Abia State., S. P. Abah , I. O. Bassey ,   Department of Agronomy, College of Crop and Soil Sciences, Michael Okpara University of Agriculture, Umudike. P.M.B 7267, Abia State., C. M. Okoronkwo, ,   Department of Agronomy, College of Crop and Soil Sciences, Michael Okpara University of Agriculture, Umudike. P.M.B 7267, Abia State., F. Ewa, . ,   Department of Biotechnology, National Root Crop Research Institute (NRCRI), Umudike.P.M.B 7006, Abia State., F. A. Nkaa, ,   Department of Plant Science and Biotechnology, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria.
Published: December 2023

Breeding is needed to enhance the poor agronomic and qualitative attributes of the majority of sweetpotato cultivars grown in Nigeria. Even though the majority of cultivars don't often flower, the flowers are essential for genetic advancements. This study aimed to assess the effect of anti-ethylene (Silver-thiosulphate) and cytokinin (6-benzyladenine) biostimulants for induction of flowering and yield, to encourage early flowering of delayed sweetpotato genotype, and to ascertain the ideal concentration of growth regulators for sweetpotato flowering induction. A randomized complete block design with three replications was fitted with a 3x3x2 factorial arrangement. The first factor consisted of three different concentrations of two plant growth regulators (PGR): silver thiosulphate (STS) and 6-benzyladenine (BA) (0, 50, and 100 ppm). Three types of sweet potatoes (Umuspo3, Buttermilk, and Tis87) constituted the second factor. After planting, the BA and STS were administered three weeks later. The sweet potato varieties sprayed with STS and BA displayed morphological and physiological challenges, such as stem drooping (Temporal) (Page 1A), which recovered in 24 hours, root swelling, stem splitting, bud and flower production, vine branching, and elongation (Plate 1B). Varieties sprayed with high concentrations of STS (100 ppm) displayed significant morphological and physiological abnormalities, while those sprayed with BA displayed a significant increase in all growth metrics. However, two of the varieties Umuspo3 and Tis87 that were sprayed with STS and BA began buds and set flowers within two weeks after the treatment, whereas the plants that were not sprayed did not flower at all. The results of the interactions showed that the combination of benzyladenine + Umuspo3 at 100% (100T1V1) was superior for yield, whereas the combination of silver thiosulphate + Umuspo3 at 100% (100T2V1) was superior for the total number of flowers/plant. The vegetative growth parameters and the flowering characteristic exhibited a substantial positive connection (P<0.05), however the correlation between the vegetative growth traits and the yield traits was negative. As a result, the higher dosage of BA and STS (100 ppm) that was employed in this experiment is most likely quite near to the ideal concentration for sweet potato flower induction. Despite not being the ideal concentration, sweet potatoes can currently be induced to flower at this level, enabling the start of breeding programs for the crop.