scholarly journals Impact of Temperature on Autumn- and Spring-initiated Inflorescence Systems within a Biennial Pruning System of Protea ‘Pink Ice’ Cut Flowers

HortScience ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 295-303
Author(s):  
Eugenie-Lien Louw ◽  
Eleanor W. Hoffman ◽  
Karen I. Theron ◽  
Stephanie J.E. Midgley
Keyword(s):  
Production Systems ◽  
Dry Weight ◽  
Base Temperature ◽  
Seasonal Temperature ◽  
Cut Flowers ◽  
Inflorescence Development ◽  
Growing Degree Hours ◽  
Growing Conditions ◽  
Vegetative And Reproductive Growth ◽  
Time Required

The potential impact of increasing temperatures driven by climate change on cultivated Protea cut flower production systems is not known. This study used a biennial pruning system in Protea ‘Pink Ice’ to track the physiological and reproductive responses in comparable phenological stages, but exposed to different seasonally determined temperature conditions. Protea ‘Pink Ice’ generally initiates inflorescences terminally on the spring flush. A limited number of shoots can initiate inflorescences on the preceding autumn flush, leading to an advanced harvesting time compared with that of the spring-initiated inflorescences. In a commercial Protea orchard in Hopefield, South Africa, gas exchange, carbohydrate availability, and vegetative and reproductive growth were compared between the two shoot types in the context of seasonal temperature differences. Leaves of shoots, which initiated inflorescences on the autumn flush, generally had higher light-saturated net carbon dioxide (CO2) assimilation capacities in autumn (April–May) and spring (October–November). There is evidence of a requirement of minimum shoot diameter of 7.6 mm (four- or five-flush shoot), as measured directly above the intercalation between the terminal (uppermost mature flush) and subterminal flush, when the subsequent flush was at budbreak stage during April (autumn) and at least five flushes to be required for floral initiation in Protea ‘Pink Ice’. Spring-initiated inflorescences had a shorter developmental period (4 months) than that of autumn-initiated inflorescences (7 months) and developed into significantly smaller (width) inflorescences with a lower width and dry weight at harvest. These inflorescences were harvested on average a month later compared with autumn-initiated inflorescences. The ambient temperature during inflorescence development played a significant role in the inflorescence growth rate, affecting the time required from visible inflorescence detection to harvest. At the calculated optimum base temperature of 9 °C, autumn-initiated inflorescences required 41,010 growing degree hours (GDH), whereas spring-initiated inflorescences required 35,872 GDH from initiation to anthesis. Under future warmer growing conditions, anticipated decreased size and dry weight of inflorescences may reduce marketability and income for Protea producers.

scholarly journals Nitrogen Source for Inflorescence Development in Phalaenopsis: II. Effect of Reduced Fertilizer Level on Stored Nitrogen Use

2014 ◽  
Vol 139 (1) ◽  
pp. 76-82 ◽  
Author(s):  
Hadi Susilo ◽  
Yao-Chien Alex Chang
Keyword(s):  
Dry Weight ◽  
Reproductive Stage ◽  
Fertilizer N ◽  
Nutrient Storage ◽  
Inflorescence Development ◽  
Nitrogen Use ◽  
N Source ◽  
N Derived From Fertilizer ◽  
Time Required ◽  
N Demand

Plants of Phalaenopsis orchid are known for their great resilience and ability to flower under less than ideal conditions, including long periods without fertilization. Significant nutrient storage is thought to account for this characteristic; however, the use of stored nutrients in Phalaenopsis has not been fully studied. We used 15N-labeled Johnson’s solution to trace the use of stored nitrogen (N) and recently absorbed fertilizer N in Phalaenopsis given various fertilizer levels during forcing. By separately labeling fertilizer N applied to Phalaenopsis Sogo Yukidian ‘V3’ plants 6 weeks before and 6 weeks into forcing, we found in the inflorescence that the ratio of N derived from fertilizer applied 6 weeks before forcing to the N derived from fertilizer applied 6 weeks into forcing was 43% to 57%. With 90% reduction in fertilizer concentration during the reproductive stage, the ratio increased to 89% to 11%, indicating that stored N becomes a significant N source for inflorescence development when fertility becomes limited. Reducing fertilizer level during the reproductive stage from full-strength Johnson’s solution down to zero decreased the dry weight of newly grown leaves, reduced the number of flowers from 10.8 to 8.9, and slightly increased the time required between initiation of forcing and anthesis. However, the overall effect of reduced fertilization on the growth and flowering of Phalaenopsis Sogo Yukidian ‘V3’ plants in this study was slight, because under little or no fertilization, more stored N was mobilized and this was sufficient to meet most of the N demand for inflorescence development.

scholarly journals Comparison of Four Production Systems for Dutch Iris in a Tobacco Transplant Greenhouse

2005 ◽  
Vol 15 (1) ◽  
pp. 173-176
Author(s):  
Carl E. Niedziela ◽  
Christopher D. Mullins ◽  
T. David Reed ◽  
William H. Swallow ◽  
Eric Eberly
Keyword(s):  
Nicotiana Tabacum ◽  
Economic Analysis ◽  
Production Systems ◽  
The Other ◽  
Local Market ◽  
Cut Flowers ◽  
Growing Conditions

Pre-cooled bulbs of two dutch iris (Iris ×hollandica) cultivars, Ideal and White Wedgewood, were grown and harvested as cut flowers in four production systems in a tobacco (Nicotiana tabacum) transplant greenhouse from late October until late January in two consecutive production years (2000-01 and 2001-02). All production systems (lily crates, lay-flat bags, pots, and float trays) utilized the same commercial peat-vermiculite, tobacco germination substrate. Stems developed more quickly but were shorter and lighter in 2001-02 than 2000-01 due to warmer growing conditions. Stems grown in float trays were shorter and lighter than other treatments in 2000-01 but similar to the others in 2001-02. Stems grown in lay-flat bags flowered earlier with similar or greater stem lengths and fresh weights as the other systems. Stems of `White Wedgewood' were longer and heavier than `Ideal'. In general, `White Wedgewood' provided more consistent production than `Ideal' in both production seasons. An economic analysis in this study concludes that a grower is unlikely to make money growing dutch iris in a tobacco transplant greenhouse using these production systems unless there is a targeted local market.

The Evidence for Reduced Glyphosate Efficacy on Acetolactate Synthase–Inhibiting Herbicide-Resistant Yellow Nutsedge (Cyperus esculentus)

Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 389-398
Author(s):  
Parsa Tehranchian ◽  
Jason K. Norsworthy ◽  
Matheus Palhano ◽  
Nicholas E. Korres ◽  
Scott McElroy ◽  
...  
Keyword(s):  
Amino Acid ◽  
Production Systems ◽  
Acetolactate Synthase ◽  
Dry Weight ◽  
Cross Resistance ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Epsps Gene ◽  
Treated Leaf ◽  
Als Inhibitors

A yellow nutsedge biotype (Res) from an Arkansas rice field has evolved resistance to acetolactate synthase (ALS)-inhibiting herbicides. TheResbiotype previously exhibited cross-resistance to ALS inhibitors from four chemical families (imidazolinone, pyrimidinyl benzoate, sulfonylurea, and triazolopyrimidine). Experiments were conducted to evaluate alternative herbicides (i.e., glyphosate, bentazon, propanil, quinclorac, and 2,4-D) currently labeled in Arkansas rice–soybean production systems. Based on the percentage of aboveground dry weight reduction, control of the yellow nutsedge biotypes with the labeled rate of bentazon, propanil, quinclorac, and 2,4-D was < 44%. Glyphosate (867 g ae ha−1) resulted in 68 and > 94% control of theResand susceptible yellow nutsedge biotypes, respectively, at 28 d after treatment. Dose-response studies were conducted to estimate the efficacy of glyphosate on theResbiotype, three susceptible yellow nutsedge biotypes, and purple nutsedge. Based on the dry weights, theResbiotype was ≥ 5- and ≥ 1.3-fold less responsive to glyphosate compared to the susceptible biotypes and purple nutsedge, respectively. Differences in absorption and translocation of radiolabeled glyphosate were observed among the yellow nutsedge biotypes and purple nutsedge. The susceptible biotype had less14C-glyphosate radioactivity in the tissues above the treated leaf and greater radioactivity in tissues below the treated leaf compared to theResbiotype and purple nutsedge. Reduced translocation of glyphosate in tissues below the treated leaf of theResbiotype could be a reason for the lower glyphosate efficacy in theResbiotype. No amino acid substitution that would correspond to glyphosate resistance was found in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene of theResbiotype. However, an amino acid (serine) addition was detected in the EPSPS gene of theResbiotype; albeit, it is not believed that this addition contributes to lower efficacy of glyphosate in this biotype.

Performance evaluation of redundant OPC UA architecture for process control

2016 ◽  
Vol 39 (3) ◽  
pp. 334-343 ◽  
Author(s):  
Rafal Cupek ◽  
Kamil Folkert ◽  
Marcin Fojcik ◽  
Tomasz Klopot ◽  
Grzegorz Polaków
Keyword(s):  
Performance Evaluation ◽  
Process Control ◽  
Production Systems ◽  
Failure Detection ◽  
Data Access ◽  
Redundant Data ◽  
Output System ◽  
Data Source ◽  
Time Required ◽  
Classical Control

Classical control applications with a centralized logic and distributed input/output system are being replaced by dynamic environments of cooperating components. Thus, the OPC (Object Linking and Embedding for Process Control) UA (Unified Architecture) is becoming more popular, because the OPC Data Access substandard is not well suited for distributed systems. Moreover, in many production systems, redundant data servers are preferred, for financial and legal reasons. Providing performance evaluation gives an estimate of the time required (and data samples lost) to switch to a backup data source for redundant OPC UA architecture, depending on the failure detection method, number of variables and redundancy mode.

Responsiveness to seasonal temperature and nitrogen among genotypes of kikuyu, paspalum and bermuda grass pastures of coastal New South Wales

1985 ◽  
Vol 25 (1) ◽  
pp. 109 ◽  
Author(s):  
CJ Pearson ◽  
H Kemp ◽  
AC Kirby ◽  
TE Launders ◽  
C Mikled
Keyword(s):  
Growth Rates ◽  
Bermuda Grass ◽  
Base Temperature ◽  
Seasonal Temperature ◽  
Potential Productivity ◽  
Average Growth ◽  
South Wales ◽  
Nitrogen Concentrations ◽  
Calcium Magnesium ◽  
Phosphorus And Potassium

Three experiments were carried out to test the hypotheses that (a) there are quantitative differences in growth rate and quality between newly registered cultivars and older cultivars in response to changes in temperature and fertility, and (b) responsiveness to temperature varies between sites because cultivars acclimatize to their current environment. Performance in simulated swards indicated that potential productivity was highest from bermuda grass (Cynodon x Burton Pearson). This was, however, a poor indicator of performance in the field, where yield of bermuda grass was depressed by weeds whereas that of kikuyu (Pennisetum clandestinum) was unaffected. In the field, a newly registered kikuyu, cv. Crofts, outyielded bermuda grass and paspalum (Paspalum dilatatum) either alone or when combined with lucerne. A further experiment compared cvv. Crofts, Whittet and common kikuyu at three levels of nitrogen at three sites. Peak growth rates were the same at all locations but Crofts outyielded the other genotypes by 60, 13 and 18% at Bega (37�S.), Camden (34�S.) and Taree (32�S.) respectively. Average growth rates varied seasonally and were correlated with temperature (r > 0.9). Analysis of temperature responsiveness (kg/ha.�C) indicated that responsiveness varied consistently between genotypes at any location. Furthermore, the base temperature (the temperature below which there was negligible growth) was the same for all genotypes at any location but it increased with increasing latitude. That is, there was a tendency to greater dormancy with increasing coldness of location. Nitrogen responsiveness was the same for all genotypes and sites. Seasonal variations in digestibility and mineral concentrations in kikuyu, bermuda grass and paspalum were similar in the field and in simulated swards; quality was the same in all kikuyu genotypes. Calcium, magnesium and nitrogen concentrations of plant tops (but not phosphorus and potassium concentrations) increased with increasing rates of application of nitrogen fertilizer.

scholarly journals Agronomic performances of Pak Choi grown with different soil cover

2015 ◽  
Vol 33 (2) ◽  
pp. 261-266 ◽  
Author(s):  
Márcia M Echer ◽  
Graciela M Dalastra ◽  
Tiago L Hachmann ◽  
Elcio S Klosowski ◽  
Vandeir F Guimarães
Keyword(s):  
Soil Cover ◽  
Block Design ◽  
Dry Weight ◽  
Bare Soil ◽  
Production Traits ◽  
Pak Choi ◽  
Randomized Block Design ◽  
Black Plastic ◽  
Growing Conditions ◽  
Set Up

An important aspect in the cultivation of vegetables is the quality of the product to be marketed, free from dirt and damage and the practice of mulching could be an option, but there is scarse information. The aim of this study was to evaluate the influence of mulching on the production traits of three cultivars of Pak Choi. The experiment was set up during March to May 2013 using a split plot randomized block design, with four replications. Soil cover treatments (white agrotextile, black agrotextile, black plastic, silver plastic, tifton straw and bare soil) were arranged in the plots, and three cultivars of Pak Choi (Green Pak Choi, White Pak Choi and Chingensai Natsu Shomi) in subplots. Height and diameter of shoots, number of leaves, fresh weight of the head and petiole, base diameter, dry weight of stem, petiole, and leaf were evaluated thirty-five days after transplantation. The total dry weight and leaf area were measured, and then we estimated the yield. There was a significant effect of soil cover and cultivar. In general, the cover with synthetic materials showed higher values on production of Pak Choi. The cultivar White Pak Choi was better adapted to the growing conditions, with an average yield of 57.78 t/ha.

scholarly journals Phyllochron estimation in intercropped strawberry and monocrop systems in a protected environment

2012 ◽  
Vol 34 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Heloísa Ferro Constâncio Mendonça ◽  
Eunice Oliveira Calvete ◽  
Alexandre Augusto Nienow ◽  
Rosiani Castoldi da Costa ◽  
Lucas Zerbielli ◽  
...  
Keyword(s):  
Linear Regression ◽  
Production Systems ◽  
Block Design ◽  
Mean Value ◽  
Angular Coefficient ◽  
Degree Days ◽  
Camino Real ◽  
Fig Trees ◽  
Time Required ◽  
Strawberry Cultivars

The phyllochron is defined as the time required for the appearance of successive leaves on a plant; this characterises plant growth, development and adaptation to the environment. To check the growth and adaptation in cultivars of strawberry grown intercropped with fig trees, it was estimated the phyllochron in these production systems and in the monocrop. The experiment was conducted in greenhouses at the University of Passo Fundo (28º15'41'' S, 52º24'45'' W and 709 m) from June 8th to September 4th, 2009; this comprised the period of transplant until the 2nd flowering. The cultivars Aromas, Camino Real, Albion, Camarosa and Ventana, which seedlings were originated from the Agrícola LLahuen Nursery in Chile, as well as Festival, Camino Real and Earlibrite, originated from the Viansa S.A. Nursery in Argentina, were grown in white polyethylene bags filled with commercial substrate (Tecnomax®) and evaluated. The treatments were arranged in a randomised block design and four replicates were performed. A linear regression was realized between the leaf number (LN) in the main crown and the accumulated thermal time (ATT). The phyllochron (degree-day leaf-1) was estimated as the inverse of the angular coefficient of the linear regression. The data were submitted to ANOVA, and when significance was observed, the means were compared using the Tukey test (p < 0.05). The mean and standard deviation of phyllochrons of strawberry cultivars intercropped with fig trees varied from 149.35ºC day leaf-1 ± 31.29 in the Albion cultivar to 86.34ºC day leaf-1 ± 34.74 in the Ventana cultivar. Significant differences were observed among cultivars produced in a soilless environment with higher values recorded for Albion (199.96ºC day leaf-1 ± 29.7), which required more degree-days to produce a leaf, while cv. Ventana (85.76ºC day leaf-1 ± 11.51) exhibited a lower phyllochron mean value. Based on these results, Albion requires more degree-days to issue a leaf as compared to cv. Ventana. It was conclude that strawberry cultivars can be grown intercropped with fig trees (cv. Roxo de Valinhos).

scholarly journals Phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca, Vitaceae) cultivated in northeastern Brazil

2016 ◽  
Vol 76 (4) ◽  
pp. 975-982 ◽  
Author(s):  
N. A. S. Nunes ◽  
A. V. Leite ◽  
C. C. Castro
Keyword(s):  
Reproductive Biology ◽  
Pollen Viability ◽  
Floral Biology ◽  
Climatic Conditions ◽  
Northeastern Brazil ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Vitis Labrusca ◽  
Degree Days ◽  
Inflorescence Development

Abstract Phenology and reproductive biology of cultivated species are important for the comprehension of the requirements for fruit and seed production and the management of pollinators. This study aimed to characterise the phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca) in northeastern Brazil during January 2011 (P1), Augst 2011 (P2), April 2012 (P3) and August 2012 (P4). We recorded the duration (days) of the phenological stages, pruning (P), woolly bud (W), budburst (B), inflorescence development (ID), flowering (F), ripening (R) and harvest (H). We analysed the floral biology, the sexual system and the breeding system. We measured the growing degree days (GDD) required to reach the subperiods P-B, B-F and F-H. The periods P1, P2, P3 and P4 lasted for 116, 125, 117 and 130 days, respectively. The number of days of harvest were similar in the same dry (P1 and P3) and rainy (P2 and P4) periods. All the periods that we recorded were shorter than those observed in other regions of Brazil, which may be attributable to the mean temperature and carbohydrate metabolism. The flowers are green, hermaphroditic, with an odour of mignonette, low pollen viability and autogamous. The base temperature of 10°C was considered the most adequate for the subperiods as has been documented for other grape varieties in Brazil. Thus, temperature was also the most adequate for the cycles, presenting a smaller standard deviation (0.119, 0.147, 0.156 and 0.153 to P1, P2, P3 and P4, respectively) when compared to a base temperature of 12°C (0.122, 0.158, 0.165 and 0.160 to P1, P2, P3 and P4, respectively). The higher and the lower observed GDD were 1972.17 and 1870.05, respectively, both above the values recorded in other parts of Brazil for same variety. The phonological results, including knowledge of growing degree days, are important to the planning of cultures at the study site and in other regions that have similar climatic conditions and make it possible to pre-determine the harvest.

scholarly journals Drought sress and the distribution of vegetative and reproductive traits of a bean cultivar

2005 ◽  
Vol 62 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Abelardo Nuñez Barrios ◽  
Gerrit Hoogenboom ◽  
Dennis Scott Nesmith
Keyword(s):  
Soil Water ◽  
Leaf Area ◽  
Reproductive Traits ◽  
Dry Weight ◽  
Main Stem ◽  
Bean Cultivar ◽  
Neutron Probe ◽  
Bean Plants ◽  
Final Yield ◽  
Vegetative And Reproductive Growth

Soil water deficits may affect the location and pattern of flower and pod production on different stem axes of a bean plant. The objective of this study was to understand the effect of drought stress on the distribution of flowers and pods on the main stem and on branches of bean plants. The experiment was conducted in a shelter field facility. Water stress was imposed from the end of the vegetative stage to physiological maturity and soil water was measured with a neutron probe every two weeks. Formation of flowers at each node of the main stem was monitored at 44 days after planting (DAP) and formation of pods at 55DAP and 65 DAP. Dry weight of stems and leaves as well leaf area were measured during the middle of the pod filling stage (55DAP). The total number of flowers reached maxima of 32 and 44 flowers per plant for the drought and irrigated treatments, respectively. Number of flowers on branches decreased 50% in the stress treatment when compared to the control. Pod setting was also reduced on the branches of the lower nodes of the main stems. Under drought, the leaf area diminished by 60.1% and 10.4% on branches and main stem, respectively. The field drought conditions of this experiment had a greater effect on the vegetative and reproductive growth of branches as compared to the main stem affecting the final yield.

scholarly journals Determination of critical pH and Al concentration of acidic Ultisols for wheat and canola crops

2016 ◽  
Author(s):  
Abdulaha-Al Baquy ◽  
Jiu-Yu Li ◽  
Chen-Yang Xu ◽  
Khalid Mehmood ◽  
Ren-Kou Xu
Keyword(s):  
Soil Ph ◽  
Crop Production ◽  
Soil Acidity ◽  
Production Systems ◽  
Southern China ◽  
Chemical Properties ◽  
Dry Weight ◽  
Hydrated Lime ◽  
Dry Land

Abstract. Soil acidity has become a serious constraint in dry land crop production systems of acidic Ultisols in tropical and subtropical regions of southern China, where winter wheat and canola are cultivated as important rotational crops. Regardless of other common existing concerns in acidic Ultisols of southern China, it needs to be investigated whether soil acidity has any effect on wheat and canola growth. There is little information on the determination of critical soil pH as well as aluminium (Al) concentration for wheat and canola crops. The objective of this study was to determine the critical soil pH and exchangeable aluminium concentration (AlKCl) for wheat and canola production. Two pot cultures with two Ultisols from Hunan and Anhui were conducted for wheat and canola crops in a controlled growth chamber, with a completely randomized design. A soil pH gradient ranging from 3.7 (Hunan) and 3.97 (Anhui) to 6.5, with three replications, was used as a treatment. Aluminium sulfate (Al2(SO4)3) and hydrated lime (Ca(OH)2) were used to obtain the target soil pH levels. Plant height, shoot dry weight, root dry weight, and chlorophyll content (SPAD value) of wheat and canola were adversely affected by soil acidity in both locations. The critical soil pH and AlKCl of the Ultisol from Hunan for wheat were 5.29 and 0.56 cmol kg−1, respectively. At Anhui, the threshold soil pH and AlKCl for wheat were 4.66 and 2.36 cmol kg−1, respectively. On the other hand, the critical soil pH for canola was 5.65 and 4.87 for the Ultisols from Hunan and Anhui, respectively. The critical soil exchangeable Al for canola cannot be determined from the experiment of this study. The results suggested that the critical soil pH and AlKCl varied between different locations for the same variety of crop, due to the different soil types and their other soil chemical properties. The critical soil pH for canola was higher than that for wheat for both Ultisols, thus canola was more sensitive to soil acidity. Therefore, we recommend that liming should be undertaken to increase soil pH if it falls below these critical soil pH levels for wheat and canola production.

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