Sometimes Low Chill Apples and Hot Desert Clinate Don't Mix

Q. I heard the Israelis established a low desert apple tree. A few orchards have been established in the Phoenix area. I would like to learn more with the intent to purchase.
 

A. There are a couple of apples suitable for the low desert developed in Israel but the quality of the apple is typically not the best, in my opinion, unless you are a big fan of ‘Yellow (Golden) Delicious’. Both “Anna’ and “Ein Shemer’ apples were bred in Israel as a “low chill” apple for warm climates, not necessarily hot desert climates.

Anna grown in Las Vegas, Nevada in the Eastern Mojave Desert

            “Low chill” refers to the chilling requirement required by some fruit trees to flower and produce fruit the next growing season. A chilling requirement is a specific number of hours below a threshold temperature, usually around 45° F, so they “recognize” winter has passed.

            Just because a fruit tree has a low chilling requirement does not necessarily mean it produces good fruit in a hot desert climate. Hot desert climates are not the best places for apples. It doesn’t mean necessarily that an apple tree won’t grow but may have trouble producing fruit and decent yields and the flavor, texture and keeping qualities may be inferior. Apple fruit frequently sunburn in our hot summer climate and develop thick skins and high sugars but lower acidity. These climates are more suitable for stone fruit such as apricots and peaches.

Immature apple in the early stages of sunburn

          

Apple fruit with severe sunburn from lack of protection from late afternoon sun (West)

  Hot deserts without cool nights close to harvest don’t develop a good balance of acids and sugars for flavor development. Cool nights are important for this. A 4000 foot elevation adds cooler nights which is very important for flavor development.

            The orchards in Arizona that I know of such as those near Wilcox, Arizona, are at a 4000 foot elevation or higher. Compare that with Phoenix at an elevation of around 1000 feet. These higher elevations and can handle some popular apples like Granny Smith, Fuji, Fuji, Gala and Pink Lady.

            Some lower chill apple varieties to try in hot desert climates include Dorsett Golden, Anna, Ein Shemer, Mutsu, Pink Lady and Sundowner. From my experience, try but proceed with caution with Fuji, Granny Smith, Gala, White Winter Pearmain, Winter Banana, Gordon, Yellow Bellflower and Pettingill. All of the apples do better with protection from late afternoon sun.