Initial Effects of Fertilization and Canopy Management on Flowering and Seed and Oil Yields of Jatropha curcas L. in Malawi

Abstract

Appropriate canopy management, including planting density and pruning, and application of fertilizer may increase flowering success and seed and oil yields of Jatropha curcas L. Two field experiments were performed from 2009 to 2011 in Balaka, Malawi, to assess the effect of planting density and pruning regime and single fertilizer application (N, P, and K) on male and female flower number and seed and oil yields of J. curcas. Planting density influenced flower sex ratio and female flower number. Branch pruning treatments did not influence the flower sex ratio but reduced seed and final oil yield by 55 % in the following year. It is claimed that J. curcas can be grown on soils with low nutrient content, but this study revealed that yield was low for non-fertilized trees. We observed higher seed and oil yields at higher N application rates (up to 203 ± 42 % seed and 204 ± 45 % oil yield increase) compared with the non-fertilized control. The study suggests thatcurrently used heavy pruning practice is not recommended for J. curcas cultivation, although it needs further longer term investigation. Applying nitrogen fertilizer is effective in increasing yield.

Effectiveness of a micronutrient delivery system fertilizer in jatropha plants is related to enhanced photosynthesis, gas exchange and biomass allocation

“…Our results evidenced direct benefits of NPK fertilization on jatropha leaf production and expansion, mainly in plants grown with no MDS (Figure 1). Recent studies investigated NPK effects on this species and have also demonstrated effective response of jatropha plants to NPK fertilization (LIMA et al, 2016;NEGUSSIE et al, 2016). In contrast, chlorophyll index in MDS-treated plants slightly varied due to NPK doses, showing high SPAD values even with no incorporation of NPK into the soil ( Figure 1C).…”

“…Studies with different fertilization strategies have indicated that jatropha requires significant amounts of nutrients to obtain satisfactory yields. Negussie et al (2016) observed significant responses of jatropha to fertilization, especially with nitrogen, resulting in increased yield. In addition, Lima et al (2016) reported that phosphate and organic fertilization together beneficially influenced plant height, number of branches, stem diameter, leaf area, number of seeds per plant, and total mass of jatropha seeds.…”

“…In this context, jatropha or physic nut (Jatropha curcas L.) is a promising tropical biofuel plant and has been considered as a potential crop for marginal environments due to its ability to grow relatively well under harsh conditions, such as scarce rainfall and poor soil (SILVA et al, 2010). Nonetheless, recent studies have revealed that yield is significantly low in non-fertilized fields (LIMA et al, 2016;NEGUSSIE et al, 2016).…”

Quantitative analysis of jatropha growth: micronutrient delivery system and NPK combined effects

“…The higher LA values observed in response to NPK incorporation evidenced direct benefits on jatropha leaf production and expansion (Figure 2A). Similarly, recent studies in the literature have investigated NPK effects on jatropha, from early development through final yield, which have demonstrated effective response of this species to NPK fertilization (LIMA et al, 2016;NEGUSSIE et al, 2016).…”

“…Jatropha (Jatropha curcas L.) is considered an important tropical biofuel plant. It is claimed that this species can be grown on soils with low nutrient content, but Negussie et al (2016) have revealed in their recent study that yield is significantly low in non-fertilized trees. In contrast, for Lima et al (2016), jatropha is a perennial species that requires expressive amounts of nutrients to produce satisfactorily.…”