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)
1 Jun 2016
Minimize Build-up In Your Water Pipes
Fisher, P. (University of Florida) and Raudales, R. (University of Connecticut)
In this case study, stain was observed on the plant foliage and on the walls of the greenhouse. Iron analysis from the well water was high at 8 ppm. In the main irrigation pipe there was a build up of brown sludge. Analysis of the sludge showed that 58% of the reported minerals was iron. To solve this problem an oxidizer (potassium permanganate) was injected into the water to precipitate the iron (into a solid form). A filter (glauconite greensand) was used to remove the iron from the water.
Greenhouse Grower June 2016 (541 KB)
1 May 2016
Pinpoint Toxicity in Your Pond Water
Fisher, P.R. (University of Florida)
A case study for a coastal Florida producer using pond water for irrigation. The pond water passed through a sand filter and chlorination treatment. The plants showed pitting and bronzing on the foliage and stunted growth. This article provides trouble shooting tips and tools used to calculate chlorination dosage.
Greenhouse Grower May 2016 (3754 KB)