Various postharvest procedures were conducted on several rose (Rosa hybrida) cultivars to determine the effects on vase life, water uptake, change in fresh weight, stage of opening, and vase life termination criteria. Vase life was influenced by cultivar and vase solution. Commercial preservative solutions resulted in a longer vase life, smaller decrease in fresh weight than the controls, and smaller increase in water uptake. Vase life of nine cultivars in distilled water ranged from a low of 7.1 days for Queen 2000 to a high of 15.3 days for Forever Young. Flower termination criteria were also cultivar specific with Black Baccara, Classy, and Charlotte most prone to bent neck and blackening of petal tips. Exogenous ethylene at 0.4 or 4.0 μL·L−1 did not affect vase life but lowered water uptake. Application of the antiethylene agent silver thiosulfate (STS) at 0.2 mm concentration significantly improved vase life in five out of the nine cultivars (Anna, Charlotte, First Red, Freedom, and Konfetti) tested, but 1-methylcyclopropene (1-MCP) at 740 nL·L−1 did not improve vase life over the control. Both vase life and water uptake were reduced when more than one stem was placed in a vase; placing 10 stems in a vase shortened vase life by 1.4 days and impeded water uptake by up to 10.6 mL/stem per day. Increasing the amount of time stems remained dry before placing in a vase reduced vase life, but recutting immediately before placing in a vase minimized the decline. Increasing the amount of stem cut off the base up to 10 cm increased vase life.
Erin P. Moody, John M. Dole, and Jared Barnes
Jared Barnes, Brian Whipker, Wayne Buhler, and Ingram McCall
Experiments were conducted to evaluate the appropriate concentration of flurprimidol for ‘Orange Tiger’ tiger lily (Lilium lancifolium), the persistence of residual effects the following year with ‘Orange Tiger’, and differences in flurprimidol’s effect between tiger lily cultivars. In Expt. 1 flurprimidol was applied as a preplant bulb soak to determine its efficacy on height control of ‘Orange Tiger’ tiger lily. Bulbs were hydrated in 17 °C water for 1 h, allowed to drain 1 h, given 10 min soaks of 0, 5, 10, 20, 40, 80, and 160 mg·L−1 flurprimidol, and then allowed to drain for 1 h before potting. In Expt. 2 ‘Orange Tiger’ tiger lilies from Expt. 1 were then planted into outdoor beds to evaluate residual carryover effects of flurprimidol. Expt. 3 involved comparison trials of ‘Pink Tiger’, ‘White Tiger’, and ‘Yellow Tiger’ tiger lilies to determine if cultivars responded differently to flurprimidol drenches. Flurprimidol at 10 to 20 mg·L−1 effectively controlled stem elongation of ‘Orange Tiger’. No residual effect of flurprimidol on ‘Orange Tiger’ plant growth was observed a year after application. Optimal concentrations of flurprimidol for ‘Pink Tiger’ and ‘White Tiger’ were 2 to 5 mg·L−1 and for ‘Yellow Tiger’ 20 to 30 mg·L−1. Results showed that preplant bulb soaks prevented excessive height and provided plants that were more suitable in height for retail sales. Differential responses of ‘Pink Tiger’, ‘White Tiger’, and ‘Yellow Tiger’ tiger lilies to flurprimidol indicate that trials are required to customize optimal concentrations for other cultivars.
Jared Barnes, Brian Whipker, Ingram McCall, and Jonathan Frantz
To produce floriculture crops like mealy-cup sage (Salvia farinacea), growers must be equipped with cultural information including the ability to recognize and characterize nutrient disorders. ‘Evolution’ mealy-cup sage plants were grown in silica-sand culture to induce, describe, and photograph symptoms of nutritional disorders. Plants received a complete modified Hoagland's all-nitrate solution of (macronutrient concentrations in millimoles) 15 nitrate-nitrogen (N), 1.0 phosphorus (P), 6.0 potassium (K), 5.0 calcium (Ca), 2.0 magnesium (Mg), and 2.0 sulfur (S) plus (micronutrient concentrations in micromoles) 72 iron (Fe), 18 manganese (Mn), 3 copper (Cu), 3 zinc (Zn), 45 boron (B), and 0.1 molybdenum (Mo). Nutrient-deficient treatments were induced with a complete nutrient formula minus one of the nutrients. The B-toxicity treatment was induced by increasing the element 10-fold higher than the complete nutrient formula. Reagent-grade chemicals and deionized (DI) water of 18 million ohms per centimeter purity were used to formulate treatment solutions. We monitored plants daily to document and photograph sequential series of symptoms as they developed. Typical symptomology of nutrient disorders and corresponding tissue concentrations were determined. Out of 13 treatments, 12 exhibited symptomology; Mo was asymptomatic. Symptoms of N, P, S, Ca, and K deficiencies and B toxicity manifested early; therefore, these disorders may be more likely problems encountered by growers. Unique symptoms were observed on plants grown under N-, Cu-, and Zn-deficient conditions. Necrosis was a common symptom observed, but use of other diagnostic criteria about location on the plant and progression of the disorder can aid growers in diagnosing nutrient disorders of mealy-cup sage.
Jared Barnes, Paul Nelson, Brian E. Whipker, David A. Dickey, Dean Hesterberg, and Wei Shi
Although many factors that influence substrate pH have been quantified, the effect from fertilizers continues to be elusive. A multifactorial experiment was conducted to test macronutrient effects using a rarely used statistical method known as the central composite design. Five nutrient factors, including nitrogen (N) carrier ratio (NH4 + vs. NO3 –) and concentrations of phosphorus (P) (as H2PO4 –), potassium (K), combined calcium (Ca) and magnesium (Mg), and sulfur (S), were varied at five levels each encompassing the proportionate range of these nutrients in commercial greenhouse fertilizers. Although a typical factorial experiment would have resulted in 55 = 3125 treatments, the central composite design reduced the number to 30 fertilizer treatments. An experiment was conducted twice in which ‘Evolution White’ mealy-cup sage (Salvia farinacea Benth.) was grown in 14-cm-diameter pots (1.29 L) in a 3 peat:1 perlite (v/v) substrate amended with non-residual powdered calcium carbonate to raise the substrate pH to ≈5.6 to 5.8. Harvests occurred after 3 and 6 weeks of growth. A statistical model described substrate pH over time with significant effects including four main effects of N carrier ratio, P, K, and combined Ca and Mg; three squared terms of N carrier ratio, P, and K; and seven interaction effects. The resulting model was used to calculate substrate pH levels between 25 and 45 days after planting, and it showed that N carrier had the greatest impact on substrate pH.