Performance of Garden Roses Under Minimal Input Conditions in North-Central Texas

Abstract

<jats:p>To enlarge the palette of environmentally-responsible landscape plants, 117 garden rose cultivars were evaluated under minimal input conditions. Other than mulching and irrigation, no other inputs were provided, including no fertilization and no pesticide applications. Plants were established in completely randomized blocks with four reps in the spring of 1998 with data collection beginning in 2000 and continued through 2002. Data on overall performance (an index comprised of flower number, percent of plant covered with flowers and plant growth) and relative chlorophyll content were collected the first and third week of each month from April through October. Disease ratings or incidence ratings were collected for <jats:italic>Diplocarpon rosae</jats:italic> Wolf (black spot), <jats:italic>Alternaria</jats:italic> sp. (petal blight) and <jats:italic>Sphaerotheca pannosa</jats:italic> (powdery mildew). Statistical analysis was performed on the mean data for all dates. `Knockout' was the top rose for overall quality with little or no disease observed, high foliage quality, and continuous flowers from spring until late in the fall. `Knockout' also ranked among the top rose cultivars in terms of overall nutrient concentrations (N, P, K, and Fe) in new growth tissue. Most of the hybrid tea roses such as `Peace' and `Double Delight' died in at least three blocks due to disease and a lack of vigor.</jats:p>

Landscape Performance of Buck Roses under Minimal-input Conditions in North-central Texas

“…Powdery mildew appeared only lightly during the study period, and mostly in year 1. .7 de 5.7 ± 0.11 3.9 ± 0.12 4.5 ± 0.12 September 5.0 c 5.0 ± 0.11 5.0 ± 0.11 4.8 ± 0.12 October 4.9 cd 5.0 ± 0.12 4.4 ± 0.10 5.2 ± 0.14 z Landscape performance rating was determined by using a criterion-referenced scale from 0 (dead plant) to 10 (strong performance), with three indices (flower quantity and quality, foliage quantity and quality, and plant habit and vigor) as described by Mackay et al (2008). Ratings were recorded once monthly during the growing season.…”

“…2009) for 1) landscape performance; 2) bloom number; 3) percent bloom coverage, defined as the estimated percentage of the plant canopy covered in blooms; and 4) drought stress. Carefree Beautyä was a strong performer in previous studies in northcentral Texas (Mackay et al, 2008;Zlesak et al, 2017) and used as an experimental standard.…”

“…To determine landscape performance, the rating scale (adapted from Mackay et al, 2008) used scores from 0 to 10, based on three indices: 1) flower quantity and quality; 2) foliage quantity and quality; and 3) plant habit and vigor. Ratings were as follows: 10 = no deductions for all three indices, 9 = slight deduction for one index, 8 = slight deductions for two indices, 7 = slight deductions for three indices or moderate deduction for one index, 6 = moderate deduction for one index and slight deduction for one index, 5 = moderate deduction for one index and slight deductions for two indices, 4 = moderate deductions for two indices, 3 = severe deduction for one index and moderate deduction for one index, 2 = severe deductions for two indices, 1 = severe deductions for three indices, 0 = a dead plant.…”

“…There are many different designations of roses, ranging from the single-flowered stems of the hybrid teas to the multiple blooms per stem of polyantha and shrub roses (American Rose Society, 2007). Unfortunately, many roses, especially hybrid teas, require frequent fertilization and irrigation, are highly susceptible to disease, especially black spot and powdery mildew, and pests (Mackay et al, 2008). Consumers today are increasingly unwilling to use high-maintenance plants and desire a rose that is medium sized (3 to 4 ft tall and wide), disease resistant, pest tolerant, and blooms throughout the growing season (Grygorczyk et al, 2013;Waliczek et al, 2015).…”

“…Unfortunately, other than Carefree Beautyä, little information is available regarding the use of Buck roses in warmer climates. Identifying roses with strong landscape performance, resistance to pests and diseases, and a tolerance for the heat and drought common in north-central Texas can be difficult (Harp et al, 2019;Mackay et al, 2008;Zlesak et al, 2017). The objective of this study was to evaluate a selection of Buck roses under minimalinput conditions in north-central Texas.…”