Apple Tree Phenology in Relation to Temperature in Sauherad (Norway)

Abstract

Plant's phenological development depends on multiple environmental factors and among these, temperature plays a key role during the early phenological development of plants. Temperature becomes even more significant in influencing phenological development in the areas that are covered with snow for a certain period a year. However, a rapid change in global temperature can be noticed in the scenario of climate change (CC). This study investigates the relationship between early phenological development of three apple cultivars i.e., Red Aroma, Summerred and Discovery with cumulative growing degree days (CGDDs) in the southern part of Norway and finds a strong positive correlation between them while moving from the green top stage to the fruit diameter (10mm) stage in the year 2016. In the similar way, study finds phenological development in two consecutive years i.e., 2015 and 2016 alike in a holistic approach. However, in the individual case of Discovery, phenological development of the year 2015 varies from 2016. In addition to that, CGGDs from first six months of two successive years seems to be similar. To gain all these results, this study made the use of multiple statistical tests. Study argues that; it is not always true that phenological development and CGDDs of one year vary from the next. Nevertheless, this study recommends for some long-term studies in the region that can generate concrete idea about phenology considering multiple environmental variables.

Apple Growing in Norway—Ecologic Factors, Current Fertilization Practices and Fruit Quality: A Case Study

“…Soil, fertilization and cultivars definitely influence composition, but mineral content has been found to vary not only between cultivars but also between years [129]. This has also been confirmed in Norway, where variations strongly depend on the year of cultivation, as climatic effects cause variation in the phenological development of apple trees and consequently in the mineral uptake capacity [130].…”

Climate Potential for Apple Growing in Norway—Part 1: Zoning of Areas with Heat Conditions Favorable for Apple Growing under Observed Climate Change

“…To be able to approximately determine the areas where the heat conditions are sufficient for growing of different cultivars, it is necessary to develop a relation between phenological development and heat conditions, usually expressed through developed bioclimatic indices which are generated using surface air temperature data (for example for Norway, ref. [15]). There are different approaches to determine the heat conditions required for achieving different phenological stages, which depend on the availability of data and required simplicity of methodology (easy to calculate).…”