Blueberry leaf ID - Ask Extension
Hi,
Just want to confirm this is chlorosis from iron deficiency. Blueberry bushes. They had low shoot growth and bad bud set, which I am guessing is ...
Knowledgebase
Blueberry leaf ID #867320
Asked May 06, 2024, 6:56 PM EDT
Hi,
Just want to confirm this is chlorosis from iron deficiency. Blueberry bushes. They had low shoot growth and bad bud set, which I am guessing is an issue from last year’s drought and slow N and nutrient uptake. So not sure if the yellowing leaves are indication of low N.
We have been adjusting pH the last few years. It is now in the 5.0 to 5.4 range, which should be good enough for iron uptake, but perhaps some of the root zone is a higher pH.
I ordered some Bonide Liquid Iron +Micronutrients to do a foliar spray. Sound good? And is that safe to apply via foliar during bloom?
Thanks!
Josh
Frederick County Maryland
Expert Response
Hi- the light yellowing between leaf veins could be caused by one or more factors, including limited uptake of iron (youngest leaves near shoot tips), magnesium (leaves at the base of young shoots), and manganese (younger leaves). Chlorosis from low levels of iron in the plant is usually not due to low iron levels in the soil but rather to high soil pH. Soil pH in the 5.0-5.4 range should not induce iron chlorosis.
Plant stressors like soil compaction, extreme weather, and crowding can also contribute to nutrient problems and plant symptoms.
Suggestions:
1. Have your soil tested by an accredited lab to get baseline data on nutrient and organic matter levels.
2. Continue to add sulfur to achieve a 4.5 soil pH.
3. Top-dress the planting area with 1-2 inches of compost, especially if the soil tests <12% organic matter (on weight basis).
4. Thin out the oldest and new, weak canes so that each plant has 12-18 canes of varying ages. Limit side-shoot growth to allow air to circulate freely between plants (no overlapping of adjacent plants).
5. Fertilize plants now if you have not already done so with ammonium sulfate or other nitrogen source high in ammonium.
We don't know if applying a foliar fertilizer of micronutrients will correct the chlorosis. Follow all label directions if you decide to apply it. Waiting until after the bloom period will reduce the risk of injuring flowers.
Jon
Plant stressors like soil compaction, extreme weather, and crowding can also contribute to nutrient problems and plant symptoms.
Suggestions:
1. Have your soil tested by an accredited lab to get baseline data on nutrient and organic matter levels.
2. Continue to add sulfur to achieve a 4.5 soil pH.
3. Top-dress the planting area with 1-2 inches of compost, especially if the soil tests <12% organic matter (on weight basis).
4. Thin out the oldest and new, weak canes so that each plant has 12-18 canes of varying ages. Limit side-shoot growth to allow air to circulate freely between plants (no overlapping of adjacent plants).
5. Fertilize plants now if you have not already done so with ammonium sulfate or other nitrogen source high in ammonium.
We don't know if applying a foliar fertilizer of micronutrients will correct the chlorosis. Follow all label directions if you decide to apply it. Waiting until after the bloom period will reduce the risk of injuring flowers.
Jon
