US (FL): Effect of phosphorus rates on tomato in calcareous soil
The objective of a new study was to evaluate the impact of different P rates on leaf tissue P concentration (LTPC), plant growth, biomass accumulation, fruit yield, and postharvest quality of tomato (Solanum lycopersicum L.) grown on a calcareous soil.
The experiment was conducted with soils containing 13 to 15 mg·kg−1 of P extracted by ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA). Phosphorus fertilizers were applied at rates of 0, 29, 49, 78, 98, and 118 kg·ha−1 of P before laying polyethylene mulch. Tomatoes were grown using drip irrigation during the winter seasons of 2014 and 2015.
No significant responses to P rates were found in LTPC during both growing seasons. Plant height, stem diameter, and leaf chlorophyll content at 30 days after transplanting (DAT) were significantly affected by P rates in 2015, but not in 2014. The responses of plant biomass were predicted by linear models at 60 DAT in 2014 and at 30 DAT in 2015. There were no significant differences in plant biomass at 95 DAT in both years.
At the first and second combined harvest, the extra large fruit yield was unaffected in 2014, but predicted by a quadratic-plateau model with a critical rate of 75 kg·ha−1 in 2015. The total season marketable yields (TSMY) and postharvest qualities were not significantly affected by P rates in either year. Phosphorous rate of 75 kg·ha−1 was sufficient to grow a tomato crop during the winter season in calcareous soils with 13–15 mg·kg−1 of AB-DTPA-extractable P.
Access the full study at HortScience.