Girdling

Abstract

'Fairchild' mandarins in the Phoenix area and 'Lisbon' lemons in Yuma were girdled beginning in November 1996. November, March and May girdling of the mandarins led to the greatest yield the first year, while March and May girdling led to the greatest yield in years 2 and 3. March girdling yield increases were generally due to greater fruit numbers, while in May, yield increases were due to greater fruit numbers and fruit size. Returns per acre suggest that March and or May girdling of mandarins will lead to greater profits for the grower. Like mandarins, lemon yields were greater following November, or November and March girdling after one year of the experiment. However, yields of these trees dropped considerably the second year, and the trees appear to be in an alternate bearing cycle. No lemon girdling treatment appears to be better than the untreated trees after three years.