Concepts for understanding fruit trees

This book presents a clear set of integrative concepts for understanding the overall physiology and growth of temperate deciduous fruit trees. The emphasis is on overarching principles rather than detailed descriptions of tree physiology or difference among numerous species of fruit trees. Although the focus is on deciduous fruit trees, many aspects apply to evergreen fruit trees and trees that grow naturally in unmanaged situations.

Response of sweet cherry buds and twigs to temperature changes – evaluated by the determination of the degradation and synthesis of sucrose

This study was undertaken to determine the degradation and synthesis of sucrose (Suc) in sweet cherry buds and the twig tissue response to a sequence of environmental temperature changes (cold (orchard) – warm (controlled temperature of ∼22 °C) – cold (orchard)). The results of two years’ (2016, 2017) findings were compared with the buds of trees and the buds of twigs in November/December in northeast Germany. The Suc content in the buds of trees and the buds of twigs under natural conditions was stable. Temperatures of ∼22 °C resulted in a significant (Suc) degradation (62%, from 39 to 15 mg/g DW) in the buds of twigs after 21 days (day of the year (DOY) 340). The significant re-synthesis (66%, to 25 mg/g DW after 21 days, DOY 361) in the orchard is noteworthy, and highlights the Suc value as a cryoprotective saccharide. The marked changes in the Suc, glucose, and fructose contents of the twigs exposed to a cold-warm-cold sequence (< DOY 319, DOY 319–340, DOY 340–361), lead to the conclusion that this adaptation is the result of tissue- and cold-specific sucrose invertases/synthases. The effect of low-temperature-active enzymes explains the role of Suc in the buds of trees during the winter rest. When using twigs for plant physiological examinations during the winter rest, results on a metabolite level should be considered when drawing conclusions concerning the overall tree physiology.

Optimasi Travelling Thief Problem Menggunakan Algoritma Tree Physiology Optimization Berbasis Hiper Heuristik

Travelling thief problem (TTP) merupakan gabungan dari permasalahan travelling salesman problem dan knapsack problem. travelling thief problem sendiri merupakan permasalahan NP-Hard sehingga permasalahan sebagian besar diselesaikan menggunakan algoritma heuristic dan terus berkembang seiring berjalanya waktu. Algoritma yang digunakan pada penelitian ini adalah simple random untuk pemilihan low level heuristic (LLH) dan tree physiology optimization (TPO) untuk langkah move acceptance dengan menggunakan model Hyper-Heuristics. Pada penelitian yang telah dilakukan sebelumnya algoritma TPO mampu menghasilkan nilai yang cukup kompetitif dengan waktu komputasi yang baik, sedangkan pemodelan Hyper-Heuristics dapat menghasilkan nilai yang konsisten pada data yang beragam. Penelitian diawali dengan memodelkan algoritma TPO menjadi Hyper-Heuristics dan diuji coba dengan data dari TSPLib. Dari hasil uji coba yang dilakukan dapat dilihat bagaimana performa algoritma baru pada data yang diuji. Berdasarkan hasil yang didapat dari penelitian ini dapat disimpulkan bahwa algoritma LLH TPO dapat mengolah data TTP dengan ukuran di bawah 100 dengan cukup baik terbukti dengan hasil yang lebih baik dari metode genetic programming based hyper-heuristic (GPHS) yang telah ada sebelumnya, namun pada data di atas 100 performa LLH TPO menurun jika dibandingkan dengan metode GPHS.

Impacts of Climate Change on Tree Physiology and Responses of Forest Ecosystems

In a changing climate, forest trees have to deal with a range of altered environmental conditions [...]