Submitted to: HortTechnology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/1/2010
Publication Date: 6/1/2010
Citation: Green, S.R., Picchioni, G.A., Murray, L.W., Wall, M.M. 2010. Yield and quality of field-grown Celosia and Gomphrena everlasting cut flowers at four planting densities. HortTechnology. 20(3): 612-619. Interpretive Summary: Four species of field-grown Gomphrena and Celosia produced marketable dried flower crops in as few as 6 to 9 weeks after transplanting and grew well under the high light intensities, high summer temperatures, and alkaline soils of the Chihuahuan desert. Planting density had little or no effect on stem yield and quality of Celosia species or Gomphrena haageana, whereas field production of Gomphrena argentea improved at the higher plant density. These species are good candidates for specialty flower crops in the semiarid southwestern U.S.
Technical Abstract: Field-grown cut flowers dried for market could provide a high-value crop selection for semiarid regions, but data on field production of flowers are limited. We conducted a field study on replicated 1.5-m2 plots to evaluate flower yield and quality characteristics of Gomphrena globosa, G. haageana, Celosia aregentea, and C. spicata, including fresh and dry stem yields, stem diameter and length, total number of harvested sprays (multiple head) and single (solitary head) stems, flower head size, and postharvest flower retention following mechanical impact. Within-row spacing of 15 or 20 cm combined with two-row or three-row per bed plantings resulted in field planting densities ranging from 66,670 to 120,010 Gomphrena plants per ha and from 100,005 to 200,010 Celosia plants per ha. All but C. argentea produced four harvests that began 22 May and ended 18 Oct., depending on species. Gomphrena globosa and G. haageana had a 5 to 6-month harvest season, two to three mid-season to late-season peak harvests, and over 1000 harvested stems totaling 1.4 to 1.8 kg dry weight per plot across the season. Celosia argentea and C. spicata had a 4.5-month harvest season, one early summer peak harvest, and fewer than 300 harvested stems totaling 0.6 to 0.7 kg dry weight per plot for the year. Seasonally-progressive increases in flowering stem length of G. globosa, G. haageana, and C. spicata, and flowering stem diameter of G. globosa, G. haageana, and C. argentea were observed. Flowering head size of the Gomphrena sp. and head length of C. spicata were largely independent of harvest season, whereas the head diameter of C. argentea increased with season. Postharvest flower retention was ˜2% higher for G. globosa than it was for G. haageana, decreased by ˜6% from early to later harvests for C. argentea and C. spicata, and was inversely related to the head size of G. globosa, G. haageana, and C. argentea. Despite the wide range in planting density, the density effect was largely limited to one of the four species, C. argentea. For that species, three-row planting (high density) provided marginal across-the-year yield enhancement (P < 0.0650), with additional significant effects (P < 0.05) as follows: an increase in the seasonal cumulative harvested number of stems, longer stems and wider flower heads later into the season, and a prolonged production of spray stems (15 cm spacing only). Results contribute to a limited scientific database on field-grown specialty cut flowers for the dried market, and demonstrate that these four species are highly adaptable to semiarid growing conditions.