Stems are swelling irregularly and bursting open?

[InhaledFreq]

I have been looking all over the forums for the answer to this but have not been able to find any info.
Experts, please help!

I had two plants, now I have one because I killed the male.
Both plants had stems burst open and a whole branch died.
It has also happened on the main stem as well as on other a few other stems.
This is bagseed, a strain known as Popcorn. Plants are about 3 months old.
More info about this grow here.

Here are the pics of the male's stem. The female has the same issue, but not as bad.

The part of the stem curving to the right was the main growth tip, right below that, where the stem changes from solid green to stripes is where the string was looped around the stem.

This is a shot of the male plant a few days ago when it was still alive, it's the plant on the right.

Does anyone know what this is, and what causes it?

Thanks you!

 

[Minus]

Re: Stems are swelling irregularly and bursting open ??

It does look to be a beetle borer or borer insect of some kind.
Did some googling and all the symptoms match.
Not knowing for sure what it exactly may be I would suggest a bit of reading and some input from more experienced growers that may have seen this.Good luck!
Marijuana Horticulture: The Indoor ... - Google Books

 

[InhaledFreq]

@Sgt_Sativa & @Midus, Thanks for the input!

When I first saw this, I thought the same thing, some type of borer. Then, stupid me, I decided it must be a problem with the plant itself. I should know to trust first instincts.
It sounds like I've got some more research to do tonight...

After reading these post, I just checked on my girl and the first thing I saw was this little black moth sitting on one of the leaves. It may just be a coincidence, but here are pics of it in just case anybody recognizes it.

Here is a pic I took right when I found it. Focus is screwed, but it's that black blur sitting on the leaf right in the center of the frame.

 

[InhaledFreq]

Update: I have been googling for hours and still have not found anything definitive. There is something called a corn borer but it looks to be much more destructive. There are over 1,100 species of boring beetles and, I have been having a hard time finding details on any of them (except for a few common ones that bore trees, dead logs and wooden furniture.)

I cleaned out all of the holes I found on the female plant (3). There is still one branch that is swollen. I'll be monitoring it to see if something bores out of it in the near future.

Afraid that's all I have for now...

 

[Minus]

I did read that there are types of moths that lay their larvae inside the stalks so you might have found the problem.Hope you get er fixed.

 

[Ms.Fox]

InhaledFreq - What is the dark matter inside of the stem that I see? Is it just dead plant matter?

 

[InhaledFreq]

not that moth you have there. harmless. id say you tied your string to tight and did this yourself. or it rubbed to much and wore the hole in it and the shit you see inside is just the pulp. stop picking at it, its not like a scab you want off...lol

Well, I thought the same thing at first... But, the problem is not only on the main stem which I had tied down, but also several branches that I have not tied down, so...

 

[InhaledFreq]

InhaledFreq - What is the dark matter inside of the stem that I see? Is it just dead plant matter?

Yes Ms. Fox, from what I can tell it does appears to be dead plant matter.

 

[Minus]

It definetly seems to be a stalk borer problem.This article best describes them.

Stalk Borers
Jeff Hahn, Assistant Extension Entomologist

Stalk borer, in and out of stem. Photo credit: Dept. of Entomology
Stalk borers are occasionally found in home gardens. They have a very broad host range, attacking over 200 species of plants, including vegetables, such as tomato, pepper, potato, corn, eggplant, asparagus, and bean, and perennials, including lily, anemone, canna, carnation, cosmos, daisy, gladiolus, hollyhock, iris, peony, phlox, and purple coneflower.

They are also known to attack weeds, including ragweed, quackgrass, groundcherry, goldenrod, lanbsquarters, smartweed, and thistle, as well as fruits, such as currant, strawberry, gooseberry, and cantaloupe and crops, including alfalfa, barley, oat, red clover, sugar beet, sweet clover, and wheat. They have even been known to attack the twigs of some trees.

Stalk borers overwinter as eggs on plant stems or on the ground on fallen leaves. They hatch sometime in May and usually attack grass stems first. As they become older and larger, they outgrow the plants they are infesting. They move at night to bore into bigger stemmed plants. They may actually move several times during their larval stage, depending on the availability of food. Stalk borers are aggressive and cannibalistic and you rarely find more than larva per plant.

The larvae are a little over one inch long when fully developed. When fully grown, stalk borers have an orange head and most of its body is chocolate brown. There is a white stripe that runs on the top of the body from the head to the end of the abdomen and another white stripe running along the sides of the body from the middle to end of the abdomen. There are also a couple of short white stripes on the side of the body near the head. Stalk borers have a smooth body with only a few hairs on it.

The larvae feed for about two to three months before moving into the soil to pupate. They remain as pupae for about three weeks before emerging sometime in September as adult moths. They lay eggs primarily in the folds and creases of grasses where they remain until the following spring. There is one generation per year.

The first sign that you have stalk borers infesting your plants is wilting leaves. Sometimes, the plant may break off, especially after strong winds, to let you know your plant has a pest. You may also see the small hole they create when they enter the stalk. When you cut into the stem, you'll find it hollowed and possibly even see the culprit still there. Younger plants are killed when attacked by stalk borer. Plants with larger, more woody stems may survive an infestation. Fortunately, this is a infrequent problem in home gardens and you are likely to only find a few stalk borers at a time there.

By the time you notice a stalk borer problem it's too late to save the plants in most cases. Your best bet is remove infested plants and kill the stalk borer as it can move on and attack other plants. It also reduces the number of stalk borers that survive to lay eggs later. It is possible to cut into infested stems with a very sharp knife to kill the stalk borer and then bind the plant and hope it survives (there isn't much to loose by trying).

Problems are more likely to occur in garden with adjacent grassy, weedy areas. Control weeds to help reduce the risk of stalk borer infestations. If this isn't possible, keep weeds cut short, especially in the spring when stalk borers are looking for feeding sites, and late summer/early fall when adults are laying eggs. Insecticide treatments is not suggested. Stalk borer problems are too sporadic making it difficult, if not impossible, to predict which plants will be attacked and when.

 

[InhaledFreq]

@Minus Wow, thanks for all the info! +reps! These stalk borers sound like nasty little bastards!

Update: Yesterday there was one stem on the plant that had swollen up but had no hole in it, I checked it today and there was a hole! So... I'm thinking something may have laid eggs inside the stem and now they are hatching and eating some plant matter and then boring out of the stem... I also found another one of those little black moths in my office this morning (the plant is in an open closet in my office). Again, the moth may be a coincidence... I'm not ruling out the possibility of stalk borers. I'll post some pics of the stem that has a new hold here in a little while when I get home from my appointment.

 

[InhaledFreq]

I'll post some pics of the stem that has a new *hold here in a little while when I get home from my appointment.

*hole

 

[InhaledFreq]

Stalk Borer

Ok, I googled stalk borer and found this page...

Stalk Borer
Papaipema nebris (Guenee), Noctuidae, LEPIDOPTERA

-----------------

DESCRIPTION

Adult - The forewings of this moth are basically reddish- or grayish-brown marked with distinct white spots or obscure smoky areas. The outer third is paler and bordered by a thin white line. The hind wings are grayish brown on the upper surface and fawn gray below. The wingspan ranges from 25 to 40 mm in diameter.

Egg - The longitudinally ribbed egg may be spherical or slightly flattened and measures 0.4 to 0.6 mm in diameter. White when first deposited, it gradually turns brownish-gray or amber before hatching.

Larva - Basically brown, the early larval instars have a dark brown band around the middle and brown or purple longitudinal stripes on all but the first four segments. The mature larva is solid white or light purple and may reach a length of 31.8 mm. Color plate.

Pupa - About 16 to 22 mm in length, the light brown pupa gradually darkens as it matures.

-----------------

BIOLOGY

Distribution - The stalk borer occurs in all areas east of the Rocky Mountains from southern Canada to the Gulf of Mexico. Highest populations are associated with fields and fence rows with large-stemmed weeds. Economically significant infestations are most common in the Piedmont, particularly in no-till plantings.

Host Plants - Stalk borers tunnel in almost any large- stemmed plant. Their host range encompasses at least 44 families and 176 species of plants. Some cultivated crops subject to infestation include corn, cotton, potato, tomato, alfalfa, rye, barley, pepper, spinach, beet, and sugarbeet. Although many weedy plants are infested, giant ragweed is preferred.

Damage - Stalk borers migrating from an earlier host infest corn seedlings 6 to 60 cm (2 to 24 inches) high, causing two types of injury. Larvae that enter the plant through the lower stalk tunnel upwards, severing the leaves from below. In this case, infested stalks are hollow and apparently healthy green leaves wilt and die. Other larvae climb plants, enter from the top, and feed on buds and rolled leaves. As they unfurl, the new leaves display ragged holes which increase in size as the leaves display ragged holes which increase in size as the leaves develop. Both forms of injury result in destruction of tassels, production of suckers and deformation of the upper plant. Soon after borers enter the seedlings, the stems often break. Frass is usually evident around the base of more mature infested plants. Once past the "whorl" stage, however, corn is somewhat resistant to the stalk borer and recovers more readily from damage. Damage is sporadic but most commonly associated with the border rows of conventionally planted corn and with no-till plantings.

Life History - Stalk borers overwintering as eggs on weedy plants. In May, the newly emerged larvae feed as leaf-miners on broadleaf plants or as stem borers on grasses. On all hosts, larvae eventually bore into the stem and feed until they kill or outgrow their host. When this occurs, they emerge at night and tunnel into new plants, including seedling corn. Developing through 7 to 16 instars, stalk borers mature in their second host. Late in July, the borers emerge, construct individual cells in the soil, and begin a 4-week pupal period. Stalk borer moths emerge in late summer and deposit eggs singly or in masses between the leaf sheath and stems where they remain until the following spring. One generation occurs each year.

Pics can be seen at the site here.
...

This sounds a lot like what I have... The plants were outside amongst tall weeds in the early summer, chewed leaves, entry holes with brown sawdust like matter, branches dying... That must be it, now I think they have outgrown the plant now, so I wonder where they have gone...

Thanks again to everyone, especially Minus, for pointing me in the right direction!

I'm taking pics now, will post next...

 

[Racefan]

If this is from a stalk borer it will be the first I've ever seen indoors. Personally I'd say you've been a little rough and are seeing the signs one gets from super cropping on accident. But I've been wrong before so who knows for sure?

 

[InhaledFreq]

If this is from a stalk borer it will be the first I've ever seen indoors. Personally I'd say you've been a little rough and are seeing the signs one gets from super cropping on accident. But I've been wrong before so who knows for sure?

The thing is, these plants were outside during the early summer months. I would bring them in at night for the most part but there were a few night were I left them outside overnight. And on top of that, I had them sitting right in the middle of some overgrown weeds (not so smart of me. )

This was really more of a test plant (was testing growing outdoors for the first time, growing in soilless mix and adding nutes for the first time, and experimenting with LST for the first time. And I'm really liking the results of the LST I might add.)

All of the rest of the stems look normal so I'm hoping that was the last of them. I'm going to go ahead and continue flowering this plant just to see how she does. Defiantly not moving her into the new grow room now, just in case.

 

[InhaledFreq]

New Photos - Re: Stems are swelling irregularly and bursting open?

pics as promised, taken about an hour ago...

 

[InhaledFreq]

I picked around in the soil around the base of the plant and also found this insect skin (just the shed skin, no insect). I'm using jiffy starting mix +20% extra perlite, so I don't know if any insect skins should be in the medium naturally or not...

 

[Racefan]

You need a drench of some sorts. Something that is sytemic because a foliar spray that just sits on the outside will not get what's inside.

 

[InhaledFreq]

You need a drench of some sorts. Something that is sytemic because a foliar spray that just sits on the outside will not get what's inside.

Are you talking about using an insecticide?

 

[InhaledFreq]

For future reference... Does anybody think that watering with a BTi solution might kill the larva when they are moving through the soil to and/or from the plant?

 

[Minus]

I've read that may work and also injecting BTi with a hypodermic at problem sites.
I've also read that once these types of problems occur it can be difficult to possibly even impossible to remedy.Good luck man.