Outdoor Gone Wrong...Any ideas?

[MichaelVick]

Hey guys. Please help. I have searched the Sick Plant guide and didn't see anything that matched.

Sorry I don't have much info for you as these pics are from a buddy's outdoor garden and I don't have all the specifics. He has been growing for 20+ years and has no idea what happened to them. He's never seen anything like it and asked me to post here to get some ideas.

The sad thing is 95% of the entire garden looks like these pics. A few branches here and there and one entire plant look normal (at the moment) but the entire crop is really trashed. You will see one pic of a good branch.

I asked him if he did anything different this year and he said the only thing he really changed was that he used the Superthrive (pictured) to condition the soil which he has never used. He doesn't think that caused the problem because his other veggies and herbs growing in the same garden getting all the same treatment are looking better than previous years! He also noted that we have had an unusually rainy summer. He said the plants didn't need nearly as much watering as in previous years. We are wondering if the wet weather in the southeast has caused some type of fungus or something.

Any ideas??? If you've seen this before please speak up! We are really disappointed and don't want this to happen again!

PLEASE HELP!

 

[MichaelVick]

 

[azad]

Looks like Fusarium wilt. a soil borne fungal disease.

 

[greekgardner]

broadmites,have you scoped them yet?

 

[MichaelVick]

Looks like Fusarium wilt. a soil borne fungal disease.

OK. Thanks Azad.

Anyone ever have this? Anyone agree?

Any proven treatments/prevention methods?

 

[MichaelVick]

broadmites,have you scoped them yet?

No we have not scoped them. I have always seen broad mite damage effect the leaves but most of these leaves are not damaged.

Have you seen BM damage like this? Do broad mites survive outside? And would they not effect all the other herbs and veggies in the garden???

 

[azad]

Poor draining soil and heavy rains is a recipe for the disease. Find a new grow patch.

 

[azad]

Fusarium wilt, the most prevalent of the two diseases generally occurs in midsummer when air and soil temperatures are high. Diseased plants first develop a yellowing of the oldest leaves (those nearing the ground). Often the yellowing is restricted to one side of the plant or even to leaflets on one side of the petiole. The affected leaves soon wilt and dry up, but they remain attached to the plant. The wilting continues on successively younger foliage and eventually results in the death of the plant. The stem remains firm and green on the outside but exhibits a narrow band of brown discoloration in the vascular tissue. This discoloration can be viewed easily by slicing vertically through the stem near the soil line and looking for a narrow column of browning between the central pith region and the outer portion of the stem.

Verticillium wilt tends to develop during the cooler periods of late spring. Symptoms of this disease are similar to Fusarium wilt. Older leaves are affected first; they turn yellow, wilt and eventually drop from the plant. Unlike Fusarium wilt, Verticillium wilt causes uniform yellowing and wilting of the lower leaves. As the disease progresses, younger leaves begin to wilt and die, until only a few healthy leaves remain at the top of the plant. Although diseased plants are not killed, they are stunted and weak and produce small fruit. Verticillium wilt also causes discoloration of the vascular system almost identical to that in Fusarium wilt except that the browning does not extend quite as far up the stem. Thus, laboratory analysis may be required to distinguish between the two diseases.

The Fusarium wilt fungus can be introduced into systems on contaminated seed or in infected transplants. Once introduced, the fungus can survive for many years in the (soil). The Verticillium wilt fungus also is a soil-borne pathogen that can attack a wide range of plants, including potato, eggplant, strawberry, black raspberry, and many common weeds. Both fungi invade the plant through the fibrous root system and disrupt water and mineral uptake within the plant. Infection and disease development in Fusarium wilt are favored by warm soil temperatures (80° F) and low soil moisture, while Verticillium wilt develops best at relatively cool (55-75 F) soil temperatures. /

Both of these fungus are typical in soil, and are probably much less common in hydroponic systems. You can reduce the danger of introducing these types of problems by NEVER mixing soil and hydroponic plants.

Below you will find a comprehensive outline of marijuana fungal infections.

More than 90 species of fungi attack Cannabis. Seedlings can be infected by damping-off fungi; the flowers and leaves are vulnerable to grey mold, yellow, brown and olive leaf spots, mildew and brown blight, pink rot, and viruses. The stalk and stems are susceptible to attack by grey mold, hemp canker, Fusarium oxysporum canker and wilt, stem nema, charcoal rot, anthracnose, and striatura ulcerosa. The roots can be diseased by Fusarium, rhizoc, sclerotium root rot, and nematodes. Alternaria alternata Keissler, a common fungal pathogen of many plants, can destroy up to 45% of hempseed in a crop.

K. Roder investigated hemp diseases, and isolated 7 strains of Sphaerella cann., 13 strains of Phoma or Phyllosticta, and 13 forms of Phomopsis, Coniothyrium, Vermicularia, Fusarium, and Cylindrocarpon. None of these species can infect the roots of hemp directly, unless the roots are weak or injured.

Gray mold (Botrytis cinerea) and hemp canker (Sclerotina sclerotiorum) can severely damage a hemp crop in wet years. In temperate regions with high humidity and low temperatures, botrytis can completely destroy a hemp crop within a week. Botrytis and hemp canker can be controlled by spraying alternately with the fungicides vinchlozolin (0.5 kg/ha) and iprodion (0.5 kg/ha) at two-week intervals from June through August. Tetramethylthiuran disulfide also is effective. Van der Werf, et al., however, found from three years of field experiments that one or two applications did not increase actual stem yield. They concluded that, “although fungal diseases may severely reduce hemp yield in the Netherlands, the use of fungicides is not worthwhile.” They recommended breeding cultivars less susceptible to B. cinerea in particular. Botrytis can be controlled by applications of sulfur followed by "AQ-10", a microbial product. Bentonite clay also can control botrytis; it is better to use California calcium-bentonite rather than the more common sodium variety. Potassium bicarbonate ("Kali-Green") also kills botrytis. (26)

Botrytis appears as "damping-off" (moldy germination) on seedlings; it can be prevented by aeration of the soil, by hydrogen peroxide, or by the Burgundy Formula. Dissolve 1 lb of calcium sulfate and 1 lb of washing-soda crystals in 10 gallons of water. Soak the seeds in this solution, then rinse with fresh water.

The Chestnut Formula also prevents damping-off. Mix 2 parts copper sulfate and 11 parts ammonium carbonate in a glass jar. Dissolve 1 oz in 2 gallons of water. Soak the seeds in this solution, then rinse them with fresh water.

Botrytis is a stem disease in fiber cultivars, arising as a gray-brown mycelial mat, later covered with conidia. The stem becomes chlorotic along the edge of the mat, then reduces to soft, shredded cankers; the plant often snaps at that point, or wilts above it. The mature floral bracts of female drug cultivars are most susceptible to infestation. Leaflets turn yellow, then wilt, and pistils become brown. Mycelia envelope the infloresences, which dissolve into gray-brown slime.

Infection by Botrytis is directly affected by the level of calicum in the plant; the higher the amount of Ca, the lower the incidence of Botrytis. Sprays of Ca-silicate (2,000 ppm) and Ca-formate (2,000 ppm) provide effective control of fungi and are safe alternatives to highly toxic fungicides.

Damping off is caused by other several fungi, mostly by the Protoctistan oomycetes Pythium aphanidermatum and P. ultimum. Other causative fungi include Fusarium solani, F. oxysporum, F. avenaceum, F. graminearum, and F. sulpurem, Rhizoctonia solani, and Macrophomina phaseolina.

The severity of infection by facultative parasites is affected by the levels of nitrogen and potassium; low N and high K provide resistance; high N and low K invite parasites.

Wilt is caused by Fusarium oxysporum f. sp. cannabis Nov. & Snyd. It first appears on 3-month old plants as a yellowish-green color and small dark spots on the lower leaves, which die but remain hanging. The plant may bend to the side of the stem that is affected.

In 1999, Ag/Bio Con, a Montana company, offered the world a mutant strain of Fusarium oxysporum as a mycoherbicide against cannabis --- an utterly insane promotion that has instigated lawsuits to cease and desist. Fusarium mutates very easily and spreads to other crops. It is an environmental disaster.

Verticillium wilt is caused by Verticillium(two species); Macrophomina phaseolina causes premature wilt (also known as charcoal rot).

Hemp twig blight is caused by Botryosphaeria maronii (Cav.) Charles & Jenkins. The leaves quickly wilt and droop and turn brown, but remain attached. The symptoms first appear on the tips of branches. The lower parts become bleached.

Two species of Colletotrichum cause anthracnose in cannabis.

Hemp canker, caused by Sclerotinia sclerotiorumi, is one of the most important diseases of cannabis. It appears as wet lesions on the branches of plants as they mature; the lesions become dark cankers. The pith fills with white mycelia. Black sclerotia then develop in the stem and in the pith. The plants wilt and collapse. The optimal temperature range for its growth and maturation of is 24-33o C. Sclerotinia can be controlled somewhat by proper drainage of the fields.

Yellow leaf spot is caused by two species of Septoria; brown leaf spot is caused by species of Phoma and Ascochyta; Phomopsis ganjae causes white leaf spot.

Severe leaf infections also are caused by strains of Sphaerella (stem browning), Phyllosticta, Cercospora, Microdiplodia, Macrosporium cann., and Pseudoperonospora (olive leaf spot), and Didymella arcuata. (32)

Didymella arcuata is found in association with the fungus Ascochyta cann. Lasch. The optimal temperature for the germination and growth of D. arcuata is 19-26o C. Its sporulation is promoted by light; its vegetative development is stimulated by darkness. (33)

Leaf spots caused by Cercospora cannabis Hara & Fukui are yellow-tan or brown. They are circular at first but become irregular and distinct.

Trichothecium roseum causes pink rot on cannabis drug cultivars in greenhouses.

Hemp rust (Melampsora cannabina) appears as orange patches on the leaves. It can be controlled by spraying with thiocarbamate.

Bacteriosis (stripe disease) is caused by Pseudomonas cannabina Sutic & Dows. var. italica Dows. Scattered reddish-violet spots (under 2 mm), surrounded by a pale yellow halo, appear on leaf blades, followed by rapid shedding. Small necrotic elongate cavities, filled with bacteria, appear on the stems.

Some less common but nonetheless virulent diseases of cannabis are anthracnose (Colletotrichum atramentarium) and brown blight, which is caused by species of Alternaria and Stemphylium.

Many of the bacterial and fungal diseases of cannabis and other crops can be controlled by applications of Bacillus subtilis, which is available in several commercial products (i.e, Serenade, manufactured by Agraquest).

Several bacteria that are pathogenic to humans have been found on Cannabis, including: Salmonella muenchen, Klebsiella pneumoniae, Euterobacter cloacae, E. agglomerans, Streptococcus (Group D), Thermoactinomyces candidus, T. vulgaris, Micropolyspora faeni, Aspergillus fumigatus, A. niger, A. flavus, A. tamarri, A. sulphureus, A. repens, Penicillium chrysogenum, P. italicum, Rhizopus stolonifer, Alternaria alternata, Curvularia lunata, and Histoplasmus capsulatum. Aspergillus can be killed by baking cannabis at 150o C for 15 minutes, but only about 15% is destroyed by smoking through a waterpipe. Microbial pathogens and toxins, however, are not destroyed by heating or other methods of sterilization.

 

[Ickis]

Being primarily an outdoor grower for many years in the northeast USA I have encountered this before and it always stumped me. I know exactly what that is now. It never used to be listed in the sick plants guide. It is a phosphorous deficiency caused by cool temps in the root zone.

I usually ran into it early in the season in late May early June in plants I had in pots or in the ground where the soil would be much cooler than the air temps. If it isn't treated early on it is difficult to get it fixed come flowering time. Because the effected leaves are sickly they can get fungus or bacteria problems that confuse diagnosis but those are not the primary issue.

Go to the infirmary and look at the picture under


Picture of Phosphorus being locked out from cooler temps.


That is the purple color the leaves start with. When I first came across it I thought it was some type of fungus.

You can try and treat with some phosphorous and even give some as a foliar spray. If caught early you can get the purple color to fade. Treated late you can only hope the new leaves and flowers will develop normally.

Untreated it will cause deformed growth of leaves and flowers. It might be too late for those plants but all you can do is try.

The way I have eliminated this is when I plant them in the ground or in the pots I give them Triple Phosphate granules on top of the soil. In a pot 1 tablespoon scattered over the top of the soil. In the ground I use a couple of table spoons. It takes awhile for them to start dissolving so I use them as soon as I plant. I also use high phosphorous bat guano on the top soil.

Pot plants love phosphorous. Even though they love it and it is difficult to give them too much you can't let the Triple Phosphate granules touch the stems or it can burn them. Same with the roots. So put it on the soil and water.

There is probably some phosphorous liquid you could mix as a foliar spray for a more immediate onset. Stitch in the sick plant thread like using Fox Farm Big Bloom to treat various things as a foliar spray.

In your first post picture #3 is a good one to see it. Also post #2 pictures show it good.

Are the plants in the ground or in pots? It doesn't matter just wondering. Heavy rains keep the soil wet and cool. Planting in the ground near streams the ground is cooler. Also in cornfields or under trees that shade the ground makes for cool spots.

Triple Phosphate at the start of the grow and some bat guano added every month has eliminated this for me.

 

[MichaelVick]

Thanks for the help Ickis. I found the picture you mentioned in the sick plant guide. It does match up.

Most of the plants were in the ground. They get some full sun but are near trees and in the shade a small portion of the day. We are in the southeast so we didn't think the temps would be too low but it has been a milder summer...

When you had the problem did you get really small, deformed, purple, dry, crumbling flowers? That is what we have...

I will pass along the info and we'll try some of your suggestions if you are certain about things.

Thanks again!

 

[Ickis]

Yes the flowers were as you described. You can try to treat them. If they are long flowering and will go to end of October they might recover some.

You need to get on this as soon as you see the purple early on in the season. I just add the Triple Phosphate at the start and use the high P guano. You can also use some high P liquid ferts in veg during the early season. You still use your veg stuff but give them extra P.

You probably won't be able to fix the ones you have now. But it won't hurt to try.