Signs of over watering vs nitrogen deficiency

sprtsguy76 · May 19, 2012

Whats your take between the two? Signs are very similar, yellowing starts at the bottom leaves and it works its way up. I'm seeing a couple of my plants showing these signs in containers. I'm pretty sure I'm not over watering as my soil is bark based but I do need some feedback. Thanks.

Damon

rnewste · May 19, 2012

Damon,

I have seen this tendency in the past with the EarthTainers, so this year I am applying Daconil on a weekly basis to see if the yellowing leaf syndrome can be delayed further into the Season.

So far, not a sign of yellow leaves this Season, but we are still in mid-May. I also think the Bat Guano *may* be having a beneficial effect - - but again, early in the trials.

Raybo

Tracydr · May 19, 2012

Don't forget that spider mites may start with yellowing leaves. I didn't realize this last year and it bit me.
I just noticed the mite damage this week so hopefully, I can stay on top of it. 107 and <10% humidity is not going to help this week.

Fusion_power · May 19, 2012

There is one other thing you didn't mention. Leaves grow old and eventually die. When they do, they normally turn yellow at the bottom of the plant and gradually the dead leaves go higher as older leaves die first. This is partly a response to shading, as the leaves lose photosynthetic efficiency, the plant is programmed to cut losses and focus on leaves that are in the sun and doing something useful. You can delay this by keeping nitrogen levels high and not shading the lower parts of the plants.

When a leaf has reduced efficiency, it is more easily infected by fungal pathogens. Plus, fungal spores are usually more prevalent closer to the ground. The net effect is that as leaves are losing their efficiency, they are also being infected with diseases like septoria and early blight. As the diseases progress, they produce new spores in such large numbers that they can overwhelm leaves higher in the plant.

One recommendation I make is to remove all leaves that are within a foot of the ground just as soon as the plants get big enough to survive the loss. They normally don't have much of a fruit load at that time so it is pretty much harmless to the plant and tends to prevent spread of disease from the soil to the lower leaves. It also opens up the bottom of the plant which increases air flow which also helps with preventing disease.

DarJones

sprtsguy76 · May 20, 2012

I understand leaves aging and dying. And most of leaves I'm seeing yellow are getting shaded out. But the overall appearance with these few plants are a dull green not a vibrant green. I understand about the risk of fungal pathogens too. But these are containered plants and I have never had much problem with disease . And they are still pretty young. I'm starting to look towards my time release fertilizer I have mixed in the soil. Its supposed to be 5-6 month. I would be happy to get 4 months out of it. But like I said my plants are still fairly young (planted out early April).

Damon

May 19, 2012	#1
sprtsguy76 Tomatovillian™ Join Date: May 2007 Location: Santa Clara CA Posts: 1,125	Signs of over watering vs nitrogen deficiency Whats your take between the two? Signs are very similar, yellowing starts at the bottom leaves and it works its way up. I'm seeing a couple of my plants showing these signs in containers. I'm pretty sure I'm not over watering as my soil is bark based but I do need some feedback. Thanks. Damon

May 19, 2012	#2
rnewste Tomatovillian™ Join Date: Apr 2007 Location: Campbell, CA Posts: 4,064	Damon, I have seen this tendency in the past with the EarthTainers, so this year I am applying Daconil on a weekly basis to see if the yellowing leaf syndrome can be delayed further into the Season. So far, not a sign of yellow leaves this Season, but we are still in mid-May. I also think the Bat Guano may be having a beneficial effect - - but again, early in the trials. Raybo

May 19, 2012	#3
Tracydr Tomatovillian™ Join Date: May 2011 Location: Laurinburg, North Carolina, zone 7 Posts: 3,207	Don't forget that spider mites may start with yellowing leaves. I didn't realize this last year and it bit me. I just noticed the mite damage this week so hopefully, I can stay on top of it. 107 and <10% humidity is not going to help this week.

May 19, 2012	#4
Fusion_power Tomatovillian™ Join Date: Feb 2006 Location: Alabama Posts: 2,250	There is one other thing you didn't mention. Leaves grow old and eventually die. When they do, they normally turn yellow at the bottom of the plant and gradually the dead leaves go higher as older leaves die first. This is partly a response to shading, as the leaves lose photosynthetic efficiency, the plant is programmed to cut losses and focus on leaves that are in the sun and doing something useful. You can delay this by keeping nitrogen levels high and not shading the lower parts of the plants. When a leaf has reduced efficiency, it is more easily infected by fungal pathogens. Plus, fungal spores are usually more prevalent closer to the ground. The net effect is that as leaves are losing their efficiency, they are also being infected with diseases like septoria and early blight. As the diseases progress, they produce new spores in such large numbers that they can overwhelm leaves higher in the plant. One recommendation I make is to remove all leaves that are within a foot of the ground just as soon as the plants get big enough to survive the loss. They normally don't have much of a fruit load at that time so it is pretty much harmless to the plant and tends to prevent spread of disease from the soil to the lower leaves. It also opens up the bottom of the plant which increases air flow which also helps with preventing disease. DarJones

May 20, 2012	#5
sprtsguy76 Tomatovillian™ Join Date: May 2007 Location: Santa Clara CA Posts: 1,125	I understand leaves aging and dying. And most of leaves I'm seeing yellow are getting shaded out. But the overall appearance with these few plants are a dull green not a vibrant green. I understand about the risk of fungal pathogens too. But these are containered plants and I have never had much problem with disease . And they are still pretty young. I'm starting to look towards my time release fertilizer I have mixed in the soil. Its supposed to be 5-6 month. I would be happy to get 4 months out of it. But like I said my plants are still fairly young (planted out early April). Damon