peat, paper, coconut fiber, rice hulls, poultry feather fiber, rice straw, dairy manure, or other organic components. One of the most common plantable biocontainers is the peat container. Although referred to as peat containers or peat pots, they are
Michael R. Evans, Matt Taylor, and Jeff Kuehny
Dennis B. McConnell and Wayne H. Smith
Three foliage plants, Dracaena fragrans, Peperomia obtusifolia and Schefflera arboricola were grown in 24 different mixes. Potting mixes were formulated using yard waste compost from two sources, a commercial mix (Metro 300) and a prepared mix (peat: pine bark sand). All potting mixes produced acceptable plants with no phytotoxicity associated with any mix. Only minor differences were discerned in the growth rate of P. obtusifolia and S. arboricola.
The growth rate of D. fragrans showed the greatest response to potting mix formulations. Plants in a standard potting mix (P/PB/S) used in the industry for D. fragrans grew slower than plants in many of the mixes containing various fractions of yard waste compost. Chemical and physical properties of the potting mixes used showed physical properties had the greatest variability. Overall, the best growth for all 3 plants was in a potting mix composed of 87.5% Metro 300/12. 5% YWC#1 and worst growth was in YWC#2 (100% composted (live oak leaves).
Pascal Braekman, Dieter Foqué, Marie-Christine Van Labeke, Jan G. Pieters, and David Nuyttens
effect of spray application technique on the spray deposition in ivy pot plants grown on hanging shelves in greenhouses. In particular, the effect of application rate, nozzle type, size and spray pressure, and the difference between the traditional spray
Jeffrey H. Gillman, Chad P. Giblin, and Gary R. Johnson
Plants that have been grown in containers for a long period of time frequently develop roots that grow in circles, following the contour of the container in which they have been planted. This condition is commonly referred to as “pot-bound.” It is considered common knowledge that if a pot-bound plant is transplanted without any treatment, its roots will continue to follow the contour of the now-removed container. There are, however, a number of transplanting techniques that are intended to reorient the roots in a direction that will be conducive to helping roots to grow out of this potentially harmful situation. These techniques include: butterflying, or slicing the rootball into two halves before planting; scoring, or making inch-deep slices around the rootball at 90° increments and an X-shaped slice across the bottom; or teasing, where roots are manually pulled out of the shape of the container in a direction perpendicular to the stem. Severely pot bound Salixalba and Tiliacordata were treated with one of the three treatments previously listed or as a control and were transplanted into an experimental field and grown for two full seasons. After two seasons, the trees were harvested and the number and size of roots escaping from the pot-bound region were recorded. None of the treatments allowed roots of any size to escape the pot-bound mass more effectively than the control.
Marco Volterrani, Nicola Grossi, Monica Gaetani, Lisa Caturegli, Aimila-Eleni Nikolopoulou, Filippo Lulli, and Simone Magni
an increase in the rate of shoot formation from crowns of ‘Tifton 85’ common bermudagrass treated with EP. Most information on PGRs is related to field applications for biomass reduction, and little is known about stolon growth regulation in pot
David Wees and Danielle Donnelly
Leachates were produced by washing Hydra-fill, a polyurethane ester foam, with water. These leachates decreased radish (Raphanus sativus L.) and tomato (Lycopersicon esculenturn Mill.) seed germination and were phytotoxic to seedlings. Washing the foam for as little as 5 minutes (compared to not washing) before collecting the leachate significantly decreased the mean seed germination time by 0.6 to 1 day. Rinsing the foam with ethanol before collecting the leachate was detrimental to germination. When used as a potting medium component, the foam reduced radish shoot and root dry weights compared to potting media without foam. Washing the foam with tap water before use resulted in increased radish shoot and root dry weights. Hydra-fill generally reduced plant performance when included in potting media. However, radish grew well in fresh 25% Hydra-fill (raw or washed) mixed with loam.
Mark H. Brand
Nursery production of many ornamental grasses involves potting of established liners into 8.5-L containers. Direct potting of bare root divisions into 8.5-L containers may represent a more efficient production method. Large and small divisions (based on number of tillers and volume) of eight ornamental grasses were potted directly into 8.5-L containers. The potting medium used was a 3 aged pine bark: 2 peat moss: 1 sand nursery mix (by volume), amended with dolomitic lime at 3 kg/yard3, and top dressed with Sierra 17-6-10 plus minors at 40 g/container, 8 to 9 month fertilizer. Plants were grown outdoors in a container nursery from May through September. All grasses tested performed well using the direct potting method, with 100% survival. Large divisions of Miscanthus sinensis cultivars produced plants with greater fresh weight, dry weight and number of tillers than did small divisions. Division size did not affect Miscanthus foliage or flower height but did affect number of flowers for `Graziella' and `Purpurascens'. Large divisions of Calamagrostis `Karl Foerster', a grass grown primarily for flowering, produced twice as many flowers as small divisions. Panicum virgatum and Pennisetum alopecuriodes showed signs of nutrient stress when grown from large divisions. Although a greater number of tillers was produced by large divisions of Panicum and Pennisetum, fresh weight, dry weight, flower height, and foliage height were similar to or less than that observed on plants from small divisions.
In Japan, mango ( Mangifera indica L.) is generally cultivated in small greenhouses in which the height of the ridge is relatively low. Therefore, pot cultivation has been introduced for the purpose of lowering tree height and suppressing tree
Amanda Wiberg, Richard Koenig, and Teresa Cerny-Koenig
There is extensive variability in physical and chemical properties among brands of retail potting media. The purpose of this study was to assess variability in seed germination and plant growth responses among and within brands. Twenty-four different brands of media, and multiple bags of five brands, were purchased at nine retail stores. Tomato (Lycopersicon esculentum) seeds were germinated in 11 different brands of media and in media from different bags of four of the same brands. Marigold (Tagetes erecta) and petunia (Petunia×hybrida) were grown to flowering in 10 brands of media. Germination varied significantly among media brands and among bags of one of the brands. Plant performance also varied significantly, with several of the brands producing plants with few flowers, long times to flowering, and low shoot and root dry weights even though all treatments received uniform applications of a complete fertilizer solution three times per week. Few relationships could be discerned between individual physical and chemical properties of the media and plant performance. Results indicate improvements in quality among brands and quality control within brands are needed in the retail potting media industry. Quality assessment tools emphasizing plant performance could improve overall media quality.
Harvey J. Lang and George C. Elliott
Autotrophic nitrifying organisms were enumerated in soilless potting media using the most probable number (MPN) technique. Populations of NH4 + and NO2 - oxidizing organisms varied widely between two soilless media—Metro-Mix 220 and 350. Estimates for NH4 + oxidizing organisms ranged from 0.7 to 7.8 × 105 organisms/cm3, while NO2 - oxidizers ranged from 1.3 to 9.5 × 105 organisms/cm3. Population numbers were similar to those typically reported in soils. There was a significant effect of medium type, NH4 + N : NO3 - N fertilizer ratio, and planting on MPN counts of both groups of organisms, with significant interaction between several of the factors. Estimates of NH4 + oxidizers were not linearly correlated with NH4 + oxidizing activity, implying low counting efficiency, heterotrophic nitrification, or rate-limiting substrate NH4 + level. In a separate study, a soilless potting medium was inoculated with pure cultures of either Nitrosomonas europaea or Nitrobacter agilis. Rates of NH4 + and NO2 - oxidation increased, respectively, as inoculum volume increased. Inoculation with nitrifying bacteria may help in the overall management of N in the rhizosphere and be feasible alternatives for the prevention of either NH4 + or NO2 - phytotoxicity with fertilizers containing urea or NH4 +.