scholarly journals Effects of nitrogen on development and growth of the leaves of vegetables. 2. Appearance, expansion growth and life span of leaves of leek plants

1995 ◽  
Vol 43 (2) ◽  
pp. 233-246 ◽  
Author(s):  
H. Biemond
Keyword(s):  
Leaf Area ◽  
Field Trials ◽  
Application Rate ◽  
Leaf Expansion ◽  
Mature Leaf ◽  
Growth Stages ◽  
Leaf Emergence ◽  
N Application Rate ◽  
Number Of Leaves ◽  
Leaf Appearance

In greenhouse pot experiments and field trials, leek cv. Albana plants were supplied with different amounts of N fertilizer at various growth stages. Leaf emergence, expansion, size and senescence were monitored. The rate of leaf appearance was not affected by N treatments and almost constant across experiments at 0.15/day. The rate of leaf expansion and the mature leaf area increased with leaf number, reaching maximum values between leaf numbers 11 and 14 and decreasing with higher leaf numbers. Both variables increased with increasing N application rate. The duration of leaf expansion was more or less constant across leaf numbers and not influenced by N treatments; the leaf expansion rate was the main factor determining mature leaf area. The rate of leaf senescence was not influenced by N treatments. Differences in total green leaf area per plant were caused by differences in the area of individual mature leaves and not by differences in the number of leaves. The specific leaf area of all leaves was more or less constant at 100 cmsuperscript 2/g.

scholarly journals Effects of nitrogen on development and growth of the leaves of vegetables. 3. Appearance and expansion growth of leaves of spinach

1995 ◽  
Vol 43 (2) ◽  
pp. 247-260
Author(s):  
H. Biemond
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Field Trials ◽  
Leaf Expansion ◽  
Mature Leaf ◽  
Leaf Emergence ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Main Factor

In a series of greenhouse and field trials, spinach cv. Trias plants were supplied with different amounts of N fertilizer in various split applications. Rates of leaf emergence and expansion were recorded, as well as final leaf size. The rate of leaf appearance varied between 0.16 and 0.57/day across experiments, but was hardly affected by N treatment. The rate of leaf expansion and mature leaf area increased with leaf number, reaching maximum values at leaf pair 3+4 or 5+6 and decreasing subsequently. Both characteristics were positively correlated with N supply. The duration of expansion was not influenced by N treatments and varied between 15 and 30 days in most experiments. The rate of leaf expansion was the main factor determining mature leaf size. Specific leaf area over all green leaves slowly decreased with time in most experiments and was around 300 cmsuperscript 2/g. As the differences in the number of leaves were small, the differences in total green leaf area per plant resulted from differences in the areas of individual mature leaves.

scholarly journals Effects of nitrogen on development and growth of the leaves of vegetables. 1. Appearance, expansion growth and life span of leaves of Brussels sprouts plants

1995 ◽  
Vol 43 (2) ◽  
pp. 217-232
Author(s):  
H. Biemond ◽  
J. Vos ◽  
P.C. Struik
Keyword(s):  
Leaf Area ◽  
Application Rate ◽  
Leaf Number ◽  
N Application ◽  
Brussels Sprouts ◽  
Leaf Emergence ◽  
N Application Rate ◽  
Pot Trials ◽  
Leaf Expansion Rate ◽  
Green Leaf Area

In greenhouse pot trials, Brussels sprouts cv. Icarus SG2004 plants were supplied with various amounts of N at different stages during growth. The rate of leaf emergence ranged from 0.39 to 0.72 per day and was significantly increased by increasing N application rate. Leaf expansion rate and mature leaf area increased with leaf number, reaching maximum values between leaf number 10 and 20 and decreasing subsequently. Plants receiving more N had a higher total green leaf area per plant, due to more and larger green leaves. Specific leaf area of all leaves declined gradually from 130-230 cmsuperscript 2/g (depending on experiment) at about 30 days after planting to 60 cmsuperscript 2/g at the end of the experiments and was usually significantly increased by increasing N application rate.

Appearance time, expansion rate and expansion duration for leaves of field-grown maize (Zea mays L.)

1994 ◽  
Vol 74 (1) ◽  
pp. 31-36 ◽  
Author(s):  
D. W. Stewart ◽  
L. M. Dwyer
Keyword(s):  
Leaf Area ◽  
Nonlinear Function ◽  
Logistic Function ◽  
Leaf Expansion ◽  
Expansion Rate ◽  
Leaf Number ◽  
Critical Parameters ◽  
Appearance Time ◽  
Time Expansion ◽  
Leaf Appearance

Date of appearance and expansion duration of leaves are critical parameters for calculating leaf area of a canopy, which is, in turn, an important component of growth. In this study, a three-line function and a logistic function were both fitted to normalized leaf area data of individual leaves from field-grown plants. Algorithms were developed relating leaf appearance time, expansion rate and expansion duration to growing degree days (GDD) from emergence. Leaf appearance time was a nonlinear function of leaf number. Both leaf expansion rate (RN) and leaf expansion duration (LN) were bell-shaped functions of leaf number (N) with RN skewed toward a lower value and LN skewed toward a higher value of N. These algorithms were used to develop a model of leaf area development detailed in a companion paper. Key words: Temperature, water stress, leaf area

scholarly journals Game browse and its impact on selected grain crops

2009 ◽  
Vol 55 (No. 5) ◽  
pp. 181-186 ◽  
Author(s):  
R. Cerkal ◽  
K. Vejražka ◽  
J. Kamler ◽  
J. Dvořák
Keyword(s):  
Leaf Area ◽  
Significant Influence ◽  
Spring Barley ◽  
Field Trials ◽  
Growth Stages ◽  
Plant Parts ◽  
Area Reduction ◽  
Mechanical Removal ◽  
The Impact ◽  
Leaf Area Reduction

This work presents the results of a survey that studied simulated plant browsing by herbivores. In 2004–2006, winter wheat, spring barley, and maize field trials were founded in order to monitor the impact of different levels of defoliation (leaf area reduction) on the yield and grain quality. The defoliation was carried out by means of mechanical removal of plant parts in the early growth stages. Selected qualitative parameters were determined in the harvested grain of wheat and barley. Statistically significant influence of leaf area reduction (LAR) on grain yield (decrease by 4–14%) was found only in maize in 2004. No statistically significant influence of the leaf area reduction on thousand grain weight (TGW) was found in any of the studied crops. The leaf area reduction in barley did not affect grain characteristics; however, it had a statistically significant influence on the quality of wheat grain. Moreover, wheat reduction statistically significantly increased the falling number (by 29–39 s) and decreased SDS test values (by 8–9 ml).

Co-ordination of stem elongation and Zadoks growth stages with leaf emergence in wheat and barley

1994 ◽  
Vol 122 (1) ◽  
pp. 21-29 ◽  
Author(s):  
E. J. M. Kirby ◽  
M. Appleyard ◽  
N. A. Simpson
Keyword(s):  
Growth Stage ◽  
Stem Elongation ◽  
Sowing Date ◽  
Development Stage ◽  
Growth Stages ◽  
Final Number ◽  
Leaf Emergence ◽  
Basal Internode ◽  
Final Length ◽  
Number Of Leaves

SUMMARYLeaf emergence, apex development stage, internode length and Zadoks principal growth stage 3 were measured over 3 years at several sites.Internode elongation and Zadoks score were strongly related to the number of emerged culm leaves. The final length of the most basal internode was very variable and contributed to variation in the relationship between Zadoks stage 30 and the number of emerged culm leaves. Variation in the length of the basal internode was related to the final number of culm leaves. Most plants had six culm leaves but the number of leaves was affected by sowing date. In an experiment where sowings were made from September to March, stem elongation and Zadoks stage 30 started at a later stage of apex development in later sowings.Recognition and prediction of culm elongation and number of emerged culm leaves is important for the application of growth regulator and fungicides. Combined with functions to predict the rate of leaf emergence and final number of leaves, the relationships described in this paper may enable Zadoks principal growth stage 3 and number of emerged culm leaves to be predicted.

scholarly journals Glyphosate Tolerance of Two Perennial Ryegrass Cultivars from Fall Applications and at Seedling Growth Stages

HortScience ◽  
2015 ◽  
Vol 50 (2) ◽  
pp. 304-309
Author(s):  
Christian M. Baldwin ◽  
Eugene K. Blythe ◽  
A. Douglas Brede ◽  
Jami J. Mayer ◽  
R. Golembiewski
Keyword(s):  
Perennial Ryegrass ◽  
Temperature Response ◽  
Field Trials ◽  
Application Rate ◽  
Growth Stages ◽  
Annual Bluegrass ◽  
Air Temperatures ◽  
The One ◽  
Fall Application ◽  
Response Trial

The use of glyphosate-tolerant perennial ryegrass (Lolium perenne L.) (PRG) cultivars JS501 and Replay provides turfgrass managers a unique option for annual bluegrass (Poa annua L.) (ABG) control. Both cultivars can tolerate a maximum glyphosate rate of 0.81 kg·ha−1 acid equivalent (a.e.) after establishment under optimal growing temperatures (16 to 24 °C). However, tolerance to applications made immediately after germination and during low air temperatures has received limited investigation. Therefore, objectives of this research were to determine the seedling tolerance and low-temperature response after a fall season glyphosate application to both cultivars. Field trials were conducted in Idaho and Oregon. For the fall application response trial in Idaho, glyphosate was applied at 0, 0.15, 0.29, 0.58, 1.16, 1.74, 2.32, and 3.48 kg·ha−1 a.e. In Oregon, glyphosate was applied at 0, 0.15, 0.29, 0.44, 0.58, 1.16, and 3.48 kg·ha−1 a.e. At both sites, applications were made between late September and early October. To determine seedling tolerance, both cultivars were sprayed with glyphosate at the one-leaf stage (LS), two LS, three LS, or four LS at rates of 0, 0.15, 0.29, and 0.58 kg·ha−1 a.e. Across all trials, ratings included PRG color, cover, and injury. At both trial locations, regression analysis revealed a rate of ≈0.27 kg·ha−1 a.e. was required to cause 20% leaf firing in the fall application response trial. In the seedling tolerance trial, glyphosate applied at 0.58 kg·ha−1 a.e. at the one LS, two LS, and three LS had color ratings 8.0 or greater; however, color ratings dropped to 4.6 when an application was made at the four LS. Based on the environmental conditions of each trial, results suggest glyphosate applications greater than 0.27 kg·ha−1 a.e. as minimum air temperatures approach 0 °C should be avoided. Also, applications should be avoided at the three to four LS if the application rate is greater than 0.29 kg·ha−1 a.e.

Discrepancies between observed and predicted growth stages in wheat

1997 ◽  
Vol 129 (4) ◽  
pp. 379-384 ◽  
Author(s):  
E. J. M. KIRBY ◽  
R. M. WEIGHTMAN
Keyword(s):  
Stem Elongation ◽  
Daily Maximum ◽  
Growth Stages ◽  
Main Shoot ◽  
Wheat Growth ◽  
Growing Seasons ◽  
Leaf Emergence ◽  
Prediction Scheme ◽  
Number Of Leaves ◽  
Input Variables

A model to predict wheat growth stage is briefly described. It is based on prediction of the number of emerged leaves and the final number of leaves on the main shoot, and the co-ordination between leaf emergence and apex development, including stem elongation. The input variables are daily maximum and minimum temperatures, date of sowing and site latitude, from which thermal time, vernalization and daylength are calculated.Selected growth stages were predicted for six sites in each of three growing seasons. The differences between observations made by independent observers and predictions were mostly 7 days or less but in three site–season combinations the average difference was >10 days. Observer errors were implicated and examined, but it is concluded that the prediction scheme must also have been partly responsible for the discrepancies.

scholarly journals Reducing N Application by Increasing Plant Density Based on Evaluation of Root, Photosynthesis, N Accumulation and Yield of Wheat

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1080
Author(s):  
Xiangqian Zhang ◽  
Shizhou Du ◽  
Yunji Xu ◽  
Chengfu Cao ◽  
Huan Chen
Keyword(s):  
Leaf Area ◽  
Plant Density ◽  
Application Rate ◽  
N Recovery ◽  
Individual Plant ◽  
N Accumulation ◽  
N Application ◽  
Area Index ◽  
N Level ◽  
N Application Rate

(Aims) To clarify the mechanisms though which dense planting could alleviate the negative effect of the reducing N rate on yield, (Methods) an experiment with four nitrogen levels—0 (N0), 120 (N1), 180 (N2) and 240 (N3) kg N ha−1—and three plant densities—180 (D1), 240 (D2) and 300 (D3) × 104 basic seedlings ha−1—was conducted. (Results) Increasing plant density decreased the root length, root volume, root surface area and root tips of individual plant while it enhanced the aforementioned root traits in population. The chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate of the individual plants were decreased with the increase in plant density and enhanced with the increase in N level. The increasing density and N application rate enhanced the leaf area index, photosynthetic high-efficiency leaf area and canopy photosynthetically active radiation of population. N accumulation per plant was decreased with increasing density and was enhanced with an increasing N application level. Within the same N level, the N accumulation in the population, N production efficiency and N recovery efficiency were consistently D3 > D2 > D1. A high N application rate with high density was not conducive to improving the NR (nitrate reductase), GS (glutamine synthetase) and GOGAT (glutamate synthase) activities. The yield could be maintained as stable or improved if decreasing by 60 kg N ha−1 with increasing 60 × 104 basic seedlings ha−1 within the range of N application in this experiment. (Conclusions) These results indicated that the yield of wheat could be improved with less N application by adjusting the compensatory effects from the plant density in populations.

scholarly journals How Does Nitrogen Application Rate Affect Plant Functional Traits and Crop Growth Rate of Perennial Ryegrass-Dominated Permanent Pastures?

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2499
Author(s):  
Tammo Peters ◽  
Friedhelm Taube ◽  
Christof Kluß ◽  
Thorsten Reinsch ◽  
Ralf Loges ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Functional Traits ◽  
Perennial Ryegrass ◽  
N Uptake ◽  
Application Rate ◽  
Plant Functional Traits ◽  
N Application ◽  
Crop Growth Rate ◽  
N Application Rate

High doses of nitrogen (N) fertiliser input on permanent pastures are crucial in terms of N surplus and N losses. Quantitative analyses of the response of plant functional traits (PFT) driving crop growth rate (CGR) under low N input are lacking in frequently defoliated pastures. This study aimed to understand the significance of PFTs for productivity and N uptake in permanent grasslands by measuring dynamics in tiller density (TD), tiller weight (TW), leaf weight ratio (LWR), leaf area index (LAI), specific leaf area (SLA), as well as leaf N content per unit mass (LNCm) and per unit area (LNCa) in perennial ryegrass (Lolium perenne)-dominated pastures, in a simulated rotational grazing approach over two consecutive growing seasons. Annual N application rates were 0, 140 and 280 kg N ha−1. The phenological development of perennial ryegrass was the main driver of CGR, N uptake and most PFTs. The effect of N application rate on PFTs varied during the season. N application rate showed the greatest effect on TD, LAI and, to a lesser extent, on SLA and LNCm. The results of this study highlight the importance of TD and its role in driving CGR and N uptake in frequently defoliated permanent pastures.

Barley yield and grain protein concentration as affected by assimilate and nitrogen availability

1998 ◽  
Vol 49 (4) ◽  
pp. 695 ◽  
Author(s):  
S. Boonchoo ◽  
S. Fukai ◽  
Suzan E. Hetherington
Keyword(s):  
Grain Yield ◽  
Protein Concentration ◽  
N Uptake ◽  
Application Rate ◽  
Growth Stages ◽  
N Availability ◽  
N Application ◽  
N Application Rate ◽  
Growing Conditions ◽  
Different Growth Stages

Two types of experiments were conducted with the malting barley cv. Grimmett to examine how assimilate and nitrogen (N) availability at different growth stages determined yield and grain protein concentration (GPC) in south-east Queensland. In one series of experiments, plants were sown in April, June, and August so that they would experience different growing conditions, and responses to N application rate were examined. Another experiment examined response of growth, yield, and GPC to variation of assimilate production pre and post anthesis, caused by the canopy manipulation treatments of opening, closure, and 50% shading at 3 different growth stages. Without N application all 3 sowings produced similar yields (1·9-2·3 t/ha), but when N was applied, yield was higher and responded more to applied N in the June sowing than in the other sowings.The different responses of grain yield to N application rate among the 3 sowing dates were not due to differences in N uptake but to the efficiency of N use; with favourable temperatures throughout crop growth, the crop sown in June utilised N most eciently to develop a large number of grainsand to produce sufficient as similates to fill these grains. When yield had a positive response to low N application rates, then there was generally no response of GPC, whereas when there was no response of grain yield to further rate of N application then GPC increased. The results of the second experiment show that N uptake depended on plant N demand at early stages of growth when N was still available in the soil, but total N content of tops at maturity was similar among canopy manipulation treatments. Canopy opening at any stage of growth tended to increase tiller number, leaf area index, and above-ground dry matter, but the effect was greater attillering stage which produced the highest yield because of the greatest number of heads. Shading reduced yield at all stages, but particularly at pre-anthesis. Shading and canopy closure during grain filling reduced grain yield, but with similar N uptake these treatments significantly increased GPC .These results indicate that GPC depends on both assimilate and N availability to grain, and GPC can increase sharply when grain yield is reduced with low assimilate availability as a result of adverse growing conditions. Responses of grain yield to applied N depended on environmental conditions, particularly the patterns of air temperature during growth, and the crop utilised N more efficiently to produce higher yield when it was not exposed to extreme temperatures during the latter stages of growth.

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