Strawberry (Fragaria ×ananassa Duch.) Growth and Productivity as Affected by Temperature

Abstract

<jats:p>Thermotolerance of photosynthesis and productivity in `Chandler' and `Sweet Charlie' strawberry plants (<jats:italic>Fragaria</jats:italic> ×<jats:italic>ananassa</jats:italic> Duch.) exposed to three temperature regimes was studied. Net CO<jats:sub>2</jats:sub> assimilation rate (A), variable chlorophyll fluorescence (Fv), efficiency of photosystem II (Fv/Fm), relative chlorophyll content, plant growth, and fruit yield and quality were measured. High temperature (40 °C day/35 °C night) was more detrimental to photosynthesis and productivity than the moderate or low temperature (30/25 or 20/15 °C). Net CO<jats:sub>2</jats:sub> assimilation rate in both cultivars was markedly reduced by 40/35 °C, although there was slight decline in `Sweet Charlie' at 30/25 °C. `Chandler' maintained significantly higher A rates than `Sweet Charlie' for at least three weeks of heat stress, indicating that `Chandler' might tolerate longer exposure to high temperature. In parallel to the decrease in A rate, intercellular CO<jats:sub>2</jats:sub> concentration (C<jats:sub>i</jats:sub>) and instantaneous water use efficiency (WUE) were significantly decreased at high temperature. `Chandler' leaves were cooler and transpired more than `Sweet Charlie' leaves, suggesting that each cultivar adopted different heat resistance mechanisms at 40/35 °C. There were changes in Fv and Fv/Fm with increasing temperature, indicating irreversible damage to photosystem II at 40/35 °C might have occurred. The trend of reduction in stomatal conductance (<jats:italic>g</jats:italic><jats:sub>S</jats:sub>) in both cultivars at high temperature did not coincide with the reduction in A rates. Decline in A rates at high temperature was more related to changes in Fv/Fm than to <jats:italic>g</jats:italic><jats:sub>S</jats:sub> activity. The optimal temperature for vegetative growth was 30/25 °C. Reduction in A rate at high temperature resulted in reduction in total leaf area (LA), shoot, root, and leaf biomasses. Strawberry roots were more responsive than shoot growth to temperatures above 20/15 °C. Fruit yield for `Chandler' was higher at 20/15 °C than at 30/25 °C, suggesting that `Chandler' might have a higher source-to-sink relationship at 20/15 °C than at 30/25 °C. Fruit skin color was temperature dependent only for `Chandler'. A quadratic relationship between flower development and duration of exposure to 30/25 °C for both cultivars was observed; more than two weeks of 30/25 °C can be detrimental to flower development. Regardless of the cultivar and duration of exposure, 40/35 °C was the temperature regime most detrimental to fruit set.</jats:p>

Temperature extremes: Effect on plant growth and development

“…In these plants, there was an increased sensitivity heat stress 7 to 15 days before anthesis, coincident with pollen development. Subjecting plants to a more intense heat stress (generally greater than 4°C above optimum) resulted in severe yield loss extending to complete crop failure (Ghosh et al, 2000;Sato et al, 2000;Kadir et al, 2006;Gote and Padghan, 2009;Tesfaendrias et al, 2010). Tomatoes under heat stress fail to produce viable pollen while their leaves remain active.…”

Thresholds, sensitive stages and genetic variability of finger millet to high temperature stress

“…Studies have shown that when plants are subjected to mild HT stress (1–4°C above optimal growth temperature), there were moderate decreases in yield (Sato, ; Tesfaendrias, McDonald, & Warland, ; Timlin et al., ; Wagstaffe & Battey, ). However, exposure to a more intense HT stress (>4°C above optimum) results in severe yield loss and even complete crop failure (Gote & Padghan, ; Kadir, Sidhu, & Al‐Khatib, ; Sato, Peet, & Thomas, ; Tesfaendrias et al., ). The impacts of HT stress on yield were quantified for major field crops [rice ( Oryza sativa L.), wheat ( Triticum aestivum L.), sorghum ( Sorghum bicolor L., Moench), pearl millet ( Pennisetum glaucum L.…”

“…However, exposure to a more intense HT stress (>4°C above optimum) results in severe yield loss and even complete crop failure (Gote & Padghan, 2009;Kadir, Sidhu, & Al-Khatib, 2006;Sato, Peet, & Thomas, 2000;Tesfaendrias et al, 2010). The impacts of HT stress on yield were quantified for major field crops [rice (Oryza sativa L.), wheat (Triticum aestivum L.), sorghum (Sorghum bicolor L., Moench), pearl millet (Pennisetum glaucum L.…”

Factors Affecting Fruit Quality in Strawberries Grown in a Subtropical Environment

“…Air temperature affects fruit size (Kadir et al, 2006), firmness (Sams, 1999), and skin color (Wang and Camp, 2000); while rainfall decreases SSC and titratable acidity (TA) (Kumar et al, 2011). Generally, environmental factors vary within harvest dates and years, interacting with genotypes (Sims et al, 1997).…”