Leaf curl?cant figure this out.

the native

the native

Well-Known Member
Fellow growers, I have been trying to figure this out. All plants have leaf curl.

3x3
300w at 60% 1.2 metres from canopy
26.1 degrees 76%humidity lights on.

ewc ,compost, pumice,DE ,bokashi,2row malted barley,peat moss,aloe powder.
20l containers.
4 weeks veg.
White stuff on plants is DE for pest management.
no ph during watering.

What do you think could be the problem.had this for abt 2 weeks.
image.jpgimage.jpgimage.jpg
 
jimihendrix1

jimihendrix1

Well-Known Member
Leaf cupping can happen for several reasons.

Overfeeding/Nitrogen
Overwatering/Underwatering.. I use a cheap PH/Light/Moisture Meter from Lowes to check moisture levels. I will check it in multiple places in the container. I NEVER let it get into DRY. Only Low Moist. NEVER to the dry zone. I also know how to check them by how heavy/Light the container is, and use both methods. But Ive been using a cheap moisture meter for 40 years with great success, though they dont work so well in really small containers.
Windburn
Light Burn
Pests.

Whats your PH?? You mention Peat. Did you add lime to balance PH? Best to add both Calcitic, and Dolomitic Lime to peat. Use 2/3 Calcitic to 1/3 Dolomite. Peat is very acidic.

What are temps when lights are out. Is the temp you measured atmospheric, or at the leaf??

Do you have good fresh air flow?? Not enough fresh air exchange combined with bright light can also cause leaf cupping because they wont be able to transpire efficiently.

Good to have temps at the leaf 78f-82f, and no less than 74f at night. If temps get to low, and plants get full strenght fertilizer it can cause burn, as plants dont use fertilizer at the same rate when its very cool. Not saying your plants are burned, they arent. Just something to think about.
 
the native

the native

Well-Known Member
Thanks mate, yes there is decent airflow ,extractor, floor fan and a clip fan.
The ewc had dolomite lime ,aloe powder and DE for a month or so. There is red wrigglers in the soil also and none have come out.
Temps are atmospheric, 23 degrees and 80% humidity when lights off.
I tend to check water by weight(the ol lift technique)bout every second to third day , I’d just give plain tap water, just enough so a lil water comes out the bottom. Maybe I should ph.
The other tent ,I’ve never phd water and they never seem to have this problem but it’s in its 5th cycle no till.
Thanks mate for your insight , really appreciate your input.
 
the native

the native

Well-Known Member
Kassiopeija said:
it doesnt work anymore as pest repellent
the DE needs to be powdery then it can enter the "insect lungs" and that kills them
Click to expand...
I sprayed the leaf's with mixed DE and water, then it dry's after awhile(just for better coverage, and also doesn't enter my lungs). I used a container that powders the DE on, onto the top soil. some of it is wet, some of it is dry. there are a few knat's but loads of them have hit the tent floor.
 
Kassiopeija

Kassiopeija

Well-Known Member
Fungus Gnats you got? they dont eat leaves, sprinkling the top soil will kill most of them.
what I do is take DE & clay pebbles in a closed box, shake, let sit then put that on top of soil. later can be easily separated from soil. also close the pot drain holes using insect nets or simular cloth. the gnats target the soil
 
the native

the native

Well-Known Member
Yes your rite, but they do land on the leafs. Yep I have some but not many.
I have thrips in my other tent , but under control. The DE that I’ve sprayed in the above pics are to stop those thrips if they ever get in. That’s a great tip with the clay pebbles tho, haven’t read about, or seen that trick before, nice.
 
the native

the native

Well-Known Member
I still can’t crack the dilemma with the leaf curl, as I want to switch these to 12/12, but hesitant with this problem.
I don’t want to change to much, just in case I make the problem worse.
I really hope it’s not the peat moss, my tap water is 8.0 ph, and with the peat been acidic it’s a tricky situation as I’ve put dolomite lime in the ewc.The ewc had dolomite lime in it for ages, so adding more will most likely not change much, and I know it takes awhile to breakdown anyways.
 
jimihendrix1

jimihendrix1

Well-Known Member
You need to get your medium PH under control. Peat is super acidic. Also need to adjust water PH.
DE doesnt enter through an insects lungs. It scraps the exoskeleton, and dehydrates them like Roach Proof. ( Boric Acid )
Thrips can cause cupping by introducing tomato wilt virus. You need to eradicate them in the other tent, not just control them. You either have them, or you dont. They will introduce virus. They need to be made extinct.

Calcitic Lime will affect PH much faster than Dolomite. You need to use a ratio of 2/3 Calcitic Lime, to 1/3 Dolomitic lime. This also balances out Calcium, and Magnesuim. Calcitic for fast PH change, and Dolomite for long term PH stabilization. They work together. Especially in Peat based mediums.
Low Calcium, and Magnesium can also cause leaf cupping. Fucked up PH can cause nutrient lockout, and cause cupping. PH is beast at 6.2 in peat based medium. Also wouldnt have hurt to add Perlite, and Vermiculite to peat. Along with MYCORRHIZAE . Also best to soak peat before use, and pour off the excess water. Peat can be hydrophobic, and shed water. Dont get peat waterlogged, but make sure it wet, and holding some water.
Add 1 ounce of Calcitic Lime, and 1/2 ounce of Dolomitic Lime for every gallon of peat. For every 2 gallons of Peat, add half gallon perlite, and half gallon Vermiculite.
Humidity is also to high. It needs to be no more than 70% during veg, and 40%- 50% during flowering. 80% humidity during flowering is going to cause potentially serious mold, and/or mildew issues.

You say you have good airflow?? But are you getting FRESH AIR, and not just moving around room air???
 
Kassiopeija

Kassiopeija

Well-Known Member
jimihendrix1 said:
DE doesnt enter through an insects lungs. It scraps the exoskeleton,
Click to expand...
"When ground, these tiny oceanic skeletal pieces are very sharp, and produce the effect of many miniature razor blades on the respiratory systems of any smaller insect or bug that inhales it. It also causes drying of the mucous membranes of breathing holes and lungs in bugs."

gardenerspath.com

How to Use Diatomaceous Earth for Pest Control | Gardener’s Path

Diatomaceous earth is a helpful tool to defend against garden pests. Learn how this natural product works and the best way to apply it on Gardener’s Path.
gardenerspath.com gardenerspath.com

srsly, I've observed large insects like house-flies or bugs cripple to death in DE - the fine powder doesnt cut their exoskeleton bc the miniblades are microscopic in contrast to insects outer shells
it enters their bodies, dries them out and irritates finer internal structures...

insects have pores overall their bodies (in between the juncts of the chitin shells) where air/oxygen can enter the body - that IS where the DE targets (that's why I put "lungs" into brackets, it's not very similar to our common understanding of a lung)
 
jimihendrix1

jimihendrix1

Well-Known Member
Diatomaceous Earth has long been known for its pest-repelling qualities. Even though it is a very fine powder and soft to the touch, on a microscopic level it is very abrasive and actually cuts the exoskeletons of insects. The damage to that protective exoskeleton is enough to dry out and kill the insect. While diatomaceous earth is a threat to bugs, it is completely safe to use around humans and animals. Be sure to only use food-grade diatomaceous earth, as the type designed specifically for pool care is toxic to humans and animals. As with any dust, be careful to not get in the eyes or lungs of birds or humans.
Diatomaceous earth powder has the sharp microscopic edges that cut through the exoskeleton of insects. This causes them to dehydrate and die. So the diatomaceous earth will kill both harmful and beneficial insects with exoskeletons that come in contact with it


1) The diatomaceous earth sticks to the insect and the powder gets stuck between their exoskeleton joints. The sharp shards and blades cut up the insect and it bleeds to death. That would be the equivalent of you rolling naked in a treacherous bed of razor blades!

2) The diatomaceous earth also absorbs the moisture of the insect when it penetrates or cuts it and the insects will dry out and die.




Diatomaceous Earth - Nature's Way Resources

Diatomaceous Earth

Diatomaceous earth (often abbreviated D.E.) comes from a soft sedimentary rock deposits called Diatomite
www.natureswayresources.com
In addition to dehydration D.E. gets caught between their exoskeleton joints and as they move it acts like little razor blades and cuts them up. It must be kept dry to work hence one must reapply

Is Diatomaceous Earth Safe for Animals? - Absorbent Products
www.absorbentproductsltd.com

Is Diatomaceous Earth Safe for Animals? - Progressive Planet

Red Lake Diatomaceous Earth is registered as a feed additive for use in livestock feed as an anti-caking agent and pelleting aid. However, food grade diatomaceous earth is also known to work well as a natural insecticide. DE works to kill pests such as bed bugs, mites, fleas, ticks and many...
www.absorbentproductsltd.com www.absorbentproductsltd.com
Jan 17, 2019 · Because insects are also small, the diatomaceous earth can easily cut their exoskeletons. The movement of their bodies across the DE, as well as their waxy exoskeletons,


In some arachnids like ticks, because of such a tough outer shell, the method of death is that it clogs up their pores, and suffocates them is true. But the main method of death to most insects, is cutting of the exoskeleton, and dehydration. So were both right.
 
bam0813

bam0813

Well-Known Member
Kassiopeija said:
it doesnt work anymore as pest repellent
the DE needs to be powdery then it can enter the "insect lungs" and that kills them
Click to expand...
I have to look into this more. This was my understanding but then heard many people dissolving it and using it in sprayers, works again when dry? Also I thought de work as a desiccant that dry and cuts exoskeletons of insects not like convential powder insecticides that would be vacuumed or inhaled through their spiracles as you mention
 
the native

the native

Well-Known Member
Thanks everyone for your input.
I will ph the water to the required ph. We are having a real problem with humidity at the moment in NZ ,raining for 3 weeks and its summer.
I can’t find calacitic lime but I believe this is it, can someone’s elaborate
seaclifforganics.nz

Superfine AgLime (calcium carbonate)

Superfine AgLime - Screened Lime From Local Otago Quarries - 40% Calcium - Improves a plants ability for nutrient uptake - Encourages beneficial soil micro/macro-organisms and water retention - Helps decrease the availability of metals such as aluminium and manganese.
seaclifforganics.nz seaclifforganics.nz

I think next time I’ll leave the peat moss out. I have also purchased a dehumidifier to help with humidity, and waiting to get more predators for the thrips. I was recommended to get two types from the people that breed them

Mite-A for Thrips Control - Beneficial Invertebrates - Bioforce

Mite-A is a highly active predator of thrips, especially onion thrips, Thrips tabaci, Western flower trips, Frankliniella occidentalis, New Zealand flower thrips, Thrips obscuratus and other thrips species. Mite-Awill also eat two spotted spider mite and other mite species, including broad...
www.bioforce.co.nz

Orius for Thrips Control (Generalist Predator) - Beneficial Invertebrates - Bioforce

Orius is a small predatory bug that predates on a wide variety of prey, including thrips, aphids, whiteflies, mites (incl. spider mites), mealybugs, psyllids and the eggs of larger insects such as butterflies and moths. PRICE: $35.00 per 500 Adults (minimum order) plus GST and Freight
www.bioforce.co.nz

hopefully this won’t take too long , I’ll most probably be in week 8 veg, before there ready to flip.
Thanks again everyone for your guidance.
 
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