PERFORMANCE OF APPLE CULTIVARS

Performance of 9 Apple Cultivars (Malus Domestica Borkh) Grafted on Two Rootstocks Grown in Lebanon

Table of Content

Abstract4

Chapter One5

Introduction5

Chapter Two11

Literature Review11

Photosynthesis32

Fruit Color? Firmness36

Soluble Solids Content (SSC)? pH? Fruit Mineral Nutrient Component41

Trunk Cross Sectional Area and Tree Size45

Fruit Drop Fruit Set46

Optimal Harvest Time47

Fire Blight Disease49

Changes During Fruit Ripening50

Chapter Three56

Introduction56

Methodology56

Method56

Rationale of the Methods57

Materials and Methods59

Chapter Four60

Results60

Survival60

Height62

Trunk Cross-Sectional Area65

Fruit Weight69

Cumulative Yield74

Cumulative Yield Efficiency79

Discussion82

Chapter Five99

Conclusion99

Abstract

This study was set out to asses the effects of different combinations of cultivar? rootstock and location on Survival (%)? Height (m) ? Trunk cross-sectional area (cm2) Fruit weight? Cumulative yield? and Cumulative yield efficiency after 8 years.

Therefore? different cultivar/rootstock combinations were established at three locations to identify their performance and to determine the most suitable for Lebanon. Study have revealed that M7 rootstock were more approapriate for the region of Lebanon. Also? Cultivars like Red Fuji and Granny Smith were among the least efficient trees compared to the remaining cultivars (Scarlet Spur? Super Chief? Red Delicious Jonagold? Gale Gala and Golden Delicious). However? different locations were not significant enough to have an effect on Survival (%)? Height (m) ? Trunk cross-sectional area (cm2) Fruit weight? Cumulative yield? and Cumulative yield efficiency of Apple Trees.

Chapter One

Introduction

"From the Garden of Eden to the big Apple? from William Tell to Johnny Appleseed? to Paris of Troy who gave the troublesome golden apple to Aphrodite which started the Trojan War? the apple has occupied a very special place in our affections both as a symbol and as one of the simplest and most delicious of Nature's gifts" (Rosanne Sanders? 1988).

The world's most important commercially produced apple cultivars belong to the species Malus domestica Borkh. Malus is one of the most important genera of pome fruits. This group probably originated by spontaneous doubling ina sterile hybrid between primitive species of the rosaceous subfamilies prunoideae and spiroideae (Westwood? 1993). The genus (Malus Mill) has 15 primary species? including two from Europe? four from North America? and the rest from Asia. Twenty five species and more than 7000 cultivars has been reported in apple? but modem commercial production is dominated by only few cultivars (Way et al.; 1990). Thus? while the genus Malus is very diverse genetically? cultivated cultivars of apple have a rather narrow genetic base (Moore and Ballington Jr.? 1990).

The domestic apple (Malus x domestica) is probably originated in the Caucasus region of southeastern Europe and possibly southwestern Siberia from natural hybridization between several species including Malus sylvestris Mill.? Malus sieversii Ldb.? and Malus baccata (L.) Borkh (Roach? 1988). Apple cultivars have also originated as a result of planned breeding? selection? and as chance seedlings. Many of the leading cultivars today were well known to previous generations of growers and consumers (Teskey and Shoemaker? 1978). Annual bearing? excellence in dessert quality? attractive appearance? pest resistant? and high production efficiency are the most recognized characteristics of an apple cultivar.

Many apple cuItivars widely grown today were discovered by chance (Ballard? 1981; cited by Derkacz et al? ...