The effect of soil temperature on lateral shoot formation and flower-bud formation in apple in the first year after budding

Under controlled environment conditions the influence of four soil temperatures (7°, 14°, 21°, and 28°C) on vegetative development and flower-bud formation of apple trees (cvs ‘Rode Boskoop’ and ‘Elstar’) were evaluated in the first year after budding. Relative air humidity was high, air temperature was 20°C. Broadly speaking, for both cultivars shoot growth clearly increased with increasing soil temperature. The effects on growth were mainly reflected in the number (not length) of the lateral shoots; the growth of the main shoot was little influenced by soil temperature. At 7°C the lateral shoots usually occurred higher along the main stem than at the higher temperatures. Flowering on the parent stem and on the lateral shoots was little affected by the soil temperatures tested. In general, flower-cluster quality was rather poor. If only clusters having more than four well-developed flowers are considered, flowering was favoured by higher soil temperatures; at 28°C, especially, cluster quality was much better than at the other soil temperatures. It is concluded that soil temperature is important in controlling the degree of lateral shoot-formation as well as the formation of well-developed flower clusters.     

东南景天茎插和叶插繁殖研究

研究了人工气候箱里东南景天在不同植物激素(NAA 1 000 mg/L、IBA 500 mg/L)和不同空气湿度(60％、80％)组合下茎插繁殖和在不同基质的叶插繁殖.结果表明:光照强度80％和温度20～25℃下东南景天叶插插穗在蛭石∶珍珠岩=1∶1基质上生根最快、根长最长、根量最多、成活率最高,且都显著优于其它基质(p＜0.05,下同);东南景天茎插在60％空气湿度下显著优于湿度80％的、插穗用IBA处理比用NAA处理要好;60％空气湿度下经IBA 500 mg/L处理过的东南景天茎插插穗的生根最快,成活率、累计发芽率、根量评分最高,发芽略慢,最长根长略短,但植株整体生长状态最好,且都明显优于其它处理,是进行茎插繁殖的最佳处理组合.该研究为东南景天的快速繁殖、资源保护以及重金属污染土壤修复应用提供技术保障.     

低温弱光对番茄苗期生长和光合作用的影响

研究了低温弱光条件对番茄苗期植株茎的长度、叶面积、根系活力、功能叶片叶绿素含量及净光合速率的影响。结果表明 :低温弱光造成番茄茎的增长和叶面积扩展减缓、叶片净光合速率降低 ,但对番茄根系活力影响不明显 ;低温逆境对于番茄茎叶生长及净光合速率的影响作用比弱光逆境更大 ;不同品种受低温弱光逆境影响的程度不同     

Bulb-dip application of growth-regulating chemicals for inhibiting stem elongation of ‘Enchantment’ and ‘Harmony’ lilies

An improved method of treating Lilium cultivars ‘Enchantment’ and ‘Harmony’ with the growth regulators Ancymidol, CCC, and Ethrel is described. When bulbs were treated, prior to planting, by immersing them for 12 h in aqueous solutions of the growth regulators, shoot elongation was more effectively inhibited than when the chemicals were applied as soil drenches. Ancymidol was the most potent inhibitor of stem elongation. Although Ethrel effectively inhibited stem growth during the first treatment season, it resulted in increased elongation of the renewal shoots. Ethrel interfered with apical meristematic activity, and induced early flower senescence. The inhibitory effects of a single bulb-dip with Ancymidol and CCC were evident on the growth of the renewal shoots in the following non-treatment season.The bulb-dip procedure offers several advantages: chemicals can be applied effectively at a much earlier development stage of the shoot; more effective control of shoot elongation is possible; significant control of shoot elongation may be obtained with lower concentrations of a growth regulator; one application of the growth regulator affected growth of the current season's shoot and also the growth of the renewal shoot in the following season; bulbs may be pretreated for use either as pot plants or for landscaping; chemically pretreated bulbs can be readily packaged and distributed without further chemical treatments being required.     

林芝地区林下凋落物作无土育苗基质初步研究

以北农1号番茄为试材,以土壤为对照,研究了菇渣、高效腐殖土、往年凋落物、当年凋落物4种基质对番茄幼苗生长状况的影响。结果表明:在出苗率、株高、茎粗、根长、单株干鲜质量、根冠比、茎叶比、鲜干比和真叶抽生数等方面,高效腐殖土、菇渣和往年凋落物均明显优于当年凋落物和对照土壤;土壤在株高、茎粗和真叶抽生数方面显著优于当年凋落物;往年凋落物具备作为优质育苗基质的特性。     

日光温室果树台田式限根栽培温度变化规律的研究

通过对日光温室台田式限根槽栽培方式的地温与气温变化规律研究.结果表明:温室内气温和地温最低值出现时间一致;气温变化快,日变幅大;地温受气温影响,变化明显滞后;随着土层加深,地温日变幅变小;升温初,台田较平作地温上升快.覆盖白色和黑色地膜都能明显提高地温.土层越浅并且距离限根槽边缘越近,地温受气温影响越大;随土层加深各部位地温差减小.台田式限根栽培有利于迅速提高地温,协调地温和气温关系.     

Dependence of urban park visits on thermal environment and air quality

Activities in urban parks contribute to greater socialization and a more active lifestyle, yet such health benefits could be mingled with health concerns – e.g., extreme thermal events or hazardous air quality, which received much less attention than the benefits. Particularly, there is a lack of empirical studies on behavioral changes under different thermal and air-quality conditions. To address the research gap, this study quantitatively measured the impact of thermal environmental parameters (air temperature, humidity, wind scale) and air quality parameters (PM_2.5, PM₁₀, NO₂, SO₂, O₃, integrated air quality index (AQI)) on the daily attendance at Haidian Park – a neighborhood park – and Chaoyang Park – an urban recreational park – in Beijing covering consecutive days from April 1, 2020 to March 31, 2021. The analysis revealed the degrees to which urban park visits were influenced by temperature and air quality. Temperature had the greatest impact on the attendance, while the impact was asymmetric: The effect of low temperature showed more elasticity than that of high temperature. The influence of air quality was not as significant as that of the air temperature. The analysis also showed that such impacts of thermal and air-quality conditions on park visits were mediated by type of activities (the everyday-recreational continuum), days (weekday/weekend), and seasons. The findings provide useful implications for tackling the wicked problem of promoting outdoor activities in parks while controlling adverse effects of thermal and air-quality conditions.     

Trees in planters – Growth,structure and ecosystem services of Platanus x hispanica and Tilia cordata and their reaction to soil drought

Urban environments are often characterized by extensive paved surfaces, exacerbating the urban heat island effect. At the same time, limited root space due to underground infrastructure poses a challenge for planting new trees in these areas. Trees in planters have emerged as popular design elements, offering innovative and sustainable greening solutions, particularly in urban environments with limited rooting space. However, growing conditions in planters may strongly impact tree growth and the provision of environmental ecosystem services (ES). In this 3-year study, we analyzed tree growth and ecosystem services (cooling by shading, CO₂-fixation) of London plane (Platanus x hispanica Münchh.) and small-leaved lime (Tilia cordata Mill.) in four planting treatments: in-ground (G), planters in the ground (PG), non-insulated plastic planters (P), and insulated planters (PI). We also recorded soil temperature throughout the experiment and implemented soil drought conditions by reducing soil irrigation for half of the trees after one year. Our findings revealed higher thermal fluctuations in soil temperature within non-insulated plastic planters (P), reaching a maximum of 45 °C, surpassing the critical temperature threshold for plant growth (>38 °C). In contrast, insulated planters (PI) effectively mitigated soil temperatures, staying below 33.8 °C. When planted in the ground (G), P. x hispanica exhibited a significantly higher stem diameter increment (52–66%) compared to other planting treatments, aligning with the provision of ecosystem services. However, T. cordata trees showed a more moderate response to planting treatments in terms of growth and ecosystem service provision. Furthermore, the implementation of soil drought conditions resulted in a reduction of up to 34% in stem diameter increment for P. x hispanica and up to 25% for T. cordata. Our results underscore the necessity of tree species-specific knowledge about growth responses to different planting treatments for effective urban planning perspectives, as the provision of ecosystem services may be influenced differently.     

设施砂壤土容重对番茄幼苗生长和根系构型的影响

土壤紧实是设施蔬菜生产的土壤障碍因子之一。在塑料大棚砂壤土条件下,用人工土柱栽培法研究了土壤容重分别为1.20、1.35和1.58 g ? cm-3的土壤对番茄幼苗生长和根系构型的影响。结果表明,随容重增大,叶片伸长速度、株高、植株含水量、鲜质量、干质量、根冠比、根表面积、根长密度和根体积密度等都显著降低。随容重增大,根系干质量、根表面积、根长密度和根体积密度在垂直面上的分布显著降低,容重1.58 g ? cm-3处理的根系全部分布在0 ~ 6 cm土层内。高容重土壤使根毛区皮层产生形变,即细胞变长,皮层下陷,根表面凹凸不平,根圆度变差,偏心率增大,降低根毛区的吸收能力。     

新型保温材料对小拱棚温度的影响

在下雪、阴天、晴天、多云4种天气下,研究了5种保温材料对大棚条件下小拱棚内温度的影响。结果表明,有膜无纺布（40 g•m^-2）+薄膜的保温效果最好,对照塑料膜处理的温度变化幅度较其他处理大,保温效果最差;土壤温度的变化相对气温变化具有滞后效应;土层越深,土壤温度的变化越滞后;土壤浅层温度变化急剧,随着土壤深度的增加温度变化趋于平缓;土壤各层最高温度出现的时间随土层深度的增加而延迟     

The effects of root-zone warming on the yield and quality of roses grown in a hydroponic system

Rose cvs Ilona, Mercedes and Sonia, budded onto R. multiflora rootstock, were grown using the nutrient film technique. A root-zone temperature of 25°C was compared with ambient root temperatures at three night-time air temperatures of 18°, 12° and ambient (9°C), and in two other experiments at 18°, 14° and 10°C. Bloom yield and stem length and diameter were recorded for a 22-week winter/spring period and for shorter periods in the following summer. In Experiment 1 Sonia responded to root zone warming (RZW) by giving 44% more blooms and a 26% increase in stem length compared with ambient root temperature. Ilona gave a yield response only at a night temperature of 12°C, but RZW resulted in 22% longer stems. Mercedes gave 22% more blooms from RZW. Plants from Experiment 1 were used for a second year in Experiment 2. Mercedes produced 113% more blooms from RZW, Sonia 61% and Ilona 42%. Stem lengths were all increased by 6-7%. Experiment 3 used first-year plants. The pattern of yield response to RZW was similar to the other experiments. Mercedes gave 61%, Sonia 24% and Ilona 18% more blooms. Ilona showed the largest increase in stem length (24%). RZW increased the amplitude of the growth flushes, but their frequency was unaffected. Yields during the subsequent summer, when temperature differences between RZW and ambient temperatures were small, indicated residual effects of the winter treatments. Sonia (Experiment 1), and Mercedes and Sonia (Experiment 2) gave significantly higher yields from the RZW treatments. There was no evidence for a decrease in yield caused by RZW, only Ilona in Experiment 3 giving a lower yield in the summer.     

Involvement of phytochrome B in DIF mediated growth in cucumber

This study aimed to compare the interaction between light quality and alternating day (DT) and night temperature (NT) under two different daily light integrals (DLI) on morphology of a wild type (wt) and a phytochrome B deficient mutant (lh) of cucumber (Cucumis sativus L.). Different light qualities were established by light quality selective plastic films. Plants were grown for 18 days (lh) or 19 days (wt) under DT/NT regimes of 25/19 °C (positive DIF), 22/22 °C and 19/25 °C (negative DIF) (12-h thermoperiod) in combination with plastic films establishing a low (0.75, LRFR) and high red (R)/far-red (FR) ratio (1.62, HRFR) and a control (R/FR of 1.11). Stem, hypocotyl and internode elongation in the wt were more affected by DIF under LRFR than HRFR. In general, length was reduced 45–50% under HRFR compared to the control, while the reduction by negative DIF was 38% on average. Hypocotyl length of the lh mutant was neither affected by temperature regime nor light quality, while negative DIF reduced stem length with 15–20% compared to positive DIF due to a delayed internode elongation. The general response pattern in both genotypes was not affected by an additional reduction in DLI of 50%. In conclusion, the strongest effect of DIF was found under a LRFR which is the opposite of findings in earlier studies with day extentions with different light qualities. In general, HRFR reduced stem elongation of cucumber more than negative DIF. The results indicate a crosstalk between light phytochrome responses and thermoperidism.     

Growth responses of some greenhouse plants to environment. II. The effect of soil temperature on Chrysanthemum morifolium Ramat

The effect of a wide range of soil temperatures (6–26°C) on growth and flowering of Chrysanthemum morifolium Ram. ‘Horim’ were studied at the favourable air temperature of 18°C. Shoot growth was severely reduced at soil temperatures below 10°C which may be explained by poor root growth, while flowering was enhanced by approximately 2 days compared to higher soil temperatures. Increasing the soil temperature to 18°C was beneficial. Further increase had no positive effect on growth. Measurements of net photosynthetic rates revealed no effect of lowering soil temperatures from 18 to 6°C.Mother plants grown at 18°C air temperature revealed no effect of soil temperatures ranging from 13 to 21°C on number and fresh weight of the cuttings. Neither did mother plants grown at the less favourable air temperatures of 12 or 15°C. Cutting production was, however, affected by air temperature.     

遮光处理对容器育柑桔幼苗生长与微环境的影响

以德尔塔（Delta）甜检和中熟娜特（Midknight）甜橙两个品种为材料,探讨不同颜色遮光网、遮光强度与遮光时间对容器育柑桔幼苗生长、水分利用、叶片净CO2代谢速率以及幼苗生长微环境如土壤温度、大气湿度的影响。结果表明：与对照相比,所有遮光处理的幼苗较高,茎干较粗,德尔塔甜橙的试验结果比中熟娜特甜橙明显;遮光5个月比遮光12周的处理效果更明显;不遮光处理利用较多的水分．途光处理间无明显差别;不这光处理的土壤温度在14：00显著高于所有遮光处理;各处理间叶片净CO2代谢速率和大气湿度无差别。     

The interaction of a dormancy-breaking cold treatment,ancymidol, and ethephon in relation to stem elongation and flower production of Lilium cultivars

Stem elongation of Lilium cultivars ‘Black Beauty’, ‘Jamboree’ and ‘Nutmegger’ was lessened by treating the bulbs with ancymidol (10 p.p.m.) or ethephon (500 p.p.m.). Ancymidol was the more effective inhibitor of stem elongation, although applied at a much lower concentration. Application of the growth regulators prior to a dormancy-breaking cold treatment provided more effective control of stem elongation than post cold-treatment application. The total number of flowers and the number of secondary flowers per stem of ‘Black Beauty’ and ‘Nutmegger’ were increased by treating the bulbs with ancymidol. However, unlike the optimal time for lessening stem elongation, enhancement of flower production was greatest when ancymidol was applied after completion of the cold treatment. Ethephon was unsatisfactory, since it inhibited flower production by ‘Black Beauty’ and ‘Nutmegger’, while ‘Jamboree’ was relatively insensitive to it, as indicated by a lack of inhibition of flower production and a small degree of inhibition of stem elongation.     

施用炭化苹果枝粉末对平邑甜茶生长及根系构型的影响

选取冬季修剪下来的‘红富士’苹果枝条,分别在400、600 和700 ℃下厌氧炭化后粉碎过筛,按照1%和2%的质量比施入2 年生盆栽平邑甜茶的盆土中,调查平邑甜茶光合性能、植株生长量、根系活力和根系构型参数等。结果表明,3 种温度热解制备的炭化苹果枝粉末明显提高平邑甜茶叶片净光合速率、株高、干径和植株干质量,明显增加根活力、根系总长度、根系直径、根系表面积和根系体积,并且明显增大根系分形维数,使根系结构复杂化;在400 ~ 700 ℃的范围内,随着炭化温度升高,炭化苹果枝粉末对平邑甜茶的作用效果也逐渐升高;土壤施用2%的炭化苹果枝粉末的作用效果大于施用1%的处理。     

Differential effects of temperature on stem length and xylem vessel length distribution in Zinnia elegans

Summary

Water transport in vascular plants depends on the hydraulic conductance of the xylem system, which is dependent on the anatomical properties, number, diameter, and length of the xylem vessels. The ability to transport water through their stems influences not only the growth of many horticultural crops, but also the post-harvest quality of cut flowers. In this study, we investigated the effects of different average daily temperatures (ADT) and the difference between day-time (DT) and night-time (NT) temperature (DIF) on stem size, the length of xylem vessels within the stem, and the length of individual vessel elements within a vessel, in Zinnia elegans. Two Z. elegans cultivars, ‘Envy’ and ‘Purple Prince’, were grown in climate chambers under all nine combinations of three DT and three NT temperatures (viz. 17ºC, 21ºC, or 25ºC). An increase in ADT was positively correlated with the lengths of the stems, internodes, and xylem vessels in both cultivars. However, the lengths of the xylem vessels were influenced more strongly than the lengths of the stems. Increasing the ADT from 17ºC to 25ºC increased stem lengths by approx. 15%, but more than doubled the lengths of the xylem vessels. The increase in xylem vessel lengths was only partly (< 10%) due to an increase in the lengths of individual vessel members, which implies that temperature (ADT) had a greater influence on the number of fused vessel elements per xylem vessel. A negative DIF (i.e., lower DT than NT temperatures) decreased stem lengths and a positive DIF increased stem lengths. DIF had no effect on xylem vessel length, probably because, other than in stem length, xylem vessel length was positively correlated with NT temperature.     

Temperature integration of Hederahelix L.: Quality aspects and growth response

Reducing energy use in greenhouses contributes to the profitability of horticulture. Important energy savings can be realized through the use of temperature integration. However, such a greenhouse heating strategy is only acceptable for commercial purposes if there are no adverse effects on plant growth and quality. During this 3-month study, Hedera helix ‘Green Ripple’ and H. helix ‘Shamrock’ were subjected to a day/night temperature regime of 20/20 °C (control) and two treatments with temperature integration over 24 h and 4 d, respectively, based on a DIF of 13.5 °C, maintaining the average temperature at the same level of the control. Temperature treatments resulted in a promotion of stem elongation. After 3 months, shoot length rose up to maximum 37.3% when temperature integration was applied. However, temperature integration reduced total dry weight and particularly root dry weight was negatively affected. In addition, assessments of relative growth rate, shoot extension rate, specific leaf area, total leaf area and pigment concentrations were performed and it was concluded that dynamic temperature regimes with longer integration periods support commercial production of English ivy.     

不同保温被外覆盖对日光温室保温及黄瓜生育的影响

试验以对温度要求敏感的黄瓜为材料,研究了3种不同保温被外覆盖下日光温室内气温和地温的变化以及越冬茬黄瓜的生长状况。结果表明:温室夜间旬平均温度、最低温度以及夜间温度的降低幅度,都表现为加厚保温被的保温效果最好,其次是普通保温被+牛皮纸被,普通保温被的保温效果最差;加厚保温被覆盖的温室内,黄瓜株高、茎粗等生长指标及产量都明显优于其它2个处理。     

Energy balance of six common landscape surfaces and the influence of surface properties on gas exchange of four containerized tree species

Gas exchange and growth of woody landscape plants is strongly affected by underlying surfaces. In urban areas, plants are subjected to energy balance characteristics of a variety of surfaces. We investigated energy balance properties of six urban surfaces: asphalt, gravel rock mulch, lava rock mulch, concrete, pine bark mulch, and turf. Each summer over a 3-year period, incoming global shortwave radiation, surface temperature, surface reflectivity (albedo), soil temperature below each surface, and soil heat flux were measured for each surface, and total incoming radiation, thermal conductivity, and longwave radiation emitted by each surface were calculated. Differences in surface properties were analyzed by regression analysis. Albedo was greatest for concrete and least for lava rock mulch, while thermal conductivity was greatest for asphalt and least for lava rock and pine bark mulches. Under maximum incoming total radiation, regression analysis indicated: soil heat flux was greatest under asphalt and concrete and least under lava rock and pine bark mulches; soil temperature below each surface was greatest for asphalt and concrete and least for pine bark mulch; surface temperature was greatest for pine bark mulch and least for turf; and longwave radiation flux of each surface was greatest for pine bark mulch and least for turf. This research revealed that more energy was conducted into the soil below asphalt and concrete, and that a greater portion of incoming radiation was prevented from entering the soil below pine bark and lava rock mulches than below other surfaces. Due to these effects, and the lack of evaporative cooling, surface temperatures were greater, and more longwave radiation was emitted from non-vegetative surfaces than from turf. In a concurrent study, we investigated if the energy balance of turf, pine bark mulch, and asphalt surfaces influenced gas exchange of four containerized tree species grown over each surface. On several occasions over a 2-year period, morning-to-evening measurements of stomatal conductance, leaf temperature, and plant water loss were made on containerized Bechtel crabapple (Malus ionensis ‘Plena’), Norway maple (Acer platanoides ‘Crimson King’), globe willow (Salix matsudana ‘Navajo’) and American plane tree (Platanus occidentalis). Leaves over pine bark mulch and asphalt intercepted more longwave radiation and generally had greater leaf temperature and leaf-to-air vapor difference than leaves over turf. As a result, trees over non-vegetative surfaces generally had lower stomatal conductance and water loss than trees over turf.