Effects of Phosphorus Ensembled Nanomaterials on Nutrient Uptake and Distribution in Glycine max L. under Simulated Precipitation

Nanoscale hydroxyapatite (nHA) was synthesized to investigate its potential as a phosphorus (P) ensembled nanofertilizer, using soybean (Glycine max L.) as a model plant. The conventional analogue phosphate (pi) was used for comparison with the synthesized nHA. Varied precipitation intensities (0%, 30%, 60%, and 100%) were simulated by adding selected volumes of the P fertilizers (nHA or pi) via foliar spray and soil amendment. The total amounts of added P were the same across all the treatments. The importance of a wash-off effect was investigated on foliar-treated seedlings by evaluating different watering heights (20, 120, and 240 cm above the seedlings). Fresh weight, pigment content, macro-, and micronutrient contents were measured in soybean tissues across all the treatments after 4 weeks of greenhouse cultivation. The synthesized nHA showed superior effects on plant nutrient content upon high precipitation intensities. For example, at 100% precipitation intensity, there was 32.6% more P and 33.2% more Ca in shoots, 40.6% more P and 45.4% more Ca in roots, and 37.9% more P and 82.3% more Ca in pods, as compared to those with pi treatment, respectively. No impact on soybean biomass was evident upon the application of nHA or pi. Further investigation into customizing nHA to enhance its affinity with crop leaves and to extend retention time on the leaf surface is warranted given that the present study did not show significant positive impacts of nHA on soybean growth under the effects of precipitation. Taken together, our findings increase understanding of the potential application of nHA as a nano-enabled fertilizer in sustainable agriculture.

Growth Response of Capsicum (Capsicum annuum L.) to Varying Levels of Phosphorus, Zinc and Arbuscular Mycorrhizae

The present study was conducted to evaluate the growth response of Capsicum (Capsicum annuum L.) to varying levels of Phosphorus (P), Zinc (Zn) and Arbuscular Mycorrhizae (AM). A pot experiment with twenty-four treatment combinations was setup in the net house. The treatment combination consisted of 4 levels of P: P0- 0, P50 - 237.5 kg ha-1 SSP, P75 - 355.5 kg ha-1 SSP and P100- 475 kg ha-1 SSP, 3 levels of Zn: Zn50- 5 Kg ha-1 ZnSO4, Zn75-7.5 Kg ha-1 ZnSO4, Zn100- 10 Kg ha-1 ZnSO4 and 2 levels of AM: I0- 0 and I15- 15 g per pot. The main objective of the study was to reduce the antagonistic interaction between P and Zn by using AM fungi. The results of combined effects of application of P, Zn and AM revealed that P, Zn addition along with AM fungi improved plant growth parameters, plant nutrient content and total nutrient uptake (both above ground and underground portion) of the plant. The results indicated increase in plant height, root length and total nutrient uptake by increasing the level of P, Zn and Arbuscular Mycorrhizae. Also, Arbuscular Mycorrhizae enhanced plant growth by reducing Phosphorus or Zinc deficiency. Antagonistic effects of P and Zn addition on plant nutrient content and total nutrient uptake were absent due to application of AM fungi. Our results indicated that by using appropriate levels of AM fungi along with P and Zn, antagonistic interactions can be reduced for maximizing the plant nutrient content and nutrient uptake which may lead to improvement in plant growth and nutrition.

The Effects of Biopesticide and Fusarium oxysporum f.sp. vanillae on the Nutrient Content of Binucleate Rhizoctonia-Induced Vanilla Plant

Binucleate Rhizoctonia (BNR) fungi are essential for the germination of vanilla seeds. Chemical control of the soil-borne pathogen might adversely affect BNR. The purpose of this study is to determine the effect of Nicotiana tabacum extract biopesticides and Fusarium oxysporum f.sp. vanillae (Fusarium) on vanilla plant nutrient content induced by BNR. Materials and Methods. The research design was completely randomized design with two factors and three replications. The first factor was biopesticide (dosage of 0, 10, 20, and 30 ml/seedling), and the second factor was the application of Fusarium. Results. The increase in the nitrogen, phosphorus, and potassium content of vanilla was affected by biopesticides and Fusarium inoculation. Fusarium inoculation has no significant effect on nitrogen and phosphorus levels but significantly affects potassium levels. The biopesticide dosage is significant for nitrogen, phosphorus, and potassium. The interaction of biopesticides with Fusarium inoculation did not significantly affect the parameters of nitrogen and phosphorus content, but significantly affected potassium content. Conclusion. The application of biopesticides and Fusarium inoculation after induction of BNR can increase nitrogen, phosphorus, and potassium content of vanilla plants.