scholarly journals Effect of fruit load of the first coffee harvests on leaf gas exchange

2021 ◽  
Vol 51 ◽  
Author(s):  
Carlos Andres Unigarro Muñoz ◽  
Lina Marcela Díaz Bejarano ◽  
José Ricardo Acuña
Keyword(s):  
Gas Exchange ◽  
Repeated Measures ◽  
Leaf Gas Exchange ◽  
Production Cycle ◽  
Phenological Stages ◽  
Randomized Design ◽  
Absolute Growth ◽  
Net Assimilation ◽  
Source Sink ◽  
Fruit Load

ABSTRACT Coffee production between the first and second harvest presents a difference in the fruit load with the plant age that could affect the leaf gas exchange. This research aimed to evaluate the effect of the increase in fruit load that occurs between the first and second harvest of the Coffea arabica L. production cycle on the measured gas exchange, at the two phenological stages of the fruit. The accessions E057, E318, E338 and E554 were used, as well as a completely randomized design, with three replications, using the accessions as treatments and the harvest measurements during the production cycle as the repeated measures. The variables yield per tree, number of fruits, absolute growth rates for height and stem, leaf area, leaf-to-fruit ratio and leaf gas exchange were measured across the phenological stages of fruit filling and ripening. The increase in the fruit load that occurs with age in the second harvest, if compared to the first harvest, showed a positive and significant effect on the net assimilation rate that was not expected for the obtained leaf-to-fruit ratios. Likewise, the differences in the assimilation rates were higher during the fruit-filling stage. This result suggests that the source-sink relationship may vary with the crop age and fruit phenological stage, and is not entirely depend on the leaf-to-fruit ratio.

scholarly journals Production of Bambusa vulgaris seedlings from rhizomes under brackish water irrigation

2020 ◽  
Vol 24 (5) ◽  
pp. 337-342
Author(s):  
Lourenço M. C. Branco ◽  
Claudivan F. de Lacerda ◽  
Albanise B. Marinho ◽  
Carlos H. C. de Sousa ◽  
Amanda S. F. Calvet ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Brackish Water ◽  
Dry Matter ◽  
Leaf Gas Exchange ◽  
Photosynthesis Rate ◽  
Seedling Production ◽  
Randomized Design ◽  
Bambusa Vulgaris ◽  
Completely Randomized Design

ABSTRACT The objective of this study was to evaluate the influence of irrigation with brackish water on the production of bamboo seedlings (Bambusa vulgaris). The experiment was carried out at the Fazenda Experimental Piroás, in the municipality of Redenção, CE, Brazil (4° 14’ 53” S, 38° 45’ 10” W, and altitude of 230 m), in a completely randomized design with five treatments and six repetitions. The treatments consisted of five irrigation water electrical conductivity (ECw): 0.5 (control); 1.5; 2.5; 3.5 and 4.5 dS m-1. At 120 days after the beginning of the application of the treatments the leaf gas exchange, relative chlorophyll index (RCI), plant height (H), shoot dry matter (SDM), H/SDM ratio, and the concentrations of Na+ and K+ in stems and leaves were evaluated. Salt tolerance indexes were calculated based on SDM, H, photosynthesis rate and RCI. The increase in the ECw reduced leaf gas exchange, and the reduction in the photosynthesis rate was caused by stomatal and non-stomatal effects. The salinity affected negatively the growth and quality of bamboo seedlings, with the greatest effects being with ECw equal to or greater than 2.5 dS m-1. Bamboo seedlings present Na+ retention in the stems and low Na+/K+ ratio in the leaves. Bamboo seedlings are tolerant to salinity up to 1.5 dS m-1, indicating that waters with this salinity can be used for seedling production of this species, without loss of growth and quality.

scholarly journals A steady-state stomatal model of balanced leaf gas exchange, hydraulics and maximal source–sink flux

2017 ◽  
Vol 37 (7) ◽  
pp. 851-868 ◽  
Author(s):  
Teemu Hölttä ◽  
Anna Lintunen ◽  
Tommy Chan ◽  
Annikki Mäkelä ◽  
Eero Nikinmaa
Keyword(s):  
Steady State ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Source Sink

scholarly journals Drought-tolerant Common Bush Bean Physiological Parameters as Indicators to Identify Susceptibility

HortScience ◽  
2019 ◽  
Vol 54 (11) ◽  
pp. 2091-2098
Author(s):  
Alefsi David Sánchez-Reinoso ◽  
Gustavo Adolfo Ligarreto-Moreno ◽  
Hermann Restrepo-Díaz
Keyword(s):  
Gas Exchange ◽  
Common Bean ◽  
Water Deficit ◽  
Leaf Gas Exchange ◽  
Leaf Thickness ◽  
Reproductive Stage ◽  
Vegetative Stage ◽  
Phenological Stages ◽  
Bush Bean ◽  
Exchange Properties

Bean crops can be displaced to marginal areas or face abiotic stresses such as water deficit. Physiological responses allow the identification of tolerant genotypes and lead to more precise breeding strategies. The objective of this research was to evaluate the physiological (leaf gas exchange properties, leaf water content, and leaf thickness) and biochemical [proline and malondialdehyde (MDA)] responses of five common bush bean (Phaseolus vulgaris L.) cultivars (ICA-Cerinza, ICA-Bachue, NUA35, Bianca, and Bacatá) under a water shortage period by irrigation suspension (15 days) at two different phenological stages [vegetative: 40–55 days after seed emergence (DAE) or reproductive: (50–65 DAE)]. A completely randomized block design was carried out with a factorial arrangement (the phenological stage as the main factor and the cultivars as the secondary factor) for a total of 10 treatments with four repetitions per treatment. Leaf photosynthesis (Pn) showed equal photosynthesis values in control plants of all cultivars (≈20 μmol·m−2·s−1). The water deficit period reduced Pn close to 55% (≈12 μmol·m−2·s−1) at both, vegetative, or reproductive stage in all cases. Similar results were also observed on leaf thickness, with a reduction of ≈10% in water-stressed plants at either vegetative or reproductive stage in all evaluated cultivars. A higher MDA and proline production were observed in plants affected by a 15-day water deficit period, mainly at the vegetative stage. The obtained results suggest that the vegetative stage presented a more negative impact on the evaluated physiological variables in most of the cultivars used. Cultivar Bachue showed lower gas exchange properties affectation and higher proline content, which may indicate that this cultivar can be tolerant to water deficit stress conditions. This study allows suggesting that proline and MDA estimation are simple, fast, and low-cost techniques to screen cultivars to obtain more precise breeding selection in common bean. Finally, common bean cultivar selection through the use of biochemical markers can be complemented by the estimation of leaf gas exchange parameters at different phenological stages.

scholarly journals Growth of yacon under artificial shading

2021 ◽  
Vol 39 (2) ◽  
pp. 133-139
Author(s):  
Ariany das Graças Teixeira ◽  
Fábio Luiz de Oliveira ◽  
Tiago P Mendes ◽  
Paulo Cezar Cavatte ◽  
Magno do C Parajara ◽  
...  
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Mass Fraction ◽  
Dry Mass ◽  
Total Biomass ◽  
Tuberous Roots ◽  
Randomized Design ◽  
Absolute Growth ◽  
Net Assimilation ◽  
Artificial Shading

ABSTRACT Yacon is a tuberous root cultivated in mild climate regions with high altitudes, but the crop shows the capacity to develop at low altitudes. The objective of this study was to evaluate growth rates and the partition of photoassimilates in yacon plants under different levels of artificial shading. The experiment was conducted in four shading levels (0%, 30%, 50% and 70%), and seven monthly harvests in a completely randomized design. We evaluated the accumulation of total dry mass on the whole plant and its parts; leaf area; leaf area ratio; leaf mass fraction; stem mass fraction; rhizophores mass fraction; tuberous roots mass fraction; estimates of relative growth rate, absolute growth, and net assimilation. The lower accumulation of total dry biomass and the lowest growth rates indicate that conditions of noticeable light restriction (70% shading) restrict the growth of yacon. Yacon plants grown under moderate shading levels (30 to 50%) showed greater capacity of accumulation of total biomass, directing part of this biomass to the tuberous roots, which directly reflects gains in the agronomic productivity of this crop, indicating that yacon has the potential to be associated with other crops, which promote a moderate shading.

scholarly journals Same Season and Carry-Over Effects of Source-Sink Adjustments on Grapevine Yields and Non-structural Carbohydrates

2021 ◽  
Vol 12 ◽  
Author(s):  
Johann Martínez-Lüscher ◽  
Sahap Kaan Kurtural
Keyword(s):  
Gas Exchange ◽  
Leaf Area ◽  
Leaf Gas Exchange ◽  
Soluble Solids ◽  
Fruit Removal ◽  
Source To Sink ◽  
Carry Over ◽  
Reserve Carbohydrate ◽  
Source Sink ◽  
Fruit Mass

The grapevine (Vitis vinifera L.) is managed to balance the ratio of leaf area (source) to fruit mass (sink). Over cropping in the grapevine may reveal itself as spontaneous fruit abortion, delayed ripening, or as alternate bearing. The aim of this work was to study the same season and carry-over effects of manipulating source to sink ratios on grapevine phenology, leaf gas exchange, yield components, berry soluble solids accumulation, and reserve carbohydrate and soluble sugar concentration in roots. Cabernet Sauvignon grapevines were subjected to defoliation (33, 66, and 100% of the leaves retained) and fruit removal treatments (33, 66, and 100% of clusters retained) arranged in a factorial design. Results from two seasons of source-sink manipulations were substantially different. In both seasons defoliation treatments affected season-long net carbon assimilation (AN) and stomatal conductance (gs) where the less leaves were retained, the greater the AN and gs, and fruit removal had no impact on leaf gas exchange. In the first season, leaf area to fruit mass was hardly related to berry soluble solids and in the second season they were strongly correlated, suggesting a degree of acclimation. Defoliation treatments had great impacts on berry size, berries per cluster, and total soluble solids in both years. Fruit removal treatments only had effects on berry mass and berries per cluster in the first season, and only on berry soluble solids in the second. The predominant effect of defoliation (carbon starvation) cascaded onto reducing root starch content, root mass and delaying of veraison and leaf senescence, as well as harvest which was delayed up to 9 weeks with 33% of the leaves retained. In a third season, where grapevines grew without treatments, defoliation treatments had resultant carryover effects, including reduced leaf area, number of berries per cluster, clusters per vine, and yield, but not on leaf gas exchange dependent on previous seasons' severity of defoliation. Balancing source-to-sink ratio is crucial to obtain an adequate speed of ripening. However, this was the culmination of a more complex whole-plant regulation where the number of leaves (source strength) outweighed the effects of fruits (sink strength).

scholarly journals Gas Exchanges of Yellow Capsicum Fertilized with Yellow Water and Cassava Wastewater

2017 ◽  
Vol 9 (12) ◽  
pp. 316
Author(s):  
Jailton Garcia Ramos ◽  
Vera Lucia Antunes de Lima ◽  
Ronaldo do Nascimento ◽  
Rafaela Felix Basílio Guimarães ◽  
Mariana De Oliveira Pereira ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Human Urine ◽  
Wastewater Reuse ◽  
Gas Exchanges ◽  
Physiological Variables ◽  
Leaf Transpiration ◽  
Randomized Design ◽  
Internal Concentration ◽  
Net Assimilation ◽  
Cassava Wastewater

Wastewater reuse has increasingly become a sustainable alternative to the efficient use of water as well as the mitigation of the negative environmental impacts generated by the release of the water to the environment in an indiscriminate way. Thus, it is very important to know and evaluate the physiological variables of gas exchanges of plants cultivated with these waters, in order to obtain precise answers their effects on plant physiology. The present study aimed to evaluate the gas exchange of yellow capsicum cultivated in soil fertilized with human urine and cassava wastewater. The experiment was conducted in a protected environment at the Federal University of Campina Grande, Campina Grande - PB. A completely randomized design with eight treatments and five replications was used. The treatments were cattle manure (T1); NPK (T2); human urine treated (T3); cassava wastewater (T4); (T3)+(T4); 2x(T3); 2x(T4); 2x(T3+T4). The volumes of the biofertilizers were defined according to the nitrogen and potassium contents of urine and cassava wastewater, respectively. At 15 and 30 days after transplanting, the variables of gas exchange, the efficient use of water and the instantaneous efficacy of carboxylation were evaluated. The data were submitted to Tukey test at 5% probability. The results indicated that there wasn’t statistical difference for efficient use of water (UEA) evaluated at 30 DAT.The treatment 5 provided the best results in relation to gas exchange, for the variables internal concentration of CO2 (Ci), net assimilation rates of CO2 (A), stomatal conductance (gs), leaf transpiration (E), higher efficiency of water use (UEA) and instantaneous carboxylation efficiency at 15 DAT, so for 30 DAT the biofertilizer that provided the best results was the T4 treatment, although there weren’t significant statistical differences among the treatments for (UEA), except for of T5.

scholarly journals Application of Kaolin-based Particle Film on Pecan Trees: Consequences on Leaf Gas Exchange, Stem Water Potential, Nut Quality, and Insect Populations

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 857E-858 ◽  
Author(s):  
Leonardo Lombardini* ◽  
D. Michael Glenn ◽  
Marvin K. Harris
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Leaf Gas Exchange ◽  
Stink Bugs ◽  
Stem Water Potential ◽  
Lady Beetles ◽  
Insect Populations ◽  
Stem Water ◽  
Net Assimilation ◽  
And Control

Trials were established in Summer 2002 and 2003 to test the consequences of the application of a kaolin-based particle film (Surround WP, Engelhard Corp.) on gas exchange, nut quality, casebearer density and population of natural predators (insects and arachnids) on pecan (Carya illinoinensis, cv. `Pawnee') trees. Film application started immediately after bud break and was repeated every 7-10 days for seven (2002) or nine (2003) times during the season. On both years, treated trees frequently showed lower leaf temperature (up to 4 °C) than untreated trees. Leaf net assimilation rate, stomatal conductance and stem water potential were not affected by film application. Nut size and quality did not differ between the two treatments. In 2003, shellout (percentage of nut consisting of kernel) was in fact 54.2% and 55.5% for treated and control trees, respectively. Moreover, the two treatments yielded similar percentage of kernel crop grading as fancy, choice, standard and damaged. Similar were also the percentages of kernels that showed damage caused by stink bugs. Only on one date the number of adult yellow pecan aphids (Monelliopsis pecanis) counted on film-treated leaves was lower than in control leaves. In general, the density of common natural predators (lady beetles, green lacewings, spiders) of pecan pests did not differ between the two treatments; however, the number of green lacewing eggs was frequently lower on film-treated leaves. In film-treated trees the number of nutlets damaged by pecan nut casebearer (Acrobasis nuxvorella) was significantly higher than that observed on trees treated with conventional insecticide (24.2% infested nutlets vs. 9.3%, respectively) and did not differ from trees that did not receive either product (29.9%).

scholarly journals Effects of Particle Film Application on Leaf Gas Exchange, Water Relations, Nut Yield, and Insect Populations in Mature Pecan Trees

HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1376-1380 ◽  
Author(s):  
Leonardo Lombardini ◽  
Marvin K. Harris ◽  
D. Michael Glenn
Keyword(s):  
Gas Exchange ◽  
Water Relations ◽  
Natural Enemies ◽  
Leaf Gas Exchange ◽  
Carbon Assimilation ◽  
Stem Water Potential ◽  
Air Temperatures ◽  
Insect Populations ◽  
Stem Water ◽  
Net Assimilation

Trials were conducted during summer months of 2002 and 2003 to evaluate the effects of a kaolin-based particle film (Surround WP, Engelhard Corp.) on gas exchange, nut quality, casebearer density and population of natural enemies (insects and arachnids) on pecan (Carya illinoinensis `Pawnee') trees. Film application was repeated for seven (2002) or nine (2003) times during the growing season. In both years, treated trees showed lower leaf temperature (up to 4 °C) than untreated trees. During the warmest hours of the day, kaolin-treated leaves were generally 0 to 2 °C cooler than air temperatures, compared to 4 to 6 °C for control leaves. Leaf net assimilation rate, stomatal conductance and stem water potential were not affected by film application. Nut size and quality did not differ between the two treatments. Shellout (percentage of nut consisting of kernel) was not affected by treatment and averaged about 55%. Crop grade distribution (fancy, choice, standard, and damaged) was also similar among treatments in both years. In both years, numbers of green lacewing eggs was less on kaolin-treated compared to control leaves. The density of common natural enemies (lady beetles, green lacewings, spiders) of pecan pests did not differ between treatments. The average number of developing nuts damaged by pecan nut casebearer (Acrobasis nuxvorella Neunzig) was significantly higher in kaolin-sprayed trees (24.2%) compared to control trees sprayed with conventional insecticides (9.3%). The results suggest that kaolin-based particle film may not be a viable alternative to conventional methods of controlling pecan pests. Also, under adequate irrigation conditions, carbon assimilation, water relations and productivity may not benefit from kaolin particle film application.

scholarly journals Salt stress induced damages on the photosynthesis of physic nut young plants

2011 ◽  
Vol 68 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Evandro Nascimento da Silva ◽  
Rafael Vasconcelos Ribeiro ◽  
Sérgio Luiz Ferreira-Silva ◽  
Ricardo Almeida Viégas ◽  
Joaquim Albenisio Gomes Silveira
Keyword(s):  
Salt Stress ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Photochemical Efficiency ◽  
Crop Productivity ◽  
Photosynthetic Performance ◽  
Limiting Factor ◽  
Physic Nut ◽  
Gas Exchange Parameters ◽  
Randomized Design

Salinity is a major limiting factor to crop productivity in the world especially in semiarid regions. The aim of this study was to evaluate the photosynthetic resistance of Jatropha curcas (L.) young plants subjected to salt stress. The experiment was carried out in a completely randomized design with treatments in a 2 x 3 factorial: two NaCl levels (0 and 100 mmol L-1) and three harvest times: 7 and 14 days of salt exposure and three days of recovery. Leaf Na+ and Cl-concentrations and the K+/Na+ ratios, after seven days of salt exposure, did not reach ionic toxic levels, suggesting that the NaCl-induced osmotic effects prevailed over the ionic ones. Under this condition, the salt stress caused reduction in leaf gas exchange parameters, such as CO2 fixation, stomatal conductance and transpiration. In contrast, salt stress did not change the photochemical efficiency of photossystem II. Conversely, after 14 days of treatment, Na+ and Clions reached very high concentrations, up to toxic levels in leaves. Under such conditions, both leaf gas exchange and photochemistry suffered strong impairment probably caused by ionic toxicity. The recovery treatment for 3d did not significantly decrease the leaf salt concentrations and no improvement was observed in the photosynthetic performance. Physic nut young plants are sensitive to high NaCl-salinity conditions, with high leaf Na+ and Cl- concentrations, low K+/Na+ ratio and great photosynthetic damages due to stomatal and biochemical limitations.

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