scholarly journals Nitrogen-Yield Relationships in Greenhouse Roses

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 789C-789 ◽  
Author(s):  
Raul I. Cabrera ◽  
Richard Y. Evans
Keyword(s):  
Dry Weight ◽  
Stem Length ◽  
N Application ◽  
Yield And Quality ◽  
Flower Yield ◽  
Yield Parameters ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Total Dry Weight ◽  
The Relationship

The establishment of critical tissue N (Ncrit) for greenhouse rose production has been primarily based on visual symptoms of N deficiency, with relatively less consideration to yield parameters. This work examined the relationship between rose leaf N concentration and flower yield and quality. Microlysimeter-grown `Royalty' rose plants were irrigated with complete nutrient solutions containing N concentrations of 30, 60, 90, 120, 150, and 220 mg·liter–1. Results after 1 year indicated no significant differences in total dry weight, number of flowers, and stem length for plants irrigated with 90 to 220 mg·liter–1 N. Tissue N concentrations were significantly lower for plants that received 30 or 60 mg N/liter. Estimated Ncrit for yield parameters were ≈2.7% of leaf dry weight. Chlorophyll content and color leaf attributes (hue, chroma, and value) were correlated with tissue N concentration. The results suggest that the rate of N application typically recommended for greenhouse roses is considerably higher than necessary.

scholarly journals Leaf Nitrogen Status on Yield and Quality of Roses

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 564C-564b
Author(s):  
Raul I. Cabrera
Keyword(s):  
Experimental Period ◽  
Leaf Nitrogen ◽  
Stem Length ◽  
Yield And Quality ◽  
Leaf Chlorophyll ◽  
N Concentration ◽  
Biomass Yields ◽  
Leaf N Concentration ◽  
Plant Yields ◽  
Leaf N

The establishment of critical tissue N levels for greenhouse rose production has been primarily based on visual symptoms of N deficiency, with relatively less consideration to yield parameters. This work examined the relationship between rose leaf N concentration and flower yield and quality. Container-grown `Royalty' rose plants were irrigated for 13 months with complete nutrient solutions containing N concentrations of 30, 60, 90, 120, 150 and 220 mg·L–1. Optimum flower and dry biomass yields, stem length, and stem weights were obtained in plants irrigated with 90 mg·L–1 N. Leaf N concentrations increased asymptotically with N applications, stabilizing at N concentrations >90 mg·L–1. Time of the year had an effect on overall leaf N concentrations, with higher values observed in the winter, and lower values in the summer. Leaf N concentrations were linearly, and significantly, correlated with leaf chlorophyll content and leaf color attributes (hue, chroma, and value). Quadratic relationships between leaf N concentration and rose plant yields were observed only for the second half of the experimental period, and depicted an apparent, and striking, plant control over tissue N status. In addition, these relationships indicated that optimum plant yields were possible during spring and summer with leaf N concentrations below the recommended critical level of 3% (as low as 2.4% to 2.5%). These results suggest that leaf N concentration per se is not a dependable indicator of rose productivity.

DO SEED MOTHER’S SITES AFFECT THE QUALITY OF THE SEEDLINGS PRODUCED

2020 ◽  
Vol 8 (10) ◽  
pp. 15-20
Author(s):  
Mohamed M. Younis ◽  
Younis Saeed Al Bugg ◽  
Siham Thannon Hussein
Keyword(s):  
Statistical Analysis ◽  
Morphological Characteristics ◽  
Dry Weight ◽  
Stem Length ◽  
Root Weight ◽  
The Third ◽  
Wet Weight ◽  
Total Dry Weight ◽  
The Relationship

This experiment was conducted in (Zawita) area in Dohuk governorate / Iraq, and the morphological characteristics were studied by selecting four sites, four trees from each site, four sectors and, choosing twenty trees in each sector. Statistical analysis (RCBD) was done using the SPSS system. Through this study, it was found that Pinus brutia Ten. In Zawita, there is a clear effect on some morphological characteristics of the seedlings resulting from it. The first site was one of the best sites followed by the second site where he gave seedlings of good quality in terms of stem length with an average of 39.25 cm and the total weight of wet and dry seedlings with averages of 13.97 and 35.34 g respectively, and the third site was the lowest studied sites and gave seedlings of less quality than the rest of the sites where he scored Stem length averaged 23.06 cm while wet and dry weight was 7.68 and 22.17 g, respectively. As for the correlation between the variables, the relationship was positive and strong among all the variables except those between the length of the root and the rest of the variables except with the characteristic of the wet root weight. The highest correlation values were between total dry weight and total wet weight recording 0.960 and the lowest between the length of the root and the dry vegetative weight where the value was 0.070.

scholarly journals Estimating Plant Nitrogen Concentration of Maize Using a Leaf Fluorescence Sensor across Growth Stages

2020 ◽  
Vol 12 (7) ◽  
pp. 1139
Author(s):  
Rui Dong ◽  
Yuxin Miao ◽  
Xinbing Wang ◽  
Zhichao Chen ◽  
Fei Yuan ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Fluorescence Sensor ◽  
Accurate Estimation ◽  
Growth Stages ◽  
Fluorescence Sensors ◽  
N Application ◽  
N Concentration ◽  
Leaf N Concentration ◽  
N Status ◽  
Leaf N

Nitrogen (N) is one of the most essential nutrients that can significantly affect crop grain yield and quality. The implementation of proximal and remote sensing technologies in precision agriculture has provided new opportunities for non-destructive and real-time diagnosis of crop N status and precision N management. Notably, leaf fluorescence sensors have shown high potential in the accurate estimation of plant N status. However, most studies using leaf fluorescence sensors have mainly focused on the estimation of leaf N concentration (LNC) rather than plant N concentration (PNC). The objectives of this study were to (1) determine the relationship of maize (Zea mays L.) LNC and PNC, (2) evaluate the main factors influencing the variations of leaf fluorescence sensor parameters, and (3) establish a general model to estimate PNC directly across growth stages. A leaf fluorescence sensor, Dualex 4, was used to test maize leaves with three different positions across four growth stages in two fields with different soil types, planting densities, and N application rates in Northeast China in 2016 and 2017. The results indicated that the total leaf N concentration (TLNC) and PNC had a strong correlation (R2 = 0.91 to 0.98) with the single leaf N concentration (SLNC). The TLNC and PNC were affected by maize growth stage and N application rate but not the soil type. When used in combination with the days after sowing (DAS) parameter, modified Dualex 4 indices showed strong relationships with TLNC and PNC across growth stages. Both modified chlorophyll concentration (mChl) and modified N balance index (mNBI) were reliable predictors of PNC. Good results could be achieved by using information obtained only from the newly fully expanded leaves before the tasseling stage (VT) and the leaves above panicle at the VT stage to estimate PNC. It is concluded that when used together with DAS, the leaf fluorescence sensor (Dualex 4) can be used to reliably estimate maize PNC across growth stages.

Resistance, tolerance, and yield of western black cottonwood infected by Melampsora rust

1992 ◽  
Vol 22 (2) ◽  
pp. 183-192 ◽  
Author(s):  
J. Wang ◽  
B.J. van der Kamp
Keyword(s):  
Disease Severity ◽  
Volume Growth ◽  
Severe Infection ◽  
Dry Weight ◽  
Stem Volume ◽  
Yield Losses ◽  
Black Cottonwood ◽  
Total Dry Weight ◽  
Significant Discovery ◽  
The Relationship

Potted ramets of 14 western black cottonwood (Populustrichocarpa Torr. & Gray) clones from southern British Columbia were inoculated with Melampsoraoccidentalis H. Jacks to produce a range of disease severities, and their size and dry weight were determined after 1 or 2 years. Response to inoculation varied significantly between clones. Clones from drier interior locations were less resistant than those from coastal or moister interior locations. Local- (within leaf) or systemic-induced resistance was not detected. Yield (total dry weight) decreased linearly with disease severity. Percent reduction in yield was greater than the cumulative percent leaf area infected for all clones. Yield losses were substantial: dry weights of ramets with disease severity levels similar to those experienced by natural cottonwood populations were about 75% of controls; heavily infected ramets were <50% of controls. Stem:root ratios increased rapidly with increasing disease severity in all clones, and at significantly different rates. Severe infection resulted in substantial mortality in the following winter and reduced initial stem volume growth in the following growing season. Tolerance, defined as the relationship between disease severity and yield, varied significantly between clones. The most significant discovery of this study was that tolerance and resistance were correlated, greater tolerance being associated with reduced resistance. The concepts of resistance, tolerance, and disease hazard, as quantified in this study, can be used to predict yield and to select the most appropriate clones for different disease hazard conditions.

The relationship between evapotranspiration and growth in the wheat crop

1966 ◽  
Vol 17 (3) ◽  
pp. 255 ◽  
Author(s):  
RA Fischer ◽  
GD Kohn
Keyword(s):  
Soil Moisture ◽  
Vegetative Growth ◽  
Dry Weight ◽  
Fertilizer Application ◽  
Wheat Crop ◽  
South Wales ◽  
Evapotranspiration Rate ◽  
Total Dry Weight ◽  
Delayed Flowering ◽  
The Relationship

In trials conducted in 1961 and 1962 at Wagga in southern New South Wales, to investigate the yield physiology of wheat, the variety Heron was grown under various cultural treatments. This paper deals with the relationship of evapotranspiration to crop growth. Vegetative growth at a given date in the spring was influenced markedly by time of sowing and fertilizer application, and to a lesser extent by sowing rate. Large differences in vegetative growth caused relatively small differences in evapotranspiration rate when soil moisture was adequate. An increase in total dry weight of 100 g/m² in early October was associated with an increase in cumulative evapotranspiration up to that time of about 0.50 in. It was concluded that although a reduced fertilizer application and reduced sowing rate (below 3b lb seed per acre) permitted higher soil moisture levels at flowering, this necessarily involved a considerable reduction in total dry weight at flowering. With delayed time of sowing, the post-flowering moisture status of the crop can be expected to deteriorate, primarily because of delayed flowering date.

scholarly journals Effect of N fertilization rate on soil alkali-hydrolyzable N, subtending leaf N concentration, fiber yield, and quality of cotton

2016 ◽  
Vol 4 (4) ◽  
pp. 323-330 ◽  
Author(s):  
Binglin Chen ◽  
Hongkun Yang ◽  
Weichao Song ◽  
Chunyu Liu ◽  
Jiao Xu ◽  
...  
Keyword(s):  
Fertilization Rate ◽  
N Fertilization ◽  
Yield And Quality ◽  
Fiber Yield ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Leaf N

scholarly journals Yield and Quality of Field-grown Celosia and Globe Amaranth Cut Flowers at Four Plant Densities

2010 ◽  
Vol 20 (3) ◽  
pp. 612-619
Author(s):  
Sabine R. Green ◽  
Geno A. Picchioni ◽  
Leigh W. Murray ◽  
Marisa M. Wall
Keyword(s):  
Dry Weight ◽  
Early Summer ◽  
Head Size ◽  
Planting Density ◽  
Stem Length ◽  
Specialty Crops ◽  
Yield And Quality ◽  
Wide Range ◽  
Flowering Stem ◽  
Amaranth Species

Field-grown cut and dried flowers could provide a high-value crop selection for New Mexico. We conducted a 1-year field study to evaluate flower yield and quality characteristics of common globe amaranth (Gomphrena globosa), ‘Strawberry Fields’ globe amaranth (Gomphrena haageana), cockscomb celosia (Celosia argentea var. cristata ‘Chief Mix’), and wheat celosia (Celosia spicata ‘Pink Candle’). Within-row spacing of 15 or 20 cm combined with two-row or three-row per bed plantings resulted in field planting densities ranging from 66,670 to 120,010 plants/ha of common globe amaranth and ‘Strawberry Fields’ globe amaranth, and 100,005 to 200,010 plants/ha of cockscomb and wheat celosia. All but cockscomb celosia produced four harvests that began 22 May and ended 18 Oct., depending on species. Both globe amaranth species had a 5- to 6-month harvest season, two to three midseason to late-season peak harvests, and over 1000 harvested stems totaling 1.4 to 1.8 kg dry weight per 1.5-m2 plot across the season. Both celosia species had a 4.5-month harvest season, one early summer peak harvest, and fewer than 300 harvested stems totaling 0.6 to 0.7 kg dry weight per plot for the year. Seasonally progressive increases in flowering stem length of both globe amaranth species and wheat celosia, and in flowering stem diameter of both globe amaranth species and cockscomb celosia, were observed. Flowering head size of both globe amaranth species and of wheat celosia varied little with harvest season, whereas the head diameter of cockscomb celosia increased with the season. Postharvest flower retention after mechanical impact was about 2% higher for common globe amaranth than it was for ‘Strawberry Fields’ globe amaranth, decreased by about 6% from early to later harvests for both celosia species, and was inversely related to the head size of both globe amaranth species and cockscomb celosia. Despite the wide range in planting density, the density effect was largely limited to cockscomb celosia. For that species, three-row planting (high density) increased the total number of spray flower (multiple head) stems, provided longer stems later into the season and wider heads midway into the season, and prolonged the production of spray stems (15-cm spacing only). Results demonstrate that these four species are excellent candidates as new specialty crops in semiarid conditions.

scholarly journals How Nitrogen Supply Affects Growth and Nitrogen Uptake, Use Efficiency, and Loss from Citrus Seedlings

1996 ◽  
Vol 121 (1) ◽  
pp. 105-114 ◽  
Author(s):  
John D. Lea-Cox ◽  
James P. Syvertsen
Keyword(s):  
Plant Growth ◽  
N Uptake ◽  
Single Application ◽  
N Application ◽  
N Supply ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Use Efficiency ◽  
Complete Nutrient Solution ◽  
Leaf N

We examined how N supply affected plant growth and N uptake, allocation and leaching losses from a fine sandy soil with four Citrus rootstock species. Seedlings of `Cleopatra' mandarin (Citrus reticulata Blanco) and `Swingle' citrumelo (C. paradisi × P. trifoliata) were grown in a glasshouse in 2.3-liter pots of Candler fine sand and fertilized weekly with a complete nutrient solution containing 200 mg N/liter (20 mg N/week). A single application of 15NH415NO3(17.8% atom excess 15N) was substituted for a normal weekly N application when the seedlings were 22 weeks old (day O). Six replicate plants of each species were harvested at 0.5, 1.5, 3.5, 7, 11, and 30 days after 15N application. In a second experiment, NH4 NO3 was supplied at 18,53, and 105 mg N/week to 14-week-old `Volkamer' lemon (C. volkameriana Ten. & Pasq.) and sour orange (C. aurantium L.) seedlings in a complete nutrient solution for 8 weeks. A single application of 15NH415NO3 (23.0% 15N) was substituted at 22 weeks (day 0), as in the first experiment, and seedlings harvested 3,7, and 31 days after 15N application. Nitrogen uptake and partitioning were similar among species within each rate, but were strongly influenced by total N supply and the N demand by new growth. There was no 15N retranslocation to new tissue at the highest (105 mg N/week) rate, but N supplies below this rate limited plant growth without short-term 15N reallocation from other tissues. Leaf N concentration increased linearly with N supply up to the highest rate, while leaf chlorophyll concentration did not increase above that at 53 mg N/week. Photosynthetic CO2 assimilation was not limited by N in this study; leaf N concentration exceeded 100 mmol·m-2 in all treatments. Thus, differences in net productivity at the higher N rates appeared to be a function of increased leaf area, but not of leaf N concentration. Hence, N use efficiency decreased significantly over the range of N supply, whether expressed either on a gas-exchange or dry weight basis. Mean plant 15N uptake efficiencies after 31 days decreased from 60% to 47% of the 15N applied at the 18,20, and 53 mg N/week rates to less than 33% at the 105 mg N/week rate. Leaching losses increased with N rate, with plant growth rates and the subsequent N requirements of these Citrus species interacting with residual soil N and potential leaching loss.

scholarly journals Nitrogen Uptake Efficiency and Leaching Losses from Lysimeter-grown Citrus Trees Fertilized at Three Nitrogen Rates

1996 ◽  
Vol 121 (1) ◽  
pp. 57-62 ◽  
Author(s):  
J.P. Syvertsen ◽  
M.L. Smith
Keyword(s):  
N Uptake ◽  
Dry Weight ◽  
Fruit Yield ◽  
Fibrous Root ◽  
N Application ◽  
Nitrogen Uptake Efficiency ◽  
Uptake Efficiency ◽  
N Concentration ◽  
Application Rates ◽  
Leaf N

Four-year-old `Redblush' grapefruit (Citrus paradisi Macf.) trees on either the relatively fast-growing rootstock `Volkamer' lemon (VL) (C. volkameriana Ten. & Pasq.) or on the slower-growing rootstock sour orange (SO) (C. aurantium L.) were transplanted into 7.9-m3 drainage lysimeter tanks filled with native Candler sand, irrigated similarly, and fertilized at three N rates during 2.5 years. After 6 months, effects of N application rate and rootstock on tree growth, evapotranspiration, fruit yield, N uptake, and leaching were measured during the following 2 years. When trees were 5 years old, low, medium, and high N application rates averaged about 79,180, or 543 g N/tree per year and about 126,455, or 868 g N/tree during the following year. Recommended rates average about 558 g N/tree per year. A lysimeter tank with no tree and additional trees growing outside lysimeters received the medium N treatment. Nitrogen concentration in the drainage water increased with N rate and exceeded 10 mg·liter-1 for trees receiving the high rates and also for the no tree tank. Leachate N concentration and total N recovered was greater from trees on SO than from those on VL. Average N uptake efficiency of medium N rate trees on VL was 6870 of the applied N and 61 % for trees on SO. Nitrogen uptake efficiency decreased with increased N application rates. Trees outside lysimeters had lower leaf N and fruit yield than lysimeter trees. Overall, canopy volume and leaf N concentration increased with N rate, but there was no effect of N rate on fibrous root dry weight. Fruit yield of trees on SO was not affected by N rate but higher N resulted in greater yield for trees on VL. Rootstock had no effect on leaf N concentration, but trees on VI. developed larger canopies, had greater fibrous root dry weight, used more water, and yielded more fruit than trees on SO. Based on growth, fruit yield and N leaching losses, currently recommended N rates were appropriate for trees on the more vigorous VL rootstock but were 22% to 69 % too high for trees on SO.

scholarly journals Variation Between Cut Chrysanthemum Cultivars in Response to Suboptimal Temperature

2007 ◽  
Vol 132 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Anke van der Ploeg ◽  
Ranathunga J.K.N. Kularathne ◽  
Susana M.P. Carvalho ◽  
Ep Heuvelink
Keyword(s):  
Growth Rate ◽  
Genetic Variation ◽  
Temperature Response ◽  
Dry Weight ◽  
Stem Length ◽  
Long Day ◽  
Cultivation Period ◽  
Optimum Response ◽  
Total Dry Weight ◽  
Response To Temperature

To breed for more energy-efficient cut chrysanthemum (Chrysanthemum morifolium Ramat.) cultivars it is important to know the variation of the temperature response existing in modern cultivars. In a greenhouse experiment with 25 chrysanthemum cultivars, a significant variation was observed in temperature response (16 °C or 20 °C) for reaction time, total dry weight produced, stem length, and flower size and number. To study this genetic variation in temperature response over a larger range of temperatures (15 °C to 24 °C), four contrasting cultivars (Annecy, Delianne, Reagan, and Supernova) were selected in a second experiment. Furthermore, a third experiment was performed in which the cultivation period was split into three phases and the influence of temperature in each of these phases was studied for the four selected cultivars. Dry weight production in all cultivars was very sensitive to temperature during the long day period. Relative growth rate showed an optimum response to temperature, with the optimum around 24 °C. Net assimilation rate also showed an optimum response to temperature, whereas leaf area ratio increased linearly with temperature. Compared with these temperature effects during the long day, the effect of temperature on absolute growth rate during the short day was, depending on the cultivar, relatively small or even absent. The reaction time, on the other hand, was very temperature sensitive, showing an optimum that was cultivar dependent. The temperature response of the total dry weight production during the whole cultivation period was, therefore, very cultivar dependent. Furthermore, depending on the cultivar, stem length increased with temperature, especially during long day, as a result of both increasing internode number and average internode length. The response of both flower size and number to temperature was also highly cultivar specific. The possibilities of using this genetic variation for breeding are discussed.

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