Onion Problems - Page 2

Gardeneer · May 30, 2016

Starting from set might be worth trying. It is still spring, if you don't have real hot weather. Onions are cool crop.

Gardeneer.

Jonnyhat · May 30, 2016

update... pulled all the onions... 75% had onion maggots

I guess I will do a BT drench of this bed.

Worth1 · May 30, 2016

Quote:

Originally Posted by Jonnyhat

update... pulled all the onions... 75% had onion maggots

I guess I will do a BT drench of this bed.

Those things suck.
I have never seen them.
What they do is eat the roots and flies come in and lay eggs around the onion.

Worth

Jonnyhat · May 30, 2016

it was kind of my screw up, i didnt know that those over wintered and the very last head of garlic I pulled out of last years bed had them. Then i went ahead and rotated the onions into that bed this year.

Jonnyhat · May 31, 2016

pretty terrible news in PA regarding onions, so have to reevaluate my situation The Allium Leafminer also known as the onion leaf miner has recently been confirmed to have invaded PA (Lancaster CO) which is a short -30 min drive from my home. this is the first confirmed infestation in the western hemisphere.

b54red · June 1, 2016

Probably the reason the onions rotted is a type of disease that can hit onions in extremely wet conditions and is carried by splash back. I lost a whole raised onion bed to this stuff once and lost most of a bed of garlic to it. I sprayed the whole bed with a stronger than usual dilute bleach spray after I removed the onions and threw them away. Do not compost them because the stuff lives in the soil and you don't want to move it around. Whenever I am growing onions and we get an extended rainy patch I will spray my onions with a dilute bleach spray with a little extra soap in it for better wetting of the onions surfaces. I definitely would not plant any new onions in that bed this year just in case you have the same disease I had. There are so many onion diseases that get worse with heavy rain so no telling what you have without talking to an expert or taking samples to an expert to examine. Sorry for your loss.

Bill

Jonnyhat · June 4, 2016

all my garlic... dunzo too

brownrexx · June 6, 2016

I see that you are from PA and you may have a different problem that you are thinking. Have you heard of the new pest in town, the Allium Leaf Miner? It has been devastating onions and leeks in Europe fro years but was just discovered in Lancaster County (where I live) in 2015.

I have an in-ground organic garden and the ALM got about 1/3 or my onion crop which I grew from seed and killed my chives in less than a week this year. I looked inside the plants and definitely identified the pupa of the ALM.

I know that you found maggots in your onions but many times the plants get damaged by the ALM and then dies of secondary causes like fungus that enters through the openings left by the miners and the crop rots.

I am currently worrying about my garlic since it is only about 15 feet away from where the chives were infected. I already found one garlic plant with a rotted bulb and I have never had this happen before.

Read this link from Penn State and see what you think.
http://ento.psu.edu/extension/vegeta...lium-leafminer

jonnyhat I posted this before I noticed your later postings so I see that you already know what the problem may be. Check the Penn State Photos. My onions look just like that.

Sorry about your crop.

Jonnyhat · June 6, 2016

yeah... this is the problem, will BT or pyrethrin work on this? Should I wrap the entire bed in black plastic to superheat it over the summer? how bout a flame weeder?

PhilaGardener · June 6, 2016

This is a very worrying pest!

You should contact your Ag Extension Office with your evidence (contact info is at the link brownrexx posted) to document the spread, and destroying the infected plants should be a priority.

Jonnyhat · June 6, 2016

Quote:

Originally Posted by PhilaGardener

This is a very worrying pest!

You should contact your Ag Extension Office with your evidence (contact info is at the link brownrexx posted) to document the spread, and destroying the infected plants should be a priority.

Already burned them. Thought they were just maggots beforet I got the alert about the borers being found in PA

brownrexx · June 6, 2016

Sorry Jonnyhat but none of the things you mentioned will work and neither will destroying the crop since they can survive as pupa in our local weeds and hatch in Mid August and then fly back to infect more crops. You can kill the pupa in your soil but next year more flies will fly right back to your garden and lay more eggs.

bt will kill caterpillars but these are inside of the leaves and I don't think that the bt will reach them. Not only that, the main reason that the bulbs rot is because the ALM have made openings into the leaves with their feeding and then fungus and bacteria gets in and rots the bulbs.

I just spoke with an entomologist at Penn State today and here are the highlights.

Of all of the states, the ALM has only been confirmed in PA so far and they have no idea how it got here. It has been in Europe for years.

There has been some "anecdotal" reports of the ALM by gardeners from some other states but it has not been confirmed by entomologists yet.

The first adults in PA were recorded on April 13 and the last ones were seen on May 23

Right now there are no adults around, just larvae and pupa. The adults die after laying their eggs.

There are 2 generations per year so new adults will start hatching in mid-August.

He does not have any photos but they have confirmed the ALM in garlic plants.

This pest will attack onions, garlic, leeks and ornamental and wild alliums.

This will really change the way we grow onions and garlic from now on. My plan next year is to plant onion sets in Late May after the first generation of the ALM adults die and then cover the plants with a floating row cover to keep the flies off after mid august if they are not ready to harvest yet.

Crop rotation is a must or there will be pupa in the ground from the previous crop and they can emerge under any covers that you may use. There may be chemical pesticides available to kill the flies but I do not know what they might be. I don't think that anyone knows what will work just yet.

Here is a picture of one of my infected onions that I grew from seed. You can see the pupa a the base of the bulb. The black thing to the right is a piece of dirt.

Jonnyhat · June 6, 2016

I did a complete soil drench of both the garlic bed and the onion bed with BT, I have also been using neem on the bare soil and on all my plants with extra regularity after this infestation. I just wonder if there is a temp threshold that will kill the pupa and larva stages

Jonnyhat · June 6, 2016

So if I am going to start from seed again it will be in a controlled environment indoors, I may just grow under lights and then move directly into a sanitary medium with row cover, the problem is there are so many wild allium plants in my back yard alone that this species is going to be a complete PITA in PA. I mean I could walk into any lawn that is not chem'd out and pick Alliums especially in early season.

PhilaGardener · June 6, 2016

Yes, really bad news :<(

June 6, 2016	#23
brownrexx Tomatovillian™ Join Date: Feb 2016 Location: Southeastern PA Posts: 1,420	I see that you are from PA and you may have a different problem that you are thinking. Have you heard of the new pest in town, the Allium Leaf Miner? It has been devastating onions and leeks in Europe fro years but was just discovered in Lancaster County (where I live) in 2015. I have an in-ground organic garden and the ALM got about 1/3 or my onion crop which I grew from seed and killed my chives in less than a week this year. I looked inside the plants and definitely identified the pupa of the ALM. I know that you found maggots in your onions but many times the plants get damaged by the ALM and then dies of secondary causes like fungus that enters through the openings left by the miners and the crop rots. I am currently worrying about my garlic since it is only about 15 feet away from where the chives were infected. I already found one garlic plant with a rotted bulb and I have never had this happen before. Read this link from Penn State and see what you think. http://ento.psu.edu/extension/vegeta...lium-leafminer jonnyhat I posted this before I noticed your later postings so I see that you already know what the problem may be. Check the Penn State Photos. My onions look just like that. Sorry about your crop. Last edited by brownrexx; June 6, 2016 at 10:06 AM.

June 6, 2016	#27
brownrexx Tomatovillian™ Join Date: Feb 2016 Location: Southeastern PA Posts: 1,420	Sorry Jonnyhat but none of the things you mentioned will work and neither will destroying the crop since they can survive as pupa in our local weeds and hatch in Mid August and then fly back to infect more crops. You can kill the pupa in your soil but next year more flies will fly right back to your garden and lay more eggs. bt will kill caterpillars but these are inside of the leaves and I don't think that the bt will reach them. Not only that, the main reason that the bulbs rot is because the ALM have made openings into the leaves with their feeding and then fungus and bacteria gets in and rots the bulbs. I just spoke with an entomologist at Penn State today and here are the highlights. Of all of the states, the ALM has only been confirmed in PA so far and they have no idea how it got here. It has been in Europe for years. There has been some "anecdotal" reports of the ALM by gardeners from some other states but it has not been confirmed by entomologists yet. The first adults in PA were recorded on April 13 and the last ones were seen on May 23 Right now there are no adults around, just larvae and pupa. The adults die after laying their eggs. There are 2 generations per year so new adults will start hatching in mid-August. He does not have any photos but they have confirmed the ALM in garlic plants. This pest will attack onions, garlic, leeks and ornamental and wild alliums. This will really change the way we grow onions and garlic from now on. My plan next year is to plant onion sets in Late May after the first generation of the ALM adults die and then cover the plants with a floating row cover to keep the flies off after mid august if they are not ready to harvest yet. Crop rotation is a must or there will be pupa in the ground from the previous crop and they can emerge under any covers that you may use. There may be chemical pesticides available to kill the flies but I do not know what they might be. I don't think that anyone knows what will work just yet. Here is a picture of one of my infected onions that I grew from seed. You can see the pupa a the base of the bulb. The black thing to the right is a piece of dirt. Last edited by brownrexx; June 6, 2016 at 09:58 PM.

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May 30, 2016	#16
Gardeneer Tomatovillian™ Join Date: Feb 2015 Location: NC - zone 8a - heat zone 7 Posts: 4,919	Starting from set might be worth trying. It is still spring, if you don't have real hot weather. Onions are cool crop. Gardeneer.

May 30, 2016	#17
Jonnyhat Tomatovillian™ Join Date: May 2015 Location: Downingtown, PA Posts: 337	update... pulled all the onions... 75% had onion maggots I guess I will do a BT drench of this bed.

May 31, 2016	#20
Jonnyhat Tomatovillian™ Join Date: May 2015 Location: Downingtown, PA Posts: 337	pretty terrible news in PA regarding onions, so have to reevaluate my situation The Allium Leafminer also known as the onion leaf miner has recently been confirmed to have invaded PA (Lancaster CO) which is a short -30 min drive from my home. this is the first confirmed infestation in the western hemisphere.

June 1, 2016	#21
b54red Tomatovillian™ Join Date: Sep 2009 Location: Alabama Posts: 7,068	Probably the reason the onions rotted is a type of disease that can hit onions in extremely wet conditions and is carried by splash back. I lost a whole raised onion bed to this stuff once and lost most of a bed of garlic to it. I sprayed the whole bed with a stronger than usual dilute bleach spray after I removed the onions and threw them away. Do not compost them because the stuff lives in the soil and you don't want to move it around. Whenever I am growing onions and we get an extended rainy patch I will spray my onions with a dilute bleach spray with a little extra soap in it for better wetting of the onions surfaces. I definitely would not plant any new onions in that bed this year just in case you have the same disease I had. There are so many onion diseases that get worse with heavy rain so no telling what you have without talking to an expert or taking samples to an expert to examine. Sorry for your loss. Bill

June 4, 2016	#22
Jonnyhat Tomatovillian™ Join Date: May 2015 Location: Downingtown, PA Posts: 337	all my garlic... dunzo too

June 6, 2016	#25
PhilaGardener Tomatovillian™ Join Date: Jan 2014 Location: Near Philadelphia, PA Posts: 1,940	This is a very worrying pest! You should contact your Ag Extension Office with your evidence (contact info is at the link brownrexx posted) to document the spread, and destroying the infected plants should be a priority.