scholarly journals (431) Evaluation of Anti-transpiration Organic Materials on Strawberry Performance

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1076A-1076
Author(s):  
Sorkel Kadir ◽  
Said Ennahli ◽  
Ben Glass

Interactive effects of different temperature regimes and anti-transpiration organic materials, Surround WP (kaolinite clay) and Raynox (sun-protectant), on two strawberry (Fragaria ×ananassa) cvs. Chandler and Sweet Charlie were investigated under controlled environmental conditions. Newly planted strawberries treated with Surround and Raynox were subjected to 20/15, 30/25, and 40/35 °C (day/night) temperature regimes and 16 day/8 night photoperiod in growth chambers for 42 d. Photosynthesis (A) and photochemical efficiency (Fv/Fm) were measured at 7-d intervals during the experiment. Plants treated with Raynox displayed greater resistance to high temperature (40/35 °C) compared to those treated with Surround. Net photosynthesis of both cultivars decreased significantly with time at 40/35 °C. There was no significant difference in photosynthetic rate between the two cultivars. Nevertheless, there was difference in plant biomass between the cultivars. Raynox provided more protection against high temperature, specifically in reducing stomatal conductance and limiting transpiration, than Surround.

1965 ◽  
Vol 16 (5) ◽  
pp. 817 ◽  
Author(s):  
D McEAlexander

Poor fruit set of sultanas in the Murray Valley is sometimes attributed to excessively high temperatures around flowering time. Experiments with small fruiting sultana vines in pots suggest that water stress is the more important factor. Fruit set was significantly less when a 3-day period of water stress was imposed at flowering or 1, 2, or 4 weeks after flowering, but not when it was imposed 6 weeks after flowering. Three days with maximum temperatures above 45°C at or 1 week after flowering did not reduce fruit set when ample water was supplied. When controlled environments combining day temperatures between 21 and 30°C with night temperatures between 19 and 25° were used, no significant differences in fruit set were found, although shoot growth increased with increasing night temperature. Shoot elongation slowed down during periods of applied water stress but recovered, when the stress was ended, to a rate greater than that of plants which had not been stressed.


2009 ◽  
Vol 21 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Carlos Cesar Ronquim ◽  
Carlos Henrique B. A. Prado ◽  
João Paulo de Souza

Growth and leaf nutrient content were compared in young potted plants of Copaifera langsdorffii in sunny and shaded areas without water stress. Besides, carbon assimilation and leaf water relations were evaluated by net photosynthesis, potential photochemical efficiency and leaf water potential during daily courses in dry and rainy periods under natural conditions in both contrasting irradiances. Higher values of total biomass, height and leaf area occurred in sunny than in shaded area. On the other hand, all young plants survived in shade under natural water stress probably by reason of fast and intense biomass accumulation in favor of roots in early development. There was no significant difference about nutrient concentration in leaves between plants growing in sunny and shaded areas. Net photosynthesis in shade increased occasionally when bunches of direct light reached the leaves. Theses sunflecks took place more frequently and at high intensity in dry period but they were more effective for net photosynthesis in rainy period. The ability of young plants to persist under natural conditions in contrasting irradiance up to 1,230 days after sowing could explain the wide distribution of C. langsdorffii in Cerrado physiognomies and in different types of forest.


Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 365-373 ◽  
Author(s):  
David T. Patterson

Texas panicum was grown in controlled-environment chambers in 16 day/night temperature regimes ranging from 19/11 to 34/26 C. After 33 days, maximum plant height, leaf area, and dry weight occurred at 34/26 C. The greatest number of tillers and leaves occurred at 34/16 C. Partitioning of plant biomass into stems increased with increasing night temperature, while partitioning into leaves tended to decrease. Partitioning of biomass into roots decreased with increasing night temperature at day temperatures of 19 or 24 C but not at 34 C. Plant dry matter production (DMP) was highly correlated with both leaf area duration (LAD) and net assimilation rate (NAR) during the first 2 weeks of growth. During the subsequent 3 weeks, DMP was highly correlated with LAD but not with NAR. The low-temperature threshold for growth of Texas panicum was approximately 11 C. Texas panicum attained 25% of its maximum growth at an average daily temperature of 21 C, 50% at 24 C, and 75% at 26 C. Texas panicum is unlikely to become a highly competitive weed outside the southern and southwestern United States.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1141a-1141
Author(s):  
J. S. Seron ◽  
S. L. Knight ◽  
L. A. Spomer ◽  
G. S. Chen

Proponents of global climate models predict a doubling of world CO2 concentration from 350 to 600 ppm by the year 2030, concurrent with a 2-5°C temperature increase. Consequences of this “greenhouse effect” on Oryza sativa L. were determined using four rice lines selected for their widespread use in cultivation and research. A 2×2 factorial design was used with CO2 at 350 and 600 ppm and day/night temperature regimes of 31/27°C and 37/33°C. Combined effects of CO2/temperature were determined during 5 harvests from seeding to reproductive maturity. Elevated CO2 enhanced dry weight and photosynthetic capacity over both temperature regimes relative to plants grown at ambient CO2. The 37/33°C day/night temperature regime increased sterility in rice by decreasing pollen shed.


2008 ◽  
Vol 133 (4) ◽  
pp. 508-514 ◽  
Author(s):  
Matthew D. Taylor ◽  
Paul V. Nelson ◽  
Jonathan M. Frantz

Sudden pH decline (SPD) describes the situation where crops growing at an appropriate pH rapidly (within 1–2 weeks) cause the substrate pH to shift downward one to two units. ‘Designer Dark Red’ geraniums (Pelargonium ×hortorum Bailey) were grown in three experiments to assess possible effects of temperature on SPD. The first experiment tested the effect of four day/night temperature regimes (14 °C day/10 °C night, 18 °C day/14 °C night, 22 °C day/18 °C night, and 26 °C day/22 °C night) on substrate acidification. At 63 days after transplanting (DAT), substrate pH declined from 6.8 to 4.6 as temperature increased. Tissue phosphorus (P) of plants grown at the highest three temperatures was extremely low (0.10%–0.14% of dry weight), and P stress has been reported to cause acidification. It was not possible to determine if the drop in substrate pH was a singular temperature effect or a combination of high temperature and low P. To resolve this, a second experiment tested a factorial combination of the three highest temperatures from the first experiment and five preplant P rates (0, 0.065, 0.13, 0.26, or 0.52 g·L−1 substrate). Regardless of tissue P concentrations, which ranged from deficient to above adequate, substrate pH decreased with increasing temperature. At 63 DAT, in the 0.065 and 0.13 P treatments, tissue P was deficient and pH decreased with increasing temperature from 5.6 to 4.7 and 5.9 to 4.7, respectively. In the 0.26 P treatment, tissue P was adequate at the lowest temperature and there was no acidification. At the mid- and highest temperatures, tissue P was deficient and statistically equivalent, yet pH decreased to 5.2 and 4.7, respectively. In the highest P treatment, tissue P levels were unaffected by temperature, above adequate, and pH declined with each increase in temperature from 6.5 to 5.0. The results at 63 DAT once more showed that temperature acted independent of tissue P and caused geraniums to acidify the substrate. In the third experiment, the amount of acidity produced by roots of plants grown at the two highest temperatures used in the first two experiments was quantified. Plants grown at the higher temperature produced 28% more acid per gram dry root. The results herein indicate that high temperature can induce SPD by geranium.


1996 ◽  
Vol 23 (5) ◽  
pp. 605 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas ◽  
IF Wardlaw

In this study, we have sought to identify the nature of the response to both moderately high (25-32�C) and very high (>32�C) temperatures by examining their interactive effects on the accumulation of functionally important proteins during grain-filling. In particular, we wished to determine if the deleterious effects of very high temperature could be alleviated by subsequently cool conditions. To this end, wheat cv. Oxley was exposed to either 21/16 or 40/16�C (day/night) from 15 to 19 days after anthesis and subsequently grown under one of three temperature regimes until maturity: 21/16 (control), 27/22 or 30/25�C. Grain samples were taken throughout grain growth and analysed for protein content and composition. Wheat proteins were separated and quantified as albumin,globulin, monomer, SDS-soluble polymer and SDS-insoluble polymer using size-exclusion high-performance liquid chromatography. The various protein fractions responded differentially and usually additively to moderately high and very high temperatures during grain-filling. Cool post-shock conditions did not alleviate the effects of very high temperature on grain protein composition. Heat treatments reduced polymer:monomer ratio because the accumulation of monomer was reduced less than that of polymer.


1971 ◽  
Vol 51 (6) ◽  
pp. 479-484 ◽  
Author(s):  
I. L. NONNECKE ◽  
N. O. ADEDIPE ◽  
D. P. ORMROD

The effects of two relative humidities and three temperature regimes on the growth and yield responses of four pea cultivars were investigated. The high day/night temperature regime of 27/17 C, compared with 17/7 C, decreased the number of pods per plant by 46, 65, 66 and 54% in the cultivars Dark Skin Perfection, Nugget, Early Sweet 11 and Elf, respectively. Continued growth at the high temperature decreased pea yield by 50% in Dark Skin Perfection and about 70% in the other cultivars. When plants were first grown at 17/7 until full bloom and then subjected to the 27/7 C regime, the high temperature treatment showed no significant effect on growth and yield. Dark Skin Perfection was the least adversely affected by high temperature. No significant differences in growth and yield were observed at 50 and 90% relative humidities.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 485b-485
Author(s):  
Lisa M. Barry ◽  
Michael N. Dana

Nurse crops are often recommended in prairie restoration planting. This work investigated several alternative nurse crops to determine their utility in prairie planting. Nurse crops were composed of increasing densities (900, 1800, or 2700 seeds/m2) of partridge pea, spring oats, spring barley, Canada wild rye, or equal mixtures of partridge pea and one of the grasses. The experimental design was a randomized complete-block set in two sites with three blocks per site and 48 treatments per block. Each 3 × 3-m plot contained 1 m2 planted in Dec. 1995 or Mar. 1996 with an equal mix of seven prairie species. The nurse crops were sown over each nine square meter area in April 1996. Plots lacking nurse crops served as controls. Evaluated data consisted of weed pressure rankings and weed and prairie plant dry weight. Nurse crop treatments had a significant effect on weed pressure in both sites. Barley (1800 and 2700 seeds/m2) as well as partridge pea + barley (2700 seeds/m2) were most effective at reducing weed pressure. When weed and prairie plant biomass values were compared, a significant difference was observed for site quality and planting season. Prairie plant establishment was significantly greater in the poorly drained, less-fertile site and spring-sown plots in both sites had significantly higher prairie biomass values. Overall, after two seasons, there was no advantage in using nurse crops over the control. Among nurse crop treatments, oats were most effective in reducing weed competition and enhancing prairie plant growth.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 357
Author(s):  
Jong Kyu Lee ◽  
Myeong Ja Kwak ◽  
Sang Hee Park ◽  
Han Dong Kim ◽  
Yea Ji Lim ◽  
...  

Plants are affected by the features of their surrounding environment, such as climate change and air pollution caused by anthropogenic activities. In particular, agricultural production is highly sensitive to environmental characteristics. Since no environmental factor is independent, the interactive effects of these factors on plants are essential for agricultural production. In this context, the interactive effects of ozone (O3) and supraoptimal temperatures remain unclear. Here, we investigated the physiological and stomatal characteristics of leaf mustard (Brassica juncea L.) in the presence of charcoal-filtered (target concentration, 10 ppb) and elevated (target concentration, 120 ppb) O3 concentrations and/or optimal (22/20 °C day/night) and supraoptimal temperatures (27/25 °C). Regarding physiological characteristics, the maximum rate of electron transport and triose phosphate use significantly decreased in the presence of elevated O3 at a supraoptimal temperature (OT conditions) compared with those in the presence of elevated O3 at an optimal temperature (O conditions). Total chlorophyll content was also significantly affected by supraoptimal temperature and elevated O3. The chlorophyll a/b ratio significantly reduced under OT conditions compared to C condition at 7 days after the beginning of exposure (DAE). Regarding stomatal characteristics, there was no significant difference in stomatal pore area between O and OT conditions, but stomatal density under OT conditions was significantly increased compared with that under O conditions. At 14 DAE, the levels of superoxide (O2-), which is a reactive oxygen species, were significantly increased under OT conditions compared with those under O conditions. Furthermore, leaf weight was significantly reduced under OT conditions compared with that under O conditions. Collectively, these results indicate that temperature is a key driver of the O3 response of B. juncea via changes in leaf physiological and stomatal characteristics.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Noémie Deldicq ◽  
Dewi Langlet ◽  
Camille Delaeter ◽  
Grégory Beaugrand ◽  
Laurent Seuront ◽  
...  

AbstractHeatwaves have increased in intensity, duration and frequency over the last decades due to climate change. Intertidal species, living in a highly variable environment, are likely to be exposed to such heatwaves since they can be emerged for more than 6 h during a tidal cycle. Little is known, however, on how temperature affects species traits (e.g. locomotion and behaviour) of slow-moving organisms such as benthic foraminifera (single-celled protists), which abound in marine sediments. Here, we examine how temperature influences motion-behaviour and metabolic traits of the dominant temperate foraminifera Haynesina germanica by exposing individuals to usual (6, 12, 18, 24, 30 °C) and extreme (high; i.e. 32, 34, 36 °C) temperature regimes. Our results show that individuals reduced their activity by up to 80% under high temperature regimes whereas they remained active under the temperatures they usually experience in the field. When exposed to a hyper-thermic stress (i.e. 36 °C), all individuals remained burrowed and the photosynthetic activity of their sequestered chloroplasts significantly decreased. Recovery experiments subsequently revealed that individuals initially exposed to a high thermal regime partially recovered when the hyper-thermic stress ceased. H. germanica contribution to surface sediment reworking substantially diminished from 10 mm3 indiv−1 day−1 (usual temperature) to 0 mm3 indiv−1 day−1 when individuals were exposed to high temperature regimes (i.e. above 32 °C). Given their role in sediment reworking and organic matter remineralisation, our results suggest that heatwaves may have profound long-lasting effects on the functioning of intertidal muddy ecosystems and some key biogeochemical cycles.


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