Controlled Environment Treatments Research Articles

Reproductive Development and Yield Components of Bario Sederhana Rice in Response to Photoperiod

A series of controlled environment treatments were conducted to quantify reproductive development and yield components of Bario Sederhana rice grown under five photoperiod regimes (8, 9, 10, 11, & 12 h). A ‘broken-stick’ linear regression of heading rate against photoperiod was used to determine the cardinal photoperiods for heading. The reproductive development towards photoperiod showed a delayed pattern in time to heading, anthesis, and maturity under lengthening photoperiod from 10 to 12 h. For example, under 10 h photoperiod the crops required 1680 °Cd (70.8 days) from emergence to heading but took an extended duration of 3147 °Cd (132.6 days) when they were sown at 12 h photoperiod. The prolonged time taken for reproductive development modified by photoperiod resulted in higher yield components. This is because the lengthening time from heading to maturity extended the duration of grain filling. The longest photoperiod of 12 h gave the highest percentage of filled spikelets (65.3%) thus consequently leading to the heaviest grain weight of 1.4 g per panicle. The base, optimum, and maximum photoperiod for heading were estimated to be 7.4 h, 10 h, and 14.8 h, respectively.

Effects of environmental control and LED supplemental lighting on strawberry growth and yield in a subtropical climate

We investigated the effects of environmental control and daytime LED supplemental lighting on the growth and yield of strawberries in a subtropical climate. Two strawberry cultivars, namely ‘Yotsuboshi’ and ‘Benihoppe’, were grown in three greenhouses from October to May as a forcing culture: (1) conventional greenhouse, with side vents open and no other environmental controls; (2) controlled environment (CE) greenhouse, equipped with an integrated environmental control system to cool air and growing medium using cooling devices controlled by sensor monitoring; and (3) LED greenhouse, equipped with an integrated environmental control system and LED supplemental lighting during the day. The conventional greenhouse had higher air and growing medium temperatures during the growing season than the CE or LED treatment greenhouse. Both cultivars had significantly lower aboveground dry-matter weight (TDM) and yield in the conventional treatment than in the CE or LED treatment. Yield in the CE treatment increased 2.4 and 2.0 times for ‘Yotsuboshi’ and ‘Benihoppe,’ respectively, relative to the conventional treatment. Additionally, yield in the LED treatment increased 3.1 and 2.5 times for ‘Yotsuboshi’ and ‘Benihoppe,’ respectively, relative to the conventional treatment. The marketable fruit ratio was higher in CE and LED treatments than in the conventional treatment for both cultivars. The number of fruits for both cultivars was significantly greater under the LED treatment than the conventional treatment. Clearly, daytime LED supplemental lighting further improved TDM and yield during the winter season, when cloudy weather and low solar radiation were persistent. However, during the spring season, when external solar radiation exceeded 20 MJ m−2 day−1, the enhancing effects of LED supplemental lighting on yield were limited. Supplemental lighting methods based on the amount of solar radiation available are necessary to allow maximum, high-quality strawberry fruit production in subtropical regions.

QTL mapping and candidate gene analysis of seed vigor-related traits during artificial aging in wheat (Triticum aestivum)

High vigor seeds have greater yield potential than those with low vigor; however, long-term storage leads to a decline in this trait. The objective of this study was to identify quantitative trait loci (QTLs) for seed vigor-related traits under artificial aging conditions using a high-density genetic linkage map of wheat (Triticum aestivum) and mine the related candidate genes. A doubled haploid population, derived from a cross between Hanxuan 10 × Lumai 14, was used as the experimental material. Six controlled-environment treatments were set up, i.e. the seeds were aged for 0, 24, 36, 48, 60, and 72 h at a high temperature (48 °C) and under high humidity (relative humidity 100%). Eight traits including seed germination percentage, germination energy, germination index, seedling length, root length, seedling weight, vigor index, and simple vigor index were measured. With the prolongation of artificial aging treatment, these traits showed a continuous downward trend and significant correlations were observed between most of them. A total of 49 additive QTLs for seed vigor-related traits were mapped onto 12 chromosomes (1B, 2D, 3A, 3B, 3D, 4A, 4D, 5A, 5B, 5D, 6D, and 7A); and each one accounted for 6.01–17.18% of the phenotypic variations. Twenty-five pairs of epistatic QTLs were detected on all chromosomes, except for 5D, 6A, and 7D, and each epistasis accounted for 7.35–26.06% of the phenotypic variations. Three additive QTL hot spots were found on chromosomes 5A, 5B, and 5D, respectively. 13 QTLs, QGEe5B, QGIe5B, QSLc5B, QSLd5B, QSLf5B, QRLd5B, QRLe5B, QRLf5B, QVId5B, QVIe5B, QVIf5B, QSVId5B, and QSVIe5B, were located in the marker interval AX-94643729 ~ AX-110529646 on 5B and the physical interval 707,412,449–710,959,479 bp. Genes including TRAESCS5B01G564900, TRAESCS5B01G564200, TRAESCS5B01G562600, TraesCS5B02G562700, TRAESCS5B01G561300, TRAESCS5B01G561400, and TRAESCS5B01G562100, located in this marker interval, were found to be involved in regulating the processes of carbohydrate and lipid metabolism, transcription, and cell division during the germination of aging seeds, thus they were viewed as candidate genes for seed viability-related traits. These findings provide the basis for the seed-based cloning and functional identification of related candidate genes for seed vigor.

An approach to the determination of winter chill requirements for different Ribes cultivars

Winter chilling is critical for flowering and fruiting of many temperate fruits, with evidence that blackcurrant (Ribes nigrum L.) cropping has been adversely affected by warm winters. Accurate models of chill accumulation in blackcurrant are required so that breeding strategies can be formulated for the generation of new cultivars with resilience to future climates. Existing models for chill accumulation have largely been derived from statistical correlation; here we report the derivation of improved models for blackcurrant using controlled environment treatments. Hardwood cuttings from a diverse set of cultivars were exposed to constant or varying chilling temperatures and the effects on bud break after transfer to a warm, permissive environment evaluated. The impact of different combinations of temperature and chilling periods were described in terms of their overall 'Effectiveness' (E). Clear genotypic differences were found, with excessive chilling often inhibiting bud break. There was a significant interaction between observed chilling response and the period of low temperature exposure. A number of chilling models to explain observed interactions between chilling temperature and time of exposure on bud break were compared; the most effective involved an optimal response to increasing chill accumulation. The effects of varying temperatures during chilling on bud break were complex, with warm temperature breaks substantially inhibiting bud development and cooler temperature breaks tending to enhance bud burst. The relevance of these models to generic studies of endodormancy is discussed, together with their potential application to the development of phenotyping screens for future breeding using diverse blackcurrant germplasm.

682 New Perspectives on the Influence of Mid-season Environment on Apple Fruit Characteristics

Growth of apple fruit can be described as an initial exponential phase lasting the 40+ days of fruit cell division followed by a more-or-less linear phase where growth is by cell expansion. Temperature is a major influence on fruit growth rate during the cell division phase, thereby affecting fruit size at maturity. However it is generally thought that temperature has less-direct impact on fruit development during the fruit expansion phase. Our observations of apple growth among regions and seasons of considerable climatic variability led us to speculate that temperature may impact directly on fruit development during fruit expansion but that responses may be interactive with carbon balance (crop load) influences. Controlled environment studies are being used to examine this hypothesis. Potted `Royal Gala' trees set to three levels of crop (one fruit per 250, 500, or 1000 cm2 leaf area) were grown from 56 to 112 DAFB in day/night temperature regimes of 18/6, 24/12, and 30/18 °C. All trees grew in field conditions prior to and following the controlled environment treatments. Treatments were harvested when 20% to 25% of fruit on trees showed the visual indicators used commercially to indicate harvest maturity. Fruit were evaluated using attributes that determine quality and that may have implications for fruit post harvest behaviour. Temperature and crop load influences on time to maturity, fruit fresh and dry weight, fruit DM content, fruit firmness, fruit airspace content and estimated fruit cortical cell size will be presented and implications discussed.

Impact of Temperature on Apple Fruit Growth

Apple fruitlet growth responses to temperature were studied, for different durations following bloom (DAFB), under controlled environment (CE) conditions. Container-grown trees of `Red Delicious', `Golden Delicious', `Braeburn', `Fuji', and `Royal Gala' were placed in different maximum/minimum temperature regimes, ranging from 9/3 to 25/15°C for various periods, including 10–40, 10–80, and 40–80 DAFB. Temperature treatments were selected to identify possible differences between mean and maximum/minimum differential effects Trees were placed outdoors following the CE treatment to allow impacts on subsequent fruit development to be determined. The impact of temperature was dramatic. For example, fruit expansion rate for `Red Delicious' varied from 0.12 mm/day at 9/3°C to 0.98 mm/day at 25/15°C. Furthermore, the cell division phase was considerably longer under cooler temperatures. The influence of post-bloom temperature, for even short durations, was evident at harvest in both fruit size and in different fruit maturity indices. Differences in temperature sensitivity were evident amongscultivars. A detailed model has been developed to integrate the responses that have been determined.

The Role of Maturation in Quality of Stackpole-Cured Peanuts1

Abstract Peanut curing studies utilizing stackpole curing led to the unique observation that extensive potential for post harvest maturation exists during slow curing. In the hull scrape maturity profile the percentage of black maturity class pods increased from 15 to 45% and 21 to 57% in ca. 30 d after stacks were prepared in 2 consecutive years. Simultaneously, the number of pods in less mature classes generally decreased. The weight percentage of black pods increased from 19 to 42% and 37 to 62% after 10 stack d in the 2 yr. A similar but less extensive maturity progression was observed in detached pods in a temperature-relative humidity-controlled environment where drying rate was faster than in stackpoles but much slower than in conventional practices. Because pod and seed sizes did not change during stackpole curing, maturation resulted in large increases in the percentage of mature peanuts (maturity distribution) in all commercial grade sizes. Moisture contents for orange and brown maturity classes related to cessation of color change in pods in both stackpoles and controlled environment treatments were about 29.0 and 22.5%, respectively. Occurrence of physiological seed maturation concurrently with hull color progressions was verified by the consistent oleic acid/linoleic acid ratio in medium grade-size peanuts within each maturity class over curing time.

Growth and Development Responses of Geranium to Temperature, Light Integral, CO2, and Chlormequat

Abstract “Red Elite” geraniums were grown from the 6th leaf stage until the visible bud stage in controlled environment (CE) chambers under 3 day/night temperature regimes (27°/13°, 23°/17°, or 20°/20°C) and under enhanced CO2 (900 μl CO2/liter air) at 27°/13°. Three daily light integral treatments, 24.6, 19.8, and 15.1 mol m−2 d−1, were imposed over each of these 4 treatments. Plants also were grown in a 22714° glasshouse with 2 daily light integral treatments (18.2 or 11.3 mol m−2 d−1). A chlormequat (CCC) drench was applied to half of the plants immediately before the treatments were started. For the period between the 6th leaf and visible bud stages, leaf area, leaf area ratio, specific leaf weight, shoot dry weight, leaf canopy height, and time to visible bud were determined mostly by daily mean temperature rather than by day or night temperature. Most plant growth characteristics, but not the flower bud development rate from 6th leaf to visible bud, were enhanced by supplemental CO2 and suppressed by CCC. After reaching the visible bud stage, plants from some treatments were moved into 24715° CE temperature conditions with or without CO2, whereas others were moved to a glasshouse until harvest at the 1st floret anthesis stage. Between visible bud and anthesis, CCC was the major factor affecting vegetative growth regardless of whether the plants were with or without supplemental CO2 in CE rooms, or in a glasshouse. Anthesis was delayed by about 10 days in the glasshouse compared to the CE treatments but was unaffected by CO2 or CCC treatments. Carbohydrate concentrations were highest (starch 14%, sugar 5%) in plant leaves grown with supplemental CO2 and without CCC, and lowest with no added CO2 but with CCC in all CE treatments. The concentrations were reduced (starch 0.5%, sugar 2.5%) in plant leaves grown in a glasshouse from 6th leaf stage to anthesis because of low daily light integrals and no supplemental CO2.

The postoperative environment of the amputation stump

This paper reviews different types of treatment of the amputation stump. Following an examination of the historical development there are sections on bandaging, semi-rigid dressings, rigid cast dressing and controlled environment treatment. The merits and demerits of each type of treatment are discussed.

Effect of Photoperiod, Night Temperature, and Frost Incidence on Development of Frost Hardiness in Pinus radiata

The role of photoperiod, night temperature, and frequency and severity of frosts on the development of frost hardiness in seedlings of Pinus radiata was studied using controlled environment treatments. In one experiment the specific effects of 9 and 14 h photoperiods and 5 and 15°C night temperatures were examined. In a second experiment, seedlings were sequentially hardened under two simulated early autumn to late winter climates, with the photoperiod and day/night temperatures progressively altered at 11 and 21 day intervals respectively. In addition, half of the seedlings raised in each simulated climate were exposed concurrently to a conditioning frost regime. Frost hardiness of the seedlings in each sequence was determined at regular intervals using a series of evaluation frosts. Frosts of between -3 and -5°C were the most effective factor in controlling the development of frost hardiness. Night temperatures as low as 1°C were also effective but not those above 5°C. A minimum photoperiod requirement of less than 11 h for up to 42 days exposure was required for low-temperature hardening. There appeared to be a response lag in the development of frost hardiness once the critical photoperiod and inductive night temperatures had been imposed. Differences between nursery sites in frost hardiness of seedling stock were attributed to differences in their environments, particularly the incidence of frosts. The final maximum frost hardiness varied between the treatments from - 7.5 to -19°C indicating that Pinus radiata has a greater potential to develop frost hardiness than was previously thought from field observations.

Controlled environment treatment (CET).

The use of a new method of improving certain physical aspects of the environment imposed on the extremity is discussed. This follows the use of Controlled Environment Treatment in amputation surgery and other specific Centres in the United Kingdom and United States of America. The protocol did not attempt to establish any system of controls, the results being based on observation and clinical impression. In other words it is an extension of CET use in an attempt to obtain a wider experience of its application. One hundrec ases involving 128 treatments are listed over a wide variety of clinical presentations. Recordings were made of the presence or absence of oedema, infection, ischaemia and pain, amongst other relevant data. Certain conclusions proved possible and staff acceptance of the system was obtained. The evidence suggests that the continued use of CET is justified in certain carefully selected clinical conditions. Further, it appears necessary to set up controlled scientific assessments of the system particularly within vascular laboratories where many relevant investigative procedures are carried out on a routine basis.

A new approach to the management of wounds of the extremities. Controlled environment treatment and its derivatives.

Controlled Environment Treatment is a new approach to wound management--for the first time it provides the surgeon with the means of controlling and optimizing the wound environment for the duration of the healing period. Equipment is commercially available and the technique is now being applied internationally; the technique has been established for the treatment of limbs--application to the trunk requires further investigation and development. Spin-offs have already occurred, one being the control of certain types of lymphoedema by the patient in their own home; the other concerns the application of plaster of Paris to produce casts having significantly superior physiological characteristics using minimal manipulative skills. The former is known as Pressure Environment Treatment, the latter is known as Controlled Pressure Casting; equipment is commercially available internationally.

Controlled environment treatment (CET) for patients with below-knee amputations.

This paper describes a new approach to early postsurgical wound management of the patient with a below-knee amputation. The method involves using the Controlled Environment Treatment (CET) machine, which wasdeveloped in England. A brief explanation of the components of the machine and its capabilities are listed. Ambient pressure, temperature, sterility, and humidity are easily controllable; advantages and disadvantages of this device over immediate post-operative plaster and conventional dressings as they relate both to wound environment and to physical therapy are mentioned. The early postsurgical therapy program used at Prosthetics Research Study is outlined.

Influence of Day/Night Temperature Under Controlled Environments on the Growth and Flowering of Limonium ‘Midnight Blue’1

Abstract The effects of 3 day/night temp (16/13, 21/18, and 27/24°C) on the growth and flowering of annual statice (Limonium ‘Midnight Blue’)3 were determined after 14, 28, and 42 days of controlled-environment treatment. A day/night temp of 16/13° severely limited seedling growth as measured by leaf number and fresh and dry wt of tops. Vegetative growth at 21/18°C was markedly greater than at 16/13°. Increasing the day/night temp further to 27/24° had no appreciable effect on leaf number but did produce additional increases in fresh and dry wt of tops. Despite the minimum amount of vegetative growth produced at 16/13°C after 42 days, this treatment resulted in the greatest number of plants flowering in the shortest time, suggesting a cool temp requirement for flower initiation in this cultivar. The stimulatory effects of a cool temp or inhibitory effects of a high temp on flower initiation persisted after the seedlings were removed from the growth chambers and placed in the greenhouse on natural long photoperiods. The feasibility of using cool-temp treatment at the seedling stage to promote flowering in this cultivar was, thereby, demonstrated.

Effects of Day and Night Temperature and Type of Container on the Growth of F 1 Hybrid Annauls in Controlled Environments

The effects of three day/night temperatures (18/12 C, 24/18 C, and 30/24 C), and two types of containers (clay and plastic) on the seedling growth of three F1 hybrid annuals were determined after 14 days of controlled-environment treatment. A day/night temperature of 18/12 C was severely limiting to the early seedling growth of ‘Blue Blazer’ ageratum (Ageratum houstonianum Mill.), ‘Pink Cascade’ petunia (Petunia hybrida Vilm.), and ‘Double Eagle’ marigold (Tagetes erecta L.). Raising the day/night temperature to 24/18 C resulted in striking increases in growth in both clay and plastic pots. Fresh and dry weights of tops for all three species were increased four- to fivefold, and leaf areas of ageratum and petunia were increased more than fivefold irrespective of container. Height and node number were also increased significantly but to a much lesser degree. A day/night temperature of 30/24 C appeared to be optimum for early seedling growth of F1 hybrid annuals the optimum being based on dry matter accumulation, stem elongation, node development, and leaf area production. Growth of lateral shoots was greatly stimulated at 30/24 C, especially in marigold. There were no appreciable differences in fresh or dry weight of tops or in leaf area between plants in clay and plastic containers at any of the three day/night temperatures.

Effects of Relative Humidity and Type of Container on the Growth of F 1 Hybrid Annuals in Controlled Environments

The effects of three levels of relative humidity (40%, 65%, and 90%) and two types of containers (clay and plastic) on the seedling growth of three F1 hybrid annuals were determined after 14 days of controlled-environment treatment. Forty percent relative humidity was severely limiting to the seedling growth of ‘Blue Blazer’ ageratum (Ageratum houstonianum Mill.), ‘Pink Cascade’ petunia (Petunia hybrida Vilm.), and ‘Double Eagle’ marigold (Tagetes erecta L.). Raising the relative humidity to 65% resulted in striking increases in fresh weight, dry weight, and leaf area, especially when clay containers were used. Height of the main shoot was increased significantly at 65% relative humidity but node number was influenced only slightly. Increasing the relative humidity further to 90% had no significant effect on fresh weight, dry weight, or percent dry weight for any of the three species, in either container. Leaf area was increased significantly at 90% only in ageratum seedlings grown in clay pots. Each species responded differently to the type of container used. The fresh weight and dry weight of petunia seedlings were significantly greater in plastic pots at every level of humidity while those of marigold seedlings were unaffected by the type of container used. Ageratum seedlings, on the other hand, had significantly greater fresh weights and dry weights in clay pots only at 90% relative humidity.