Effect of Browsing on the Growth of Jojoba Seedlings in the Dry-Lands of Kenya

Jojoba is a desert shrub, introduced in the marginal areas of Kenya during 1980s. Jojoba domestication is being faced by browsing problems due to pastoralism in these areas. Massive browsing of leaves lowers photosynthesis leading to decline in plant functions. An experiment was set up in Maungu, with the aim of determining the effect of browsing on jojoba seedlings. The experimental design was a randomized complete block design with three treatments replicated three times. The treatments consisted of varying levels of browsing as follows: non browsed, 50% browsed and fully browsed. Seedlings were raised for six months before sampling. Variables assessed were: survival, height, root-collar diameter, leaf size, root length and number, internode length, sprout number, root/shoot ratio and total biomass. ANOVA was performed to determine differences among the treatments whilst significant differences among the means were separated using least significant difference (LSD) at p ≤ 0.05. Results showed fully browsed seedlings were significantly lower in height (26.2 cm), internode length (9.7 mm), leaf length (18.3 mm) and width (10.4 mm) and total fresh plant biomass (11.0 g) compared to the non browsed ones which showed 31.1 cm, 23.2, 36.1 and 16.6 mm and 17.8 g, respectively. On the other hand, fully browsed seedlings showed significantly higher root/shoot ratio. Seedling growth was negatively affected by severity of browsing which resulted in stunted growth. The study recommended that browsing of seedlings should be prevented since it hinders plant growth.