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Chapter 8
Fig. 8.6. Linear regression between stomatal density and cold tolerance of ten olive cultivars. Cold tolerance: 1 = hardy, 7 = very susceptible (from Roselli and Venora, 1990).
Fig. 8.7. Parabolic correlation between stomatal perimeter and cold tolerance of olive trees. Cold tolerance: 1 = hardy, 7 = very susceptible (from Roselli and Venora, 1990).
In comparison with deciduous fruit trees, olive trees have greater stomatal density. Figure 8.6 shows the linear correlation between stomatal density and cold tolerance of ten varieties, while Fig. 8.7 shows the parabolic relationship between stomatal perimeter and cold tolerance. Electrolytic conductivity Electrolytic conductivity is a sensitive method and is utilized to determine differences between olive cultivars with regard to frost resistance (Murray et al.,