ISHS Acta Horticulturae 818: I International Symposium on Pomegranate and Minor Mediterranean Fruits
EFFECTS OF AIR TEMPERATURE, RELATIVE HUMIDITY AND SOLAR RADIATION ON FRUIT SURFACE TEMPERATURES AND SUNBURN DAMAGE IN POMEGRANATE (PUNICA GRANATUM L. CV. HICAZNAR) |
| Authors: | K. Yazici, L. Kaynak |
| Keywords: | arid region, excessive heating, fruit, leaf, tree canopy, orchard |
| Abstract:
A major problem in arid and semi arid regions is the excessive heating of the tree canopy and fruit, especially those exposed to direct solar radiation. Under such conditions, fruit and leaf surface temperatures may reach very high levels having undesirable effects on fruit skin properties (e.g., sunburn). The goal of this research was to determine the effect of temperatures, relative humidity and solar radiation on fruit surface temperature and sunburn damage on pomegranate (Punica granatum L. cv. Hicaznar). This trial was separately conducted on the most important pomegranate fruit cultivar Hicaznar, in experimental orchards of the Batı Akdeniz Agricultural Research Institute in Turkey in 2003 and 2004. In these trials values for temperature, humidity, radiation and amount of light were recorded by means of a micro metos ag climate station in the experimental area and, their effects on fruit surface temperatures (FST) and sunburn were determined. The surface temperatures of the fruits were measured with thermocouples throughout the season. The fruit surface temperatures that cause sunburn vary between 41°C and 47.5°C depending on air temperature. Maximum FST exceeded 47.5°C in some days of July, August and September during the experimental period in the orchard. Maximum daily air temperatures were highly correlated with maximum FST and never exceeded 41-47.5°C in days when maximum air temperature was below 30°C. Mean solar radiation between 610 Wm-2 and 900 Wm-2 was also highly correlated with maximum FST. The ratios of relative humidity around 70% and 80% inversely showed correlation with maximum FST. | |
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