28 Sep 2016
Remediating Paclobutrazol From Irrigation Water Using Activated Carbon
Grant, G.A., Fisher, P., Barrett, J.E., Wilson, C.P. (University of Florida)
Recirculating irrigation water can sometimes have residual agrichemicals present, such as paclobutrazol. Paclobutrazol is an active ingredient used in plant growth regulators to control plant height. The objective of this project was to use granular activated carbon filtration (GAC) to remove paclobutrazol using different contact times. A 0.05 mg·L-1 (50ppb) paclobutrazol solution was passed through a small-scale, 0.50 to 4.75 mm particle size (8x30 mesh) coconut coir GAC system. A bioassay of broccoli seeds and begonia seedlings were used to show the effect of before and post GAC filtered water. Paclobutrazol concentration decreased by 90% or 99% with a contact time of 12 seconds or 59 seconds GAC, respectively. Overall, this experiment showed that granular activated carbon has the potential to remediate paclobutrazol from irrigation water to below biologically-active concentrations.
ASHS Abstract 2016 Grant (270 KB)
14 Sep 2016
When to Fertigate: The Influence of Substrate Moisture Content on Nutrient Retention in Containerized Crop Production
McPherson, S., Owen, J.S., Brindley, J., Fields, J.S. (Virginia Tech)
The efficient use of fertilizers is key to increase profitability for the agriculture industry (nursery and greenhouse). Fertigation efficiency increased as pine bark substrate moisture increased (38% to 56% gravimetrically). It was hypothesized that mineral retention occured with uniformly distributed water.
SNA Research Conference Vol. 60 2015
SNA When to fertigate (179 KB)
1 Jun 2016
Nutrient Remediation using Two Plant Species in a Floating Treatment Wetland System
Garcia, L.M., Majsztrik, J.C., Bell, N.L., White, S.A. (Clemson University)
Excess nutrients are often present in production runoff from nurseries and greenhouses because fertilizers are used to grow plants. In 2015, we conducted trials with floating treatment wetlands (FTWs) to determine how much nutrients soft rush (Juncus effusus) and pickerelweed (Pontederia cordata) could absorb. When harvested after 20 weeks, with pond nutrient concentrations averaging 10 ppm N and 3 ppm P, a 1-acre are of planted FTWs would remove 88 lbs. of N and 15 lbs. of P if planted with soft rush or 1,320 lbs. of N and 255 lbs. of P if planted with pickerelweed.
ASHS Abstract (78 KB) ASHS Presentation (774 KB)