Apples

Early this month, the Baltimore City Department of Public Works issued a Required Boil Water Advisory for parts of Baltimore City and a Precautionary Boil Water Advisory for a larger portion of the city and part of Baltimore County due to E. coli being identified in municipal water in parts of the city. While the Department of Public Works (DPW) has received the all-clear from the Maryland Department of Environment to lift the boil water advisory, below are some tips for farmers in the event a similar event happens in the future.

As apples ripen, among many other processes, they begin to increase their production of the ripening hormone ethylene. As ethylene is being produced, it leads to notable changes in apple quality, which include changes in color, texture, and flavor. Furthermore, increased ethylene production also leads to the phenomenon of pre-harvest drop, which refers to the abscission of the fruits from the tree before horticultural maturity. The production of ethylene results in weakened tissue in the abscission zone (the region where the pedicel of the apple is connected to the supporting limb) leading to cell wall breakdown and eventual drop.

Although harvest is one of the most frantic times of the season, peak harvest time needs to be balanced with preventative practices to help ensure that the crop has optimal quality for satisfying consumer demands, and to ensure profitability of the operation. The degree of fruit quality can be highly determined by the preharvest, at harvest and postharvest practices in an orchard. Profits can be maximized by producing appealing fruit, by minimizing fruit damage and loss. Authors: Morgan Jacobs, Candidate for B.S. in Physiology and Neurobiology and Dr. Macarena Farcuh, Assistant Professor and Extension Specialist University of Maryland, College Park

Fuji apples are among the top cultivars produced in the US. This late season cultivar stands out for its great quality and consumer acceptability, as well as for its good storage potential. Nevertheless, overall Fuji apple fruit quality can be impacted by several factors, including environmental conditions, preharvest management practices, stage of maturation at harvest, and postharvest storage temperatures, each affecting fruit marketability. Fruit maturity at harvest is a critical factor affecting postharvest ripening and flavor development, and therefore a determinant of postharvest handling of fruit. Too early a harvest may result in pronounced lack of flavor development, while late-harvested fruit undergoes rapid firmness loss during storage. In contrast, harvest of unripe fruit enhances a number of desirable characteristics, such as lengthened ripening period and delayed decline in firmness, acidity and green ground-color relative to ripe fruit. On the other hand, less mature fruit generally do not develop typical full flavor, and as a result taste is often strongly impaired. The objective of this research is to evaluate the effect of different harvest maturities and different storage temperatures on fruit quality and ripening patterns in Fuji apples grown under the Mid-Atlantic conditions.

Return bloom is a crucial factor in maintaining crop yields in apple trees year-to-year, especially in strong biennial bearing cultivars. In apples, the fate of the flower buds for the following season is determined between 4-8 weeks after full bloom. Therefore, production of high loads of fruit or vegetative tissue during this period can deplete the tree’s energy which can compromise return bloom for next year. Certain cultivars have higher tendencies for bienni-al bearing such as Fuji, Honeycrisp, and Red Delicious, and they initiate flower formation much earlier in the season than the annual cropping cultivar such as Gala, Macintosh, and Rome. Authors: Pranoy Basu & Macarena Farcuh, Ph.D. Assistant Professor and Extension Specialist University of Maryland, College Park; Title: Using Plant Growth Regulators to Improve Apple Return Bloom

The remnants of Hurricane Ida dumped much rain throughout the region. This is a reminder that any fungicides that had been applied need to be reapplied, especially since we are in the harvest season. Fruits are still susceptible to fruit rots and sooty blotch and flyspeck. In addition, Marssonina blotch is another disease that favors wet conditions. Marssonina blotch can defoliate trees quickly and, if pressure is high, potentially cause fruit issues in storage. It is important that growers remain vigilant and keep fruit covered with fungicides during the harvest period. This is especially important for later harvested varieties and varieties intended to be kept in long term storage.

What is Controlled Atmosphere and why do we use it? To maintain stored fruit quality after harvest, it is essential to understand and control key factors such as genetic background (cultivars/rootstock used), orchard management practices, environmental conditions such as orchard history, and fruit maturity at harvest and postharvest storage conditions. Harvest maturity and postharvest storage conditions are specific for most apple cultivars, so adequate preparation must be taken for each individual cultivar grown under their specific environmental conditions.