Species-specific fertilization can benefit container nursery crop production

Abstract

. 2015. Species-specific fertilization can benefit container nursery crop production. Can. J. Plant Sci. 95: 251Á262. To determine the responses of six container-grown shrub species to different controlled-release fertilizer (CRF) application rates, plant growth and root-zone traits were evaluated following fertilization with Polyon † 16Á6Á13, 5Á6 month CRF incorporated at 0.60, 0.89, 1.19, 1.49 and 1.79 kg m (3 N. The six species tested at a southwestern Ontario, Canada, nursery were Cornus stolonifera 'Flaviramea' (yellow-twig dogwood), Euonymus alatus 'Compactus' (dwarf winged euonymus), Hydrangea paniculata 'Grandiflora' (Pee Gee hydrangea), Physocarpus opulifolius 'Nugget' (Nugget ninebark), Spiraea japonica 'Magic Carpet' (Magic Carpet spirea), Weigela florida 'Alexandra' (Wine and Roses weigela). Different species responded differently to the CRF rates applied. For the majority of species at the final harvest, growth index, plant height, canopy area, leaf area and above-ground dry weight were greater in high vs. low CRF rates; however, different species had different optimal CRF application rates or ranges: 1.49 kg m (3 N for Hydrangea and Spiraea, 1.19 kg m (3 N for Weigela, 1.19 to 1.49 kg m (3 N for Cornus and Physocarpus, and 50.60 kg m (3 N for Euonymus. Based on these speciesspecific optimal fertilizer rates or ranges, growers can group plant species with similar fertilizer demands, thereby reducing fertilizer waste and maximizing plant production. . Les six espe`ces teste´es dans une pe´pinie`re du sud-ouest de l'Ontario, au Canada, e´taient le cornouiller stolonife`re (Cornus stolonifera) Flaviramea, le fusain aile´(Euonymus alatus) Compactus, l'hortensia panicule´(Hydrangea paniculata) Grandiflora, le physocarpe a`feuilles d'obier (Physocarpus opulifolius) Nugget, la spire´e du Japon (Spiraea japonica) Magic Carpet et le weigela (Weigela florida) Alexandra. Les espe`ces re´agissent diffe´remment au taux d'ELL applique´. Pour la plupart, a`la re´colte, l'indice de croissance, la hauteur du plant, la superficie du feuillage, la surface foliaire et le poids sec des organes ae´riens sont plus importants avec un taux d'application d'ELL e´leve´qu'avec un faible taux. Cependant, la fourchette des taux d'application ou le taux d'application optimaux d'ELL varie avec l'espe`ce : 1,49 kg de N par m 3 pour Hydrangea et Spiraea, 1,19 kg de par m 3 pour Weigela, 1,19 a`1,49 kg de N par m 3 pour Cornus et Physocarpus, et50,60 kg de N par m 3 pour Euonymus. Les producteurs pourraient regrouper les plantes qui requie`rent une fertilisation similaire en fonction des taux d'application optimaux ou des fourchettes optimales e´tablis pour ces espe`ces, ce qui re´duirait les re´sidus et maximiserait la production.

Effect of Topdressed Controlled-release Fertilizer Rates on Nursery Crop Quality and Growth and Growing Substrate Nutrient Status in the Niagara Region, Ontario, Canada

“…On 7 May 2015, Osmocote Plus 15N-3.9P-9.9K, 5-6 month (ICL Specialty Fertilizers, Dublin, OH) and Plantacote 14N-3.9P-12.5K, 6-month Homogeneous NPK with Micros (Kam's Growers Supply, Inc., Guelph, ON), were each topdressed by hand to containers to deliver rates of 1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 g N/pot. Fertilizer rates were selected based on general nursery crop recommendations made by fertilizer suppliers, nursery grower suggestions, and previous studies (Agro, 2014;Agro and Zheng, 2014;Alam et al, 2009;Clark and Zheng, 2015). The mean initial growing substrate pH values were 7.32 and 7.39, and the electrical conductivity (EC) values were 0.8 and 0.4 mS · cm -1 , for spirea and weigela, respectively (n = 12), on 7 May 2015, evaluated using the pour-through method (Wright, 1986).…”

“…Most commonly, nutrients are provided during container nursery crop production in Ontario, Canada, and throughout North America through the application of CRFs (Alam et al, 2009;Chen et al, 2011;Yeager and Cashion, 1993). However, soon after CRF application, a short duration of nutrient leaching at high levels is frequently seen with CRFs, which is especially problematic in fluctuating environmental conditions as experienced in outdoor nursery production (Alam et al, 2009;Clark and Zheng, 2015;Hershey and Paul, 1982;Narvaez et al, 2012;Newman et al, 2006). Warm outdoor temperatures and regular rain and irrigation events during early-season outdoor container nursery crop establishment (i.e., in May and June) provide ideal conditions for nutrient release from CRFs, which elevates nutrient levels in the growing substrate.…”

“…Individual CRF types are characterized by their release duration, based on the prill coating specifications, which are determined in controlled laboratory conditions at a constant temperature and moisture. However, during outdoor nursery production, CRF release duration is also influenced by fluctuating outdoor temperatures, and variable precipitation levels; therefore, the actual nutrient release duration may vary considerably from the laboratory-determined value (Agro and Zheng, 2014;Clark and Zheng, 2015). For example, CRF release durations of 5-6, 6-7, 8-9, and 10-12 months are commonly used in Ontario nursery production; however, the observed duration of nutrient release has been shorter than expected for CRFs (Agro and Zheng, 2014;Clark and Zheng, 2015;Husby, 2000).…”

“…However, during outdoor nursery production, CRF release duration is also influenced by fluctuating outdoor temperatures, and variable precipitation levels; therefore, the actual nutrient release duration may vary considerably from the laboratory-determined value (Agro and Zheng, 2014;Clark and Zheng, 2015). For example, CRF release durations of 5-6, 6-7, 8-9, and 10-12 months are commonly used in Ontario nursery production; however, the observed duration of nutrient release has been shorter than expected for CRFs (Agro and Zheng, 2014;Clark and Zheng, 2015;Husby, 2000). In addition, despite similarly described longevities, different CRF types have dissimilar nutrient release patterns, even under greenhouse conditions (Cabrera, 1997).…”

“…In Ontario, many nurseries transplant in the spring, and fertilization of newly planted container-grown nursery crops commonly occurs at generalized rates for low-, medium-, or high-feeding crops, or at one rate for the entire nursery. Previous temperate climate research has indicated the optimum CRF rates and ranges for springplanted nursery crops are species specific with excess incorporated CRF causing a high growing substrate nutrient status and nutrient loss (Agro, 2014;Clark and Zheng, 2015). For some species, or at some Ontario nurseries, fall planting is preferred and CRF is often applied to the surface of the growing substrate (i.e., topdressed) the following spring, instead of being incorporated at planting in the fall.…”