While the early apples have been harvested, it's not too late to enjoy later-ripening fruit. From October to early November, many apple cultivars are available at pick-your-own orchards and at farm markets in Missouri. Although harvest dates vary from year to year, a general schedule of ripening for common apple cultivars is listed in Table 1. This year harvest is delayed in some areas due to the heavy rainfall and flooding in many parts of the state. Also, organic producers may have a limited supply of apples due to severe infection with apple scab, cedar apple rust, fire blight, and other diseases. However, there is a good supply of most conventionally-grown apples.
Harvesting apples at the "right time" will enhance and preserve the flavor and quality of the fruit. For example, fruit harvested too early is small in size with hard flesh and will taste starchy. In contrast, over mature fruit will have a dark, dull color with greasy peel and will taste starchy or have off flavors.
|Rome Beauty||Oct. 1|
|Early Pink Lady||Oct. 10|
|Arkansas Black||Oct. 15|
|Granny Smith||Oct. 15|
|Pink Lady||Nov. 5|
Several factors affect the harvest date. The fewer the number of apples on a tree, the more rapid fruit matures, resulting in an earlier harvest date. A heavy crop load will delay the harvest date. Also, high levels of nitrogen generally delay red color development, and induces flesh softening and early fruit drop. However, the most important factor influencing the harvest is temperature throughout the growing season. Apple cultivars vary in their response to temperature. For example, cultivars such as 'Jonagold' and 'Honeycrisp' favor cool northern climates, whereas 'Jonathan' and 'Arkansas Black' are well-adapted to warm growing areas.
There are several ways to determine the proper time of harvest. A good indicator of apple maturity and harvest is peel color. Peel color changes from green to yellow as the fruit matures and is ready for harvest. For apples that are primarily red in color, often the shift in color can be evaluated by looking for the color change on the side of the apple that has not been exposed to sunlight. When picking apples, be aware that fruit doesn't ripen simultaneously on a tree and multiple harvests may be required. Fruit exposed to sunlight will ripen first, with shaded, interior fruit ripening later. However, because of the influence of nitrogen on color, other indicators, such as flesh firmness, and sugar and starch content can be used in conjunction with change in peel color to determine the proper time of harvest.
Firmness and sugar and starch content are easily evaluated by tasting the fruit. When the peel color starts to change from green to yellow, pick two fruit on opposite sides of the tree at about shoulder height. As you bite into the fruit, assess the flesh firmness and note the sweetness and absence of starchy flavors. If starchy flavors are detected, sample the fruit 5 to 7 days later and taste them again. When the taste of the fruit is acceptable to your palate, harvest the apples and refrigerate them immediately. If apples were harvested prematurely, leave them at room temperature for a week or two before cold storage. Most apples can be stored in the refrigerator for about three months. When refrigeration is delayed or over mature fruit is harvested, internal breakdown of the flesh occurs.Most commercial growers use instruments, such as a penetrometer, to measure the firmness of the flesh and a refractometer to assess sugar content. Hard 'Red Delicious' fruit will measure 16.5 pounds, while ripe fruit will measure 8 pounds, and over-ripe will be less than or equal to 7 pounds. The refractometer measures soluble solids (i.e., sugars) and values are displayed as degrees Brix. Apple cultivars vary in soluble solids content at harvest. 'Fuji' apples are normally very sweet and will have high Brix values (>18), while 'Red Delicious' will be lower. Industry standards in some states require 'Red Delicious' and 'Golden Delicious' apples to have minimum Brix values of 10 and 11, respectively, at harvest.
REVISED: October 3, 2019