Senna obtusifolia

Cultivation Details

Plants succeed in the tropics and subtropics^[1]. Prefers a deep, well-drained, moderately fertile sandy loam and a position in full sun^[1]. The plant can spread freely and it is considered to be a weed in many parts of the world - for example, an estimated 600,000 ha of land are infested with it in Queensland (Australia)^[2]. Sicklepod is a short-day plant, but exact light requirements for flower initiation differ by provenance^[2]. It is self-pollinating and inter-specific crosses have not yielded viable seed^[2]. Sicklepod is closely related to Senna tora, but the latter can be recognized by its shorter pedicels^[2]. The distinction between S. Obtusifolia, S. Occidentalis and S. Tora is not always properly made; names have often been misapplied and vernacular names may apply to all of them^[2]. The presence of S. Tora in Africa is doubtful and references to it probably concern S. Obtusifolia^[2]. While the wider genetic variation of this plant is found in the New World, there is obvious scope for selection for vegetable use even within the African populations^[2]. Farmers already select plants that taste less bitter, are less fibrous and have easy-to-pick leaves^[2]. Australia may start a breeding programme based on seed stock collected from all over the area of distribution in the near future^[2]. Breeding would aim at high seed and gum yield, good gum quality and adaptation to mechanized cultivation^[2]. In India seeds for gum production are presently harvested from the wild. As far as is known, Senna obtusifolia is only grown commercially in Korea for medicinal uses, with seed yields as high as 2.6 t/ha^[2]. The plant is an alternative host of Alternaria cassiae, which affects crops such as cowpea (Vigna unguiculata) and several Solanum species^[2]. There are conflicting reports on whether or not this tree has a symbiotic relationship with certain soil bacteria, so it is unclear as to whether this tree fixes atmospheric nitrogen^[3].