Effect of seasonality, graft type and scion characteristics on propagation of Vitex payos in the drylands of Kenya

Abstract

This study focused on Vitex payos (Lour) Merr. which is a high valued indigenous fruit tree known for its social (nutritional and medicinal use) and economic potential in Kenya. However, domestication of this species is hampered by limited information on its vegetative propagation. The objective of the present study was to determine the effect of seasonality and grafting methods on graft take-off and survival. Scions were collected and evaluated using wedge, saddle and splice grafting methods. The experiment was conducted in a glasshouse under a complete randomized block design. Development, growth and survival of terminal shoots and lateral branch were assessed. Analysis of variance (ANOVA), post-hoc and regression analyses were performed using GenStat software 16th edition. There was significant difference in the number of terminal shoots developed across grafting methods (F2,159 = 3.60; p = 0.029). Similarly, there were significant differences in the mean growth of the terminal shoots across seasons and grafting types. Wedge grafts registered the highest number of terminal shoots followed by splice grafts. Wedge grafts that were done during the month of October recorded the tallest shoots on average. Growth of lateral shoots across the seasons and grafting methods were significantly different (p < 0.05). However, grafting method and season had no effect on survival of the grafts even though survival declined significantly over time. The findings of this study show that wedge grafts registered the best performance. Grafting in October or when the tree is almost breaking dormancy is recommended for better growth performance.    Key words: Vitex payos, vegetative propagation, grafting method, seasons, graft-take.