Page 13 - Griffin Gazette Issue 1 - 2022

Environmental conditions also have a significant impact
• Florel does not have translaminar movement
so uniform coverage is essential for on the performance of Florel. Slower drying of foliar spray
applications increase the activity of this PGR, all other
consistent results. Spray from both sides of factors being equal. Make applications during periods of
the crop when possible. lower light. Cloudy days are a good choice but making
applications early or late in the day can provide similar
• Florel enhances plant stress. Delay results. If shade curtains are available, they can provide a
applications until recently transplanted liners good option as well. Lower air velocity in the greenhouse
have established in the new container. Avoid equates to slower drying, so make applications when the
applications to plants that are under water exhaust fans can be safely left off for an hour if possible.
stress or other physiological stressors. Higher temperatures hasten drying, however Florel’s
response to higher temperatures is more complex than
• Spray water pH must be 5.0 or lower after that. Research from Roberto Lopez, Michigan State
the addition of Florel. Florel is acidic but high University, deserves a closer look.
alkalinity water sources may keep it from
sufficiently dropping the spray water pH. Ambient temperature at application influences efficacy
Remedies include acidified water or using a 57 63 68 73 79 °F
product called Indicate 5 that reduces the
pH of the spray water and indicates the pH
by means of a color change.
45 45 46 45 41
• Not every crop responds well to Florel. 63 64 67 67 48
Torenia is an example of a crop that reacts
negatively to Florel. It forms hard leathery
foliage and experiences an unusually long 51 49 49 51 40
bloom delay based on grower reports. 7 6 7 7 5
Growers have also reported defoliation Figure 2. Roberto Lopez, Michigan State University
Roberto Lopez, Michigan State University
of euphorbia, dipladenia, mandevilla and
purslane from 500 ppm applications. Some Two of the best ways to evaluate the effectiveness of a
growers have had success with those 4 Florel application are comparing the number of branches
crops by experimenting with lower rates. per plant and the days to bloom. Responsive plants
Trial Florel first on any crop that you do not sprayed with Florel will typically take longer to bloom
have prior experience with. GGSPro can than untreated plants. In the image above you will see
that when temperatures at the time of application under
help you identify crops that do and do not growth chamber conditions were increased from 57° to
respond well to Florel. 73°F that the number of branches per plant and the days
to bloom were very uniform. This was true for petunias
and ivy geraniums, two crops known to respond well to
Florel. The remarkable result was that at 79°F there was
about a 20-25% decrease in branches per plant and the
plants bloomed 4-11 days sooner than those treated at
lower temperatures.
This research indicates that somewhere between 73°
and 79°F there is a dramatic reduction in the activity of
Florel. This has significant implications for crops produced
later in the spring and summer when nighttime or early
morning applications may be required to insure effective
applications.
Florel is a valuable PGR tool for many crops. Understanding
the factors that influence performance and accounting for
those factors can lead to more consistent and reliable
results.

Figure 1 | Euphorbia defoliated Read and follow the entire label. Labels can change
by 500 ppm Florel application without notice, stay up to date with current labeling.

GRIFFIN GAZETTE 2022 | 13