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Sweet & Cheeky!

Hi y’all, welcome back to the blog. These last couple of weeks at FREC, my fellow summer research assistant, Megan, and I have been focusing mainly on our project given to us by Dr. Schupp.

Our project focuses directly on a new club variety of apple called Sweet Cheeks. They are a cross between Honey Crisp and Pink Lady apples. Unfortunately, it has a fruit finish issue, mainly with russetting. This project will study which general sector of the tree has the most russet and which side of the apple it is prominently featured on.

The trees we were given to use are top worked trees, which mean the were planted as one variety, in this case, Gala, and then they were cut off where the rootstock and the scion join. Then, scions of the new variety (this is where the Sweet Cheeks come in) are placed in notches in trunk that is still in the ground. The scions are secured and left to grow.

We were given 5 of these trees, which we then divided into 6 sectors using flagging tape. Fist we divided the tree horizontally, determining an upper and lower canopy. This line was placed equidistant between the second and third wire of the trellis system. Second, we divided the tree into outer and inner canopy by dividing the tree vertically into three sections, creating an outer north, inner, and outer south.  If you’re lost (don’t worry, I was), refer to the picture below. With these divisions, we created 6 sectors of the tree. These sectors are: upper outer north, upper inner, upper outer south, lower outer north, lower inner, and lower outer south.

After this, Megan and I counted all of the apples in each sector. Then, we went through and counted the apples with signs of russet. We also rated whether the russeting was “low”, “moderate”, or “severe”. Russet usually initially appears as small black dots around the sides of the apple, typically on the exposed side that receives the most sun.

From there, we determined percent russeted in each sector. Just from this, we noticed that apples in the upper canopy had more russet because of their increased exposure to sun.

Additionally, to quantify severity, we harvested around a dozen apples from the surrounding sweet cheeks trees of which we considered “low” severity and around a dozen of which we considered “moderate” severity. We then took pictures of them and ran through a digital image analysis program that gives us a percentage of russet on the apple. To do this, one of the researchers there, Edwin, built a photo box using PVC pipe, poster board, and lamps. It has boards and pipes at the top, which can hold a camera that is used to capture the images. All you have to do is slide the apples in on the apple tray covered in blue fabric and click the capture button. I will insert a photo of the photo box. It is a picture taken from above because I was the one adjusting the camera.

We will survey the Sweet Cheeks again in August and at harvest time to determine whether the russet is early or late onset.

Next week, I hope to delve deeper into the other research projects that Dr. Schupp is working on and share with you how much I have learned!

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