A greenhouse study was conducted to determine the influence of media containing varying volumetric proportions of composted cotton gin trash and pine bark on the growth of Coleus × hybridus 'Golden Bedder'. All media treatments were amended with 1.5 lbs/yd3 Micromax and 8 lbs/yd3 dolomite. Plant height, shoot dry weight, and visual quality ratings were determined six weeks after potting. Media composed of 100% cotton gin trash produced plants with significantly less height and shoot dry weight. Height inhibition was apparent by 3 weeks after potting. Coleus grown in media composed of 60-1002 pine bark had higher visual quality ratings than those grown in media having cotton gin trash as the primary constituent.
Allen D. Owings
Allen D. Owings
The LSU Agricultural Center and Louisiana Nursery and Landscape Association initiated an ornamental plant promtion, marketing, and recommendation program in 1996. Called `Louisiana Select', this program is intended to actively promote outstanding ornamental plants to Louisiana's gardening consumers. In addition, it provides county agents and industry professionals information on plants that should be recommended. The selection committee consists of an extension horticulturist, two county agents, a landscape contractor, a wholesale greenhouse grower, a wholesale woody ornamental producer, and two representatives from retail garden centers. Plants are usually promoted in the spring and fall of each year. Plants previously named as Louisiana Select recipients include `New Orleans Red' (Red Ruffle) coleus, mayhaw, `Henry's Garnet' virginia sweetspire, `Homestead Purple' perennial verbena, `Telstar' dianthus, bald cypress, `New Gold' lantana, `Confetti' lantana, `Trailing Purple' lantana, `Dallas Red' lantana, `Silver Mound' lantana, `Lady in Red' salvia, `New Wonder' scaevola, `Goldsturm' rudbeckia, and `Foxy' fox-glove. A theme (“Fall is for Planting Native Trees”) has also been promoted. Point of purchase signs promoting the Louisiana Select program and individual plants are made available to garden centers. Significant sales increases ranging from 300% to 2500% have been reported for seelcted plants with annual bedding plants and perennial flowers enjoying the greater sales volume increases.
Allen D. Owings
The LSU Agricultural Center and Louisiana Association of Nurserymen initiated an ornamental plant promotion and recommendation program in 1996. Called `Louisiana Select', this program is intended to actively promote outstanding ornamental plants to Louisiana's gardening consumers. Plants are promoted in the spring and fall of each year and have included `New Orleans Red' coleus, mayhaw, `Henry's Garnet' Virginia willow, `Homestead Purple' verbena, `Watchet' azalea, `Telstar' dianthus, bald cypress, `New Wonder' scaevola, “Fall is for Planting Native Trees”, and lantana (`New Gold', `Dallas Red', `Confetti', `Trailing Purple', and `Silver Mound'). Point of purchase signs and banners promoting the `Louisiana Select' program and individual plants are provided to retail garden centers. Significant sales increases ranging from 300% to 2500% have been reported for the selected plants, with annual bedding plants and perennial flowers enjoying the greater sales increases. Plants for promotion are selected by a committee of wholesale greenhouse producers, retailers, landscape contractors, and cooperative extension service personnel.
Allen D. Owings
Allen D. Owings and Steven E. Newman
Four rates of seven plant growth regulators were foliar-applied to 11.4 liter containers of Photinia × fraseri after initial root establishment. Growth regulators studied were uniconazole, paclobutrazol, dikegulac-sodium, ancymidol, 6-BA, GA4+7 and, 6-BA + GA4+7. Six months after application, plant height, plant width, growth index, and number of lateral and terminal branches were recorded.
Applications of uniconazole (30 mg a.i./liter), 6-BA alone or in combination with GA4+7, and dikegulacsodium stimulated lateral branching. The number of lateral branches increased linearly as paclobutrazol rates increased from 60 to 180 mg a.i./liter. Growth index decreased with increasing application rates of uniconazole and paclobutrazol, while the growth index of photinia treated with other growth regulators wasn't affected by application rate. Plant height was increased in GA4+7 treated plants.
Allen D. Owings and Steven E. Newman
The action of foliar-applied uniconazole, paclobutrazol, dikegulac-sodium, ancymidol, 6-BA, GA4+7, and 6-BA + GA4+7 On container–grown Photinia × fraseri was studied over a one year period. Vegetative growth habit was evaluated at three month intervals. Shoot dry weight and histological examination of stern anatomy in the apical meristematic region was conducted at experiment termination.
Several plant growth regulators, primarily uniconazole, 6-BA, 6-BA + GA4+7, and dikegulac-sodium, stimulated lateral branching. Linear increases in lateral branching occurred as application rates increased. High application rates of uniconazole and paclobutrazol created an asymmetrical growth habit and decreased dry weight accumulation.
Allen D. Owings and Edward W. Bush
A study was initiated at Bracy's Nursery, Amite, La., in Apr. 1997 to evaluate the influence of seven controlled-release fertilizer sources and three top-dressed application rates in production of 4-gal (15.7-L) containers of `LaFeliciana' peach and swamp red maple. The fertilizers tested were Osmocote Plus 15-9-11, Osmocote Plus 16-8-12, Woodace 20-5-10, Woodace 20-4-11, Customblen 24-4-6, Nutricote (Type 270) 17-7-8, and Nutricote (Type 360) 17-6-8. Application rates were 1.75, 2.25, and 2.75 lb N per cubic yard. The experiment was completely randomized within blocks (species) and each treatment was replicated five times. A control treatment was also included. For `LaFeliciana' peach, Nutricote and Osmocote yielded the superior results when shoot height and visual quality ratings were determined in October (6 months after initiation). Increases in application rate did not significantly increase shoot height or visual quality ratings in most cases. For swamp red maple, shoot height was not affected by fertilizer source or application rate. Caliper ranged from 19.2 to 23.0 mm but was only slightly influenced by fertilizer source and application rate. Visual quality ratings were significantly higher for Osmocote Plus 16-8-12 when compared to some of the other fertilizer sources.
Allen D. Owings, Charles E. Johnson, and M. LeRon Robbins
Educational and research opportunities utilizing native plant species are being developed by the LSU Agricultural Center through the recent establishment of a native plant arboretum at the Calhoun Research Station. Plants indigenous to Louisiana and surrounding states are being collected and planted in the arboretum for evaluation of potential values for landscaping, in food industries, and/or wildlife management. Native trees being studied include species of oak (Quercus), maple (Acer), hickory (Carya), and dogwood (Cornus). Lesser known species of holly (Ilex) and hawthorn (Crataegus), are being evaluated for commercial production and landscape potential. Fruit being collected for field orchard studies include mayhaw (Crataegus opaca), pawpaw (Asimina triloba), and several native plums (Prunus spp.).
G. Stephen Crnko, Edward W. Bush, and Allen D. Owings
A study was initiated to determine the effects of fall fertilization, specifically N application rate and additions of supplemental K on the production of woody ornamental shrub species. The influence of two slow-release sources of K (4- and 8-month) in the form of K2SO4, three K application rates (0, 1, 2 lb/yd3), and four incorporated application rates of N (0, 1, 2, and 3 lb/yd3) from Osmocote Plus+ 15-9-11 were evaluated on the growth of `Fisher Pink' Indian azalea, glossy abelia, and `Tuscarora' crape myrtle. Growth of `Fisher Pink' azalea, as determined by shoot height and shoot width, increased as N rate increased from 1 to 3 lb/yd3 when compared to the control. The resulting growth index improved at the 2 and 3 lb/yd3 N rate when compared to the 0 and 1 lb/yd3 N rates. Height and width of glossy abelia at the 1 lb N rate with or without supplemental K applications increased when compared to some glossy abelia at the 3 lb N rate (primarily those with supplemental K). Glossy abelia at the 2 lb/yd3 N rate with 2 lb/yd3 N from 4-month 0-0-46 had significantly greater shoot dry weight when compared to the 3 lb/yd3 N rate with 2 lb/yd3 N from 8-month 0-0-46. The 1 to 3 lb/yd3 N application rate had more of a response on growth index, visual quality, and visual color on `Tuscarora' crape myrtle as compared to the 0 lb/yd3 N rate. In this study, the potential influence of supplemental K applications on plant growth was mostly evident for glossy abelia at the 2 lb/yd3 N rate and was not evident on azalea or crape myrtle.
Allen D. Owings, Edward W. Bush, and Mitchell W. Goyne
Leachates were collected at 3-month intervals over 12 months to determine the influence of bark, controlled-release fertilizer, and dolomitic lime sources and dolomitic lime application rates on pH of nursery media. The randomized complete-block design was arranged as a factorial and included three bark sources (pinebark, hardwood, and pinebark + hardwood), two fertilizer sources (Nutricote 17-7-8 and SierraBlen 18-7-10), and two dolomitic lime sources (microencapsulated granular and pulverized). Dolomitic lime application rates were 0, 5, 10, and 15 pounds per cubic yard. Leachate pH was influenced over the one-year evaluation period by fertilizer source, bark source, and application rate of dolomitic lime. Dolomitic lime source was not a significant factor in adjustment of leachate pH. Pinebark medium had lower leachate pHs than hardwood medium and the medium containing hardwood and pinebark. Dolomitic lime influenced leachate pH of pinebark medium more than the other bark sources. SierraBlen was more acid-forming than Nutricote.