March
2017

 

By
B. Rosie Lerner
 
Purdue
Extension
Consumer Horticulturist

 

Check out Rosie's book: Possum in the Pawpaw Tree

 

 

 

03-02-17

Question and Answer


Rotten apples and Indiana Big Tree Register

Black rot suspected on Northern spy apples
Black rot suspected on Northern Spy apples

Photo credit: W.F., Portland, Ind.

Q. We have fruit trees, including Yellow Delicious, Red Delicious, McIntosh and Northern Spy. We use an all-purpose spray. The Northern Spy has very large apples, and they all rot. This past season, we didnít get one good apple from it although it was loaded. What spray could we use for this, and what is this disease called? - W.F., Portland, Ind.

A. Apples can fall victim to a number of different soft rot diseases. The symptoms in your photo appear consistent with black rot, and Northern Spy is particularly susceptible to this fungal disease. While multipurpose sprays can help prevent or at least reduce the occurrence of this disease, they may not be enough during unusually wet seasons, like last year. Many growers had problems because the rain kept washing the fungicide off. You can read more about this and other apple rot diseases at https://fff.hort.purdue.edu/article/end-of-season-thoughts-on-rots/ and https://fff.hort.purdue.edu/article/summer-diseases/.

If the problem continues this season, you might want to consider sending in a sample to the Purdue Plant and Pest Diagnostic Lab at http://www.ppdl.purdue.edu for a more conclusive diagnosis.

Q. We have a huge sycamore tree on our property Ė we guess it is probably around 100 feet tall. Our neighbors think this might be the largest sycamore in the state. Does anyone keep track of tallest trees in Indiana? How can I find out if mine is a record-holder? - R.C., Marion County

A. The Indiana Department of Natural Resources maintains the Indiana Big Tree Register, and you can see the records online at http://www.in.gov/dnr/forestry/8169.htm. The official register considers the total height, the trunk circumference at 4 1/2 feet above the soil line, and the average spread of the crown. The current Indiana champion sycamore is listed as 122 feet tall.

Information on how to measure your tree, as well as instructions for nominating a tree for the Register is available at http://www.in.gov/dnr/forestry/8275.htm.

 

Writer: B. Rosie Lerner
Editor: Cindie Gosnell,