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W.T. Witte, M.T. Windham, R.J. Sauve, and P.C. Flanagan

Fifty-five accessions of commercially available crape myrtle cultivars were established with 10 single-plant replications during Fall 1993 and Spring 1994. Drip irrigation began on a regular basis May 1994 and plants were fertilized regularly. In contrast to the 1994 growing season with heavy powdery mildew infestation, little powdery mildew occurred in 1995. Mean growth index (GI = centimeter height + centimeter mean width) was calculated for each cultivar in Fall 1994 and 1995. Fastest growth occurred in `Tuskegee' and `Biloxi' (GI = 276, 246, respectively), followed by a group including `Tonto', `Comanche', `Choctaw', `Hardy Lavender', `Natchez', `Potomac', and `Tuscarora' (GI = 185 to 227). Slowest growth occurred in the group including `Pecos', `Seminole', `Baton Rouge', `Petite Orchid', `Bourbon Street', `Cherokee', `Monink Pink', `Moned Red', `Delta Blush', `Low Flame', `New Orleans', `Monow', and `World's Fair' (GI = 5 to 53). Data will be presented on powdery mildew ratings and physiological injury sustained during Winter 1995–96.

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W.T. Witte, M.T. Windham, R.J. Sauve, and P.C. Flanagan

Sixty accessions of commercially available lilac cultivars were planted May 1994 and immediately placed under drip irrigation and fertilized regularly. Powdery mildew appeared in July 1994 and was rated on a scale of 0 (healthy) to 5 (totally mildewed) in July, August, and September. Mean growth index (GI = cm height + cm mean width) was calculated for each cultivar in Fall 1994 and 1995. Fastest growth (GI = 75 to 45 respectively) occurred in the group including chinensis `Rothomagensis', meyeri `Dwarf Korean', reticulata `Ivory Silk', prestoniae `Isabella', `Mrs. Harvey Bickle', `Excel', `Katherine Havemeyer', `Mme. F. Morel', `Silver King', `Leon Gambetta', `Mount Baker', and microphylla `Superba'. Data will be presented on powdery mildew ratings for the 1995 season.

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Guihong Bi, Williams B. Evans, and Glenn B. Fain

measurement and the average of the three readings was recorded. Plant growth index [(height + widest width + perpendicular width) ÷ 3] and number of fully open flowers were also recorded. Plant height was measured from medium surface to the tallest plant part

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He Li, Matthew Chappell, and Donglin Zhang

controlled-release fertilizer (Everris) annually. Total growth index measurements were taken in the first week of May 2014, 2015, and 2017. Measurements included height (ground level to the tallest point), width at the widest point, and width perpendicular to

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Pablo R. Hidalgo, Frank B. Matta, and Richard L. Harkess

The effects of various substrates with or without earthworm [Eisenia fetida (Savigny, 1826] castings on growth of marigolds were evaluated. In addition, the physical and chemical properties of such substrates were determined. Castings had a greater nutrient content than the remaining substrates. The 4 pine bark: 1 sand treatment (v/v) (PBS) had higher P, K, and Zn than 7 peat moss: 3 perlite (v/v) (PP). PP had the lowest nutrient content of all substrates. Castings (C) had the highest pH followed by 1 PBS: 1 C (v/v), 2 PBS: 1C (v/v) and 3 PBS: 1C (v/v). Sunshine Mix 1 and PP had the lowest pH. EC (ER) was increased by castings, which had high ER. Castings and PP had the greatest percentage pore space. Water-holding capacity was greatest for 2 PBS: 1C (v/v) compared with Sunshine Mix 1 followed by castings. Earthworm castings increased plant growth index, stem diameter, root growth, dry weight, and flower number of marigolds compared with PP, Sunshine Mix 1, and PBS. All mixtures of castings (C) with PP, PBS, except 3 PBS: 1C (v/v), increase the growth index of plants. 1 PP: 1 C (v/v), increased flower number compared with all substrates without castings. Castings alone increased number of open flowers, but did not differ from 1 PP: 1 C or 3 PP:1 C.

Open access

Kaitlin Barrios and John M. Ruter

of data collection. Growth index (GI) was calculated as height × width1 × width2 to reflect overall plant volume in cubic centimeters and increases were calculated as differences from Day 1 to a specific week of data collection. Chlorophyll meter

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Eric T. Stafne and Barbara J. Smith

from the pruning treatments, received the same level of management and environmental exposure. Harvest index was calculated by dividing fruit yield by cane weight ( Price and Munns, 2018 ). The growth index (GI) was calculated as GI = H + [(L + W)/2

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Federica Larcher and Valentina Scariot

number of branches produced were recorded per each pot. Plant height and diameters were used to calculate the growth index = π {[(w 1 + w 2 )/2]/2} 2 h, according to Hidalgo and Harkess (2002) . To indirectly measure leaf chlorophyll content and plant

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Pablo R. Hidalgo and Richard L. Harkess

Experiments were conducted to evaluate earthworm castings (vermicompost) as a substrate for poinsettia (Euphorbia pulcherrima Willd.) `Freedom Red' production. Vermicomposts produced from sheep, cattle, or horse manures were mixed at different ratios with 70 peatmoss: 30 perlite (v/v) to create 13 substrates. Chemical and physical properties were measured on all substrates used. Growth index, foliar and bract area, and dry weight were greater on plants grown in substrates with castings from sheep or cattle manure. These castings had greater initial nutrient content than the castings from horse manure. Mixtures of castings and peat produced better plant responses than castings alone. Better plant responses were sometimes associated with values outside the recommended pH and electrical conductivity levels for poinsettia production. The highest values obtained for growth index, foliar and bract area, dry weight, and root development were produced in the substrates with moderate pore space or water holding capacity. Substrates with greater air space produced plants with greater dry weight and root development than substrates with less air space. The highest quality plants were grown in substrates with 25% castings from sheep or cattle manures.

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Daike Tian, Ken M. Tilt, Jeff L. Sibley, Floyd M. Woods, and Fenny Dane

Lotus (Nelumbo) is a highly valued plant with a long history for vegetable, ornamental, and medicinal use. Little information is available on the effects of planting time on performance of lotus, especially when grown in containers. The objectives of this study were to find a suitable planting time and to determine best management practices that are of importance for container lotus production. Effects of planting time and disbudding on plant growth indices in southeast Alabama were evaluated in a container production system for the ornamental lotus, N. nucifera ‘Embolene’. Results indicated that plant growth indices were little influenced by different planting dates in March, but were much influenced by planting dates with a difference over a month between February and May. Plants potted and placed outdoors in March and April performed best, and lotus planted in the greenhouse in February and planted outdoors in February and May performed worst. Flower number was not largely influenced by the planting time, but flowering characteristics, especially the flowering peaks, were different among treatments. Planting lotus outdoors between March and May produced the largest return. Influence of planting time on plant growth indices of lotus appeared to be explained by effects of growth-season climate conditions after planting. Disbudding had no impact on plant height but significantly increased underground fresh weight and the number of propagules. Therefore, disbudding should be considered a best management practice to maximize the yield of rhizomes or propagules. Positive linear, quadratic, or cubic relationships were detected among emerging leaf number, underground fresh biomass, and propagule number. Based on the regression models, the yield of lotus rhizomes or propagules can be predicted by the number of emerging leaves. This research provided a guide for nurseries, researchers, and collectors to select the best time to plant lotus outdoors.