Reversible Leaflet Movements in Relation to Drought Adaptation of Cowpeas, Vigna unguiculata (L.) Walp

1979 ◽  
Vol 6 (3) ◽  
pp. 265 ◽  
Author(s):  
KA Schakel ◽  
AE Hall
Keyword(s):  
Vigna Unguiculata ◽  
Environmental Conditions ◽  
Heat Load ◽  
Controlled Environment ◽  
Field Observations ◽  
Canopy Architecture ◽  
Percentage Cover ◽  
Temperature Variations ◽  
Drought Conditions ◽  
Drought Effects

Two aspects of the heliotropic responses of leaflets of V. unguiculata cv. California Blackeye No. 5 were studied: the environmental conditions responsible for the responses, and the significance of the leaflet orientation responses for adaptation. In the field under drought conditions, leaflets were observed to sun-track (diaheliotropism) in the morning and sun-avoid (paraheliotropism) by becoming more vertical in the afternoon. Overnight irrigation of droughted plants in the field resulted in leaflet movements on the day after irrigation similar to those of the well watered plants. Leaflets of well watered plants were diaheliotropic during the morning and evening, and essentially horizontal during the late morning and afternoon. Controlled-environment studies confirmed field observations of drought effects on leaflet movement and showed that leaflet orientation responses are reversible within 3 h after irrigating droughted plants. Temperature variations similar to those experienced in the field had only small effects on leaflet orientation. Vertical leaflet movement affected canopy architecture and significantly reduced percentage cover at midday. Manually moving the vertical leaflets of droughted plants caused substantial changes in leaflet temperatures, indicating that leaflet movement could substantially reduce heat load, water use, and water deficits in cowpeas.

FIELD OBSERVATIONS OF SEA SALT SPRAY AT THE HOKURIKU AND TOHOKU AREA AND EFFECTS OF ENVIRONMENTAL CONDITIONS

2021 ◽  
Vol 77 (2) ◽  
pp. I_445-I_450
Author(s):  
Fuminori NAKAMURA ◽  
Chimedtseren OTGONBILEG ◽  
Takeru MASUDA ◽  
Keiichi KANDA ◽  
Takumi SHIMOMURA
Keyword(s):  
Environmental Conditions ◽  
Salt Spray ◽  
Sea Salt ◽  
Field Observations

scholarly journals Development of MILIONCAST, an Improved Model for Predicting Downy Mildew Sporulation on Onions

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 695-702 ◽  
Author(s):  
Tijs Gilles ◽  
Kath Phelps ◽  
John P. Clarkson ◽  
Roy Kennedy
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Temporal Pattern ◽  
Random Model ◽  
Controlled Environment ◽  
High Humidity ◽  
Potted Plants ◽  
Effects Of Temperature ◽  
Improved Model ◽  
Accuracy Of Prediction

The effects of temperature and relative humidity on Peronospora destructor sporulation on onion (Allium cepa) leaves were studied under controlled environmental conditions. Sporangia were produced most rapidly at 8 to 12°C after 5 h of high humidity during dark periods. The greatest number of sporangia was produced at 100% relative humidity (RH), and sporulation decreased to almost nil when humidity decreased to 93% RH. A model, named MILIONCAST (an acronym for MILdew on onION foreCAST), was developed based on the data from these controlled environment studies to predict the rate of sporulation in relation to temperature and relative humidity. The accuracy of prediction of sporulation was evaluated by comparing predictions with observations of sporulation on infected plants in pots outdoors. The accuracy of MILIONCAST was compared with the accuracy of existing models based on DOWNCAST. MILIONCAST gave more correct predictions of sporulation than the DOWNCAST models and a random model. All models based on DOWNCAST were more accurate than the random model when compared on the basis of all predictions (including positive and negative predictions), but they gave fewer correct predictions of sporulation than the random model. De Visser's DOWNCAST and ONIMIL improved their accuracy of prediction of sporulation events when the threshold humidity for sporulation was reduced to 92% RH. The temporal pattern of predicted sporulation by MILIONCAST generally corresponded well to the pattern of sporulation observed on the outdoor potted plants at Wellesbourne, UK.

Propanil Plus Methyl Parathion on Rice (Oryza sativa)

Weed Science ◽  
1988 ◽  
Vol 36 (3) ◽  
pp. 335-339 ◽  
Author(s):  
Gene D. Wills ◽  
Joe E. Street
Keyword(s):  
Oryza Sativa ◽  
Soil Moisture ◽  
Environmental Conditions ◽  
Methyl Parathion ◽  
Field Experiments ◽  
Controlled Environment ◽  
Planting Dates ◽  
Effects Of Temperature ◽  
Effect On Yield ◽  
Wilting Point

Effects of propanil [N-(3,4-dichlorophenyl)propanamide] applied to three- to four-leaf rice (Oryza sativaL.) 1 or 7 days before, after, or tank mixed with methyl parathion (O,O-dimethyl-O-4-nitrophenyl phosphorothioate) were determined under different environmental conditions. Field experiments determined the effect on yield of drill-seeded rice, ‘Labelle’ for two planting dates in 1982 and ‘Lemont’ for one planting date in 1986. Treatments were applied at sunrise and at noon. Growth chamber and greenhouse experiments determined the effects of temperature, relative humidity (RH), and soil moisture on response of Labelle rice. In all experiments, propanil, both alone and with methyl parathion, resulted in 20 to 30% leaf burn during the first week after treatment with rapid recovery to less than 10% injury after 3 to 4 weeks. In field experiments, yields were not reduced in the treated rice below that in the untreated controls. In controlled-environment experiments, rice was not injured by propanil plus methyl parathion more than by propanil alone after 2 to 4 weeks. Both treated and untreated rice were injured more by the environmental conditions of high (40 C) temperature, low (40%) RH, and low (near the wilting point) soil moisture than by low (30 C) temperature, high (100%) RH, and flooded soil.

scholarly journals Reaction of dwarf cashew clones to Colletotrichum gloeosporioides isolates in controlled environment

2010 ◽  
Vol 67 (2) ◽  
pp. 228-235
Author(s):  
Ana Maria Queijeiro López ◽  
John Alexander Lucas
Keyword(s):  
Environmental Conditions ◽  
Host Resistance ◽  
Colletotrichum Gloeosporioides ◽  
Anacardium Occidentale ◽  
Controlled Environment ◽  
Production Loss ◽  
Structural Barriers ◽  
Anthracnose Disease ◽  
Brazilian Northeast ◽  
Significant Production

The cashew (Anacardium occidentale L.) crop is an important source of income for the population of the Brazilian Northeast, and anthracnose disease caused by Colletotrichum gloeosporioides leads to significant production loss. However, there is little information on either the host resistance or the variation in the aggressiveness of the pathogen under controlled environment. The reaction of commercial (CCP-06, CCP-09, CCP-76 and CCP-1001) and one non-commercial (CAP-14) dwarf cashew clones was assessed against 36 isolates of this fungus controlled environmental conditions. All the isolates, including those from hosts other than cashew, were able to cause lesions on leaves and stems of most clones, albeit to different degrees. Clone CCP-06 was the most susceptible, while clone CCP-1001 showed a level of resistance to a number of the isolates, including isolate 905, while isolates 910 and 912 were aggressive to all clones. Injury increased the susceptibility of the clones to all isolates, indicating that resistance also might be associated with structural barriers that hinder penetration. Ripened cashew apples (8-week-old), of commercial clones were susceptible to isolates 905 and 910. Immature pseudo-fruits (2-week-old), with exception of clone CCP-76 which was susceptible to both isolates showed resistance against these isolates, suggesting the presence of structural and chemical barriers. Developed nuts (8-week-old), however, were more resistant than immature nuts (2-week-old) to both isolates, probably due to their thicker exocarp cuticle and reduced number of stomatal pores.

Factorial Analysis in the Ecology of Rocky Subtidal Areas Near Brest (West Brittany, France)

1991 ◽  
Vol 71 (3) ◽  
pp. 515-536 ◽  
Author(s):  
A. Castric ◽  
C. Chasse
Keyword(s):  
Environmental Conditions ◽  
Coastal Waters ◽  
Wave Action ◽  
Hydrodynamic Conditions ◽  
Substrate Type ◽  
Percentage Cover ◽  
Rocky Subtidal ◽  
Characteristic Species ◽  
Number Of Individuals ◽  
Strong Tidal Current

In order to investigate the characteristic species and the relative importance of selected environmental conditions of rocky bottom communities in coastal waters and to estimate their richness, 27 sites in the Brest area were surveyed by diving. The abundances of underwater species, from a check-list of 115, were plotted as number of individuals or colonies in m2 or in percentage cover of the rock, against the environmental conditions (depth, bedrock slope, substrate type and sediment nature of the nearest soft bottom). Raw data were converted to biovolume expressed as mm3 m–2 and expressed as log 10 (x + 1).Various correspondence analyses were applied to these data: the first included bedrock slope (lit/dark surfaces) and takes into account the four biological formations according to the depth. It shows zonation with depth and decreasing light as factor 1, hydrodynamic conditions (waves or current) as factor 2, mixing of estuarine and oceanic waters as factor 3 and turbidity as factor 4. Four species assemblages emerge from these four axes, for which the main species contributing to the four axes may be considered as characteristic species. These correspond well to four broad communities described in British waters: very exposed to wave-action, semi-exposed to wave-action, exposed to strong tidal current, very sheltered sites. The second analysis, in which lit and dark surfaces are distinguished, but some very close sites are fused together, shows in detail the photophilous or sciaphilous nature of the species. Values of hydrodynamic conditions and percentage of surface light plotted on the 'stations-points' of the graphs allow drawing of a factorial network which may be used as hydrodynamic and illumination scales.

scholarly journals Influence of Cold-Hardening and Soil Matric Potential on Resistance to Speckled Snow Mold in Wheat

Plant Disease ◽  
2008 ◽  
Vol 92 (7) ◽  
pp. 1021-1025 ◽  
Author(s):  
Zenta Nishio ◽  
Norio Iriki ◽  
Kanenori Takata ◽  
Miwako Ito ◽  
Tadashi Tabiki ◽  
...  
Keyword(s):  
Cold Hardening ◽  
Controlled Environment ◽  
Field Observations ◽  
Soil Matric Potential ◽  
Matric Potential ◽  
Breeding Programs ◽  
Snow Mold ◽  
Influence Of Temperature ◽  
Mold Resistance ◽  
Wheat Lines

The influence of soil matric potential, cold-hardening temperature, and duration on resistance to speckled snow mold caused by Typhula ishikariensis in wheat was investigated. Six winter wheat lines were subjected to cold-hardening temperatures of 2 or 4°C for 1, 2, 3, or 4 weeks with soil matric potential of –0.1 or –0.01 MPa. Plants were inoculated with T. ishikariensis after cold-hardening, incubated at 10°C for 25 days in the dark, and then evaluated for regrowth. Overall recovery from snow mold was least when plants were hardened at 2°C for 1 week at –0.01 MPa and greatest when hardened at 4°C for 4 weeks at –0.1 MPa. Survival of plants following snow mold was greater when plants were cold-hardened at 4 than at 2°C and at –0.1 than –0.01 MPa soil matric potential. The greatest difference in survival among lines and correlation with field observations occurred when plants were hardened at 4°C at –0.1 MPa matric potential for 3 weeks. Understanding the influence of temperature and soil matric potential during cold-hardening on speckled snow mold resistance will be useful to breeding programs developing snow-mold-resistant cultivars under controlled environment conditions.

scholarly journals Both Traditional and Semi-bush Tropical Pumpkin Can Be Intercropped with Beans or Cowpeas

HortScience ◽  
2004 ◽  
Vol 39 (3) ◽  
pp. 525-528 ◽  
Author(s):  
Patrick Chesney ◽  
Linda Wessel-Beaver ◽  
Donald N. Maynard
Keyword(s):  
Puerto Rico ◽  
Phaseolus Vulgaris ◽  
Vigna Unguiculata ◽  
Growth Habit ◽  
Fruit Size ◽  
Cucurbita Moschata ◽  
Percentage Cover ◽  
Maximum Percentage ◽  
Stages Of Growth ◽  
Short Season

Most cultivars of tropical pumpkin (Cucurbita moschata Duchesne) are large, trailing plants. New semi-bush (SB) genotypes need to be tested against traditional long vine (LV) types. Both types of pumpkin have large amounts of interplant space during the early stages of growth that might allow for the planting of an intercrop. To test this hypothesis, as well as the performance of tropical pumpkins of varying growth habit, double rows of beans (Phaseolus vulgaris L.) or cowpeas [Vigna unguiculata (L.) Walp.] were intercropped between rows of SB or traditional LV tropical pumpkin in Spring and Fall 1993 in Lajas and Isabela, Puerto Rico. In general, interactions between intercrop treatment and pumpkin genotype were not significant. At its maximum percentage cover (MC) the LV genotype covered, or nearly covered, the entire plot while the SB genotype covered 50% of the plot or less. The SB pumpkin was harvested 5 to 27 days earlier than the LV type. Yield was two to 12 times greater, and average fruit size three to six times greater in the latter. Planting of an intercrop did not reduce pumpkin yield. Green-shelled yields of intercropped legumes averaged ≈700 kg·ha-1. Genotype of the pumpkin maincrop did not affect legume green-shelled yields in Lajas. In Isabela, legume green-shelled yields were 50% higher in SB than in LV pumpkin plots. Legume dry grain yields were greatly reduced in LV compared to SB plots. Intercropping of tropical pumpkin with a short season legume that can be harvested green-shelled is an efficient intercropping system that offers additional yield from the legume without sacrificing yield from the pumpkin maincrop. Both SB and LV pumpkins can be used in an intercrop system, but pumpkin yields were much greater with the LV genotype.

scholarly journals (295) Measuring and Reporting Growing Conditions in Controlled Environments

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1009B-1009
Author(s):  
Marc W. van Iersel
Keyword(s):  
Plant Growth ◽  
Environmental Conditions ◽  
Working Group ◽  
International Committee ◽  
Controlled Environment ◽  
The North ◽  
Controlled Environments ◽  
Air Speed ◽  
Growing Conditions ◽  
Replication Of Experiments

Do you accurately measure and report the growing conditions of your controlled environment experiments? Conditions in controlled environment plant growth rooms and chambers should be reported in detail. This is important to allow replication of experiments on plants, to compare results among facilities, and to avoid artefacts due to uncontrolled variables. The International Committee for Controlled Environment Guidelines, with representatives from the U.K. Controlled Environment Users' Group, the North American Committee on Controlled Environment Technology and Use (NCR-101), and Australasian Controlled Environment Working Group (ACEWG), has developed guidlines to report environmental conditions in controlled environment experiments. These guidelines include measurements of light, temperature, humidity, CO2, air speed, and fertility. A brochure with these guidelines and a sample paragraph on how to include this information in a manuscript will be available.

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