how many chilling hours are required by apple plant to complete vernalization
Answers
Explanation:
This really depends on the cultivar. There are over 8,000 apple varieties worldwide and more being introduced annually. Most apple varieties need 500-1,000 chill hours or temps below 45 F. (7 C.) but there are some low chill varieties available that need no more than 300 chill hours. Low chill varieties need less than 700 chill hours and can withstand hotter summers than other varieties. Medium chill varieties are apples that need chill hours of between 700-1,000 chill hours and high chill apples are those that require more than 1,000 chill hours. Low chill and medium chill apples can generally be grown in high chill regions, but high chill apples will not thrive in low chill climes. Although most apples need high chill hours, there are still plenty of medium to low chill cultivars. Fuji, Gala, Imperial Gala, Crispin, and Royal Gala all require chill times of at least 600 hours. Pink Lady apples need between 500-600 chill hours. Mollie’s Delicious requires 450-500 chill hours. Anna, a golden delicious type of apple, and Ein Shemer, a yellow/green cultivar, tolerate areas with 300-400 chill hours. A truly low chill apple, Dorsett Golden, found in the Bahamas, requires less than 100 hours.