scholarly journals Foliar N Application on Tea Plant at Its Dormancy Stage Increases the N Concentration of Mature Leaves and Improves the Quality and Yield of Spring Tea

2021 ◽  
Vol 12 ◽  
Author(s):  
Mei-Ya Liu ◽  
Dandan Tang ◽  
Yuanzhi Shi ◽  
Lifeng Ma ◽  
Qunfeng Zhang ◽  
...  
Keyword(s):  
Winter Dormancy ◽  
Soil Fertilization ◽  
N Application ◽  
Foliar N ◽  
Mature Leaves ◽  
N Concentration ◽  
Tea Plants ◽  
Fertilization Level ◽  
Complementary Strategy

Over 30% of the Chinese tea plantation is supplied with excess fertilizer, especially nitrogen (N) fertilizer. Whether or not foliar N application on tea plants at the dormancy stage could improve the quality of spring tea and be a complementary strategy to reduce soil fertilization level remains unclear. In this study, the effects of foliar N application on tea plants were investigated by testing the types of fertilizers and their application times, and by applying foliar N under a reduced soil fertilization level using field and 15N-labeling pot experiments. Results showed that the foliar N application of amino acid liquid fertilizer two times at the winter dormancy stage was enough to significantly increase the N concentration of the mature leaves and improved the quality of spring tea. The foliar application of 2% urea or liquid amino acid fertilizer two times at the winter dormancy stage and two times at the spring dormancy stage showed the best performance in tea plants among the other foliar N fertilization methods, as it reduced the soil fertilization levels in tea plantations without decreasing the total N concentration of the mature leaves or deteriorating the quality of spring tea. Therefore, foliar N application on tea plants at its dormancy stage increases the N concentration of the mature leaves, improves the quality and yield of spring tea, and could be a complementary strategy to reduce soil fertilization levels.

Nursery and field fertilization of 2 + 0 ponderosa pine seedlings: the effect on morphology, physiology, and field performance

1990 ◽  
Vol 20 (11) ◽  
pp. 1766-1772 ◽  
Author(s):  
J. F. Gleason ◽  
M. Duryea ◽  
R. Rose ◽  
M. Atkinson
Keyword(s):  
Ponderosa Pine ◽  
Field Performance ◽  
Frost Damage ◽  
The Other ◽  
Seedling Morphology ◽  
N Application ◽  
Foliar N ◽  
Growing Seasons ◽  
N Concentration ◽  
Seed Zone

Ponderosa pine (Pinusponderosa Laws.) from two seed zones in central Oregon were grown at two nurseries where they were subjected to fall applications of N, N + K, or no fertilizer. For one seed zone, foliar N concentration increased from 1.47 to 1.53% for the N application and to 1.57% for N + K application. For the other seed zone, seedlings did not show any differences in foliar N after nursery fertilization. Seedlings that received the N application appeared to be less susceptible to frost damage, but nursery fertilization had little or no effect on seedling morphology or bud break. One month after outplanting 2 + 0 seedlings back to their respective seed-zone sites, slow-release fertilizer pellets were placed 10–13 cm from half the trees. Soils at the outplanting sites differed in mineral content, percent organic matter, and pH. The nursery-fertilized seedlings with increased N concentration grew more than control seedlings during the first season. Field-fertilized seedlings at the less fertile field site grew more in the second and third growing seasons, indicating that field fertilization after outplanting is more effective on nutrient-poor sites. Soil fertility had a greater impact on seedling performance than did nursery- and field-fertilizer treatments. At the less fertile site, N concentration decreased by 14% during the first growing season and increased by 22% during the second season, whereas at the more fertile site it increased during both the first season (12%) and the second season (6%). Seedlings at the more fertile site almost doubled in height in the 3rd year and were more than 20 cm taller than those at the other site.

scholarly journals Self-Configuring CVS to Discriminate Rocket Leaves According to Cultivation Practices and to Correctly Attribute Visual Quality Level

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1353
Author(s):  
Michela Palumbo ◽  
Bernardo Pace ◽  
Maria Cefola ◽  
Francesco Fabiano Montesano ◽  
Francesco Serio ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Irrigation Management ◽  
Classification Performance ◽  
Quality Level ◽  
Cultivation Conditions ◽  
Computer Vision Systems ◽  
Soilless Cultivation ◽  
Fertilization Level ◽  
Non Destructive

Computer Vision Systems (CVS) represent a contactless and non-destructive tool to evaluate and monitor the quality of fruits and vegetables. This research paper proposes an innovative CVS, using a Random Forest model to automatically select the relevant features for classification, thereby avoiding their choice through a cumbersome and error-prone work of human designers. Moreover, three color correction techniques were evaluated and compared, in terms of classification performance to identify the best solution to provide consistent color measurements. The proposed CVS was applied to fresh-cut rocket, produced under greenhouse soilless cultivation conditions differing for the irrigation management strategy and the fertilization level. The first aim of this study was to objectively estimate the quality levels (QL) occurring during storage. The second aim was to non-destructively, and in a contactless manner, identify the cultivation approach using the digital images of the obtained product. The proposed CVS achieved an accuracy of about 95% in QL assessment and about 65–70% in the discrimination of the cultivation approach.

Growth and N status of Populus in mixture with red alder on recent volcanic mudflow from Mount Saint Helens

1990 ◽  
Vol 20 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Paul E. Heilman
Keyword(s):  
Late Summer ◽  
Height Growth ◽  
Phosphorus Fertilization ◽  
Cross Sectional ◽  
Red Alder ◽  
Total N ◽  
Foliar N ◽  
N Concentration ◽  
The Mean ◽  
Foliar N Concentration

Eleven months after the May 1980 eruption of Mount Saint Helens in southeastern Washington, United States, three Populus clones were planted in an experiment on the Toutle River mudflow deposit. The trees grew at an abnormally slow rate and by 3 years were overtopped by a dense stand (14 600 ± 3600 trees/ha) of red alder seeded naturally onto the site. Over the 6-year period of the study, the total N content of the soil increased an average of 56 kg•ha−1•year−1•. Foliar N concentration in Populus increased significantly from a mean late summer – early autumn value in the 2nd year (1982) of 0.69% N to a value of 2.06% N at the end of the seventh growing season. The mean annual height growth of the largest Populus averaged <0.5 m/year in the first 3 years, increasing to an average of over 1.0 m/year in the 5th and 6th years. Fertilizer treatments with N (as urea) and N + P (as urea plus treble superphosphate) placed in the soil near the individual Populus at a maximum rate of 5.3 g N/tree increased height growth in the year of fertilization (1982) and the following year (the response in height growth for the 2 years totaled 64%). After 1984, no significant effects of fertilizer on height growth, total height, or diameter were evident. Nitrogen fertilization significantly increased foliar N concentration (1.54% N with the highest N treatment vs. 0.69% N in the control) in the year of treatment only. Phosphorus fertilization had no significant effect on growth or foliar P concentration. At 6 years, only 2% of the Populustrichocarpa Torr. & Gray clone and 13% of the tallest Populus hybrid were equal to or above the mean height of alder dominants and codominants (6.2 m). Additionally, the diameter growth of Populus was severely limited: the trees had only 8% of the cross-sectional area of "normal" trees for their height. Results indicated that on sites of low N such as the mudflow, Populus may not compete satisfactorily in mixture with alder. Such behavior is in sharp contrast to sites of high N, where red alder cannot compete with Populus.

Total nitrogen concentration in leaves of potatoes (Solanum tuberosumL.) as an index of nutritional status

1976 ◽  
Vol 87 (2) ◽  
pp. 293-296 ◽  
Author(s):  
A. Gupta ◽  
M. C. Saxena
Keyword(s):  
Total Nitrogen ◽  
Tuber Yield ◽  
Critical Concentration ◽  
Nitrogen Concentration ◽  
Curvilinear Relationship ◽  
N Application ◽  
Total N ◽  
Potato Plants ◽  
N Concentration ◽  
Total Nitrogen Concentration

SummaryLeaf samples were collected, at weekly intervals, throughout the growing season, from potato (Solanum tuberosumL.) plants supplied with varying amounts of nitrogen (0, 60, 120, 180 and 240 kg N/ha) and analysed for total N. Application of nitrogen increased the N concentration in the green leaves at all stages of growth. There was a significant curvilinear relationship between the final tuber yield and the total N concentration in the leaves at 48–90 days after planting in 1968–9 and at 79–107 days after planting in 1969–70. The N concentration at 70–90 days after planting was consistently related to the final tuber yield in both years. Thus this period was ideal for assessing the nitrogen status of potato plants. The critical concentration of total nitrogen generally decreased with advance in age. It ranged from 4·65% at 76 days to 3·30% at 90 days during 1968–9, whereas in 1969–70 it ranged from 4·20% at 79 days to 3·80% at 93 days. During the period from 83 to 86 days the critical percentage was around 3·6% in both the years.

scholarly journals Nitrogen Application and Leaf Harvesting Improves Yield and Nutritional Quality of Beetroot

2017 ◽  
Vol 27 (3) ◽  
pp. 337-343 ◽  
Author(s):  
Salfina S. Mampa ◽  
Martin M. Maboko ◽  
Puffy Soundy ◽  
Dharini Sivakumar
Keyword(s):  
Block Design ◽  
Root Diameter ◽  
Total Protein Content ◽  
Root Weight ◽  
Nitrogen Application ◽  
Root Yield ◽  
N Application ◽  
Leaf Yield ◽  
Leaf Harvest

Beetroot (Beta vulgaris), commonly known as table beet, is used as a staple in the diet of many people through the consumption of the entire plant, leaf, and the root. The objective of this study was to assess the effects of nitrogen (N) application and leaf harvest percentage on the yield and quality of roots and leaves of beetroot. The treatment design was a randomized complete block design with five levels of N (0, 60, 90, 120, and 150 kg·ha−1) combined with three leaf harvest percentages (0, 30, and 50) and replicated three times. The first leaf harvest was initiated 35 days after transplanting (DAT) by removing the outer matured leaves and the second harvest occurred 80 DAT by removing all the leaves. The results showed increases in leaf and root yield with an increase in N application. Nitrogen application at 90 and 120 kg·ha−1 increased fresh leaf weight, leaf number, and fresh and dry root weight, including root diameter and length with the exception of leaf area which was significantly higher at 120 kg·ha−1 N. Magnesium and iron leaf content, and N root content were significantly improved by the application of 120 kg·ha−1 N. Leaf harvest percentage did not have a significant effect on leaf yield or leaf and root mineral content. However, dry root weight was significantly reduced by the 50% leaf harvest. Leaf harvest at 30% or 50% increased total protein content of the roots of beetroot, whereas an increase in N application decreased concentration of total proteins. Results demonstrate that leaf and root yield, as well as magnesium, zinc, and iron leaf content, increased with the application of 120 kg·ha−1 N, whereas 30% leaf harvest did not negatively affect root yield.

scholarly journals EFFECTS OF NITROGEN AND PHOSPHORUS ON THE YIELD AND CHEMICAL COMPOSITION OF MEADOW FOXTAIL

1975 ◽  
Vol 55 (4) ◽  
pp. 949-954 ◽  
Author(s):  
M. C. J. VAN ADRICHEM ◽  
J. N. TINGLE
Keyword(s):  
Chemical Composition ◽  
Crude Protein ◽  
Dry Matter ◽  
Nitrogen And Phosphorus ◽  
N Application ◽  
Dry Matter Digestibility ◽  
P Content ◽  
Mn Content ◽  
N Rates

The effects of spring-applied nitrogen (0, 56, 112 and 224 kg/ha) and phosphorus (0 and 27.4 kg/ha) on the dry matter (DM) yield and forage quality of successive harvests of meadow foxtail (Alopecurus pratensis L.) were investigated. Nitrogen increased DM yield, crude protein, Cu, K and Zn contents and decreased P, Ca, Mg and Mn contents. Application of P in combination with N increased K content in the first cut and arrested the decline of P content due to N application in all cuts. The levels of dry matter digestibility and Cu declined in successive cuts whereas Mn content increased. At low N rates, Ca and Mg contents increased as the season advanced.

scholarly journals Ethephon Reduces Maize Nitrogen Uptake but Improves Nitrogen Utilization in Zea mays L.

2022 ◽  
Vol 12 ◽  
Author(s):  
Yushi Zhang ◽  
Yubin Wang ◽  
Churong Liu ◽  
Delian Ye ◽  
Danyang Ren ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
N Uptake ◽  
Utilization Efficiency ◽  
N Application ◽  
Total N ◽  
N Concentration ◽  
High Plant Density ◽  
Ethephon Treatment ◽  
N Use

Increasing use of plant density or/and nitrogen (N) application has been introduced to maize production in the past few decades. However, excessive planting density or/and use of fertilizer may cause reduced N use efficiency (NUE) and increased lodging risks. Ethephon application improves maize lodging resistance and has been an essential measure in maize intensive production systems associated with high plant density and N input in China. Limited information is available about the effect of ethephon on maize N use and the response to plant density under different N rates in the field. A three-year field study was conducted with two ethephon applications (0 and 90 g ha−1), four N application rates (0, 75, 150, and 225 kg N ha−1), and two plant densities (6.75 plants m−2 and 7.5 plants m−2) to evaluate the effects of ethephon on maize NUE indices (N agronomic efficiency, NAE; N recovery efficiency, NRE; N uptake efficiency, NUpE; N utilization efficiency, NUtE; partial factor productivity of N, PFPN), biomass, N concentration, grain yield and N uptake, and translocation properties. The results suggest that the application of ethephon decreased the grain yield by 1.83–5.74% due to the decrease of grain numbers and grain weight during the three experimental seasons. Meanwhile, lower biomass, NO3- and NH4+ fluxes in xylem bleeding sap, and total N uptake were observed under ethephon treatments. These resulted in lower NAE and NUpE under the ethephon treatment at a corresponding N application rate and plant density. The ethephon treatment had no significant effects on the N concentration in grains, and it decreased the N concentration in stover at the harvesting stage, while increasing the plant N concentration at the silking stage. Consequently, post-silking N remobilization was significantly increased by 14.10–32.64% under the ethephon treatment during the experimental periods. Meanwhile, NUtE significantly increased by ethephon.

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