Need help with diagnosis!

UI’ve got some leaf symptoms in my outdoor ladies that I’m not sure about. I’m thinking it’s bugs and some fungus, like leaf spot/septoria. I’m hoping to get some confirmation and some treatment recommendations. We’re finally drying out here but my plants went through a very unusual rain event with HUGE amounts of rain for 2.5 weeks. The temps are ranging from lows in the lower 70°’s and highs from 82°-87°. They’re various autoflowering strains ranging in age from 42-55 days old and are in 10 gallon grow bags with a mixture of amended FF soils. I’ve been feeding the FF Bloom Trio nutes but started feeding Mega Crop, Bud Explosion and Sweet Candy today. I’ve been occasionally treating with Serenade, spinosad soap and Neem oil throughout the grow.

The wet weather and the warming fall sunshine have brought out a SWARM of “army worms” (order: Lepidoptera) that are covering the property. It’s typical at this time of year but they’re awful and cause huge crop damage! When I saw the first one, 2 days ago, I started spraying BT. More on the plants today so I sprayed again. So, they’re certainly contributing to my issues; but they’re not the only problem. I have checked the leaves (both sides) with a loupe and I can’t find ANY bugs crawling but there are some (few) unmoving little things that look like microscopic grains of rice on the underside; and many of the fan leaves have these TINY white specks on the top side - not huge numbers or in patches but the ARE there.

I’m getting these little white/tan spots/specks, surrounded by a brown ring on the fan leaves as you can see in the picture below. In addition, there’s some patchy yellowing going on; but the yellowing is pretty much limited to some older fan leaves and a few down low to the ground and near the main stem. Finally, there’s some necrosis starting on these yellowing leaves. I’m thinking it’s Septoria/yellow spot fungus and either army worm bites or grasshopper bites? Treatment: a copper based fungicide drench and continue with Serenade spray and continue BT, Neem oil and spinosad soap for critters?

2 other plants have developed this strange pattern. They’re packing on the flower but I can’t figure out what’s causing this or what to do. It’s not everywhere but there’ll be 3 leaves here and two over there and another couple on another part of the plant. One of these girls is my oldest -55 days - and is really packing on the buds. I don’t think this is part of the natural progression of things. Any idea what’scausing this and what to treat it with??

Im planning to get some Grandevo (chromobacterium subtsugae strain PRAA4-1T) and some PFR-97 (20% WDG isaria fumosorosea Apopka) but I need to save up for it. They’re amazing products, from all my research, and they’re a totally organic approach to pests but it’s, in NO way, cheap. Lol! It’s damn expensive stuff. Here’s a terrific video (that I have a lot of faith in) covering organic methods of controlling pests:

So, for the time being I need suggestions that are in the normal price range. Whatchy’all got got for me?? Sure could use some help!

@Mrcrabs @PurpNGold74 @Growit

@SmoknGranny @LF-the-OG @Hogmaster @HvtAna1988

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@TDubWilly @tanlover442 @mountainman1 @dbrn32 @Countryboyjvd1971 @highcountrygal @1BigFella @CovertGrower @garrigan62

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Not sure exactly what that is, sorry.

Thanks for the honesty. :cry::+1:

BTW- that HLG 600H light you helped me with is running great! Plants loving it!

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Hi @DTOM420. The first couple of pics are showing as a classic potassium deficiency, possibly helped by all the wet weather you have been having. The weather and the humidity are perfect conditions for fungus so continue with your serenade. Hope this helps. Plant in last photo is stacking nicely .

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In this article we will discuss:

Signs of leaf septoria
How to avoid and cure leaf septoria
Marijuana plant symptoms

Yellow leaf spot, also known as leaf septoria, are caused by Septoria cannabis and S. neocannabina. These are fungal pathogens aimed specifically at marijuana plants.

It is brought about by warm weather and rain and effect marijuana grown outdoors. It may also show up in nitrogen- deficient plants. Read this article and learn how to identify and treat yellow leaf spot.

Signs of leaf septoria

Signs of leaf septoria weed

Yellow leaf spot initially shows up on the lower leaves of your plant. These spots may vary in shade from white to a grayish brown to yellow, initially displaying little circular lesions. Once it starts to grow it starts looking like a bump and its size continues to increase.

Yellow leaf spot will harm the leaves and often times the stems of the plant, although it won’t cause the crop to die off. If for any reason this is not properly cared for it will lessen the marijuana plants yield. The affected leaves will become dry where the spot is and overtime break and produce a hole at the point where the spot started off.

Not sure if your marijuana plants suffer from a yellow leaf spot infection? Check the article Marijuana diseases for a list with pictures of all possible marijuana diseases

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How to avoid and cure leaf septoria

Cure yellow leaf spot cannabis

The most affected leaves will become totally yellow, dry out and fall off. You will want to get rid of the leaves that fell off or else you will end up with a landing turf for spores to overwinter. Basically, they will hide out until the weather warms up and then that’s when they will wreak havoc. Yellow leaf spot spores do their dirty work through traveling by water, wind and clinging on to things that pass by.

You can avoid the damage yellow leaf spot causes your plants through crop rotation. Basically, after every harvest you will pick a new location to plant. If you are not able to do this, then after harvest, completely get rid of all leftovers from the last vegetation and till the soil really good to make sure all remains are gone.

Download my free marijuana grow guide at this link for more growing tips

Get the location ready using sterilized compost and mix it well into the soil. Doing this will give the new crop plenty of nitrogen to provide a good, strong start. If you don’t have any ready compost, you can mix in blood meal, fish meal or soybean meal to the dirt that is already there.

Therefore, you will be certain to have all the necessary nitrogen for your plant. Make sure you proper disinfect any tools you used with rubbing alcohol or peroxide prior to putting them away.

One more thing you can try when beginning a new marijuana bed is adding a fungicide to the planting location prior to putting the seedlings and seeds there. You have the option to buy one of the many natural solutions pre-made (at this link here) or you can make your own.

Applying helpful bacteria, like Bacillus Pumilis or a good fungi like Trichoderma will help the soil if you don’t have any compost to use. Also, you may try spraying the site with essential oil combinations with cinnamon, coriander, neem, sesame or clove. Fine misting the soil with compost tea or even baking soda will aid in avoiding yellow leaf spot spores from making a home at your site.

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Marijuana plant symptoms

  • white/grayish brown/yellow spots on leaves
  • Circular lesions on lower leaves
  • A small pimple looking bump
  • Leaves dry and fall off

Remember to water your plants early mornings or early evening time. Never water the leaves, only the soil. By doing this, the sunlight will not burn the leaves. Again, if your plants gets infected by yellow leaf spot, it is important to always remove and completely destroy all affected leaves.

If you don’t do this, you will most likely regret it. Affected leaves still contain the problem and can come back to haunt you because yellow leaf spot easily clings on to things and travels from one destination to the next.

Remember that plants with strong genetics have less change of getting sick and are less vulnerable for pests and diseases. So make sure to buy cannabis seeds from a trusted seed bank.

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Thanks mountainman1! I did feed them with a heavy PK nute yesterday and I’m going to remove all the yellowing leaves just in case

I have some bags of mushroom compost. Would top dressing with an inch/3cm of that mushroom compost help? I don’t have and bacteria on hand but I could order some. I found these: but I don’t know how long they’d take to arrive. I don’t have a local source. I do feed both endo and ecto mycorrhizae on a regular basis. Any other products you can suggest - especially US-available products?

I went to that web-site heck I mite order some of that myself.

This is just a few I use,





Plus a few others but this is what I came out with and this wqas inside grow…



Thanks Garrigan! I’m going to too dress with the mushroom compost I have and I may order some of those tabs just to try. I’m kinda tapped right now, setting up my indoor room. I also reached out to Berger to see if they’re available in my area. Did you know they make a cannabis specific product line? I appreciate the help!

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