scholarly journals Phenological study of populations of Cnidoscolus quercifolius in the Western Seridó, Paraiba state, Brazil

Rodriguésia ◽  
2019 ◽  
Vol 70 ◽  
Author(s):  
Érica Caldas S. de Oliveira ◽  
Everaldo O. Costa Júnior ◽  
Pedro D. Fernandes ◽  
Zelma Glebya M. Quirino
Keyword(s):  
Photosystem Ii ◽  
Water Potential ◽  
Quantum Efficiency ◽  
Rainy Period ◽  
Intensity Index ◽  
Growing Seasons ◽  
Precipitation Water ◽  
Two Populations ◽  
Peak Phase ◽  
Activity Indices

Abstract The phenological patterns of two populations of Cnidoscolus quercifolius were evaluated in the western Seridó region of Paraiba state, Brazil, from March 2009 to February 2011, with data collected monthly. The evaluations have addressed the quantitative method of analysis that represents the activity indices for both populations growing seasons (fall and sprout) and reproductive (flowering and fruiting), and also studied the intensity index Borchert, who evaluated the flow leaves. The stages were evaluated with respect to variations in rainfall, water potential of plant and quantum efficiency of photosystem II. The bud in the two populations occurred in the late dry season and transition into the rainy season, with peak leafing in January and November 2010 and was negatively correlated with rainfall (rs = -0.54 p <0.05). Leaf fall showed the peak phase in October 2009 and 2010, showing a direct relationship with water potential and photosynthetic quantum efficiency. The flowering and fruiting had greater synchrony in the seasonal rainy period, fruit set was positively correlated with precipitation values during the study period (rs = 0.56 p <0.05). The phenological events of C. quercifolius show marked seasonality in relation to precipitation, water potential and the quantum efficiency of photosystem II.

scholarly journals The Effect of Grapevine Age (Vitis vinifera L. cv. Zinfandel) on Phenology and Gas Exchange Parameters over Consecutive Growing Seasons

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 311
Author(s):  
Vegas Riffle ◽  
Nathaniel Palmer ◽  
L. Federico Casassa ◽  
Jean Catherine Dodson Peterson
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Management Practices ◽  
Leaf Water ◽  
Sugar Accumulation ◽  
Gas Exchange Parameters ◽  
Growing Season Length ◽  
Growing Seasons ◽  
Exchange Parameters

Unlike most crop industries, there is a strongly held belief within the wine industry that increased vine age correlates with quality. Considering this perception could be explained by vine physiological differences, the purpose of this study was to evaluate the effect of vine age on phenology and gas exchange parameters. An interplanted, dry farmed, Zinfandel vineyard block under consistent management practices in the Central Coast of California was evaluated over two consecutive growing seasons. Treatments included Young vines (5 to 12 years old), Control (representative proportion of young to old vines in the block), and Old vines (40 to 60 years old). Phenology, leaf water potential, and gas exchange parameters were tracked. Results indicated a difference in phenological progression after berry set between Young and Old vines. Young vines progressed more slowly during berry formation and more rapidly during berry ripening, resulting in Young vines being harvested before Old vines due to variation in the timing of sugar accumulation. No differences in leaf water potential were found. Young vines had higher mid-day stomatal conductance and tended to have higher mid-day photosynthetic rates. The results of this study suggest vine age is a factor in phenological timing and growing season length.

scholarly journals Seasonal Drought Induces Hydraulic Dysfunction, Not Carbohydrate Depletion, for Robinia Pseudoacacia in a Semi-humid Forest

2021 ◽  
Author(s):  
Qingyin Zhang ◽  
Xiaoxu Jia ◽  
Mingan Shao
Keyword(s):  
Drought Stress ◽  
Water Potential ◽  
Forest Decline ◽  
Robinia Pseudoacacia ◽  
Area Index ◽  
Drought Period ◽  
Humid Forest ◽  
Seasonal Drought ◽  
Growing Seasons ◽  
Hydraulic Failure

Abstract BackgroundShifts in rainfall patterns that are associated with climate change are likely to cause widespread forest decline in regions where droughts are predicted to increase in duration and severity. However, causes of forest decline and their physiological mechanisms remain unclear, particularly the roles of carbon metabolism and xylem function. To explore the response of hydraulic architecture and non-structural carbohydrates (NSC) traits under seasonal drought, we conducted a manipulation experiment in a Robinia pseudoacacia plantation in 2015 and 2016 in Loess Plateau of China. Sap-flow, leaf area index, water potential, non-structural carbohydrate concentrations, and hydraulics in different organs were measured. ResultsThe mean pre-dawn and midday leaf water potential after two growing seasons of drought stress was significantly lower (-2.2 MPa and -2.7 MPa, respectively) than those of control trees (-1.5 MPa and -2.0 MPa, respectively). Drought stress accelerated the loss of conductivity, and promoted the formation of narrow hydraulic safety margins, which indicated that hydraulic failure could be a good predictor of “physiological drought” in trees when subjected to two growing seasons of drought. Both sugar and starch concentrations in stems and roots were similar in all trees throughout the drought period, which indicated that trees maintained good coordination between carbon supply and demand when confronted with two growing seasons of drought.ConclusionsOur results emphasized that hydraulic failure plays the predominant role in causing tree death during highly intense drought, while whether "carbon starvation" occurs during tree mortality remains to be tested in longer (multi-year) but less intense drought.

scholarly journals Summer Diet of Two White-tailed Deer, Odocoileus virginianus, Populations Living at Low and High Density in Southern Québec

2004 ◽  
Vol 118 (3) ◽  
pp. 360 ◽  
Author(s):  
Claude Daigle ◽  
Michel Crête ◽  
Louis Lesage ◽  
Jean-Pierre Ouellet ◽  
Jean Huot
Keyword(s):  
Odocoileus Virginianus ◽  
Feeding Habits ◽  
High Density ◽  
Rumen Content ◽  
Régime Alimentaire ◽  
Food Items ◽  
Growing Seasons ◽  
Content Analyses ◽  
Two Populations ◽  
Foraging Time

We investigated summer diets of two White-tailed Deer (Odocoileus virginianus) populations through rumen content analyses. Samples from 93 deer were collected in a low density, LD (1 deer/km2) and a high density, HD (14 deer/km2) area of southern Québec during the growing seasons of 1997 and 1998. Availability of preferred forage in forests was greater in LD than in HD, whereas agriculture covered a larger proportion of the area in HD than LD. Rumen composition differed between the two populations. Deer from HD consumed less forbs and leaves of shrubs and trees than did LD deer, whereas they consumed more fruits, grasses and farm crops. The rarity in HD rumens of food items common in LD, as well as in many parts of the White-tailed Deer range (i.e., Lilliacae), indicated that deer could not compensate for the rarity of preferred forest forage by increasing foraging time and had to feed on cultivated crops. Rumen contents of LD deer had a higher level of cell solubles and lignin, which reflected their greater reliance on quality forage growing in forests. Feeding habits and forage quality can explain why deer body size decreased in HD between the 1970s and 1990s whereas LD deer remained large.Nous avons examiné le régime alimentaire estival de deux populations de cerf de Virginie (Odocoileus virginianus) par l’analyse du contenu des rumens. Des échantillons ont été prélevés sur 93 cerfs provenant d’un secteur à faible densité de cerfs, LD, (1 cerf/km2) et d’un secteur à haute densité, HD, (14 cerfs/km2) du sud du Québec durant la saison de croissance des végétaux de 1997 et 1998. La disponibilité des aliments forestiers préférés des cerfs était plus grande dans LD que dans HD alors que la proportion du territoire agricole était supérieure dans HD. La composition des rumens des cerfs de chacune des régions différait. Les cerfs de HD ont consommé de moins grandes proportions de plantes herbacées et de feuilles d’arbustes et d’arbres que ceux du secteur LD, mais de plus grandes proportions de fruits, de graminées et de plantes agricoles. La rareté dans les rumens du secteur HD d’aliments communs dans ceux du secteur LD et dans plusieurs autres régions de l’aire de répartition du cerf (e.g., Lilliacae), indique que les cerfs du secteur HD ne pouvaient compenser pour la rareté de leurs aliments préférés par un accroissement de la durée de la quête alimentaire, et qu’ils devaient consommer des plantes agricoles. Les cerfs de LD ont mangé des aliments contenant plus de solubles cellulaires et de lignine que ceux de HD, ce qui reflète une consommation de plantes forestières de bonne qualité. Le régime alimentaire et la qualité de la nourriture peuvent expliquer pourquoi la taille des cerfs de HD a diminué entre les années 1970 et 1990 alors que celle des cerfs de LD est demeurée grande.

Problems with the taxonomy of Phytoptus tetratrichus Nalepa 1890 (Acari: Eriophyoidea) inhabiting Tilia spp.: Analysis based on morphological variation among individuals

Zootaxa ◽  
2011 ◽  
Vol 2988 (1) ◽  
pp. 37 ◽  
Author(s):  
GRAŻYNA SOIKA ◽  
MARCIN KOZAK
Keyword(s):  
Leaf Surface ◽  
Leaf Roll ◽  
Morphological Characters ◽  
Canonical Variate ◽  
Qualitative And Quantitative ◽  
Growing Seasons ◽  
Leaf Surfaces ◽  
Tilia Tomentosa ◽  
Two Populations ◽  
Damage Symptoms

The purpose of this research was to investigate both the qualitative and quantitative morphological traits of Phytoptus tetratrichus Nalepa 1890 populations inhabiting three different lime tree species: Tilia cordata Mill., Tilia tomentosa Moench and Tilia americana L.. Morphological characters of two populations collected from T. cordata and T. tomentosa over three successive growing seasons were compared with the aid of canonical variate analysis. Additionally, individuals occurring on T. americana in a consecutive year were also studied. Protogyne and deutogyne females were differentiated using both qualitative and quantitative traits. For deutogyne females, individuals from all combinations of Tilia species × year (which constituted populations for comparison) clearly differed from each other. However, the differences between populations from T. cordata and T. tomentosa were less distinct. For protogyne females, observed differences were clearly visible. The between-season variation in morphological characters such as body size appeared to be quite large, indicating that morphological analysis based on observations from only a single season can be inaccurate. Deutogyne females of P. tetratrichus were observed to cause various types of damage symptoms: leaf-roll galls along the leaf edges of T. cordata; small round erinea on the lower leaf surface and small wart-like galls on the upper leaf surface of T. tomentosa; fingerlike galls on both leaf surfaces of T. americana.

Daily and seasonal changes of water potential in cereals

1976 ◽  
Vol 273 (927) ◽  
pp. 565-580 ◽  
Keyword(s):  
Environmental Factors ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Stomatal Closure ◽  
Leaf Age ◽  
Stomatal Resistance ◽  
Leaf Water ◽  
Wheat Crop ◽  
Growing Seasons ◽  
Winter Wheat Crop

The paper reports measurements of the water relations of a barley crop (cv. Proctor) and a winter wheat crop (cv. Maris Huntsman), grown on the same site at Sutton Bonington. Throughout the two growing seasons, days were chosen when hourly measurements could be made of leaf water potential, by means of a pressure chamber, and of stomatal resistance, by means of a diffusion porometer. Environmental factors, e.g. radiation, temperature, humidity, were recorded concurrently. Relationships between leaf water potential, stomatal resistance and environmental factors are explored and compared for the two cereals. In particular, as frequent measurements were made over two months, the influence of leaf age on responses to environmental factors can be examined. On selected days with bright sunshine and dry soil the response of both cereals to water stress is analysed with particular reference to the control of evaporation by stomatal closure

scholarly journals Tree Transplant Size Influences Post-Transplant Growth, Gas Exchange, and Leaf Water Potential Of ‘October Glory’ Red Maple

1995 ◽  
Vol 13 (4) ◽  
pp. 178-181 ◽  
Author(s):  
Daniel M. Lauderdale ◽  
Charles H. Gilliam ◽  
Donald J. Eakes ◽  
Gary J Keever ◽  
Arthur H. Chappelka
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Shoot Elongation ◽  
Leaf Water ◽  
Red Maple ◽  
Trunk Diameter ◽  
Growing Seasons ◽  
Large Trees ◽  
Use Efficiency

Abstract Effects of red maple transplant size [3.8 cm (1.5 in, small) and 7.6 cm (3.0 in, large) trunk diameter] on growth were evaluated at park and residential planting sites in Mobile, AL, during 1993 and 1994. Gas exchange and leaf water potential of transplants were monitored. Small trees had greater shoot elongation than large trees during both growing seasons. In 1994, small trees had greater height increases than large trees. Trunk diameter increases of small transplants were twice those of large transplants in 1994. Photosynthesis, leaf conductance, transpiration, and water use efficiency were higher for small transplants than large transplants on every observation date. In August 1993, pre-dawn and daily leaf water potentials were higher (less negative) for small trees than for large trees.

scholarly journals WHEAT CULTIVARS: RESPONSE TO IRRIGATION AND SOWING DATES

1996 ◽  
Vol 53 (2-3) ◽  
pp. 217-222
Author(s):  
A.E. Klar ◽  
T. Hossokawa
Keyword(s):  
Triticum Aestivum ◽  
Water Potential ◽  
Soil Water ◽  
Aluminium Toxicity ◽  
Triticum Aestivum L ◽  
Wheat Cultivars ◽  
Growing Seasons ◽  
Yield Level ◽  
Sowing Dates ◽  
Similar Yield

This study was carried out in an Alfisol-Oxisol transition sandy-clay texture, using six wheat cultivars (Triticum aestivum, L.): two tall and tolerant to soil aluminium toxicity (BH-1146, and IAC-18), and four semi-dwarf cultivars - Anahuac, IAC-162, IAC-24, and IAC-60 - of which only the first two are sensitive to soil aluminium toxicity. Two minimum soil water potentials (ys) levels were used: 1. watered, when Ys reached about -0.05 MPa; 2. dry, when the water potential reached around -1.5 MPa. Two sowing dates, 05/22/92 and 06/11/92, were used. The results showed that Anahuac and IAC-60 are the most indicated cultivars for the studied region; when irrigated all cultivars presented similar yield level under no irrigation conditions; the irrigation was not sufficient to avoid yield differences between the two growing seasons; differences in rainfall were important for the crop in the dry treatment for both seasons.

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