major limitation to the increased use of zoysiagrass. Zoysiagrass establishment by plugs or sprigs can take up to 2 years, or longer, to reach complete coverage ( Hume and Freyre, 1950 ; Sifers et al., 1992a , 1992b ). Delayed establishment may
( Hickman, 1986 ; Ahmad et al., 2014 ), and decreasing abiotic stresses ( Bañón et al., 2006 ) in ornamental potted and nursery plants. Ancymidol is also used extensively for ornamental plug production and plant growth management ( Miranda and Carlson, 1980
to the exclusion of other products or vendors that may be suitable. We gratefully acknowledge the work of student interns Matthew Stevens and Emma Wallace for their assistance in plug conditioning and environmental monitoring. We thank Nihal Rajapakse
Tomatoes (Lycopersicon esculentum Mill. cv. Jet Star) seedlings grown in small cells (plugs) in trays holding 200, 406, or 648 plants per flat (28 × 55 cm) were larger after 6 weeks as cell size increased, but all were acceptable. Other seedlings, transplanted at weekly intervals from plug trays to plastic cell packs (48 cells per 28 × 55-cm flat), were of similar size during weeks 1-3; seedlings from 648-plug trays were smaller than the others by week 5-6. Seedlings from 200-plug trays planted at weekly intervals into containers where plant-plant competition was absent were larger through 6 weeks than those from 406- and 648-plug trays. Early marketable and total yields were similar for plants held in 406-plug trays 1 to 4 weeks before their transfer to 48-cell flats, but yield decreased for those held 5 to 7 weeks.
concentrations of B and lead to the development of visual symptoms of B deficiency. Materials and Methods ‘Dynamite Yellow’ pansy, ‘White Storm’ petunia, and ‘Festival Apricot’ gerbera seeds were sown in 288-plug trays cut into 2 × 2-cell flats (each cell: 2 cm
). Instead, practitioners recommend using plugs of prairie dropseed in restored sites (B. Carter, personal communication, 26 Aug. 2019). Using plugs in place of direct seeding was determined to be a viable way to establish species that are rare, with
The preservation/restoration of prairie ecosystems is part of our responsibility as stewards of the earth. Success in reestablishing prairie plant communities has been quite variable and far from optimum. This cooperative project between the University of Wisconsin-River Falls (UWRF) and Carpenter Nature Center examine the use of horticulture plug technology as a means of improving the quality, availability, production efficiency and transplant survivability of herbaceous frob prairie species for use in prairie restoration efforts.
Data on growth rates and winter survival of bare-root seedlings and plug seedlings of Rudbeckia hirta, Ratibida pinnata and Zizea aurea in prairie test plots will be presented. The plug seedlings were stockier plants, had well developed root systems, and demonstrated excellent performance as transplants in prairie restoration efforts.
mechanisms of plant growth. Materials and Methods Plant material and growth conditions. Seeds of watermelon [ Citrullus lanatus (Thunb.) Matsum. & Nakai] cv. Zaojia 84-24 were sown in 72-cell plastic plug trays (50 cm 3 per cell) filled with a substrate
Ageratum, begonia, marigold, and salvia seedlings in plug cells were stored in coolers to determine the effects of temperature, light, and storage time on growth and forcing time of seedlings after transplanting, and to determine the optimum storage temperatures for each crop. Photosynthetic photon flux densities of 0, 1, and 5 μmol·m-2.s-1 were combined with temperatures of 0.0, 2.5, 5.0, 7.5, 10.0, and 12.5C to create 18 storage environments. Sample plants were removed from each treatment at 1-week intervals for 6 weeks, and were forced into flower. In all four species, temperatures of 0.0 and 2.5C caused chilling injury and then death as plants were stored for progressively longer periods. Storage at 0.0 and 2.5C also delayed flowering when chilling injury was not severe enough to cause death. In general, plants stored better in the light than in darkness. Darkness tended to limit the time seedlings could be stored, but for each crop, the addition of just 1 μmol·m-2.s-1 extended the storage durations to 6 weeks at one or more temperatures. Storage of all four species was possible for 6 weeks, but there were significant variations between the temperatures and storage durations each species could tolerate. Optimal temperatures were 5-7.5C for begonia, 5C for marigold, and 7.5C for salvia and ageratum.
Salvia (Salvia splendens F.), vinca (Catharanthus roseus L.), and pansy (Viola × wittrockiana Gams.) were examined to determine efficacy of growth retardants for inhibiting stem elongation of seedlings in the plug stage and after transplanting to 10-cm pots. Studies on salvia showed plugs sprayed with single applications of ancymidol at 10 or 20 ppm, paclobutrazol at 30 or 60 ppm, or daminozide/chlormequat tank mix at 2500/1500 ppm inhibited plug elongation by 17% to 22%. Pansy plugs were sprayed either once or twice with ancymidol at 5, 10, or 15 ppm. Number of applications was statistically significant with two applications reducing elongation by an average of 35%, whereas a single application resulted in a 23% average reduction. Ancymidol concentration was significant in reducing stem elongation with increasing rates in pansy; however, the concentration and application time interaction was not significant. In both pansy and salvia, plant size at flowering was similar to controls after transplanting. Vinca plugs were sprayed with ancymidol at 5, 10, or 15 ppm either the 3rd week, 4th week, or both weeks after sowing. As ancymidol concentrations increased, plug height decreased, and the concentration effect was greater week 3 than at week 4. Two applications of ancymidol was most effective in retarding stem elongation (36%) followed by one spray the 3rd week (29%) and one spray during week 4 (20%).