Yazar "Flore, James A." seçeneğine göre listele

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    Determination of physical damage thresholds of strawberry leaves (Fragaria x ananassa cv. Honeoye)
    (Wfl Publ, 2012) Makaracı, Ahmet Zafer; Flore, James A.
    Damage thresholds of strawberry plants (Fragaria x ananassa) were investigated by mechanical damage. Mechanical damage was applied by 10%, 20% and 30% of the leaf area of a fully expanded single leaf removal. Strawberry leaves that were mechanically damaged did not recover their photosynthetic capacity at any damage level. Chlorophyll fluorescence (F-v/F-m) values were not affected from the mechanical damage. Increasing damage levels decreased the ability of the strawberry leaf to use light and carbon dioxide in photosynthesis. Difference in stomatal conductance and transpiration rates were insignificant. Internal CO2 (C-i) levels were higher in damaged plants compared to the control plants.
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    Determination of physical damage thresholds of strawberry leaves (Fragaria × ananassa cv. Honeoye)
    (WFL Publisher Ltd., 2012) Makaracı, Ahmet Zafer; Flore, James A.
    Damage thresholds of strawberry plants (Fragaria × ananassa) were investigated by mechanical damage. Mechanical damage was applied by 10%, 20% and 30% of the leaf area of a fully expanded single leaf removal. Strawberry leaves that were mechanically damaged did not recover their photosynthetic capacity at any damage level. Chlorophyll fluorescence (Fv/Fm) values were not affected from the mechanical damage. Increasing damage levels decreased the ability of the strawberry leaf to use light and carbon dioxide in photosynthesis. Difference in stomatal conductance and transpiration rates were insignificant. Internal CO2 (Ci) levels were higher in damaged plants compared to the control plants.
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    The Use of Chlorophyll Fluorescence to Determine the Effects of Different Acclimation Temperatures on Strawberry Leaves Exposed to Mild Frost Damage
    (Int Soc Horticultural Science, 2009) Makaracı, Ahmet Zafer; Flore, James A.
    This research was conducted to understand the effects of different acclimation temperatures on strawberry (Fragaria x ananassa) leaves exposed to mild frost damage. Measurement of chlorophyll fluorescence (F-v/F-m) is a quick method for determining cold damage to the plant photosynthetic apparatus. Potted strawberry plants of the cultivars 'Honeoye' and 'Chandler' were grown in a temperature controlled (24-26 degrees C day, 18 degrees C night) greenhouse in East Lansing, MI, USA until the plants had five fully expanded leaves. Plants were then exposed to either 4 degrees C, 8 degrees C or 12 degrees C in three temperature controlled rooms for two days before being exposed to a simulated mild frost at -2 degrees C for six hours. A completely randomized plot design was used for this experiment with twenty plants in each treatment plot. Control plants were untreated. Plants exposed to -2 degrees C were brought back to the greenhouse where chlorophyll fluorescence was measured for five consecutive days. Leaves exposed to -2 degrees C were not affected by frost until the third day of measurements, at which time chlorophyll fluorescence values (F-v/F-m) were significantly lower than those of control plants. Different acclimation temperatures did not affect the F-v/F-m values. On the third day 'Chandler' plants exposed to -2 degrees C had lower F-v/F-m values than those of 'Honeoye'. Complete recovery was observed on the fourth day of measurements. In conclusion, we observed delayed, transitory damage to the photosynthetic process in strawberry leaves subjected to temperatures of -2 degrees C for 6 hours, but complete recovery occurred within 4 days.