Flowering and Non-Flowering Spur Leaf Characteristics of 'Amasya' Apple and Its Comparison with Other Cultivars

Abstract

Understanding the attributes of spur leaves in apple trees is essential to gain more insight into the complex process of fruit development and quality. However, limited literature is available about the spur leaf characteristics of the 'Amasya' apple cultivar. In this work, the Soil Plant Analysis Development (SPAD) and leaf area were investigated in flowering and non-flowering spur leaves of 'Amasya' and six common apple cultivars. Significant differences among cultivars were observed for the SPAD and spur leaf area. The median SPAD readings in 'Amasya' were 32.63 and 26.23 for the flowering and nonflowering spurs, respectively, which were the relatively low values among studied cultivars. The maximum SPAD value was measured in flowering spurs of 'Cripps Pink' (45.03). SPAD values were found to be lower in non-flowering spurs compared with flowering ones for all the studied cultivars, which confirms that decline in chlorophyll content coincided with a gradual decline in productivity. A notably significantly lower spur leaf area was found in 'Amasya', whereas the highest spur leaf area was in 'Cripps Pink'. However, no statistical difference was observed between flowering and non-flowering spur leaf areas within the same cultivars. The present results provided a general framework of SPAD and spur leaf areas in 'Amasya' and other apple cultivars when spurs had flowers or not. Knowledge of these characteristics provides a basis for building a model related to yield elaboration of apple trees.

Comprehensive Analysis of Flowering Patterns in One-Year-Old Long Shoots of Apple Cultivars with Contrasted Bearing Habits

“…In contrast to the number of vegetative or generative buds, there was a clear difference in floral bud quality variables in shoot zones between biennial bearing and regular bearing cultivars studied. These findings confirm that floral bud quality, especially spur leaf properties, is strongly associated with the bearing capacity of apples (Ferre and Schmid 2004;Elsysy and Hirst 2017;Atay and Atay 2022). A sufficient amount of spur leaves in apples is crucial for long-term productivity due to its effect on photosynthetic performance, carbohydrates, phytohormones, and nutritional status (Ferree et al 2001;Wertheim and Schmidt 2005;Madail et al 2012;Atay and Atay 2022).…”

“…Furthermore, we also counted the number of spur leaves per inflorescence. The size of the spur leaves was determined based on a scale ranging from 1 to 5, as previously described in Atay and Atay (2022). In summary, this scale consists of five different intervals: 1) 0-10 cm², 2) 11-20 cm², 3) 21-30 cm², 4) 31-40 cm², and 5) >41 cm² spur leaf area.…”