- 7 



If you intend to plant one of these rootstock-scion combina- 

 tions that has been shown to be poorly anchored, several sugges- 

 tions may be made. 



1. Purchase trees that have been budded at least 18 inches 

 high. 



2. Avoid planting trees on soil types not favorable for deep 

 rooting . 



3. Avoid planting trees on windy sites. 



4. Provide support for newly planted trees to minimize whip- 

 ping of the tree and thus encourage adventitious root 

 formation along the entire below-ground portion of the 

 rootstock. 



Of the six rootstocks included in this experiment, MM 104 

 appeared the least tolerant to the wet conditions of the last 4 

 years. This agrees with reports of others who have found that 

 MM 104 rootstock does not perform well on poorly drained sites. 

 However, the differences in leaf color, terminal growth and fruit 

 size between trees on MM 104 and the other rootstocks was not 

 great. The other rootstocks in this trial (MM 106, M 7, Robusta 5, 

 Seedling, M 2) are considered intermediate in their tolerance to 

 high moisture conditions. Differences among these intermediately 

 tolerant stocks were not observed. Yellowing of the leaves and 

 reduced terminal growth were noted to a limited extent on all 

 rootstocks indicating that all rootstocks in this test were injured 

 by the excessive moisture conditions. 



Planting trees on poorly drained sites is hazardous at best 

 and is not recommended. However, if a grower wishes to take the 

 chance and plant on a poorly drained site, one suggestion may be 

 made. Plant trees that have been budded on M 13 rootstock. This 

 rootstock has been shown to be somewhat tolerant to wet soil con- 

 ditions, but it should be noted that scion varieties budded on 

 this rootstock grow to a size similar to those budded on seedling 

 roots . 



*************** 



HAY MULCH MAY BE A VALUABLE SUPPLEMENT TO A HERBICIDE 



PROGRAM IN ORCHARDS 



William J. Lord 

 Department of Plant and Soil Sciences 



Several years ago, we showed that simazine, a pre-emergence 

 herbicide, accumulated in the hay mulch under apple trees. As a 



