Because of the depletion of phosphate resources and the need for phosphate in agricultural production, the use of low-grade phosphate rocks (PR) is necessary. Partially acidulated PRs (PAPR) are effective phosphate fertilizers from low-grade PR. Herein, we analyzed the changes in properties such as hygroscopicity and phosphate solubility, as well as the applications of the improved PAPR produced, using PRs from Burkina Faso. As the amount of added sulfuric acid increased, the amount of soluble phosphate in the PAPR also increased. However, at PAPR100 and above, the PAPRs became stickier, making them difficult to use as fertilizers. Adding both calcium and potassium carbonates improved the hygroscopicity and pH (H₂O) while maintaining sufficient phosphate solubility. Pot experiments showed that the application of these PAPRs resulted in sorghum yields comparable to those of commercial single superphosphate (SSP). These results indicate that the addition of carbonate to the PAPR production process makes phosphate fertilizer easy to handle and yields phosphate fertilizers using low-grade PRs that are as effective as an SSP.

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Several priming methods were applied to cassava cuttings, a vegetatively propagated crop, and their effects were investigated for the improvement of cutting establishment and initial growth as the objective. Regardless type of solute, soaking the cuttings in solutions occurred the water absorption and the increase of their moisture contents. Although no effect on survival rate and uniformity of germination was observed in all experiments, MGT and t50, which are indicators of germination rate were shortened by nutrient and hydropriming for more than 12 hours soaking. In addition, a negative correlation between MGT and total dry weight was observed. As the results above, it is considered that early germination and establishment of the cuttings by hydropriming and nutrient priming led to promote initial growth of cassava cuttings. On the other hands, the effect on hormonal priming with 4-CPA was observed only under wet soil condition, and negative effects on dry matter production and germination in osmo priming with PEG 6000 treated even with mild stress conditions of −0.07 MPa. Although further research is needed into the conditions to maximize the effects of nutrient and hydropriming, it is expected that the establishment and initial growth of cassava cuttings are improved by nutrient and hydropriming which do not require complicated process or large amount of materials.

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The purpose of this study was to evaluate the effect of the foliar spraying of Pentakeep® Super which is a foliar fertilizer formulated with 5-aminolevulinic acid (5-ALA) designed to enhance plant growth and development through improved nutrient absorption and stress resistance on the fruit growth and quality of the low-chill early ripening peach ‘KU-PP1’. Varying Pentakeep® Super concentrations (0.2 mL·L^-1, 0.4 mL·L^-1, and 0.6 mL·L^-1) were sprayed at intervals of 30, 45, and 60 days after full bloom on the leaves of ‘KU-PP1’ peach; four branches per tree during the 2020 and 2021 seasons. Pentakeep® Super treatment increased the photosynthesis rate of ‘KU-PP1’ peach compared to the control. Fruit maturity was accelerated by the Pentakeep® Super treatment in both seasons, and fruit weight and size increased in all treatments compared to that of the control. Furthermore, the TSS content was observed highest in the control during both years. The fruit color (a* and b*) was enhanced in the Pentakeep® Super-treated fruits in both years. Based on our findings of positive correlations between Pentakeep® Super and fruit quality attributes, we concluded that the Pentakeep® Super treatment produced superior results compared with control.

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