Managing Your August Apple Harvest

August is National Peach Month, but lately it has become an equally important month for apple growers. With the favorable market-window for high quality early-season fruit, growers are increasing their August harvests.  How did this happen?

Years ago, early yellow apples like Lodi and Transparent ripened and softened extremely quickly.  Growers had to “sell them or smell them.”  As a result, these varieties were used primarily for homemade applesauce.  In the past few decades, this all changed with new early-season apple varieties. First there was Paulared, a McIntosh-type apple that developed red color even when it matured in warm weather.  While this variety did well for years, it too had a very short shelf life and eventually declined in popularity. 

About twenty years after Paulared was widely planted, Gala came to the fore.  Gala resulted from two breeding crosses made in New Zealand.  The first crossed Delicious and Cox’ Orange Pippin to yield Kidd’s Orange Red.  Kidd’s Orange Red was then crossed with Golden Delicious to produce Gala.  From its genetics, Gala combined the earliness of Cox with the flavors and shelf life of Delicious and Golden Delicious. 

In the 1980s, Dr. Art Thompson said Gala was “the best new variety I have fruited in my career.”  Why was Art so positive about Gala?  Perhaps it was when Gala hit farmers markets in mid-August, it had the flavor and the shelf-life of a fall apple.  Art also observed that Gala’s availability led to increased sales of peaches at farmers markets.  

Gala started out as a yellow apple with a red cheek resembling its parent, Golden Delicious.  With the number of red strains available now, red Gala fruit increasingly resemble their red grandparent, Delicious (See photo 1).  With a slower ripening process and much longer shelf life, Gala has moved from a novel early apple variety to one marketed year-round in most supermarkets. 

More recently, Honeycrisp, a breeding selection from Minnesota has been widely planted.  In Maryland, we typically pick both Gala and Honeycrisp in mid-to-late August.  At the same time that Maryland growers began planting Honeycrisp, there was also an increase in intensive, tall-spindle apple plantings.  The tall-system trellis system on dwarfing rootstocks such as Bud 9 and Geneva 41 puts most fruit into full sunlight.  That canopy leads to better quality fruit, but also heats the fruit and speeds fruit development and ripening (See photo 2).  Early varieties, tall-spindle systems and years with an early bloom and/or extreme summer heat has pushed apple harvest ahead in the past few years. 

During the past few years we have seen problems with late-harvested Gala fruit in the mid-Atlantic Region.  Late harvested Gala fruit have two problems.  First they are prone to rain cracking.   Once in storage, they can become unmarketably soft by the time they are packed.  The difficulty finding harvest labor, coupled with the increase in August apple plantings sometimes leads to ripe fruit being unmarketably soft after refrigerated storage. 

One solution has been to plant redder strains of Gala.  This allows growers to pick fruit earlier before it develops ripening-related red color.  In the case of Gala, red selections are now marketed that are almost 100 percent red.  For better or worse, some red Gala fruit now resemble their grandparent, Delicious. 

When thinking about long-term storage, remember FILO; first in last out.  While it seems counter-intuitive, early harvested apples have a longer storage life than late harvested fruit.  Of course, when wholesale prices are good early in the season, storing fruit is not the primary thought for many. 

Commercial orchards currently use two chemicals to regulate the synthesis and action of ethylene, the so-called “fruit ripening hormone.”  AVG is an ethylene-synthesis inhibitor, while 1-MCP is an inhibitor of ethylene action.  AVG (marketed as ReTain) is widely used by Gala growers to delay the maturity and act as a stop-drop spray on a portion of their crop.  While AVG delays ethylene synthesis in the fruit, it also delays red color development, the conversion of starch to sugar, flesh softening and fruit abscission triggered by ethylene.

In the past few years, 1-MCP (marketed as SmartFresh) has greatly improved the quality and marketability of stored apples.  This is now routinely applied to harvested apples and typically gives benefits on firmness after storage. This works well if the fruit are storage-mature but not tree-ripe at harvest.  Once the fruit have tree-ripened, the softening enzymes are present in the fruit and it is too late to get the full benefits of 1-MCP.

With all these factors leading to an earlier and earlier apple harvest season, growers, consultants and extension faculty should begin monitoring fruit maturity now.  Be ready for this year’s earlier than average apple harvest. 

To help fruit growers with apple maturity evaluations, the Walsh and Beaulieu Lab is funded by a Pennsylvania Apple Grower Grant.  For more information and weekly updates about this, email cswalsh@umd.edu.

Tall spindle, high density planting systems improve light penetration into the canopy and red color development of apple fruit.  

View "Managing Your August Apple Harvest” in the latest edition of Vegetable & Fruit News.