Fertilizer strategies during production of container-grown floriculture crops have carry-over effects on the performance of these plants during postharvest; and for the consumer, these methods have the potential to add value, differentiate product quality, and increase consumer success and repeat sales. Several fertilizer strategies are available to provide residual fertilizer to container-grown ornamental plants because many consumers are unlikely to fertilize plants after sale (Oliveira et al., 2016). These strategies include a) incorporating a slowly soluble fertilizer into the root substrate before planting that continues to release nutrients after the point of sale, or b) applying a slowly or completely soluble fertilizer immediately before the point of sale. For example, Oliveira et al. (2016) showed high rates of controlled-release fertilizer (CRF) incorporated into the substrate or applied as a top-dress to the substrate surface increased plant performance [number of flowers, SPAD chlorophyll index, dry weight, and tissue nitrogen (N)] during a simulated consumer phase compared with plants that received only water-soluble fertilizer (WSF) during production.
Plant growth regulators (PGRs) applied during production also have carry-over effects on plant growth and habit for the consumer (Davis, 1991; Keever and Kessler, 2008; Latimer and Baden, 1994). Foliar applications of PGRs during production of a range of ornamental container crop species has been shown to suppress shoot growth during simulated shipping and retail environments as well as in the landscape (Keever and Kessler, 2008; Latimer, 1991). Chemicals such as paclobutrazol are also effective at controlling plant growth when taken up by roots (Latimer and Whipker, 2012; Ruter, 1996), and these are sometimes applied as a substrate drench or mixed with the applied fertilizer solution (Million et al., 2002).
Oliveira et al. (2016) only evaluated solid fertilizers that were either incorporated or top-dressed, rather than liquid fertilizer applications, and they did not evaluate the combined effects of increased fertilizer plus a PGR on consumer performance. Application immediately before the point of shipping (POS) of a high concentration of liquid forms of mineral or slow-release fertilizers may reduce labor cost compared with top-dressing solid fertilizer. Cost and labor savings are important in a highly competitive market, and a recent national grower survey (Sparks, 2020) found that labor and production cost are among the top four issues for the United States floriculture industry.
The objective of the first experiment was to compare strategies using WSF, CRF, and organic slow-release fertilizers (SRF) to provide adequate nutrition during both production and the consumer phases with container-grown petunia (Petunia ×hybrida). The second objective was to evaluate the potential of irrigating with a high rate of WSF plus a PGR as the final irrigation of production and immediately before sale to suppress shoot growth and extend plant quality during a simulated retail consumer phase.
Broschat, T.K. & Moore, K.K. 2007 Release rates of ammonium-nitrogen, nitrate-nitrogen, phosphorus, potassium, magnesium, iron, and manganese from seven controlled-release fertilizers Commun. Soil Sci. Plant Anal. 38 843 850
Burnett, S.E., Mattson, N.S. & Williams, K.A. 2016 Substrates and fertilizers for organic container production of herbs, vegetables, and herbaceous ornamental plants grown in greenhouse in the United States Scientia Hort. 208 111 119
- Search Google Scholar
- Export Citation
Burnett, S.E. Mattson, N.S. Williams, K.A. 2016 Substrates and fertilizers for organic container production of herbs, vegetables, and herbaceous ornamental plants grown in greenhouse in the United StatesScientia Hort. 208 111 119 10.1016/j.scienta.2016.01.001
Cabrera, R.I. 1997 Comparative evaluation of nitrogen release patterns from controlled-release fertilizer by nitrogen leaching analysis HortScience 32 669 673
Carson, L.C. & Ozores-Hampton, M. 2012 Methods for determining nitrogen release from controlled-release fertilizers used for vegetable production HortTechnology 22 20 24
Davis, T.D. 1991 Post-production performance of uniconazole-treated zinnia and marigold plugs HortTechnology 1 49 52
Fan, X.H. & Li, Y.C. 2010 Nitrogen release from slow-release fertilizers as affected by soil type and temperature J. Soil Fert. Plant Nutr. 74 1635 1641
Gibson, J.L., Pitchay, D.S., Williams-Rhodes, A.L., Whipker, B.E., Nelson, P.V. & Dole, J.M. 2007 Nutrient deficiencies in bedding plants Ball Publ. Batavia, IL
Keever, G.J. & Kessler, J.R. 2008 Paclobutrazol effects on bedding plants during production, shipping, and the retail environment when applied in production J. Environ. Hort. 26 123 127
Latimer, J.G. 1991 Growth retardants affect landscape performance of zinnia, impatiens, and marigold HortScience 26 557 560
Latimer, J.G. & Baden, S.A. 1994 Persistent effects of plant growth regulators on landscape performance of seed geraniums J. Environ. Hort. 26 150 154
Latimer, J.G. & Whipker, B. 2012 Selecting and using plant growth regulators on floricultural crops Virginia Coop. Ext. Publ 430 102
Li, Y. & Mattson, N.S. 2019 Effect of organic fertilizer source and rate on growth and nutrient leachate profile of greenhouse-grown cucumber HortTechnology 29 450 456
Million, J.B., Barrett, J.E., Nell, T.A. & Clark, D.G. 2002 One-time vs. continuous application of paclobutrazol in subirrigation water for the production of bedding plants HortScience 37 345 347
Mills, H.A. & Jones, J.B. Jr. 1996 Plant analysis handbook II: A practical sampling, preparation, analysis, and interpretation guide MicroMacro Publ. Athens, GA
Oliveira, S.F., Fisher, P.R., Huang, J. & Mello, S.C. 2016 Strategies to provide fertilizer for both production and consumer phases of petunia HortTechnology 26 164 175
Purcell, L.C. & King, C.A. 1996 Total nitrogen determination in plant material by persulfate digestion Agron. J. 88 111 113
Ruter, J.M. 1996 Paclobutrazol application method influences growth and flowering of ‘New Gold’ lantana HortTechnology 6 19 20
Sparks, B.D. 2020 State of the greenhouse industry: Top business concerns by region 23 Oct. 2020. <https://www.greenhousegrower.com/management/state-of-the-greenhouse-industry-top-business-concerns-by-region/>