Temperature affects color and quality characteristics of ‘Pink’ wax apple fruit discs

Red color plays a very important role when wax apple fruits are purchased. Temperature is one of the key factors among those influencing red color development. We evaluated the effects of temperature on color formation and other quality characteristics of ‘Pink’ wax apple fruit discs by using constant, slow-increase, fast-increase, transient shifting to high temperature, shifting to high temperature for different length of time and different day/night temperature regimes. The results show temperature has pronounced effects on quality attributes of wax apple fruit discs. Anthocyanin and total soluble solid (TSS) were greatest in the 20 °C treated discs under constant temperatures. In the slow-increase and fast-increase treatments, quality attributes in disc were better in treatments with a final temperature of 25 °C than of 30 °C. The concentration of soluble sugars (SS), starch, total phenolic compounds (TPC), free amino acids (FAA) and soluble protein (SP) all decreased with increasing temperature. Transient shifting to high temperature of 30 °C for 1-day had no effect on pigmentation but treatment periods from 3- to 5-days had a substantial adverse effect. At 30 °C for 5-days, exposed discs had the lightest weight and shortest diameter as well. Both SS and TPC decreased in the 3- and 5-day treatments. When temperature was shifted from 20 to 30 °C for 2 to 11 days, the widest and heaviest discs were found in the 5-day treatment. Anthocyanin and TSS concentration decreased following increased length of exposure to high temperature. Pigmentation of discs exposed to high temperature treatment was worse than in uncultured controls. Both protein and FAA concentrations decreased after culture. Among the 5 different day/night temperature combinations, discs under 25/20 °C had the highest anthocyanin and TSS concentrations, while those under 30/15 °C had the worst.     

Higher than optimum temperature under CO2 enrichment influences stomata anatomical characters in rose (Rosa hybrida)

There is little available information on the effects of temperature and CO₂ enrichment on stomata anatomical characteristics of plants. Effect of these two microclimates was studied on five rose (Rosa spp.) cultivars, viz. ‘First Red’ (used as check), ‘Arjun’, ‘Raktima’, ‘Raktagandha’ and ‘Pusa Pitamber’. Budded, single-stemmed rose cultivars having five lateral buds were grown in controlled environment growth cabinets under enriched CO₂ (1000 μmol mol⁻¹) and optimum (28/18 °C, T₀) or high (35/25 °C, T₁) temperature for 50 days. All observations were made on the abaxial leaf surface. Significant increases in stomatal density (68.7%), index (29.6%) and epidermal cell density (37.3%) were recorded in plants grown at high temperature over control with CO₂ enrichment. The cultivars responded differently in terms of length and width of guard cell and stoma (pore) under high temperature, however, the values averaged over treatments showed a significant reduction in these parameters. Further, number of stomata per leaf was higher (28.3%) in plants grown at high temperature, except First Red. A reduction in mean leaf area (26.7%) and dry mass (32.0%) was recorded at high rather than optimum temperature. The specific leaf area was maximum in Arjun (87%) while in First Red, a 14% reduction was noted at high temperature.     

Analysis and modeling of gas exchange processes in Scaevola aemula

Scaevola aemula is a popular ornamental crop cultivated as a bedding plant or for hanging baskets. We characterized gas exchange properties of S. aemula ‘New Wonder’ in response to photosynthetically active radiation (PAR), carbon dioxide concentration, and leaf temperature. Net CO₂ assimilation rate (A) was responsive to CO₂, exhibiting a saturation when intercellular CO₂ concentration (C_i) was greater than 600 μmol mol⁻¹. Net CO₂ assimilation rate and dark respiration rate (R_d) were 23.1 and 2.3 μmol m⁻² s⁻¹, respectively, at 25 °C and PAR = 1500 μmol m⁻² s⁻¹. Net CO₂ assimilation rates were similar at leaf temperatures between 20 and 30 °C but significantly reduced at 15 °C. These gas exchange results were used to test the extendibility of a coupled gas exchange model previously developed for cut-roses. Utilizing the gas exchange data measured at 25 °C leaf temperature, several model parameters were independently determined for S. aemula. Model predictions were then compared with observations at different leaf temperatures. The model predicted the rates of net CO₂ assimilation and transpiration of S. aemula reasonably well. Without additional calibration, the model was capable of predicting the temperature dependence of net CO₂ assimilation and transpiration rates. Applying the model to predict the effects of supplemental lighting and CO₂ enrichment on canopy photosynthesis and transpiration rates, we show that this model could be a useful tool for examining environmental control options for S. aemula production in the greenhouse.     

花后温度和湿度条件对台农1号杧坐果率的影响

为探索杧果坐果率与开花后温度和湿度条件的关系,以台农1号杧为试材,应用生物统计学方法计算分析了80个温度和湿度自变量与不同时期坐果率的相关关系。结果表明:(1)花后14d的坐果率受温度和湿度条件影响最大。(2)花后7d两性花坐果率与花后1～6d平均空气相对湿度呈显著直线线性负相关,与花后1～2d、1～4d、1～6d的平均最高温度、平均温度、平均最低温度、>10℃积温无显著相关关系。(3)花后14d坐果率与花后6～10d的平均最高温度、4～10d平均温度、2～10d平均最低温度、4～14d>10℃积温呈显著或极显著的直线相关;与花后1～14d平均最高温度、平均温度呈显著的多项式线性相关;与花后1～14d平均空气相对湿度呈极显著的直线线性负相关。(4)花后25d坐果率与花后1～10d的平均最高温度、平均温度、>10℃积温以及花后1～14d平均最高温度呈显著的多项式线性相关。(5)有利于花后14d坐果的花后4～14d的下限平均温度为20.6℃,最适温度为24.7℃。     

Growth and development of Lilium longiflorum ‘Nellie White’ during bulb production under controlled environments : II. Effects of shifting day/night temperature regimes on scale bulblets

One-year old scale bulblets of Lilium longiflorum Thunb. ‘Nellie White’ (Easter lily) were grown for 107 days during growth period 1 (GP-1) in six growth chambers under constant day/night temperature regimes of 30/26, 26/22, 22/18, 18/14, 14/10 and 10/6 °C. Subsequently, half of the plants in each temperature regime were transferred to 18/14 °C and the other half continued at the six constant temperature regimes. Both groups of plants were grown for an additional 89 days in growth period 2 (GP-2). Continuous temperatures of 26/22, 26/22–22/18 and 26/22–18/14 °C produced the greatest increase in basal bulb fresh weight (the main planted bulb), basal bulb circumference and stem bulb fresh weight, respectively. However, shifting these optimal temperatures to 18/14 °C during GP-2 resulted in a lower increase in basal bulb fresh weight and circumference. The optimum range for stem bulb production was expanded to 30/26–14/10 °C by shifting to 18/14 °C. The greatest increase for basal root growth occurred at 14/10–10/6 °C and for stem root growth at 14/10 °C. The temperature shift did not affect either root type. Maximum increase for stem length was at 26/22 and 22/18 °C and for stem plus leaf weight at 14/10 °C under constant temperature regimes. Transferring the plants from 10/6 to 18/14 °C resulted in the greatest increase in stem length and from 10/6 and 14/10 to 18/14 °C in the greatest increase in stem plus leaf weight. The greatest increase in the number of leaves occurred at 26/22 and 10/6 °C, but this growth parameter was unaffected by shifting to 18/14 °C, indicating that leaf number was determined in GP-1. Bulbils developed only when bulbs at high GP-1 temperature regimes (30/26 and 26/22 °C) were transferred to 18/14 °C during GP-2. Lower temperatures tended to favor an increase in flower bud production under continuous temperature regimes, while shifting to 18/14 °C increased flower bud production after initially high and low temperatures. Meristem abortion was greatest at 30/26 °C followed by 26/22 °C, but was not affected by temperature shifts in GP- 2. Thus, it is concluded that the abortion was induced or initiated during GP-1.     

龙眼光合作用对环境温度的响应和适应

在年生长期中测定了龙眼叶片光合作用对测度的影响,结果发现,龙眼光合作用最适温与最适温下的光饱和光合速率都有一定的季节变化,但季节变幅不大,不同季节的光合最适温在２２～２８℃之间,光合最适温与植株前５－１０天所处的环境平均气温密切相关,春秋季光合最适明显高于环境气温,夏季光合最适明显低于环境气温,光合最适温随光照强度的变化而变化,这些结果显示了龙眼光合作用对环境温度的特殊要求。     

Using remote sensing to predict outbreaks of Oestrus ovis in Namibia

The Directorate of Veterinary Services of the Ministry of Agriculture, Water and Rural Development of Namibia issues warnings to farmers in the south of the country about the likelihood of infestation of small-stock by the nasal bot fly, Oestrus ovis. Farmers can then treat their stock at the most appropriate time. The O. ovis puparia develop at shallow depths in the soil and the timing of emergence is directly dependent on climatic conditions, specifically the number of degree-days above a particular threshold soil temperature. Based on temperature measurements from only a few stations scattered throughout the country, the veterinary department warnings lack precision in space and time. This paper presents an attempt to support the programme of warnings with accumulated temperature information from Meteosat satellite images, in order to strengthen predictions of the time of emergence in specific places, and to improve the precision and reliability of warnings given to farmers.     

Analysis of micro-climate on the programs of urban infrastructure regeneration in J city,Republic of Korea

The purpose of this study is to simulate urban micro-climate change due to the variation of wind flow and temperature assuming situations before and after applying programs using urban infrastructure regeneration technologies (UIRTs), and to then quantitatively estimate effectiveness on the urban regeneration schems. UIRTs focus on improving the recycling efficiencies of reclaimed water and biogas produced and to enforce the linkage among all environmental infrastructures associated with water, waste, and energy in an urban block. To implement the micro-climate analyses, data such as land use, topography, building height and materials, and weather conditions were collected, and the results estimated based on fluid simulations of cold wind and temperature variation pathways. There were three programs used in the urban regeneration project in J city: river restoration, traditional market revitalization, and a primary school eco-school. The height of cold wind from the ground level was significantly elevated, and the maximum wind velocity differential between before and after increased by 0.12 m/s due to the expansion of the waterfront space and grassland through the three programs. Overall, a temperature at the ground level dropped by 1.6 °C. Based on these results, the three programs improved the urban environment at ground level, and might ultimately be capable of diminishing the urban heat island effect and mitigating the energy consumption of urban areas.     

基于ZigBee无线网络的大棚种植温度监测系统

针对大棚种植温度监测系统,讨论了无线温度监测系统的技术要求,阐述了基于ZigBee无线检测网络的系统结构与硬件、软件设计。随着规模农业的快速发展,无线网络农业自动化系统将有非常广阔的推广应用前景。     

^60Co—γ射线诱发的籼型温敏核不育水稻叶色突变系变异分析

＾６０Ｃｏ－γ射线诱发的８个灿温敏核不育系水稻叶色突变系可分为三种类型，即叶色突变高温表达型、低温表达型及温钝型。