What if Pennsylvania apples disappeared?

After a long winter, most people give a sigh of relief at the first sign of spring, but not Mark Boyer. For Boyer, spring means the need for critical action that could make or break his family's Pennsylvania apple orchard. 

“Once we see blossoms, we have about ninety days to prepare for next year,” Boyer says. “It’s the single most important decision a farmer can make.”  

With so much at stake, Boyer called up someone he trusted: Shanthanu “Shan” Kumar. Kumar leads Penn State’s fruit tree team, a group of researchers and educators dedicated to supporting farmers. Their work is vital for the success of agriculture in Pennsylvania, ensuring that healthy, high-quality apples, peaches, pears, cherries, and other tree fruits reach store shelves.

The Challenge: Making Locally Grown Fruit Profitable and Healthy  

The key to a successful harvest is a process called crop load management. This process involves carefully balancing the number of fruits on a tree, allowing the tree to produce higher-quality fruit.

Kumar, an assistant professor of tree fruit at Penn State, explains that this process has the most impact on a farm’s bottom line. If farmers remove too many blossoms or fruitlets, they won't have enough fruit to sell. If they remove too few, the apples will be small, less sweet, and more prone to disease. It's a high-stakes gamble that affects everything from the farm's survival to prices at the grocery store. With the right expertise, however, that risk can be managed.  

Feeding the Nation and Pennsylvania’s Economy  

Boyer's orchard is a key part of a thriving industry. Pennsylvania ranks fourth in the nation for apple production, with over 21,000 acres of orchards producing 400 to 500 million pounds of apples every year. This is a cornerstone of commercial agriculture in the state. With orchards in all sixty-seven counties, Penn State’s team of tree fruit experts is always busy, especially during thinning season.

Historically, removing fruitlets, or thinning, has been done by hand. This is a time-consuming, labor-intensive process. Over the past thirty years, many growers have turned to chemical thinners that cause excess fruit to drop off. Applying chemical thinners also requires favorable weather conditions. Kumar's blossom thinning research offers a more precise method that helps growers improve fruit size and overall quality.