Testing Biodegradable Seedling Containers as an Alternative for Polythene Tubes in Tropical Small-Scale Tree Nurseries

Polythene tubes are the most commonly used seedling containers and their adoption can be attributed to high water retention that enhances seedling establishment as well as the desire for low-cost readily-available containers by nursery operators. Polythene tubes have drawbacks, however, because they adversely affect seedling root growth and are an environmental hazard. This study was conducted in Meru, Eastern Kenya, to investigate whether small-scale tree nursery operators are likely to adopt biodegradable seedling containers (cellulose papers and banana sheaths). It was hypothesised that biodegradable containers are better for seedling growth and are more environmental friendly than the widely used polythene bags. The study assessed the frequency of watering and growth (height and basal diameter) of Calliandra calothyrsus seedlings produced in various biodegradable containers under three conditions with varying watering requirements, i.e. light tree shade, shade net and polythene chambers, the first being widely used by farmers. The performance of these seedlings was later monitored in the field. Seedlings produced in biodegradable containers required more frequent watering than those in polythene bags under light tree shade and shade nets but less frequent in polythene chambers. Seedlings produced in polythene tubes had higher growth rates in the nursery, but when transplanted to the field, they were overtaken by those grown in the biodegradable containers due to transplanting shock after the polythene containers were removed. Biodegradable seedling containers can therefore be adopted in areas where water is not very limiting, and evaporation rates could be reduced and water-use efficiency improved by raising seedlings in simple polythene structures.