diagnosis please

[pashi2004]

Hi everyone i'm new here and this is my first grow , the set up was provided by a third party so im not that switched on when it comes to the more technical side of things but im learning fast, so here goes , the plants came as 2 week old cuttings and vegitated 24rs for 4 weeks under two 250wt inviro lights , they are in John Innes soil Ph 7.5 , they've been on 12-12 under 1 x 600wt and 1x 250wt for 2 weeks , they have been fed on ionic nutrient solution ' soli grow , soil bloom and soil boost , I had a thrip problem 3 weeks ago which i treated with firstly with a dip of garlic and soapy water followed by spraying with bayer garden provado ultmate bug killer once and then again 1 week later with pythrim.
I have 4 pics to post up the first 2 are of what i suspect is lamp burn and the second 2 are possibly nitro def .
As i explained im new at this and i can only provide the details im in possession of but i will do my best to answer any question asked . This is an amazing site and ive learned so much but would appreciate any help anyone can give,












hope these pics are clear enough , many thanks for any replies

 

[Leaf]

The soil with a pH of 7.5 is too high, shoot for 6.5 or somewhere in the range of 6-7... this could be causing nutrient lock out, and in your case it looks to me as though it is manganese.

Try watering with ph'd water in the low 6 range to bring the ph of the soil down.. water with a 10-15% runoff.. this can also help to leech out excess salts (if any). Once the pH is down, you should start to see an improvement.

You could also add some micronutrient to the soil, for example a teaspoon of Pro Clay mixed with a litre of water will help. Good luck.

 

[Claude Hopper]

I think Leaf called it: Manganese. It's not nitrogen.

 

[Stress_test]

It looks to me more like a Nitrogen deficiency.

Hope this helps? Compare this chart with your plants, it usually lets you give a pretty good diagnosis.

 

[vince514]

I agree with leaf a ph of 7.5 is way too high for MJ to thrive.....aim for 6.2-6.5 IMHO works best for me....and as per a lock out it could be a number of things , one thing i took into consideration is that you've bee spraying alot of chemicals on them in a rather short period of time maybe that burning might be attributed to the bug spray....IMHO

but mos likely its a lock out and possible burning from the spray...i dunno
hope all goes well ....

 

[darrmann]

ph, people point to deficiencys but dont point out what cause these. Almost all basic nutes have a good range of nutrients. The first thing to check like others said is ph. soil needs to be around 6.5 to 6.8 hydro 5.2 to 6.2. bring down ph and your problems will go away. And why so many different bug killers? I would stick with one instead of trying 4 different things in one week. Could possibly be why they look burnt.

 

[bobman]

Before you go running all around chasing ph just stop. Plants looks good overall you have done a great job. Soil ph is something of a myth and if you try changing it you are going to fuck things up worse. The key to soil is to start with a good soil and amend it with a lot of perlite. Two things are at play here. Number one looks like they could use a bigger pot. I would pot up. That is probably causing that yellowing in the lower leafs. How big are they and what size is that pot? Number 2 looks like you sprayed for bugs under the lights or put them under the lights again to soon after spraying. That will cause this kind of leaf damage. Whenever spraying move the plants out of the light for at least a half an hour.

 

[pashi2004]

Just to address one issue' i used the bayer garden spray just the once because its systemic and stays in the plant for up to 6 week and i wanted it out of the plants system before harvest. I used the pythrim just once firstly because it breaks down naturally and also because thrips develop immunity to it if you use it to often . So far the thrips havent returned even though i know the little critters are in the soil and will return at some point the plan is to keep them on the back foot til i harvest, after this im going hydro and its going to be done by the book .

 

[Phedrosbenny]

PH is a little high.Probably causing lock out.It definetly IS NOT a MYTH.This is a good sight for people to get answers to their growing problems.Too bad everytime somebody asks a question people that dont know what they are talking about get on and give BAD ADVICE.

Check and see if they are root bound.

 

[pashi2004]

hi bobman , ive 9 plants in total 4 of them are the same species and are in the smaller pots and are about 18'-2ft high , these are the ones with the leaf yellowing , the other plant ( with the leaf burn ? ) is one of three that are in slightly bigger pots and are about 2ft+ high but the other two show no problems , the other two plants i have are g7 and although small have some fantastic flowers appearing and are doing really well . This is whats confused me , How can only 4 plants have a deficiency when they are all fed the same and all sit in the same soil ? and if all plants have been sprayed witht he same bug spray wouldnt they all have leaf burn ? By the way tent temp is steady at 32deg

 

[bobman]

buddy i grew in soil for eight years and yes ph in soil is mostly a myth. its not the soil that fucks up it you fucking up the soil. Ph fucks up in soil because the soil is to wet and never dries or there is a salt build up. A flush and good dry will solve the problem. but no lets tell new growers to chase ph soil problems and see how well that works. Soil is simple end of story and most soil are ph stable right out of the bag so yes ph in soil is mostly a myth

 

[Phedrosbenny]

buddy i grew in soil for eight years and yes ph in soil is mostly a myth. its not the soil that fucks up it you fucking up the soil. Ph fucks up in soil because the soil is to wet and never dries or there is a salt build up. A flush and good dry will solve the problem. but no lets tell new growers to chase ph soil problems and see how well that works. Soil is simple end of story and most soil are ph stable right out of the bag so yes ph in soil is mostly a myth

Just letting you know...Thats all I grow in is soil.Before you start telling him to flush because of salt build up...why not ask him what he is using to see if he could actually have a salt build up.

And PH in soil isnt a myth.Your giving bad advice.

Checked out your profile..Didnt see any of those 8 years of beautiful plants you grew.

 

[bobman]

So the plants are in flower? How big are the containers? How much perlite did you mix in?

 

[bobman]

Oh, I know soil is so tricky and the ph gets so out of wack. Most new growers make the mistake of either having too heavy a soil and watering to much throwing things out of wack. but no lets tell them all to add this and add that and chase there tail. give me a break

 

[Phedrosbenny]

Didnt tell him to add anything..My guess would be they are root bound...I didnt give him bad advice..That was you..remember..BIG TIME..lols..give me a break

 

[Phedrosbenny]

Oh, I know soil is so tricky and the ph gets so out of wack. Most new growers make the mistake of either having too heavy a soil and watering to much throwing things out of wack. but no lets tell them all to add this and add that and chase there tail. give me a break

And I thought you said PH in soil was a myth?


Hope the OP can read that for what it is.

 

[bobman]

thats what i said fucktard root bound was part of the problem

 

[Phedrosbenny]

Fucktard..lols....Well that showed your intelligence.

Havent made it to 30 yet have you..

Grown ups dont say "fucktard" bro.

And now your gonna change your posts ..huh.

 

[bobman]

yes the actually soil's ph is a myth. so read it how you want. if you start will a semi decent soil there is nothing that can not be solved by:
1 a good flush
2. a good wet dry cycle
3. adding enough perlite

 

[Phedrosbenny]

You know you contradicted yourself..right?

Good Luck to you and your plants.

Bye