scholarly journals Effect of Two Levels of Deficit Irrigation on Photosynthesis, Canopy Light Interception, and Yields in Prune

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 837F-837
Author(s):  
Bruce D. Lampinen ◽  
Kenneth A. Shackel
Keyword(s):  
Photosynthetic Rate ◽  
Deficit Irrigation ◽  
Light Interception ◽  
First Year ◽  
Severe Stress ◽  
Stress Treatment ◽  
Stem Water ◽  
Dry Fruit ◽  
Moderate Stress ◽  
Canopy Light Interception

Two levels of deficit irrigation were applied to mature French prune trees based on gradually declining midday stem water potentials decreasing to –1.5 MPa (moderate stress) and –2.5 MPa (severe stress) by harvest. The moderate and severe stress treatments resulted in 32% and 51% water savings, respectively, compared to the fully irrigated control. The average photosynthetic rate and dry fruit yield for the moderate stress treatment were not significantly lower than those for the fully irrigated control. The severe stress treatment had significantly lower photosynthetic rates from late morning until sunset on most days. However, this lower photosynthetic rate did not result in significantly lower dry fruit yields. There were no significant differences in light interception as measured diurnally or over the course of the season in the first year of the study. However, light interception and photosynthetic differences might be expected to be more pronounced in subsequent years, due to carryover effects.

scholarly journals Determination of carbohydrate accumulation and plant growth dynamics in snowdrop (Galanthus elwesii Hook.) response to moisture levels in different substrates

2021 ◽  
Vol 20 (6) ◽  
pp. 59-70
Author(s):  
Arda Akçal
Keyword(s):  
Growth Dynamics ◽  
Total Sugar ◽  
Survival Strategy ◽  
Severe Stress ◽  
Total Carbohydrate ◽  
Carbohydrate Accumulation ◽  
Stress Treatment ◽  
Storage Organs ◽  
Moderate Stress

In terms of botany, geophytes are known by their own survival strategy due to have a swollen storage organs. Snowdrops (Galanthus, 20 spp.; Amaryllidaceae) are important type of wild-sourced ornamental bulb genus in all geophyte species. Also, have a great deal of potential for use on landscape designs. Whereas, not much study has been done regarding the growth dynamics of snowdrops at harsh environmental conditions. This experiment was conducted to evaluate the effects of abiotic stress conditions on the performance of snowdrop (Galanthus elwesii Hook.) in soiless culture. Substrates and moisture were the variables. Peat + perlite and cocopeat were used as a substrate in pots. Moisture levels were applied; ML1, ML2 (well-watered and moderately tolerant treatments), ML3 (moderate stress) and ML4 (severe stress). Moisture had a statistically significant effect (P < 0.05) on circumference size, height and weight of the snowdrop bulbs. Plant height and carbohydrate accumulation were also affected by moisture levels in different substrates. The correlation between total carbohydrate (r = 0.95) and starch (r = 0.98) were positively determined. The reduced sugar, total sugar, starch and total carbohydrate values were increased by the severe stress treatment (ML4).

scholarly journals 115 Nitrogen fertilizer effects on above ground sward characteristics and beef heifer performance from native warm-season grass blends

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 26-27
Author(s):  
Caroline Chappell ◽  
Landon Marks ◽  
Katie Mason ◽  
Mary K Mullenix ◽  
Sandra L Dillard ◽  
...  
Keyword(s):  
Nutritive Value ◽  
Warm Season ◽  
Ground Cover ◽  
Application Rate ◽  
Light Interception ◽  
Botanical Composition ◽  
Forage Production ◽  
Beef Heifers ◽  
Fertilizer Application Rate ◽  
Canopy Light Interception

Abstract A 2-yr study was conducted at Black Belt Research and Extension Center in Marion Junction, AL, to evaluate the effect of nitrogen (N) fertilizer application rate on forage production characteristics, nutritive value, and animal performance of beef heifers grazing a mixture of native warm-season grasses (NWSG) including big bluestem, little bluestem, and indiangrass. Six, two-hectare plots were randomly assigned to one of two treatments (0 or 67 kg N ha-1 applied in early April; n = 3 replications per treatment). Paddocks were continuously stocked with four weaned Angus × Simmental beef heifers (initial BW 288 ± 7 kg) from late May/early June through mid-to-late August during 2018 (73 grazing d) and 2019 (70 grazing d), respectively. Put-and-take cattle were used to manage forage to a target of 38 cm. Forage mass and canopy heights were collected every two weeks during the trial. Visual ground cover ratings, canopy light interception, and botanical composition were measured at the beginning and end of the trial in each year. Hand-plucked samples were collected every two weeks during the grazing trial to determine forage nutritional value. Data were analyzed using the PROC MIXED procedure in SAS 9.4, and differences were declared significant when P ≤ 0.05. Nitrogen fertilized NWSG had greater crude protein (P &lt; 0.0001), sward heights (P = 0.0003), and canopy light interception at the beginning of the season (P = 0.0049) compared to non-fertilized paddocks. However, there were no differences (P ≥ 0.05) among N-fertility treatments for mean forage mass, heifer ADG, or BCS across the 2-yr study. Botanical composition data indicated that indiangrass decreased from 64% to 61% (P = 0.0022) and weed pressure increased from 11% to 15% (P = 0.0064) across the summer grazing season. Canopy light interception decreased by 51% from early June to August in fertilized NWSG and 26% in unfertilized paddocks, respectively. These data illustrate that NWSG systems may provide a viable grazing system in the summer months under reduced N inputs.

scholarly journals GAMBARAN STOMATITIS AFTOSA REKUREN DAN STRES PADA NARAPIDANA DI LEMBAGA PEMASYARAKATAN KELAS II B BITUNG

e-GIGI ◽  
2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Melky G. Junhar ◽  
Pieter L. Suling ◽  
Aurelia S. R. Supit
Keyword(s):  
Oral Cavity ◽  
Sampling Method ◽  
Recurrent Aphthous Stomatitis ◽  
Aphthous Stomatitis ◽  
Mild Stress ◽  
Severe Stress ◽  
Cross Sectional ◽  
Class Iib ◽  
As Stress ◽  
Moderate Stress

Abstract: Prisoners are individuals who have been convicted of crimes and were sentenced to prison so they lost their freedom. Lost of freedom can cause stress. Stress is the ability of a person to survive under pressure without causing disturbance. Recurrent aphthous stomatitis (RAS) is a manifestation in the oral cavity which is usually triggered by some predisposing factors such as stress. This study aimed to describe recurrent aphthous stomatitis and stress among prisoners in prison class IIB Bitung. This study was cross-sectional with total sampling method. All prisoners who had experienced recurrent aphtous stomatitis (RAS) while in prison class IIB Bitung. The results showed that among the 56 respondents there were 53 male respondents (94.64%) and 3 female respondents (5.36%); 19 (33.93%) got mild stress, 18 (32.14%) moderate stress, 16 (28.58%) severe stress, and 3 (5.35%) very severe stress.Keywords: prisoner, stress, recurrent aphthous stomatitis (RAS)Abstrak: Narapidana adalah individu yang telah terbukti melakukan tindak pidana dan kemudian oleh pengadilan dijatuhi hukuman atau pidana serta kehilangan kebebasan. Kehilangan kebebasan menimbulkan terjadinya stres pada narapidana. Stres merupakan kemampuan individu untuk bertahan dalam menghadapi berbagai tekanan tanpa mengakibatkan gangguan. Stomatitis aftosa rekuren (SAR) merupakan manifestasi yang timbul dalam rongga mulut yang biasanya dipicu oleh beberapa faktor predisposisi, salah satunya stres. Tujuan penelitian yaitu mengetahui gambaran stomatitis aftosa rekuren dan stres pada narapidana di Lembaga Pemasyarakatan (LP) Kelas IIB Bitung. Jenis penelitian ini menggunakan desain potong lintang. Semua narapidana yang pernah mengalami Stomatitis Aftosa Rekuren (SAR) saat berada di Lembaga Pemasyarakatan kelas II B Bitung. Hasil penelitian menunjukkan bahwa dari 56 responden terdapat 53 responden berjenis kelamin laki-laki (94,64%) dan terdapat 3 responden berjenis kelamin perempuan (5,36%). Hasil pengukuran stres menunjukkan bahwa dari 56 responden 19 responden (33,93%) mengalami tingkat stres ringan, 18 responden (32,14%) mengalami tingkat stres sedang, 16 responden (28,58%) mengalami tingkat stres berat dan 3 responden (5,35%) mengalami tingkat stres sangat berat.Kata kunci: narapidana, stres, stomatitis aftosa rekuren.

Assess level of stress among working and non-working women residing in selected areas in a view to develop an information booklet

2021 ◽  
pp. 373-375
Author(s):  
Satish N. Choure
Keyword(s):  
Stress Level ◽  
Degrees Of Freedom ◽  
Working Women ◽  
Sampling Technique ◽  
P Value ◽  
Research Approach ◽  
Severe Stress ◽  
Information Booklet ◽  
Stress Score ◽  
Moderate Stress

Assess level of stress among working and non-working women residing in selected areas in a view to develop an information booklet. Objectives: 1. To assess level of stress among working women. 2. To assess level of stress among non-working women. 3. To compare the level of stress among working and non-working women. Material and Methods: The research approach adopted in this study is Evaluatory approach. Non-experimental descriptive comparative research design was used. The sample were selected by non-probability convenient sampling technique sample size was 120 (60working women and 60 non-working women). Results: 1. 85% of the working women had severe stress (score 18-25) and 15% of them had moderate stress (Score 26-33). 2. 35% of the non-working women had severe stress (score 18-25) and 65% of them had moderate stress (Score 26-33). 3. Average stress score in employed women was 22.5 which was 26.2 in unemployed women. Z-value for this test was 7.8 with 118 degrees of freedom. Corresponding p-value was small (less than 0.05), the null hypothesis is rejected. The stress level among working is significantly more than that in non-working women. Conclusion: The stress level among working is significantly more than that in non-working women.

scholarly journals Pasture characteristics of Italian ryegrass and milk production under different management strategies

2012 ◽  
Vol 47 (6) ◽  
pp. 863-868 ◽  
Author(s):  
Marcolino Frederico Miguel ◽  
Henrique Mendonça Nunes Ribeiro Filho ◽  
Steben Crestani ◽  
Fabiana da Rocha Ramos ◽  
Tereza Cristina Moraes Genro
Keyword(s):  
Dry Matter ◽  
Nutritional Value ◽  
Lolium Multiflorum ◽  
Management Strategies ◽  
Growing Season ◽  
Light Interception ◽  
Italian Ryegrass ◽  
Neutral Detergent Fiber ◽  
Low Light ◽  
Canopy Light Interception

The objective of this work was to assess the effects of the sward structure of Italian ryegrass (Lolium multiflorum), during the first grazing cycle, on its morphological and bromatological characteristics throughout the growing season, and on the performance of dairy cows. The treatments consisted of two structures obtained as a function of canopy-light interception: high-light interception (HLI) and low-light interception (LLI), with different pre-grazing heights in the first grazing cycle. Pasture was managed under rotational grazing with a herbage allowance not below 30 kg dry matter (DM) per cow per day. Three grazing cycles, with a grazing interval of 30 days, were evaluated. Pre-grazing herbage mass was greater (2,240 vs. 1,656 kg ha-1 DM), but the proportion of leaf blades was smaller (0.35 vs. 0.43) for HLI swards. Neutral detergent fiber (NDF) content and organic matter digestibility (OMD) were similar between treatments in the first grazing cycle, but in the second and third ones NDF was greater, and OMD lower, for the HLI swards. Milk yields were greater for cows grazing LLI swards (19.4 vs. 21.1 kg per day). Initial grazing with 90% of light interception promotes greater nutritional value in the subsequent cycles.

scholarly journals Growth, physiology and yield responses of cabbage to deficit irrigation

2014 ◽  
Vol 41 (No. 3) ◽  
pp. 138-146 ◽  
Author(s):  
C. Xu ◽  
D.I. Leskovar
Keyword(s):  
Plant Growth ◽  
Water Content ◽  
Leaf Area ◽  
Photosynthetic Rate ◽  
Deficit Irrigation ◽  
Total Yield ◽  
Rio Grande ◽  
Fresh Weight ◽  
Growth Physiology ◽  
Yield Responses

Field experiments were conducted in two seasons to investigate growth, physiology and yield responses of cabbage (Brassica oleracea L. cvs Pennant and Rio Grande) to deficit irrigation. In 2012 season, 50% of crop evapotranspiration (ETc) irrigation temporarily decreased plant size, reduced leaf area, fresh weight, relative water content, specific leaf area and gas exchange during late development, and decreased head fresh weight, size, marketable and total yield. Deficit irrigation at 75% ETc had little influence on plant growth and physiology, but it still reduced both marketable and total yield. In 2013 season, 75%&nbsp;ETc irrigation had little influence on plant growth, leaf characteristics, photosynthetic rate, head fresh weight and size, but it temporarily increased chlorophyll and carotenoid content, and decreased stomata conductance, transpiration, and marketable yield. Pennant, the green-head cultivar, had higher photosynthetic rate, head fresh weight, marketable and total yield than the red-head cultivar Rio Grande. In both seasons, deficit irrigations did not influence cabbage head dry weight, indicating that most yield reduction under deficit irrigations is related to water content. &nbsp;

scholarly journals Response of a clingstone peach cultivar to regulated deficit irrigation

2010 ◽  
Vol 67 (2) ◽  
pp. 164-169 ◽  
Author(s):  
Thomas Sotiropoulos ◽  
Dimitrios Kalfountzos ◽  
Ioannis Aleksiou ◽  
Spyros Kotsopoulos ◽  
Nikolaos Koutinas
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Photosynthetic Rate ◽  
Deficit Irrigation ◽  
Prunus Persica ◽  
Fruit Growth ◽  
Leaf Water ◽  
Stage Ii ◽  
Soluble Solids ◽  
Regulated Deficit Irrigation

Regulated deficit irrigation (RDI) involves inducing water stress during specific fruit growth phases by irrigating at less than full evapotranspiration. The objectives of this research were to study the effects of RDI perfomed at stage II of fruit growth and postharvest, on productivity of clingstone peaches, fruit quality as well as photosynthetic rate and midday leaf water potential. The research was conducted in a commercial clingstone peach (Prunus persica L. Batch cv. A-37) orchard in Greece. Trees were irrigated by means of microsprinklers and their frequency was determined using local meteorological station data and the FAO 56 Pennman-Monteith method. Photosynthetic rate was measured by a portable infrared gas analyzer. Midday leaf water potential was measured by the pressure chamber technique. During the years 2005 and 2006, the treatment RDII with irrigation applied at growth stage II of the peach tree did not affect productivity, fresh and dry mass of fruits. RDII reduced preharvest fruit drop in comparison to the control. RDII as well as the combined treatment RDII plus RDIP with irrigation applied at postharvest, at both years reduced shoot length of the vigorous shoots inside the canopy. RDII in comparison to the control increased the soluble solids content of the fruits and the ratio soluble solids/acidity. However it did not affect fruit acidity and fruit firmness. RDII as well as RDII plus RDIP in 2006 increased 'double' fruits and fruits with open cavity in comparison to the control and RDIP. Water savings were considerable and associated with the climatic conditions of each year.

scholarly journals Tree light capture and spatial variability of understory light increase with species mixing and tree size heterogeneity

2016 ◽  
Vol 46 (7) ◽  
pp. 968-977 ◽  
Author(s):  
Gauthier Ligot ◽  
Aitor Ameztegui ◽  
Benoît Courbaud ◽  
Lluís Coll ◽  
Dan Kneeshaw
Keyword(s):  
Three Dimensional ◽  
Weighted Average ◽  
Structural Heterogeneity ◽  
Light Interception ◽  
Tree Size ◽  
Dimensional Structure ◽  
Transmitted Radiation ◽  
Long Run ◽  
Forest Heterogeneity ◽  
Canopy Light Interception

Mixed and multi-layered forest ecosystems are sometimes more productive than monospecific and single-layered ones. It has been suggested that trees of different species and sizes occupy complementary positions in space, which would act as a mechanism to increase canopy light interception and wood production. However, greater canopy light interception reduces the average amount and variability of transmitted radiation, offering fewer opportunities for all species to regenerate and to maintain forest heterogeneity in the long run. We investigated whether increasing overstory heterogeneity indeed results in greater canopy light interception and lower variability in transmittance. We modeled the three-dimensional structure of forest stands with three typical forest structures, 10 mixtures of four tree species, and three different basal areas. We used the forest light interception model SamsaraLight and performed three-way analyses of covariance to analyze the effects of the three varied components of forest heterogeneity. We found no evidence that increasing structural heterogeneity increases canopy light interception. However, the light interception by mixed canopies was greater than the weighted average of light interception by the corresponding pure canopies. Variability in transmittance increased in some cases with compositional heterogeneity and, to a lesser extent, with tree size inequalities. The advantage of heterogeneous forests is in opportunities for natural regeneration, as well as in opportunities to enhance canopy light interception.

Sealed environment chamber for canopy light interception and trace hydrocarbon analyses

1999 ◽  
Vol 24 (3) ◽  
pp. 271-280 ◽  
Author(s):  
M.A. Dixon ◽  
B. Grodzinski ◽  
R. Côté ◽  
M. Stasiak
Keyword(s):  
Light Interception ◽  
Environment Chamber ◽  
Canopy Light Interception
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