Authors: Joyce G. Latimer, Extension Specialist, Greenhouse Crops; Virginia Tech
Publication Number 430-102, November 2001
Table 4. Chemical costs for growth retardant sprays and drenches*.
| Spray applications | Drench applications | ||||||
|---|---|---|---|---|---|---|---|
| Chemical and costz | Conc. applied (ppm) | Amount of chemical needed for 5 gallons of sprayy | Cost per 1000 ft2 of bench area sprayedx | Milligrams of active ingredient per 6 inch pot | Conc. applied (ppm) | Fluid oz. of chemical needed for 5 gallons of drench solution | Cost per 100 six inch pots |
| A-Rest $56 per quart | 2 | 4.8 fl oz. | $8.40 | 0.125 | 1.1 | 2.56 | $2.80 |
| 5 | 12.1 fl oz. | $21.18 | 0.25 | 2.1 | 5.12 | $5.60 | |
| 10 | 24.2 fl oz. | $42.35 | 0.375 | 3.2 | 7.68 | $8.41 | |
| 26 | 2.0 quarts | $112.00 | 0.50 | 4.2 | 10.24 | $11.21 | |
| 33 | 2.5 quarts | $140.00 | NOTE: A-Rest drench figures are based on applying 4 fluid oz. of drench per 6 inch pot. | ||||
| 66 | 5 quarts | $280.00 | |||||
| B-Nine $353 per 5 pounds | 750 | 0.59 oz. | $2.60 | ||||
| 2,500 | 1.97 oz. | $8.69 | |||||
| 5,000 | 3.92 oz. | $17.30 | |||||
| Bonzi $106 per quart | 2 | 0.32 fl oz. | $1.06 | 0.1183 | 1 | 0.16 | $0.33 |
| 5 | 0.80 fl oz. | $2.65 | 0.2366 | 2 | 0.32 | $0.60 | |
| 10 | 1.60 fl oz. | $5.30 | 0.4832 | 4 | 0.64 | $1.33 | |
| 20 | 3.20 fl oz. | $10.60 | 0.5915 | 5 | 0.80 | $1.66 | |
| 30 | 4.80 fl oz. | $15.90 | 1.1835 | 10 | 1.60 | $3.31 | |
| 45 | 7.20 fl oz. | $23.85 | 1.7744 | 15 | 2.40 | $4.97 | |
| 60 | 9.60 fl oz. | $31.80 | 2.3659 | 20 | 3.20 | $6.63 | |
| NOTE: Bonzi drench figures are based on applying 4 fluid oz. of drench per 6 inch pot. | |||||||
| Cycocel $70 per quart | 750 | 4.07 fl oz. | $8.90 | 354.88 | 2,000 | 10.8 | $22.25 |
| 1,500 | 8.13 fl oz. | $17.78 | 532.32 | 3,000 | 16.2 | $33.37 | |
| 2,000 | 10.84 fl oz. | $23.71 | 709.76 | 4,000 | 21.7 | $44.49 | |
| NOTE: Cycocel drench figures are based on applying 6 fluid oz. of drench per 6 inch pot. | |||||||
| Florel $19 per quart | 500 | 8.09 fl oz. | $4.80 | ||||
| 1,000 | 16.18 fl oz. | $9.61 | |||||
| Sumagic $97 per quart | 2 | 2.56 fl oz. | $7.76 | 0.03 | 0.25 | 0.32 | $0.62 |
| 5 | 6.40 fl oz. | $19.40 | 0.06 | 0.51 | 0.65 | $1.23 | |
| 10 | 12.80 fl oz. | $38.80 | 0.12 | 1.01 | 1.3 | $2.46 | |
| 15 | 19.20 fl oz. | $58.20 | 0.24 | 2.03 | 2.6 | $4.92 | |
| 20 | 25.60 fl oz. | $77.60 | 0.36 | 3.04 | 3.90 | 7.38 | |
| 30 | 38.40 fl oz. | $116.40 | NOTE: Sumagic drench figures are based on applying 4 fluid oz. of drench per 6 inch pot. | ||||
zCosts were averaged from three sources. Price will vary with supplier and quantity ordered.
yAssuming an application rate of 2 quarts per 100 ft2, this amount of spray will treat 1,000 ft2 of bench area.
xAssuming an application rate of 2 quarts per 100 ft2 of bench area. The cost per pot or flat can be calculated by dividing the figures in this column by the number of pots or flats per 1,000 ft2.
*Adapted from D. Bailey and B. Whipker. 1998. Height Control of Commercial Greenhouse Flowers. NC Coop. Ext. Serv. Horticulture Information Leaflet 528.
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