Interiorscape conditions were used to compare plant growth and water use between a commercially produced medium with hydrophilic polymer and a traditional peat-lite medium. 15 cm pots of parlor palm and pothos were grown in either the medium with polymer or a peat-lite medium. Fertilizer treatments applied to both media included: 1.2 kg N/m3 Osmocote 14N-6.1P-11.6K and 500 ppm (mg/kg) N of Peter's 20N-8.7P-16.5K. Plant height, width, top fresh and dry weight, quality and foliage color were determined for parlor palm and top fresh and dry weight and quality were determined for pothos. Plants grown in the peat-lite medium receiving either liquid fertilizer or slow-release fertilizer were significantly greater in all parameters measured than those growing in the medium with polymer that received liquid fertilizer. Plants grown in the medium with polymer had greater growth and quality with the slow-release fertilizer than liquid fertilizer treatments. The number of days until watering was not extended in the medium with hydrophilic polymer.
Melinda S. Conner and Gerald Klingaman
Deborah A. Tolman, Alexander X. Niemiera, and Robert D. Wright
Seedlings of 30-, 35, 40-, -45, and 50-day-old marigold (Tagetes erecta Big. `Inca Gold') in 500-ml plastic pots containing a 1 peat: 1 perlite (v/v) medium were treated with several fertilizer levels (N at 20, 50, 80, and 110 mg·liter-1); solution nutrient levels in the medium were determined 6 hours later. Older/larger container-grown plants absorbed more N, P, and K from the medium solution than younger/smaller plants. Also, older plants (>40 days) absorbed at least 88% of the solution N regardless of N treatment. Nitrogen absorption, regardless of plant age, increased as N application rates increased. The latter result implies that even though total N absorption increases with plant age/size, nutrient levels in the medium solution for optimal growth and nutrient uptake may be similar regardless of plant size.
Sherry L. Hilscher and John E. Preece
Kankakee mallow is an endangered herbaceous perennial that is indigenous to Kankakee County, Illinois. Stock plants were from seeds pretreated in 82°C water prior to greenhouse germination and growth. Nodal explants were disinfested and placed in vitro onto agar-solidified MS medium containing 0, 0.1, 1.0, 5.0, or 10.0 μM BA and 1.0 μM IBA. Axillary shoots grew and elongated best when the medium contained no cytokinin. BA tended to result in a rosette pattern of leaves. Within hours of placing the original explants in vitro and shortly after subsequent transfers were made (even when there was no cutting) a bright pink exudate appeared in the medium. The most vigorous cultures tended to form the most exudate. Microshoots were placed in a high humidity container in vermiculite wetted with water. Rooting was 50% without auxin. Plants were transplanted into pots containing peat-lite medium and successfully acclimatized to the greenhouse.
Rajendra Maurya*, Nathu Ram Godara*, and Ram C. Yadav*
Influence of culture media and hormone concentrations on plant regeneration from rose (Rosa hybrida L. cv. Raktagandha) leaf segments were investigated. Leaves were excised from healthy, well-grown and mature plants. Leaf segments (4-5 mm long) were sectioned and cultured on Murashige and Skoog (1962) medium containing different concentration of growth hormones. Callus formation was most prolific (97.09%) on MS medium containing MS basal salts + 0.5 mg·L-1 BAP + 2.0 mg·L-1 2,4-D. maximum (56.67%) organogenesis or shoot differentiation was achieved on MS modified medium supplemented with 1.0 mg L-1 BAP + 0.1 mg·L-1 NAA + 10.0 mg·L-1 Adenine Sulphate. The highest percentage (93.73%) of in-vitro rooting was observed in half-strength MS basal medium containing 0.5 mg·L-1 IBA. Rooted plants were transferred in to sterilized potting mixture and grown in a greenhouse.
Thomas M. Rathier
Two year-long, factorial experiments were conducted on Rhododendron catawbienses (cv. Roseum elegans) grown in 2.3-liter plastic pots. I) Annual N rates of 0, 0.4, 0.8, 1.6, and 3.2 g/pot were applied as NH4NO3 (SBL) or sulfur-coated urea (SR) to plants potted in a composted hardwood bark (CHB)/peatmoss (P)/sand (S) medium. Plant growth and quality was best at 0.8 g N/pot for SBL and 1.6 and 3.2 g N/pot for SR. II) Annual N rates of 0.8 (SBL) and 2.4 (SR) g/pot were chosen as optimum rates and applied to plants potted in the following media: pine bark (PB)/P/S; CHB/P/S; P/S; and PB/CHB/P/S. Plant growth and N uptake was best in PB/PS. Plant quality was best in P/S. NO3 in leachate did not differ among media, but was greater in SBL. Total N immobilized in media was greater in PB/CHB/P/S. N recovered from SR-treated pots as unused fertilizer did not differ among media. Total applied N recovered was 90% for SBL and 51% for SR.
Robert H. Stamps
Impatiens `Dazzler Violet', Petunia × hybrida `Carpet Blue', and Spathiphyllum `Ty's Pride' plugs were planted in 10-cm pots containing a commercial peat-based soilless growing medium composed of Canadian 60 peat: 20 vermiculite: 20 perlite (by vol) not treated with surfactant. Growing medium was treated, or not treated, 1) at planting, 2) during production, and/or 3) preshipment with experimental surfactants. The production phase consisted of growing plants on raised benches in a greenhouse until they reached marketable size. Phytotoxicity, plant water use and growth were determined. At the beginning of the postproduction phase, growing medium in all pots was brought to container capacity. Plants were then dried to wilting three times. Water loss and water retained on rewatering and times to wilt and recovery were recorded. Surfactant treatments caused no foliar phytotoxicity and did not delay flowering for petunia or spathiphyllum. However, surfactant treatments delayed flowering for impatiens by ≈4 days. Surfactant treatments increased top growth of petunia but not of the other crops. Postproduction, water retention at rewatering, and times to wilt were increased for petunia and spathiphyllum when they were in surfactant-treated medium. For impatiens, treatments had no effects on water retention or wilting, probably due to the small root systems and limited attendant medium dewatering for this crop. Generally, all three experimental surfactants performed similarly and weekly and preshipment surfactant applications were of no additional benefit compared to a single initial application at planting.
Kirk W. Pomper, Snake C. Jones, and Eddie B. Reed
The pawpaw [Asimina triloba (L.) Dunal] is a native American tree fruit with potential in edible landscapes and as a new fruit crop. A split-plot experiment (main plot: fertilizer level and subplot potting medium) was conducted in the greenhouse to identify the best growing medium for production of pawpaw seedlings. Seeds were sown in rootrainers containing one of the following media: 1) Promix (control); 2) 6 pine bark:1 mason sand (v/v); 3) 1 mason sand: 1 sphagnum peat; and 4) 4 pine bark:1 mason sand:1 sphagnum peat. When seedlings had at least two to three leaves, weekly fertigation of seedlings began, using 0, 250, or 500 ppm Peters 20N-20P-20K. Germination rate at 10 weeks was similar in all media, at about 80%. The plants were destructively harvested 10 weeks after imposition of fertigation treatments. Both potting media and fertigation influenced leaf number and height; however, there was a significant interaction between these main effects. Leaf number and height for plants in medium 3 were similar to those of the control (medium 1), at about 11 leaves and 18-cm plant height, respectively, at 500 ppm fertigation. Plants in media 2 and 4 were about half as tall and had about half as many leaves as control medium plants at 500 ppm fertigation. Plant leaf area and biomass data will be discussed.
Jameel M. Al-Khayri, Feng H. Huang, and Teddy E. Morelock
Callus, induced in the dark from leaf tissue of spinach (Spinacia oleracea L. cv. Fall Green) on Murashige and Skoog (MS) medium supplemented with (in mg·liter -1) 2 kinetin and 0.5 2,4-D regenerated shoots upon transfer to a medium containing 2 kinetin, 0.01 2,4-D, and 1 GA3. Complete plants were established by stimulating rooting of the shoots with 1 mg IBA/liter and transferring them to potting soil; survival was 60%. Chemical names used: N-(2-furanylmethyl)-1H-purin-6-amine (kinetin); 2;4-dichlorophenoxy acetic acid (2,4-D); gibberellic acid (GA3); 1H-indole-3-butanoic acid (IBA).
Jyothi Prakash Bolar, John L. Norelli, Herb S. Aldwinckle, and Viola Hanke
To root tissue-cultured apple cultivars, shoots from proliferating cultures were first transferred to root induction medium with IBA for 1 week in the dark. Shoots were later transferred to the same medium without IBA and incubated under light for elongation of the roots. Rooted shoots were then transferred to Jiffy-7s supplemented with biological plant protectant and fertilizer, and incubated in plastic humidity trays. After 2 to 3 weeks, plants were transferred to pots and covered with plastic bags to facilitate acclimation. This technique has resulted in 70% to 100% of shoots selected in vitro producing vigorously growing, healthy plants in the greenhouse. Chemical name used: indolebutyric acid (IBA).
The usefulness of cover crops for weed management in strawberries were evaluated. Wheat (Triticum aestevum L.), rye (Secale cereale L.), and crimson clover (Trifolium incarnatum L.) were grown in individual pots then killed by tillage or herbicide and followed in the same pots by plantings of bermuda grass [Cynodon dactylon (L.) Pers.], yellow nutsedge (Cyperus esculentus L.), crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.], or strawberries (Fragaria ×ananassa `Cardinal'). Rye and wheat tilled into the medium generally increased the growth of strawberries and decreased the growth of bermuda grass. Rye and wheat residues appeared to suppress growth of weeds and strawberries when the residues remained on the medium surface. Crimson clover had little affect on the growth of weeds or strawberries. Yellow nutsedge and crabgrass were not significantly affected by cover crop residues.