Lagerstroemia Research Articles

Water Stress- and Nutrient Solution-mediated Changes in Water Relations and Amino Acids, Organic Acids, and Sugars in Xylem Fluid of Prunus salicina and Lagerstroemia indica

The effects and interactions of water stress and nutrient solution on water relations and concentrations of amino acids, organic acids and sugars in xylem fluid of `Methley' plum (Prunus salicina Lindl.) and `Carolina Beauty' crape myrtle (Lagerstroemia indica L.) during midday were determined. Container-grown plants were irrigated with water or nutrient solution (i.e., osmolarity = 138 mm) for 15 days, then irrigation was either continued or terminated for the next 5 days. The experiments were analyzed as factorial designs for each species separately, with the nutrient solution and irrigation status the last 5 days as the main factors. Xylem fluid tension increased ≈ 2- to 3-fold and leaf conductance to water vapor and transpiration were reduced ≈ 10-fold by withholding irrigation for both species; plant water relations of L. indica were also influenced by the nutrient solution. For both species, the osmolarity of xylem fluid was not altered by withholding irrigation. The predominant organic compounds quantified in both species were amides (i.e., glutamine and asparagine), arginine, and citric and malic acids. Sugars represented a small proportion (i.e., generally ≤ 1%) of total osmolarity. Irrigation altered the chemical profile of amino acids and organic acids to a greater degree than the nutrient solution. Water stress induced a 3-fold increase in total organic acids in xylem fluid of both species. The osmolarity and the concentration of most organic compounds in xylem fluid of P. salicina were not significantly affected by the nutrient solution. Arginine increased markedly in concentration by withholding irrigation or with the application of nutrient solution for L. indica. The concentration of most organic compounds did not vary greatly in response to variations in soil water or nutrient status. In conclusion, soil water-or nutrient-mediated changes in plant water relations exceeded changes in xylem fluid chemistry.

サルスベリの花色素と花色変異

1. To understand the mechanism of flower colour variations from red to purple in crape myrtle cultivars, absorption spectra and Hunter's L, a, b values of intact petals were measured. In this study 67 cyanic plants were classified into two groups : red group, λmax' 524544 nm; b/a, (- 0.183) (+0.165) : purple group, λmax, 555 570 nm; b/a, (-0.785) (-0.442). Relatively strong absorption about 360 nm was recognized in purple flowers, and high negative correlation (r = -0.897***) was obtained between b/a and E360/EVIS max.2. Three anthocyanins from the red and purple flowers were isolated, analysed chromatographically and spectrally, and their ratios determined.All 67 plants contained the 3-glucosides of delphinidin, petunidin, and malvidin as the major anthocyanins. The ratios among these anthocyanins varied widely, but had no correlation to Hue values (b/a), except that in the red group there was a negative correlation between b/a and the relative malvidin 3-glucoside concentration, and a positive one between b/a and relative delphinidin 3-glucoside conc.3. The pH values measured by tightly pressing the petals to a flat electrode varied from 4.2 to 5.1, but there was no correlation between these values and flower colour. 4. Crude aqueous extracts from the red and purple flowers were partitioned with ethyl acetate and the organic fraction was concentrated; the aqueous fraction was dissolved in a buffer solution. Visible absorption maxima shifted bathochromically when the above two fractions from red and purple flowers were combined.5. Ellagic acid derivatives detected in the purple flowers are assumed to be the main agents for the blueing of the 'flowers in crape myrtle.

564 PB 415 A COMPARISON OF COLD HARDINESS AMONG LAGERSTROEMIA INDICA × FAURIEI CULTIVARS GROWN IN ZONES 7 AND 8 USING DIFFERENTIAL THERMAL ANALYSIS

During recent freezes in the mid-south, crape myrtles have suffered severe freeze damage. Some increased levels of cold hardiness have been observed in the National Arboretum crape myrtle releases, but the degree of tolerance has not been documented. The relative cold hardiness of five hybrid crape myrtle cultivars `Muskogee', `Natchez', `Osage', `Tuskegee' and `Yuma' was determined using differential thermal analysis. Stem samples were collected from established trees at two locations, Poplarville, Zone 8 and Starkville, Zone 7 once per month from October through April. Freezing point suppression was determined from five samples from each cultivar and location. Observed exotherms ranged from -7C to -13C.

Seasonal Cold Hardiness Differences of Three Woody Plant Taxa during the Production Stage and as Established Landscape Plants

Abstract Seasonal cold hardiness levels of Crape myrtle (Lagerstroemia L. ‘Natchez’), Leyland cypress [× Cupressocyparis leylandii (A.B. Jacks. and Dallim.) Dallim. and A.B. Jacks.] ‘Haggerston Gray’ and Lacebark elm (Ulmus parvifolia Jacq. Allee™) were determined for nursery production and established landscape plants grown at the same location. Differences in cold hardiness between the growth treatments were taxon specific. During October, November and December, nursery-grown crape myrtle plants were up to 11°C (20°F) less cold hardy than those established in the landscape. Differences in Leyland cypress cold hardiness were detected, but were not as great as in crape myrtle. During October, November and December newly transplanted Leyland cypresses were from 3 to 6°C (5 to 11°F) less cold hardy compared to established landscape plants. Differences occurred between nursery production and established landscape plants of lacebark elm in January and February.

Microirrigation Affects Growth and Root Distribution of Trees in Fabric Containers

Lagertroemia indica L. × fauriei Koehne (`Natchez' crape myrtle) crown width increased after 13 months as irrigation frequency increased from every 3 days to every day, and the irrigated area around the fabric container increased from 20% to 100% of the circular area within 20 cm beyond the container. Restricting irrigation to within the fabric container plus 20% of the area 20 cm beyond the container edge resulted in less height and width for crape myrtle, but had no effect on root growth, compared to irrigating 100% of area 20 cm beyond the container. Restricting the pattern of irrigation to the container plus 20% of the area 20 cm beyond the container resulted in greater free-root weight (roots < 5 mm in diameter) within the container for laurel oak (Quercus laurifolia Michx.) compared to irrigating the container plus 100% of the area 20 cm beyond the container. Height, width, and caliper of oak were not different among treatments.

The effect of different foodplants on cocoon crop performance in the Indian tasar silkworm Antheraea mylitta Drury (Lepidoptera: Saturniidae)

Cocoon crop performance through seasonal rearings of Antheraea Mylitta Drury larva on three primary foodplants Asan (Terminalia tomentosa W. & A.), Arjun (Terminalia arjuna W. & A.), Sal (Shorea robusta Gaertn.) and three secondary foodplants, Ber (Ziziphus jujuba Gaertn.), Sidha (Lagerstroemia parviflora Roxb.) and Dha (Anoegeissus latifolia Wall.) indicate better performance in winter crops than those of a rainy and autumn season. Sal, among primary foodplants, appeared uneconomical in terms of total cocoon shell (raw silk) production in spite of a superior cocoon formation Overall performance was superior in Asan than all other foodplants during all the seasons. Performance on Ber was higher than Sal and other secondary foodplants, a situation not heretofore documented. The grada- tion of foodplant with regard to performance (total raw silk production) was, in decreasing order of productivity: Asan, Arjun, Ber, Sal, Sidha, Dha. At the State Tasar Research Farm (Area 20 ha) Durgapur, Orissa, a number of foodplants were selected at random for rearing of A. mylitta larva. The three Combretaceae foodplants chosen were Asan (T. tomentosa), Arjun (T. arjuna), and Dha (Anoegeissus latifolia Wall.). One foodplant from the Dipterocarpaceae, Sal (S. robusta) was selected as well as one Melostomaceae, Ber (Ziziphus jujuba Gaertn.), and one Lythraceae, Sidha (Lagerstroemia parviflora Roxb.). For each foodplant species, 10000 freshly hatched healthy hatchlings were separated into five groups of equal size and brushed onto a number of plants for each of three seasons. The cocoon crop performance was evaluated by effective rate of rearing (ERR% = 100 total cocoons yielded / total larvae brushed), cocoon weight, pupa weight, and shell weight. These

FALL PRUNING EFFECTS COLD HARDINESS OF FIELD-GROWN CRAPE MYRTLE

The effects of fall and winter pruning on cold hardiness of field-grown Lagerstroemia L. `Natchez' (crape myrtle) were determined. In the first year (1990-1991) pruning prior to January reduced cold hardiness estimates of `Natchez' crape myrtle by 3C compared to controls. In the second year (1991-1992) fall pruning also reduced cold hardiness estimates by 3C on the January and February test dates. Pruning in January or later is recommended for `Natchez' crape myrtle to assure maximum cold hardiness. Similar cold hardiness estimates of `Natchez' crape myrtle were obtained from field trials compared to lath tests conducted the previous year.

The significance of the dormant stage in the growth cycle of deciduous plants for biogeochemical uranium prospecting, India

Abstract Three plant species, Shorea robusta, Emblica officinalis and Lagerstroemia parviflora , have higher uranium uptake capacities and more uniform distribution than other species growing over and near the Jajawal Uranium Deposit, India. The twigs of these species were sampled at the onset of summer to assess their relative efficiencies in delineating U anomalies. The trees of L. parviflora were in their dormant stage, bearing no leaves or flowers at the time of sampling. At that time S. robusta had growing leaves and flowers and E. officinalis had only young leaves, therefore both species were in the active stage of their growth cycle. The average concentration of U (0.87 ppm) in twigs of L. parviflora was higher than the average of 0.33 and 0.32 ppm U in twigs of S. robusta and E. officinalis , respectively. The biogeochemical contrast for U shown by L. parviflora in the dormant stage was higher than the other two species during their active growth. The magnitude of the anomalies varied, with L. parviflora giving the most pronounced anomalies.

Susceptibility of Crape Myrtle, Lagerstroemia indica L., to the Crapemyrtle Aphid (Homoptera: Aphididae) in North Florida

Thirty seven cultivars of the crape myrtle, Lagerstroemia spp., were evaluated in a two year study in north Florida for susceptibility to the crapemyrtle aphid, Tinocallis kahawaluokalani (Kirkaldy). Numbers of crapemyrtle aphids per leaf were monitored each week from June to October in 1990 and 1991. Peak aphid numbers occurred in both years during the last week in July. Cultivars with L. fauriei parentage, and cultivars that are susceptible to or those with resistance to powdery mildew had significantly higher aphids per leaf than cultivars considered tolerant of powdery mildew. Aphid numbers were not related to flower color or leaf area, but tall and semi-dwarf cultivars had significantly more aphids than dwarf or medium-sized cultivars. Mean number (± SE) of aphids per leaf per sample date varied from a low of 6.2 ± 1.7 on ‘Centennial Spirit’ to 84.8 ± 19.1 on ‘Biloxi’.

Design and Testing of Urban Landscapes for Water Conservation

Studies were conducted to provide information on water use by woody ornamentals and how it is affected by plant selection, the urban environment and landscape management practices. Study 1 evaluated water relations of containerized native versus non-native woody ornamentals. Study 2 explored how energy transport from bare soil, turfgrass, and pine-bark mulched surfaces affect transpiration of crape myrtle. Study 3 quantified the effect of pruning and chemical growth regulation using uniconazole on water use of hibiscus. The investigations provided information which indicated that it may be possible through more innovative designs and better management practices to reduce total landscape irrigation by 80%.

Cooling and Warming Effects on Cold Hardiness Estimations of Three Woody Ornamental Taxa

Cooling treatments of 2, 4, and 6C/hour or warming at 25, 4, or 0C influenced the cold hardiness estimates of x Cupressocyparis leylandii (A.B. Jacks. and Dallim.) Dallim. and A.B. Jacks. (Leyland cypress), Lagerstroemia indica L. (crape myrtle), and Photinia ×fraseri Dress `Birmingham' (redtip photinia) at four times during the year. New growth from all taxa, especially spring growth, was injured or killed at higher temperatures by the fastest cooling rate and/or by warming at 25C. Cold hardiness of Leyland cypress was unaffected by the cooling and warming treatments. Crape myrtle had a significantly higher lowest survival temperature (LST) when warmed at 25C than at 4 or 0C. Photinia leaves and stems cooled at 6C/hour or warmed at 25C generally resulted in a higher LST than those cooled more slowly or warmed at lower temperatures. Cooling rates of 14C/hour and warming at 0 to 4C should be used in freeze tests with Leyland cypress and crape myrtle. For leaves and stems of photinia, 2C/hour cooling and warming at 0 to 4C should be used.

Hydrocarbon emissions from twelve urban shade trees of the Los Angeles, California, Air Basin

The large-scale planting of shade trees in urban areas to counteract heat-island effects and to minimize energy use is currently being discussed. Among the costs to be considered in a cost/benefit analysis of such a program is the potential for additional reactive organic compounds in the atmosphere due to emissions from these trees. In this program, 15 species of potential shade trees for the Los Angeles Air Basin were studied and emission rates were determined for 11 of these trees, with one further tree (Crape myrtle) exhibiting no detectable emissions. The emission rates normalized to dry leaf weight and corrected to 30°C were (in μg g −1 h −1), ranked from lowest to highest emission rate: Crape myrtle, none detected; Camphor, 0.03; Aleppo pine, 0.15; Deodar cedar, 0.29; Italian Stone pine, 0.42; Monterey pine, 0.90; Brazilian pepper, 1.3; Canary Island pine, 1.7; Ginkgo, 3.0; California pepper, 3.7; Liquidambar, 37; Carrotwood, 49. In addition to the emission rates per unit biomass, the biomass per tree must be factored into any assessment of the relative merits of the various trees, since some trees have higher biomass constants than others. The present data shows that there are large differences in emission rates among different tree species and this should be factored into decision-making as to which shade trees to plant. Based solely on the presently determined emission rates, the Crape myrtle and Camphor tree are good choices for large-scale planting, while the Carrotwood tree and Liquidambar are poor choices due to their high isoprene emission rates.

Growth of Container-grown Trees Transplanted from the Field or Grow-bags

Crape myrtle (Lagerstroe-mia L. × `Natchez'), live oak (Quercus virginiana Mill.), and Chinese pistachio (Pistacia chinensis Bunge) were planted into a sandy loam soil directly in the field or in grow-bags. Root and top growth were measured in March and July of the second year. Some of the trees were transplanted to 20-gal (76-liter) containers in March or July and grown for 3 months. Chinese pistachio developed a poor root system in field soil and was not ready for harvest in March or July. There was no difference in height, caliper, or top fresh weight for crape myrtle. Caliper and top fresh weight were similar for live oak trees. However, live oaks grown by traditional field production methods were taller than trees produced in grow-bags. With March transplanting, both crape myrtle and live oak trees from traditional field plantings were taller than trees transplanted from grow-bags 3 months after transplanting into containers. Tree top weight, caliper, and root ratings were similar for March-transplanted crape myrtle. Live oak trees transplanted from grow-bags had similar caliper and top weight but a higher root rating. July-transplanted crape myrtle trees had similar values for all variables 3 months later. All live oaks died when transplanted from traditional field plantings to containers in July. All live oaks grown in grow-bags survived transplanting.

WATER RELATIONS OF SHRUB AND GROUNDCOVER LANDSCAPE COMMUNITIES

Landscape plantings have been designed traditionally using aesthetic criteria with minimal consideration given to water requirements. The primary objective of this research was to develop quantitative information on water use of plant communities conventionally used in urban landscapes. Pots of Photinia × Fraseri (photinia Fraseri), Lagerstroemia indica 'Carolina Beauty' (crape myrtle), or Ligustrum japonicum (wax leaf ligustrum) were transplanted from 3.8 l into 75.7 l pots with either Stenotaphrum secundatum 'Texas Common' (St. Augustinegrass), Cynodon dactylon × C. transvallensis 'Tiffway' (bermudagrass), Trachelospermum asiaticum (Asiatic jasmine), or left with bare soil. Whole community water use was measured gravimetrically. In addition, sap flow rates were recorded for shrub species with stem flow gauges. Sap flow measurements were correlated to whole community water use recorded during the same time intervals. Whole community water use differed due to the groundcover component; bermudagrass, Asiatic jasmine, and bare soil communities used less water than St. Augustinegrass communities. Differences were also noted in stomatal conductance and leaf water potential among the species.

TIME-RELEASE FERTILIZERS AND MEDIA AFFECT GROWTH OF CONTAINER-GROWN LAGERSTROEMIA AND LIGUSTRUM

One-year-old liners of Firebird crape myrtle (Lagerstroemia indica L. 'Firebird') and Vicary golden privet (Ligustrum X vicaryi) were planted in 7.6 liter containers. The growing media consisted of 3 pinebark: 1 Canadian peat moss: 1 sand and 3 sawdust: 1 Canadian peat moss: 1 sand (v/v/v). Both media were amended with NH4NO3 and dolomite. Several controlled release fertilizers at varying rates were incorporated into each medium prior to planting. Thirty, 60 and 90 days after planting, leachate samples were collected and tested for E.C. and pH. Fertilizer Sierra (17-6-10) and Osmocote (18-7-13) resulted in maximum shoot dry weight with both species and media types followed by Osmocote (24-4-8) and Escote (20-4-11). Plants grew equally well in pinebark and sawdust medium. After 30 and 60 days leachate from Sierra (17-6-10) had highest E.C. levels. Osmocote (18-7-13 and 24-4-8) recorded highest E.C. at 90 day sampling date. The sawdust medium had higher pH values than the pinebark.

Influence of Herbicides on Shipping Quality of Landscape Plants

Abstract Japanese barberry ‘Crimson Pygmy’, Crape myrtle ‘Byers Hardy Lavender’ and azalea ‘Girard Scarlet’ were treated with either Southern weedgrass control (pendimethalin) at 3.4 kg a.i./ha (3.3 a.i.lb/A) or Ornamental Herbicide-2 (oxyfluorfen + pendimethalin) at 3.4 kg a.i./ha (3.3 lb a.i./A) or 6.7 kg a.i./ha (6.6 lb a.i./A) prior to simulated shipping in an enclosed environment. No injury was observed on any plants as a result of herbicide treatments.

Paint-On Application of Acephate for Aphid Control on Crape Myrtle

Orthene 75 S™ (acephate) in a 3:1 and 4:1 (v:v ratio) water slurry was painted on the trunks of row-planted, seedling crape myrtle, Lagerstroemia indica, for control of the crape myrtle aphid, Tinocallis kahawaluokalani. The amount of slurry banded on the trunk was based on the trunk diameter of test plants. Evaluation of the treatments was made by periodic counts of aphid populations. Treatments showed four weeks control of aphid populations after apparent absorption through the bark. No phytotoxicity was observed as a result of any treatments.

Fuelwood characteristics of certain hardwood and softwood tree species of India

The acute shortage of fuelwood in rural India and greater emphasis on the development of the fuelwood needs of the people has necessitated the identification of tree species which can be utilized as fuelwood. Twenty-six perennial species growing in their natural habitat in Central India and 16 indigenous and exotic Pinus species from the Himalayan region at Kalika were collected for screening fuelwood properties; calorific value, density, ash, silica, moisture, nitrogen, volatile matter and Fuel Value Index. The results suggest that Woodfordia fruticosa, Gardenia turgida, Gardenia resinifera, Litsea sebifera, Acacia donaldi, Wrightia tinctoria, Alanagium savifolium, Sterblus asper, Mitragyna parvifolia and Lagerstroemia parviflora have good fuelwood properties among perennial hardwoods and Pinus oocarpa, Pinus patula, Pinus pseudostrobus and Pinus ponderosa are desirable softwood species.

Pruning Effects on the Cold Hardiness of `Haggerston Gray' Leyland Cypress and `Natchez' Crape Myrtle

The effects of late summer, fall, and winter pruning on the cold hardiness of × Cupressocyparis leylandii (A.B. Jacks. and Dallim.) Dallim. and A.B. Jacks. `Hag gerston Gray' (Leyland cypress) and Lagerstroemia L. `Natchez' (crape myrtle) were determined. Pruning in late summer through early winter significantly reduced the cold hardiness of both taxa. The maximum difference in cold hardiness between pruned trees and controls for × Cupressocyparis leylandii `Haggerston Gray' in October, December, January, and February was 3, 3, 2, and 6C, respectively. The maximum difference in cold hardiness between pruned plants and controls for Lagerstroemia `Natchez' in December, January, and February was 3, 4, and 2C, respectively. Early spring pruning of Leyland cypress and late winter or early spring pruning of crape myrtle are suggested from these data.

Transpiration by Crape Myrtle Cultivars Surrounded by Mulch, Soil, and Turfgrass Surfaces

A study was conducted to explore how surface materials, including pine bark mulch, bare soil, and turfgrass, affect water use of diverse cultivars (dwarf weeping, dwarf upright, standard weeping, and standard upright) of crape myrtle (Lagerstroemia indica L.). Daily water use was measured gravimetrically, and instantaneous rates of sap flow were measured using heat balance stem flow gauges. Plants of all cultivars surrounded by the mulched surface lost 0.63 to 1.25 kg·m-2·day-1 more water than plants on the soil surface and 0.83 to 1.09 kg·m-2·day-1 more than plants surrounded by turf. The surface temperature of the mulch was higher than that of the other surfaces, resulting in greater fluxes of longwave radiation from the surface. Because of the greater energy load, plants on the mulched surface had higher leaf temperatures and higher leaf-air vapor pressure deficits (VPD) throughout the day. Plants on the mulched area also had higher stomata1 conductances during most of the day compared with those on bare soil and turfgrass surfaces.