Marijuana Plant Problems and Cures - Page 2

veinarde · #11 10-16-2006, 08:03 AM

this is one of my plants after 3 weeks from seed

Jonezy · #12 10-20-2006, 02:40 PM

hey guys im a bit of a beginner at growing. built a box, got the growing and budding bulbs.my plants are growing in soil and are budding nicely, but the leaves look unhealthy, kind of yellowish. im totally stabbing in the dark as i have no idea about PH, food and lighting:
bit worried about going in a shop to get "PH" stuff.
got the lights on for eight hours, ok i hope?
how often should i feed and water??
what do i need to purchase?? hope some one can help?? theres so much information its hard to know where to start XXX Jonezy

Jonezy · #13 10-20-2006, 02:41 PM

hey guys im a bit of a beginner at growing. built a box, got the growing and budding bulbs.my plants are growing in soil and are budding nicely, but the leaves look unhealthy, kind of yellowish. im totally stabbing in the dark as i have no idea about PH, food and lighting:
bit worried about going in a shop to get "PH" stuff.
got the lights on for eight hours, ok i hope?
how often should i feed and water??
what do i need to purchase?? hope some one can help?? theres so much information its hard to know where to start XXX Jonezy

Bong Patrol · #14 11-28-2006, 01:04 AM

Wow i'm back in school! A lot to sift thru! But great info!

Want to hear my opinion? No? Well to bad! I think you said you were in the last week or so of budding. Well guess what! It's fall to the plant. Just as all plants start to change color and leafs start to fall off, your plant is more than likely going thru it's fall season. The buds start to take in all they can from the plant! Part of it's survival mode per-say. But since we don't allow seeding to take place on our plant, the plant I think is requiring more nutes! Last week of flowering you should be flushing! That is my opinion like it or not! I only say this because I grow White Widow and they alway's do this to me about a week or two before the end of the flowering cycle.

#15 11-28-2006, 01:21 AM

i was going to reply to him until i noticed it was posted over 1 months ago. no help for him now, should have posted in newb central.. this is the wrong place. p.s. for anyone out there, this is heat stress, if your plant looks like this take them out of the heat you have them in asap. it is true that with the light heat the top leaves will do this but if you have a heating fan in cold temps you can also build to much heat and your whole plant will look like this, look:

the top leaves are new. thats why they look okay but the rest of them are heat stressed. keep in mind heat builds up.. get a thermometer.

Vote 2 Legalize Marijuana · #16 12-12-2006, 02:22 AM

Take caution when using Phosphorus on your vegging plants. High amounts of Phosphorus can induce male flowers. This is an art that is not practiced by many anymore since the introduction of Gibberellic Acid, but if the right condition exists it can and will happen.

Now I know some of you out there are saying right now "No Way", but this is true. Basically what happens is the plant is put in a state of shock per say, just like erratic lighting will do the same, causing the plant in time to induce male flowers. This is not an easy thing to do without killing your plants. Like I said above, this is an art that is not practiced by many anymore since the introduction of Gibberellic Acid

There are only three ways to induce male flowers on a female cannabis plant.

1. High amounts of Phosphorus.

2. Erratic lighting.

3. Gibberellic Acid.

Out of the three, Gibberellic Acid is the only real way to do this anymore because it is faster and safer. A little bit of study in the area of Agricultural Science and the History of Agriculture will tell you of these methods. Somewhere here around my house I still have my books from college that explains of this practice. Will try to locate if need be.

Terry_Tokabolla · #17 12-12-2006, 02:19 PM

This is great.. nice to see that plant abuse pictures reproduced here. I had been looking for it.

Now, we just need a picture section about bug damage!

I cannot see any bugs... but the leaves have tears in between the veigns (on the fleshy part of leaf).. cutting all the way through. Otherwise these are very healthy

edit... found a bug this morning.. I think that these pics are, aphid damage! (made a post outside this thread re: helping me get rid of them)

blackout · #18 12-30-2006, 11:21 PM

Quote:

Originally Posted by OmegaVermelho

Sulphur (S)
Sulfate is involved in protein synthesis and is part of the amino acids, cystine and thiamine, which are the building blocks of proteins. It is active in the structure and metabolism in the plant. It is essential for respiration and the synthesis and breakdown of fatty acids.

Sulphur (S) deficiency:
The initial symptoms are the yellowing of the entire leaf including veins usually starting with the younger leaves. Leaf tips may yellow and curl downward. Sulfur deficiencies are light green fruit or younger leaves with a lack of succulence. Elongated roots and woody stem. Although it's hard to see in figure 19, the upper stems of this plant are purple. Although many varieties of cannabis do get purplish stems, the trait generally extends the entire length of the plant's stem, and not just near the top as in this specimen.

Figure 19

Sulphur Toxicity:
Leaf size will be reduced and overall growth will be stunted. Leaves yellowing or scorched at edges. Excess may cause early senescence.

Calcium (Ca)
Calcium plays an important role in maintaining cell integrity and membrane permeability.

Calcium Deficiency:
Young leaves are affected first and become small and distorted or chlorotic with irregular margins, spotting or necrotic areas. Bud development is inhibited, blossom end rot and internal decay may also occur and root may be under developed or die back. Deficiency will cause leaf tip die-back, leaf tip curl and marginal necrosis and chlorosis primarily in younger leaves. Symptoms: young leaves develop chlorosis and distortion such as crinkling, dwarfing, developing a strap-like shape, shoots stop growing and thicken.

Calcium Toxicity:
Difficult to distinguish visually. May precipitate with sulfur in solution and cause clouding or residue in tank. Excess calcium may produce deficiencies in magnesium and potassium.

Iron (Fe)
Iron is an important component of plant enzyme systems for electron transport to carry electrons during photosynthesis and terminal respiration. It is a catalyst for chlorophyll production and is required for nitrate and sulfate reduction and assimilation.
Iron deficiency:
- Pronounced interveinal chlorosis similar to that caused by magnesium deficiency but on the younger leaves.
-Leaves exhibit chlorosis (yellowing) of the leaves mainly between the veins, starting with the lower and middle leaves.

Caused by factors that interfere with iron absorption of roots: over irrigation, excessive soluble salts, inadequate drainage, pests, high substrate pH, or nematodes. This is easily corrected by adding an iron supplement with the next watering.

Fe is unavailable to plants when the pH of the water or soil is too high. If deficient, lower the pH to about 6.5 (for rockwool, about 5.7), and check that you're not adding too much P, which can lock up Fe. Use iron that's chelated for maximum availability. Read your fertilizer's ingredients - chelated iron might read something like "iron EDTA". To much Fe without adding enough P can cause a P-deficiency.

Note : When adding iron to the solution, it is often necessary to not use fertilizer for that watering. Iron has a tendency of reacting with many of the components of fertilizer solutions, and will cause nutrient lockup to occur. Read the labels of both the iron supplement and the fertilizer you are using before you attempt to combine the two.

Figure 20

Iron Toxicity:
Excess accumulation is rare but could cause bronzing or tiny brown spots on leaf surface.

Manganese (Mn)
Manganese is involved in the oxidation reduction process in the photosynthetic electron transport system. Biochemical research shows that this element plays a structural role in the chloroplast membrane system, and also activates numerous enzymes.
Manganese Deficiency:
Interveinal chlorosis of younger leaves, necrotic lesions and leaf shredding are typical symptom of this deficiency. High levels can cause uneven distribution of chlorophyll resulting in blotchy appearance. Restricted growth and failure to mature normally can also result.
-Mn gets locked out when the pH is too high, and when there's too much iron. Use chelated Mn.
Manganese Toxicity:
Toxicity:Chlorosis, or blotchy leaf tissue due to insufficient chlorophyll synthesis. Growth rate will slow and vigor will decline.

Chlorine (Cl)
Chloride is involved in the evolution of oxygen in the photosynthesis process and is essential for cell division in roots and leaves. Chlorine raises the cell osmotic pressure and affects stomata regulation and increases the hydration of plant tissue. Levels less than 140 ppm are safe for most plants. Chloride sensitive plants may experience tip or marginal leaf burn at concentrations above 20 ppm.
Chlorine Deficiency:
Wilted chlorotic leaves become bronze in color. Roots become stunted and thickened near tips. Plants with chlorine deficiencies will be pale and suffer wilting.
Chlorine Toxicity:
Burning of leaf tip or margins. Bronzing, yellowing and leaf splitting. Reduced leaf size and lower growth rate.

Boron (B)
Boron biochemical functions are yet uncertain, but evidence suggests it is involved in the synthesis of one of the bases for nucleic acid (RNA uracil) formation. It may also be involved in some cellular activities such as division, differentiation, maturation and respiration. It is associated with pollen germination.
Boron Deficiency:
Plants deficient in boron exhibit brittle abnormal growth at shoot tips and one of the earliest symptoms is failure of root tips to elongate normally. Stem and root apical meristems often die. Root tips often become swollen and discolored. Internal tissues may rot and become host to fungal disease. Leaves show various symptoms which include drying, thickening, distorting, wilting, and chlorotic or necrotic spotting.
Boron Toxicity:
Yellowing of leaf tip followed by necrosis of the leaves beginning at tips or margins and progressing inward before leaves die and prematurely fall off. Some plants are especially sensitive to boron accumulation.

Copper (Cu)
Copper is a constituent of many enzymes and proteins. Assists in carbohydrate metabolism, nitrogen fixation and in the process of oxygen reduction.
Copper Deficiency:
Symptoms of deficiency are a reduced or stunted growth with a distortion of the younger leaves and growth tip die-back. Young leaves often become dark green and twisted. They may die back or just exhibit necrotic spots. Growth and yield will be deficient as well.
Copper Toxicity:
Copper is required in very small amounts and readily becomes toxic in solution culture if not carefully controlled. Excess values will induce iron deficiency. Root growth will be suppressed followed by symptoms of iron chlorosis, stunting, reduced branching, abnormal darkening and thickening of roots.

Molybdenum (Mo)
Molybdenum is a component of two major enzyme systems involved in the nitrate reeducates, this is the process of conversion of nitrate to ammonium.
Molybdenum Deficiencies:
Often interveinal chlorosis which occurs first on older leaves, then progressing to the entire plant. Developing severely twisted younger leaves which eventually die. Molybdenum deficiencies frequently resemble nitrogen, with older leaves chlorotic with rolled margins and stunted growth.
Molybdenum Toxicity:
Excess may cause discoloration of leaves depending on plant species. This condition is rare but could occur from accumulation by continuous application. Used by the plant in very small quantities. Excess mostly usually does not effect the plant, however the consumption of high levels by grazing animals can pose problems so she might not be too good to smoke.

Sodium (Na)
Sodium seems to encourage crop yields and in specific cases it acts as an antidoting agent against various toxic salts. It may act as a partial substitute for potassium deficiencies. Excess may cause plant toxicity or induce deficiencies of other elements. If sodium predominates in the solution calcium and magnesium may be affected.

Silicon (Si)
Silicon usually exists in solution as silicic acid and is absorbed in this form. It accumulates as hydrated amorphous silica most abundantly in walls of epidermal cells, but also in primary and secondary walls of other cells. It is largely available in soils and is found in water as well. Inadequate amounts of silicon can reduce tomato yields as much as 50%, cause new leaves to be deformed and inhibit fruit set. At this time toxicity symptoms are undetermined.

Cobalt (Co)
Cobalt is essential to many beneficial bacteria that are involved in nitrogen fixation of legumes. It is a component of vitamin B12 which is essential to most animals and possibly in plants. Reports suggest that it may be involved with enzymes needed to form aromatic compounds. Otherwise, it is not understood fully as to its benefit to plant growth, but it is considered essential to some animal health issues.

very,very ,good post ,lots of good photos to go with the info,good onya.

mogie · #19 12-31-2006, 04:50 PM

To use the Problem-Solver, simply start at #1 below. When you think you've found the problem, read the Nutrients section to learn more about it. Diagnose carefully before making major changes.
1) If the problem affects only the bottom or middle of the plant go to #2. b) If it affects only the top of the plant or the growing tips, skip to #10. If the problem seems to affect the entire plant equally, skip to #6.
2) Leaves are a uniform yellow or light green; leaves die & drop; growth is slow. Leaf margins are not curled-up noticeably. >> Nitrogen(N) deficiency. b) If not, go to #3.
3) Margins of the leaves are turned up, and the tips may be twisted. Leaves are yellowing (and may turn brown), but the veins remain somewhat green. >> Magnesium (Mg) deficiency. b) If not, go to #4.
4) Leaves are browning or yellowing. Yellow, brown, or necrotic (dead) patches, especially around the edges of the leaf, which may be curled. Plant may be too tall. >> Potassium (K) deficiency. b) If not, keep reading.
5) Leaves are dark green or red/purple. Stems and petioles may have purple & red on them. Leaves may turn yellow or curl under. Leaf may drop easily. Growth may be slow and leaves may be small. >> Phosphorus(P) deficiency. b) If not, go to #6.
6) Tips of leaves are yellow, brown, or dead. Plant otherwise looks healthy & green. Stems may be soft >> Over-fertilization (especially N), over-watering, damaged roots, or insufficient soil aeration (use more sand or perlite. Occasionally due to not enough N, P, or K. b) If not, go to #7.
7) Leaves are curled under like a ram's horn, and are dark green, gray, brown, or gold. >> Over-fertilization (too much N). b) If not, go to #8…
The plant is wilted, even though the soil is moist. >> Over-fertilization, soggy soil, damaged roots, disease; copper deficiency (very unlikely). b) If not, go to #9.
9) Plants won't flower, even though they get 12 hours of darkness for over 2 weeks. >> The night period is not completely dark. Too much nitrogen. Too much pruning or cloning. b) If not, go to #10...
10) Leaves are yellow or white, but the veins are mostly green. >> Iron (Fe) deficiency. b) If not, go to #11.
11) Leaves are light green or yellow beginning at the base, while the leaf margins remain green. Necrotic spots may be between veins. Leaves are not twisted. >> Manganese (Mn) deficiency. b) If not, #12.
12) Leaves are twisted. Otherwise, pretty much like #11. >> Zinc (Zn) deficiency. b) If not, #13.
13) Leaves twist, then turn brown or die. >> The lights are too close to the plant. Rarely, a Calcium (Ca) or Boron (B) deficiency. b) If not… You may just have a weak plant.

The Nutrients:
Nitrogen - Plants need lots of N during vegging, but it's easy to overdo it. Added too much? Flush the soil with plain water. Soluble nitrogen (especially nitrate) is the form that's the most quickly available to the roots, while insoluble N (like urea) first needs to be broken down by microbes in the soil before the roots can absorb it. Avoid excessive ammonium nitrogen, which can interfere with other nutrients. Too much N delays flowering. Plants should be allowed to become N-deficient late in flowering for best flavor.
Magnesium - Mg-deficiency is pretty common since marijuana uses lots of it and many fertilizers don't have enough of it. Mg-deficiency is easily fixed with ¼ teaspoon/gallon of Epsom salts (first powdered and dissolved in some hot water) or foliar feed at ½ teaspoon/quart. When mixing up soil, use 2 teaspoon dolomite lime per gallon of soil for Mg. Mg can get locked-up by too much Ca, Cl or ammonium nitrogen. Don't overdo Mg or you'll lock up other nutrients.
Potassium - Too much sodium (Na) displaces K, causing a K deficiency. Sources of high salinity are: baking soda (sodium bicarbonate "pH-up"), too much manure, and the use of water-softening filters (which should not be used). If the problem is Na, flush the soil. K can get locked up from

mogie · #20 12-31-2006, 04:51 PM

from too much Ca or ammonium nitrogen, and possibly cold weather.
Phosphorous - Some deficiency during flowering is normal, but too much shouldn't be tolerated. Red petioles and stems are a normal, genetic characteristic for many varieties, plus it can also be a co-symptom of N, K, and Mg-deficiencies, so red stems are not a foolproof sign of P-deficiency. Too much P can lead to iron deficiency.
Iron - Fe is unavailable to plants when the pH of the water or soil is too high. If deficient, lower the pH to about 6.5 (for rockwool, about 5.7), and check that you're not adding too much P, which can lock up Fe. Use iron that's chelated for maximum availability. Read your fertilizer's ingredients - chelated iron might read something like "iron EDTA". To much Fe without adding enough P can cause a P-deficiency.
Manganese - Mn gets locked out when the pH is too high, and when there's too much iron. Use chelated Mn.
Zinc - 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.
Check Your Water - Crusty faucets and shower heads mean your water is "hard," usually due to too many minerals. Tap water with a TDS (total dissolved solids) level of more than around 200ppm (parts per million) is "hard" and should be looked into, especially if your plants have a chronic problem. Ask your water company for an analysis listing, which will usually list the pH, TDS, and mineral levels (as well as the pollutants, carcinogens, etc) for the tap water in your area. This is a common request, especially in this day and age, so it shouldn't raise an eyebrow. Regular water filters will not reduce a high TDS level, but the costlier reverse-osmosis units, distillers, and de-ionizers will. A digital TDS meter (or EC = electrical conductivity meter) is an incredibly useful tool for monitoring the nutrient levels of nutrient solution, and will pay for itself before you know it. They run about $40 and up.
General Feeding Tips - Pot plants are very adaptable, but a general rule of thumb is to use more nitrogen & less phosphorous during the vegetative period, and the exact opposite during the flowering period. For the veg. period try a N:P:K ratio of about 10:7:8 (which of course is the same ratio as 20:14:16), and for flowering plants, 4:8:8. Check the pH after adding nutrients. If you use a reservoir, keep it circulating and change it every 2 weeks. A general guideline for TDS levels is as follows:
seedlings = 50-150 ppm; unrooted clones = 100-350 ppm; small plants = 400-800 ppm; large plants = 900-1800 ppm; last week of flowering = taper off to plain water. These numbers are just a guideline, and many factors can change the actual level the plants will need. Certain nutrients are "invisible" to TDS meters, especially organics, so use TDS level only as an estimate of actual nutrient levels. When in doubt about a new fertilizer, follow the fertilizer's directions for feeding tomatoes. Grow a few tomato or radish plants nearby for comparison.
PH - The pH of water after adding any nutrients should be around 5.9-6.5 (in rockwool, 5.5-6.1). Generally speaking, the micro-nutrients (Fe, Zn, Mn, Cu) get locked out at a high pH (alkaline) above 7.0, while the major nutrients (N, P, K, Mg) can be less available in acidic soil or water (below 5.0). Tap water is often too alkaline. Soils with lots of peat or other organic matter in them tend to get too acidic, which some dolomite lime will help fix. Soil test kits vary in accuracy, and generally the more you pay the better the accuracy. For the water, color-based pH test kits from aquarium stores are inexpensive, but inaccurate. Invest in a digital pH meter ($40-80), preferably a waterproof one. You won't regret it.
Cold - Cold weather (below 50F/10C) can lock up phosphorous. Some
varieties, like equatorial sativas, don't take well to cold weather. If you can keep the roots warmer, the plant will be able to take cooler temps than it otherwise could.
Heat - If the lights are too close to the plant, the tops may be curled, dry, and look burnt, mimicking a nutrient problem. Your hand should not feel hot after a minute when you hold it at the top of the plants. Raise the lights and/or aim a fan at the hot zone. Room temps should be kept under 85F (29C) -- or 90F (33) if you add additional CO2.
Humidity - Thin, shriveled leaves can be from low humidity. 40-80 % is usually fine.
Mold and Fungus - Dark patchy areas on leaves and buds can be mold. Lower the humidity and increase the ventilation if mold is a problem. Remove any dead leaves, wherever they are. Keep your garden clean.
Insects - White spots on the tops of leaves can mean spider mites
underneath.
Sprays - Foliar sprays can have a "magnifying glass" effect under bright lights, causing small white, yellow or burnt spots which can be confused with a nutrient problem. Some sprays can also cause chemical reactions.
Insufficient light - tall, stretching plants are usually from using the wrong kind of light.. Don't use regular incandescent bulbs ("grow bulbs") or halogens to grow cannabis. Invest in fluorescent lighting (good) or HID lighting (much better) which supply the high-intensity light
that cannabis needs for good growth and tight buds. Even better, grow in sunlight.
Clones - yellowing leaves on unrooted clones can be from too much light, or the stem may not be firmly touching the rooting medium. Turn off any CO2 until they root. Too much fertilizer can shrivel or wilt clones - plain tap water is fine.