Your tree might also become stunted (meaning it doesn’t grow as much as it should) or bloom at the wrong time of the year (e. g. , in summer or fall instead of spring).
The yellowing of leaves with citrus greening can look similar to other conditions, such as root rot or a nutrient deficiency. However, the yellowing caused by citrus greening tends to look more random and less symmetrical than other types of yellowing.
If you cut the lemon open, you may notice that the central core is curved or misshapen or that the seeds look shriveled or discolored. The fruit might also have an unpleasant taste. Small or lopsided fruits can also be a sign of stubborn disease, a less common infection that is spread by leafhoppers. [7] X Research source
Lemons can also remain partially green for other reasons, such as unusually warm weather in the spring. [10] X Expert Source Michael Simpson, PhDRegistered Professional Biologist Expert Interview. 8 September 2021. If your lemons are still green but your tree seems otherwise healthy, then their color isn’t necessarily a cause for concern.
Do a search using terms like “agricultural extension office near me. ”
The borders of the lesions sometimes develop a yellow halo or have a waterlogged appearance. The lesions are typically brown, but they may develop a grey or white center as the disease progresses.
While the inside of the fruit isn’t usually affected by these lesions, some of them can cause the rind to crack and make it easier for other infections to move in. [15] X Research source You might also notice lesions on the stems.
Severe infections are most common in very warm and wet conditions, e. g. , if your lemon trees have been exposed to tropical storms.
Since there are many conditions that can cause these symptoms, don’t assume your tree has citrus canker based on sparse leaves alone. Look for the more characteristic lesions on the fruit and leaves as well.
The laws regarding the management of citrus canker vary from one place to another. Depending on where you live, you may be required to remove all citrus trees within a certain radius of the affected tree(s).
Brown or brick-red spots with grey or black centers. These lesions may have green halos around them. Lots of tiny, slightly raised bumps that are tan or dark brown, without grey or black centers. These are more likely to appear on lemons that are still green. Large, flat, dark-brown spots with raised cracks on them. These may eventually turn into the more typical lesions with grey or black centers as the fruit matures. Small, reddish, freckle-like spots that are irregular in shape. These most often appear on mature fruits.
In addition to causing fruit drop, virulent spots can grow through the rind and affect the quality of the fruit itself.
You might also notice similar lesions on the stems and twigs.
Cleaning up any leaf litter around the tree promptly Removing severely infected trees Irrigating your grove or orchard to keep your trees well-hydrated and prevent leaf drop
In the early stages, it’s easy to confuse these lesions with the ones caused by black spot. However, citrus scab lesions are typically lighter in color and more raised than black spot lesions.
Leaves that are severely infested might appear deformed, twisted, or crumpled. [27] X Research source You might also notice scabby lesions on the twigs and stems.
First application during the spring flush, or the period of rapid plant growth in early spring Second application during petal fall Third application 3 weeks after petal fall
