-12' 



TREE FRUIT PHYSIOLOGY TRIALS UNDERWAY AT 

 THE CD. A. FARM OF FRELIGHSBURG , QUEBEC"^ 



Raymond L. Granger 

 C.D.A. REsearch Station 

 St-Jean-sur -Richeleiu 

 Quebec, Canada J3B 6Z8 



Response of apple trees to mycorrhizal fungus : In vitro 

 propagated apple trees of the clones Mailing Merton 111 (MMlll) 

 and Mailing 7 (M7) were planted in pots containing sterile chips 

 of baked Montmorillonite clay and placed in a greenhouse. At 

 planting time they were inoculated with vesicular-arbuscular 

 (VA) mycorrhizal fungus ( Glomus epigaeus ), fed weekly for 15 

 weeks with a Long Ashton solution and watered with distilled 

 water as needed. Tree height was measured once a week. At 

 the end of the experiment both the total leaf area and the 

 volume of the root system of every tree were also measured. 

 Root samples of every tree were then stained with red Fuschin 

 for microscopic examination. 



The weekly measurements showed the heights of the M7 

 mycorrhizae- treated trees to be 1.7 times greater than those of 

 the control group (Table 1) . 



Table 1. Mean effect of Glomus epigaeus on the growth of two 



z 

 Numbers in a column followed by a different letter are signi- 

 ficantly different at odds of 19 to 1. 



Similarly, after 15 weeks the total leaf area and the root 

 volume of the former were 1.9 and 1.4 times greater than the 

 latter, growth differences having appeared three weeks after 

 inoculation. At the end of the experiment microscopic examination 

 revealed that the roots of both clones of inoculated M7 trees 

 were colonized by the fungus (Table 2). However, no growth 

 differences were observed on the trees of the MMlll clone (Table 1) 



1 

 Talk presented at the Annual Summer Meeting of the Massachusetts 

 Fruit Growers' Association, Inc., July 15, 1981 



