Abstract
Jatropha curcas is an oil-bearing semi-evergreen shrub or small tree with potential as a source of sustainable biofuel, yet information regarding vegetative and fruit biomass in relation to plant architecture is lacking. Research conducted in Indonesia used the tree based functional branch analysis (FBA) model as a non-destructive method to estimate above and belowground biomass, and plant architecture. The FBA utility for shrubs was unknown and required modification. This research used destructive measurements to validate modifications to the FBA model that included sub-categorisation of the tapering coefficient for twig, branch, and wood diameter classes, and addition of a fruit load parameter in the distal link. The modified FBA model confirmed jatropha to be a shrub rather than a tree, producing variable estimates for aboveground biomass. This variation was due to morphological plasticity in the length–diameter relationship of the branches that diverged from fractal branching architecture. Fruit biomass variation between replicates was not well estimated and total proximal root diameter was a poor predictor of total root biomass, due to the proximal roots having enlarged water storage structures that do not follow fractal branching assumptions. Jatropha fruit was shown to predominate on twigs with a diameter between 0.9 and 1.4 cm. Understanding the correlation between fruit development and plant architecture will be necessary for fine-tuning the FBA model for future commercial breeding and selection. The high degree of morphological plasticity displayed by jatropha requires consideration when determining plant biomass.
Highlights
Jatropha curcas L. is a semi-evergreen shrub or small tree with oil-rich seeds, belonging to the Euphorbiaceae (Divakara et al 2010)
Tree parameters for aboveground biomass determination were generated from 1754 links and belowground biomass derived from 3182 links from ten trees
Sometimes branches alternate in a herringbone pattern with unequal distances between links, or situated only at one side in an unequal herringbone pattern (Fig. S1)
Summary
Jatropha curcas L. is a semi-evergreen shrub or small tree with oil-rich seeds, belonging to the Euphorbiaceae (Divakara et al 2010). The disagreement occurs because jatropha has a range of phenotypes; shrub-like, multi-stemmed growth habits with height \5 m, and tree-like, single-stemmed growth habits with height [5 m (Sunil et al 2013). This problem is not restricted to jatropha as Scheffer et al (2014) found that 9.2 % of the tree species assessed were classified as shrubs in the TRY (plant traits) database. An understanding of jatropha growth and reproductive biology in combination with breeding for available commercial high yielding planting material, optimum management practices, and suitable growing environment are still lacking (Achten et al 2014; Edrisi et al 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
