Yellowing Problem 5 weeks into Flowering

Hi -

This is my first post here, and I haven't been active on any boards since overgrow went down. I'm an old-timer and dont usually need to ask for advice, but have been having some problems lately and figured maybee one of you guys has a good idea whats going on.

Background on the plants....
Soil: Fafard 3B mix augmented with sunleaves Jamaican and Indonesian guano.
Water: Reverse Osmosis with botanicare Cal-Mag Plus - pH nutral (according to test paper)
Nutes: Complete Bio-Biz series, superthrive, dutch master folitech series.
Lighting: 1000w HPS Hortilux
Strain: Gravity


My problem is the yellowing on the uppur leaves. Normally i wouldnt pay it any mind and choke it up to the start of end of season yellowing. This looks a little to pronounced and is starting a little too soon. I still have 3 weeks and some odd days left. I was thinking maybee a iron deficiency, except I'm using cal-mag so that doesnt make sense.

Any Ideas?

sorry can't see the pic well enough to see is the yellowing going form a light yellow to a dark yellow? If it is it could be a potassium problem or it may be just yellowing at the end of the flowering.
Potassium plays a big role as well. Having good amounts of potassium in your plants helps in having sturdy and thick stems, disease-resistance, water respiration, as well aids in photosynthesis. Potassium is also found in the whole plant. It is necessary for all activities having to do with water transportation. Potassium is necessary for all stages of growth, especially important in the development of Buds.

Having to little of Potassium in your plants causes the plants leaves to show retarded growth and show a scorched tip and edges around the leaves. Plants may stretch and your branches can be easily broken or weak. Don’t get this deficiency confused with iron, because it almost acts like iron but to tell the difference in the two is: for potassium the tips of the leaves curl and the edges burn and die. Older leaves may show a red color and leaves could curl upwards. Dead patches (Necrosis) can happen on the margins of larger fan leaves thus, the leaves will eventually die off and turn brown. The Older leaves will show different patches of color (mottle) and turn yellow between the veins, following by whole leaves that turn dark yellow and die. The plants overall growth slows down, mostly when they are in vegetative stage. To little amount of potassium also slows the growth of buds during flowering stages. Dark edges will appear around the edges of the leaf when the deficiency is starting to happen. When your Relative humidity is low, you can almost bet your going to soon get a potassium deficiency from your plants perspiration.
Potassium can get poorly absorbed when having too much Calcium or ammonium nitrogen, and maybe cold weather. Having to much sodium (Na) causes potassium to be displaced. SO keep those in mind… Parts affected by a Potassium Deficiency are: older leaves and leaf margins.


When you have too much Potassium in your soil, it can lead to big troubles, like salt damage and acid fixation of the root system, as well as too much potassium can cause a calcium deficiency. Your fan leaves will show like a light to a dark yellow to whitish color in between the veins. Due to a molecular imbalance, potassium toxicity can cause a reduced uptake and lead to the deficiencies of Mg, and in some cases, Ca. Also leads to the other nutrients to not be absorbed properly leading to lots of other deficiency such as: magnesium, manganese, zinc and iron and can cause problems with calcium as well.



Problems with Potassium being locked out by PH troubles
Soils with excessive Leeching and High ph soils and or water.Soils that are potassium fixated. An excess of kitchen salts (sodium) in the root system/enviroment.


Soil

Potassium gets locked out of soil growing at ph levels of 4.0-5.5
Potassium is absorbed best in soil at a ph level of 6.0-9.5. (Wouldn’t recommend having a ph of over 7.0 in soil) anything out of the ranges listed will contribute to a Potassium deficiency.


Hydro and Soil less Mediums

Potassium gets locked out of Hydro and Soil less Mediums at ph levels of 4.0-4.5, 6.0-6.5.
Potassium is absorbed best in Hydro and Soil less Mediums at ph levels of 4.7-5.3, 6.7-8.5. (Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.) Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a potassium deficiency.



Solution to fixing a Potassium deficiency
Any Chemical/Organic nutrients that have potassium in them will fix a potassium deficiency. Again Peters All Purpose plant food 20-20-20, will cure the potassium deficiency , Miracle grow Tomato plant food, Miracle grow All purpose plant food.( Only mixing at ½ strength when using chemical nutrients, or it will cause nutrient burn!) Some other supplements of potassium are: Wood ashes, which are fast absorption, Kelp Meal, which is medium absorption, Greensand, which is slow absorption, granite dust, which is slow absorption. Sulfate of Potash, Sulfate of Potash Magnesia, Muriate of Potash, which are medium absorption. FOXFARM GROW BIG HYDROPONIC CONCENTRATE, which is fast absorption. (FFGB can bring your ph down as well) Earth Juice Meta-K, which is fast acting. (Can bring down your ph as well) Leaves will never recover, but the plant will show recovery after about 4 to 5 days when using a fast acting nutrient.

Note: Wood Ashes, can make your ph go up a bit, so please monitor your ph when using it.
Now if you added to much chemical nutrients and or organics, (which is hard to burn your plants when using organics) you need to flush the soil with plain water. You need to use 2 times as much water as the size of the pot, for example: If you have a 5 gallon pot and need to flush it, you need to use 10 gallons of water to rinse out the soil good enough to get rid of excessive nutrients.


Picture 1 and 2 shows a Potassium deficiency ( Thank You General Ganja for letting me use Picture 1!)




Last edited by MynameStitch : 03-16-2008 at 06:52 PM. Reason: New Title

Light too close? They need a little nitrogen? Nute lock out?

Any ways i think they will finish flowering with out any problems to the harvest.

Nice grow by the way.

Nitrogen or Light to close. Nitrogen will start outside the leaf working inward. I am looking at the same thing and I to am 5 weeks. Heres some pics of mine. Go by where yellowing starts and if its leaving green or yellow veins etc. read on .......


Nitrogen (N) Mobile Element and Macro Element

Benefit: Nitrogen plays a very big role in your plants; this one element is directly responsible for production of chlorophyll, photosynthesis, Amino Acids, which are the building block of Proteins. The myriad of enzymes which help the plants growth in leaves stems and the how well the vigor of your plants is.

Nitrogen is the biggest mobile element meaning it can travel anywhere on the plant.
Usually the def will start on the lower to middle part of the plant, and then will usually happen to older leaves first. Then the deficiency will work its way up the plant. Your plant can be green on top, then yellowing on the lower leaves when the deficiency is starting out. Yield will be greatly reduced without good amounts of nitrogen in your plants. Sometimes in bad cases the leaves will turn a purplish color along with the yellowing.

Unlike a magnesium deficiency, nitrogen def will start from the tips and work its way back to the leaf node. Nitrogen and Magnesium get confused. The best way to tell them apart is, nitrogen deficiency starts around the tips and works its way to the back of the leaves, where a magnesium deficiency will cover the entire outer part of the leave and make the entire leaves yellow leaving the veins to stay green. If your plants are having a slow growth rate and have yellowing of the leaves, then most likely it’s a nitrogen deficiency.
Towards the middle to end of flowering stages, the plant will show a nitrogen deficiency almost always. This process is completely normal and just let the plant naturally yellow out as it uses it's stored nutrients. This actually helps you by getting ready for final flushing and then harvesting. At this point DO NOT not use nitrogen to fix the problem. The yellowing leaves will then eventually drop off after the plant is done with them.

Parts affected by a nitrogen deficiency are: Older foliage, going to whole plant, Petioles (rare) cases.


Now for having too much nitrogen in your growing mediums or soil. The plant will have like an overall DARK green look and have delayed maturity. Due to Nitrogen being involved in vegetative growth, to much nitrogen will result in tall plants with weak stems. New growth will be very lively and plant transpiration will be high, but not always. Nitrogen toxicity can be seen when there are very very dry conditions almost as if there was a drought, which may show a burning effect. If you give your plants ammonium based nutrients they may show NH4+ toxicity, which will show a smaller plant growth and lesions that occur on stems and roots, leaf margins that will roll downward. Also the big fan leaves will have “the claw” look. The tips will point down but the leaves will stay up as if when you bend your fingers downwards. Leaves can be twisted when growing… mainly new growths. Roots will be under developed along with the slowing of flowering. Yields will be decreased, because to much nitrogen in early stages of flowering slows down bud growth. Water uptake is slowing down from the vascular breakdown of the plants as well. Too much potassium and nitrogen will lock out calcium as well.

Nitrogen or Light to close. Nitrogen will start outside the leaf working inward. I am looking at the same thing and I to am 5 weeks. Heres some pics of mine being yellow. At five weeks things will start to yellow on some plants cuz its useing its reserves out of the leafs but Im not sure if your genetics do this ? Go by where yellowing starts and if its leaving green or yellow veins etc. read on .......


Nitrogen (N) Mobile Element and Macro Element

Benefit: Nitrogen plays a very big role in your plants; this one element is directly responsible for production of chlorophyll, photosynthesis, Amino Acids, which are the building block of Proteins. The myriad of enzymes which help the plants growth in leaves stems and the how well the vigor of your plants is.

Nitrogen is the biggest mobile element meaning it can travel anywhere on the plant.
Usually the def will start on the lower to middle part of the plant, and then will usually happen to older leaves first. Then the deficiency will work its way up the plant. Your plant can be green on top, then yellowing on the lower leaves when the deficiency is starting out. Yield will be greatly reduced without good amounts of nitrogen in your plants. Sometimes in bad cases the leaves will turn a purplish color along with the yellowing.

Unlike a magnesium deficiency, nitrogen def will start from the tips and work its way back to the leaf node. Nitrogen and Magnesium get confused. The best way to tell them apart is, nitrogen deficiency starts around the tips and works its way to the back of the leaves, where a magnesium deficiency will cover the entire outer part of the leave and make the entire leaves yellow leaving the veins to stay green. If your plants are having a slow growth rate and have yellowing of the leaves, then most likely it’s a nitrogen deficiency.
Towards the middle to end of flowering stages, the plant will show a nitrogen deficiency almost always. This process is completely normal and just let the plant naturally yellow out as it uses it's stored nutrients. This actually helps you by getting ready for final flushing and then harvesting. At this point DO NOT not use nitrogen to fix the problem. The yellowing leaves will then eventually drop off after the plant is done with them.

Parts affected by a nitrogen deficiency are: Older foliage, going to whole plant, Petioles (rare) cases.


Now for having too much nitrogen in your growing mediums or soil. The plant will have like an overall DARK green look and have delayed maturity. Due to Nitrogen being involved in vegetative growth, to much nitrogen will result in tall plants with weak stems. New growth will be very lively and plant transpiration will be high, but not always. Nitrogen toxicity can be seen when there are very very dry conditions almost as if there was a drought, which may show a burning effect. If you give your plants ammonium based nutrients they may show NH4+ toxicity, which will show a smaller plant growth and lesions that occur on stems and roots, leaf margins that will roll downward. Also the big fan leaves will have “the claw” look. The tips will point down but the leaves will stay up as if when you bend your fingers downwards. Leaves can be twisted when growing… mainly new growths. Roots will be under developed along with the slowing of flowering. Yields will be decreased, because to much nitrogen in early stages of flowering slows down bud growth. Water uptake is slowing down from the vascular breakdown of the plants as well. Too much potassium and nitrogen will lock out calcium as well.

Hi,

I'm also and old time Overgrower The FAQ is still up everywhere, just google OG FAQ.

From Nietsche's Charts:

Zinc Deficiencies:
Deficiencies appear as chlorosis in the inter-veinal areas of new leaves producing a banding appearance as seen in figure 18. This may be accompany reduction of leaf size and a shortening between internodes. Leaf margins are often distorted or wrinkled. Branch terminals of fruit will die back in severe cases.
Also gets locked out due to high pH. Zn, Fe, and Mn deficiencies often occur together, and are usually from a high pH. Don't overdo the micro-nutrients, lower the pH if that's the problem so the nutrients become available. Foliar feed if the plant looks real bad. Use chelated zinc. Zinc deficiency produces "little leaf" in many species, especially woody ones; the younger leaves are distinctly smaller than normal. Zinc defeciency may also produce "rosetting"; the stem fails to elongate behind the growing tip, so that the terminal leaves become tightly bunched.

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I'd say it's the ph. Measure your run-off, not what you feed and see how high it is. If it's higher than you, lower it

Error404 what is the science behind testing run off ?? How does it become a higher PH or PPM than your res ??

coopdevillan said:

Error404 what is the science behind testing run off ?? How does it become a higher PH or PPM than your res ??

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The soil/rootmass in later stages of flowering will often lower the ph because of the built up of ferts thus far.

Here is an excellent excerpt from bald1:

How to test the pH of your soil mix

Measuring the pH of soil is just as important as with hydro applications, but few people know how to test soil pH to see if it is within the optimum range for growing robust healthy plants. Here I will try to explain my method of testing any soil / soilless mix, enabling me to spot any problems and correct them if necessary.

Firstly, wait till your soil has dried out and is due for its next watering schedule. Then take some plain water that you usually water your garden with, and adjust the pH to 7.0. You must make sure that you know the exact pH of the water going into your soil, and the neutral 7.0 is best, but anywhere from 6.5 – 7.0 will suffice.

Then place your pot into a bowl of some sort to catch the runoff water, and then start to water your soil slowly (with your pH- corrected plain water) till the water starts to drip from the bottom.
It’s the first drops of water that will give you the best reading of your soil, so make sure to water slowly till you see the first droplets. Then remove the pot from the bowl to eliminate excess water entering the bowl. Then perform the pH test on the runoff and compare it too your initial test.
The results of the runoff test will likely be lower than your starting value of 7.0. If this is the case, a small drop of 0.5 pH to 6.5 pH (example) would be ok and your soil needs no further alterations at the moment. But that’s not to say that it won’t need any future tests at all, just not at this time.

[Editor’s note: It may be beneficial to obtain an initial sample, as well as a ‘full flush’ sample in seperate bowls. In addition, test several plants in the garden just to verify your results]

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Ph of as low as 6 in Soil will be ok, lower than that is not recommended.

Calcium overdose if u ask me. Flush with just RO and half strength of whatever PK booster you are using. don't use cal mag for awhile and at a lower dose. What brand nutrients are you using? If the Cal is above 3.0% then you shouldn't hardly ever need to use cal mag and when you do at a very low dose. Just my opinion but I do have some good results myself

I just reread your post..... botanicare has a few different base nutrient lines. All of them have a pretty high calcium ratio. If you are using the CN17 then you do not need Cal Mag at all.... the base is like 3.7% cal I think and that is plenty for RO water. I think you really did OD on cal and now you are locking out all kinds of stuff. Like I said before Straight RO and my 1/4 to 1/2 strenght PK booster. Flush those suckers reallllll good even if they are wet right now. Again Just my opinion but I do have some good results myself

Please help. I have too Much Nitrogen in my girls what do I do?? I only have 3 weeks of flowering left? should I flush and bend them all too make the best of it. will this help the plant use up its N?

OK..my 2 cents.Reverse osmosis lowers PH typically the longer it sits the more it lowers. Always no matter how much you pay for soil no matter how good they say it is garden lime the soil so it maintains proper PH.If it goes to low (this is what i think it is from the RO)Pour some PHed water into the soil. collect run off..test run off ph. If to low flush plant with PHed water Put garden lime on the top and flush through the soil garden lime will not let the ph in the soil go over 7 and will add calcium to the soil your plants love.You will know what the problem is as soon as you test the run off PH. good luck

Kumar.420.HPS said:

Please help. I have too Much Nitrogen in my girls what do I do?? I only have 3 weeks of flowering left? should I flush and bend them all too make the best of it. will this help the plant use up its N?

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Chillax. i dont see any leaf burning so let them go with just some plain water and use the energy up.Let them finish doing their thing they will tell you when they are done. and dont over water i see a little leaf droop as if you just flushed them.

Im gonna.. lol. I just put so much into it from seeds outa my bag to now! thanx i think im just a bit freaked. every one will be better then the last!

here is some up too date pics of the problem. much worse today on two plants.