HOW TO HANDLE POWDERY MILDEW

Info on Powdery Mildew:

Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of fungi in the order Erysiphales. This is one of the easier diseases to spot, as the symptoms are quite distinctive. Infected plants display white powder-like spots on the leaves and stems. They look almost as if someone tipped a spray-paint can upside down and sprayed up in the air, letting the paint “dust” or fall onto the leaves and stems. It might be identified incorrectly as dust that has accumulated on the leaves. The lower leaves are the most affected, but the mildew can appear on any part of the plant that shows above the ground. As the disease progresses, the spots get larger and thicker as massive numbers of spores form, and the mildew spreads up and down the length of the plant. In most cases this fungal growth can be partially removed by rubbing the leaves. This growth will eventually affect the fruit or flowers. Nutrients are removed from the plant by the fungus and this can result in a general decline in the growth and vigor of the plant. Severe powdery mildew infection will result in yellowed leaves, dried and brown leaves, and disfigured shoots and flowers. Powdery mildew fungi produce airborne spores and infect plants when temperatures are moderate (60 to 80 degrees F.). It prefers high humidity; above 50% to thrive. It can spread and colonize without water being directly on the leaves. Powdery mildew is notoriously hard to kill, and is the second most common problem that we run into with gardeners. Infection definitely depends on the location the garden is in. Higher humidity locales will encounter problems with powdery mildew more frequently than gardens in dryer environments. Below we list a good set of solutions for this disease.

General Remedies and Environmental Control:

Temperature above 80 degrees F. will ward off Powdery Mildew. If using CO2 you can take your plants from their ideal 86 degrees F. to upwards of 90-92 degrees F, at the plant level, which will deter the growth of this mold. Humidity below 45% (40% is about the lowest you will want to go to not avoid hurting your plants.) If none of the other remedies below can be procured, than sodium bicarbonate can be used. Simply mix 1 tsp. of Baking Soda, 1 quart purified water, and 1-2 drops of a soft detergent into a spray bottle and apply to any infected area. Continue re-applying every 2-3 days, or as needed.

Sulfur Burners/Vaporizer:

Sulfur Vaporizers (Burners) are the best overall remedy to the powdery mildew problem. It is what commercial greenhouses use for a very good reason - it works. Sulfur changes the pH on the leaf surface, making it inhospitable for plant growth. If you want the “final solution” to an infestation, than use a burner. They smell something awful (Sulfur is not safe to inhale. Do NOT enter the sulfur cloud) and create a huge amount of smoke when being burned. Use a Digital Timer in conjunction with our Sulfur Burner and your exhaust/inline fan(s); this will manage the Sulfur application and prevent exhaust fans from turning on while the Sulfur is being applied. Hooking the burner up to a timer is critical. We also recommend having the exhaust fan hooked up to another timer (turning on after the Sulfur burner has been turned off) to vent the room.

Application Instructions:

For best results make sure to follow these instructions closely:

For preventative use turn on the unit for 4-5 hours 2 times per week.

For active infestation turn on the unit 4-5 hours 4 times per week. Can use up to 6-8 hours a night for severe infestations. Also the cup needs to be adjusted properly over the heat plate (lower the cup down all the way, so that it rests on the heating element), and the right amount of sulfur needs to be added (the cup must be cleaned, and filled half-way up with approx. 100g. of sulfur) or a flame can result from the canister within. Make sure to turn OFF exhaust fans and lights during operation.

Make sure plants are dry. , Burners are lit during the plants “night” (dark) cycle only.

Our (Yellow) Electric Vaporizer / Burner

Filling - Thoroughly clean any debris from the cup. Fill the cup half full (approx. 100g. of sulfur). Do not overfill as this could cause the unit to boil over. Boiling over is very dangerous - if this occurs, keep the cup only half full.

Cup Placement within unit – lower the cup down all the way so that it rests on the heating element.

Coverage Area - 1,000 Sq. Ft.

Placement of Unit - The burner should be hung (by its handle) 2-3 feet above plants (make sure it is hung vertically / not sideways or any other way). Make sure this is ample air flow going around the unit.

Safety Precautions:

Adjust plate properly within (all the way down) so it is resting on the heating element.

Wear protective clothing (This should include a “sulfur rated” mask, gloves, eye protection, long sleeves, pants and shoes.)

Perform all Vaporization of sulfur at night.

Do NOT enter or inhale the sulfur cloud.

Make sure leaves are dry before vaporization begins.

Do NOT attempt to “fix” or repair burner if there is a problem. Please bring back to the shop.

Do NOT touch unit while it is ON.

Wash all produce before consumption.

* For storage - keep sulfur in original package in a cool dark place. Make sure to keep away from children. Sulfur tends to take in moisture, so the packaging must be closed tightly and securely after each use, if you want it to last.

Please Note:

Our Sulfur is 99% pure and is made to be used for Sulfur burners. Because of our sulfur is so pure, it will smell less than others on the market. Sulfur is environmentally friendly and relatively non-toxic. It is used on many different types of fruits and flowers for disease control.

WARNING

DO NOT use a sulfur burner on or near plants that have been foliar sprayed with any type of oil-based additives, pesticides or other products within the last 30 days or the plants can catch on fire.

Mildew Cure:

Mildew Cure works almost as well.  Mildew Cure must be mixed

with a wetting agent such as coco-wet. It uses Sodium Bi-Carbonate as its main mode of action as well as essential oils.

Application of Mildew Cure:

Quart Sprayer - Mix 1.5 tsp / Quart of Mildew Cure add wetting agent and mix. Apply to entire plant(s) with sprayer.

Gallon Sprayer - Mix 1 oz / Gallon of Mildew Cure add wetting agent and mix. Apply to entire plant(s) with sprayer.

For severe infestations, up to 3x normal dosage can be applied. (Ex. 3 oz / Gallon) Make sure to first apply weaker application rate to plants first. Then begin to step up the dosage. Call with any questions or concerns.

Penetrator and Zone:

Penetrator and Zone provides a 2 part stopping action. The first is its ability to change the pH at the leaf level. It raises it and helps make the leaf zone un-hospitable to the Powdery Mildew spores. The Second is the MonoChloramine itself which is a sterilizing agent which can kill the Mildew itself.

Application of Penetrator and Zone Blend

Quart Sprayer - Mix 2ml of zone, 15ml of penetrator into a Quart/Liter of Purified (Reverse Osmosis) Water.

Gallon Sprayer - Mix 8mL of Zone, 60mL of Penetrator into a Gallon of Purified (Reverse Osmosis) Water.

Neem Oil

Neem oil is also known to help prevent powdery mildew from “taking root” and thus colonizing a garden. Neem works best if sprayed consistently every 3 days. We suggest Einstein Oil because it is “cold pressed” and retains more of the active ingredients than other products. Mix with Coco-wet and apply at lowest dosage at first. Raise dosage up slightly every spray until max application rate is reached.

Application Instructions:

Apply this spray every 3 days. Build dosage up from lowest to highest than ride highest dosage out until 4th week of Bloom.

Quart Sprayer - Mix 1/2-2tsp of Einstein Oil and a few drops of Coco-Wet per Quart of “warmed up” purified (RO) water.

Gallon Sprayer- Mix 2-8tsp. of Einstein Oil and a 1/4 tsp of Coco-Wet per Gallon of “warmed up” purified (RO) water.

Zero Tolerance - Either Original or Herbal Fungicide

This herbal Fungicide is made from the highest quality oils of clove, rosemary, thyme, and wintergreen. Mix with Coco-wet and apply at lowest dosage at first. Raise dosage up slightly every spray until max application rate is reached. I t's made from pure food grade ingredients and is plant, people and pet friendly. Zero Tolerance is bio-degradable and environmentally safe so you can use it without worry. It eliminates Powdery Mildew, Gray & White Mold, Black Spot, and most molds and fungi. This stuff is new - yet very powerful.

Application Instructions:

Quart Sprayer - Dilute Zero Tolerance in 1/2 - 1/3 from the bottle (RTU bottle). Dilute 1/2-1/3 with Purified Water.

Spray 1 time at diluted strength. Then Spray with 3/4 strength Zero Tolerance 1/4 part water. Once plants are

use to Zero Tolerance they can be sprayed at full strength.

Bayer Advanced Disease Control

When all else fails Bayer Disease control is hands down the best powdery mildew killer that you can legally buy. It is a systemic fungicide, it soaks into the plant material and kills the fungus at its core. It the stays in the plant material for up to 4 weeks and protects the plant from the inside out. It is part of the Triazole family of fungicides the same as eagle 20ew. This Product can be used as late as Day 7 of flower.

Preventative

If used as a preventive treatment it is highly unlikely that you will have any problems while in flower. I like to use the product 3 times, twice in Veg and once on day 7 of flower. If used in conjunction with keeping your environment in the right conditions you will never have an issue again.

Application Instructions:

Quart sprayer- Dilute Bayer Disease control ½ tsp into 1 quart of reverse osmosis water. Spray plant with the lights off top to bottom. Let the plants fully dry and turn the lights back on.

When spraying make sure to follow these rules:

Gallon Sprayer- Dilute Bayer Disease control 2 tsp into 1 gallon of reverse osmosis water. Spray plant with the lights off top to bottom. Let the plants fully dry and turn the lights back on.

1. Use a pesticide Respirator. 2. Wear fluid proof gloves. 3. Wear long sleeves and pants and take off and wash as soon as application is finished. 4. Wear eye protection.

Tobacco Mosaic Virus real cause and cure

I have been seeing a lot of "TMV/Virus/Disease issue posts all over grow forums. Thought I would post some information.

This is a new problem to SoCal Growers as this is usually an issue up north. This problem started to hit the SoCal scene in late 2009 (all over the grow forums). Many can agree that broad mites are a new issue now to be concerned about, but can easily be taken care of if treated the same as Spider Mites (or any kind of pest) and are easily passed down from one grower to the next.

It seems there has been a huge issue going on with many growers in California which end up destroying crops and losing strains ( PLEASE KEEP IN MIND, ITS EASY TO DISMISS PLANT PROBLEMS AND SAY ITS BUGs, YOU MUST BE ABSOLUTELY SURE, BY LOOKING THROUGH A MICROSCOPE). There is a misconception that these damages such as, Yellowing Top, slow growth, stunted growth, curling, pale stem, blotches, pistils being destroyed, etc are being associated with TMV/CMV (Tobacco/Cucumber Mosaic Virus).

In fact, the symptoms are similar,  ALL LAB TESTS CONFIRM NO TMV/CMV, as if this was true, the entire community would definitely be feeling this. There hasn't been any SOLID evidence by anyone that these damages are strictly related to TMV (or other virus). Many Tests have been conducted by many growers with always TMV being ruled out.

These Broad Mites usually have a hard time colonizing in perfect growing environments, but once allowed, they will stay and not leave unless treated

Believed to be symptoms of TMV or other viruses (given the fact that no broad mites exist). There isnt any factual evidence that this is the cause of a virus. When a plants immune system is down, it shows such mosaic symptoms on fan leaves but will never progress to destroy the plant.

If you are experiencing growth like this most likely your dealing with Broad Mites. These mites are extremely small, you CANNOT see them with the naked eye.

Many people have tested for TMV/CMV and always the tests come out negative for TMV virus.

Here is a picture to give an idea how small these things are. This is a White fly, and Broad Mites are on it.

Here is some information gathered about These mites, Broad Mites or cyclamen Mites.

(Order: Acari, Family: Tarsonemidae, Polyphagotarsonemus latus.

Tiny broad mite adult carrying an immature mite.
Description:
Adult: Adults are very tiny with the female body length of 0.2 to 0.3 mm and males about half the size of females. Adults are broadly oval and whitish to yellow-green but appear somewhat translucent except under extreme magnification. They have four pair of legs, with the front two pair widely separated from the posterior two pair. The last pair of legs appears threadlike.

Immature stages: The appearance of the egg is the key characteristic generally used to verify plant infestations by broad mites. The eggs are nearly transparent with the exception of rows of whitish circular projections that give the eggs a speckled appearance. The larval and pupal stages appear similar to the adults but are smaller. The larval stage has six legs and the pupal stage has eight legs.

Biology:
Life cycle: Adults move short distances by walking, but are dispersed long distances by wind or by attaching to and 'hitch-hiking' on winged insects such as aphids and whiteflies. Eggs are laid singly on the lower surface of young apical leaves and flowers. Average egg production is reported as 40 to 50 eggs per female. Eggs hatch is about two days and the larval and pupal development requires a total of 2 to 3 days. Adult males emerge first and will carry female pupae to younger tissues. Females emerge and generally mate immediately. Unmated females produce only males which may then mate with the female, assuring production of subsequent females. The entire life cycle requires about one week under favorable conditions and typically occurs in the youngest terminal growth. Broad mites are generally not found on fully opened leaves.

Seasonal distribution: Broad mites have a wide host range and can occur throughout the year in tropical climates. Reproduction does not occur below 13°C nor above 34 degrees. Temperatures of about 25°C and humid conditions are most favorable. Cold winters and hot, dry summers usually limit populations in Georgia. Rainy fall seasons provide optimal conditions for broad mites in south Georgia, and the greatest damage usually occurs at these times.


Scarring and russetting of pepper fruit caused by broad mite.
Damage to Crop:
Broad mite has a large host range including 60 families of plants (including Cannabis). Its vegetable hosts include beet, beans, cucumber, eggplant, pepper, potato and tomato. Damage is especially severe in bell pepper. Damage is caused by secretion of a plant growth regulator or toxin as the mite feeds, and significant damage can occur at very low pest density. Symptoms include leaf and fruit distortions, shortening of internodes, blistering, shriveling and curling of leaves, and leaf discoloration. Much of this can be easily confused with viral disease, micronutrient deficiency, or herbicide injury. Fruit may be deformed, split, or russeted. Infestations in pepper can cause a bronzing of terminal growth and are frequently associated with a characteristic 's'-shaped twisting of the main stem in leaves. Damage may appear for weeks after the mites have been controlled, and when combined with the difficulty in detecting mites, makes evaluation of control measures difficult and has likely led to reports of control failures.

Management:
The broad mite's minute size and ability to damage plants at very low densities generally results in plant injury serving as the first indication of an infestation. When damage is noted, terminals of symptomatic plants should be examined under magnification to verify the presence of broad mites. Damage will usually start in small clumps in a field and can spread rapidly. Some acaricides provide excellent control, but examination of plant terminals is necessary to evaluate control success, as damage can continue to appear for two weeks after successful control.

Generalized Summery:

Adult
The adults are white-yellow, about 0.2 mm long, and the male is extremely active.

Immature stages
Eggs laid on the underside of leaves are oval, translucent and covered with five or six rows of white tubercles.

Life history
The life cycle through egg, two nymphal stages, to adult takes between 6 to 9 days.

Distribution
Occurs in all papaya districts but is only a major problem in southern Queensland.

Host range
Broad mite is a serious pest of lemons, Hickson and Ellendale mandarins and occasionally grapefruit. Wide range of other hosts including papaya, capsicum and most nursery plants.

Management
Importance
Major and frequent, more often in autumn in southern Queensland. Minor and infrequent in northern Queensland.

Damage
Broad mite attacks the growing point and the underside of young leaves causing hardening and distortion. Broad mite damage is often confused with injury caused by hormone herbicides because in both cases the leaves become claw-like with prominent veins. Grey or bronze scar tissue between the veins on the underside of the leaves distinguishes mite from hormone damage. Broad mite infestation can sometimes be confirmed with a X 10 hand lens although they have often disappeared before the damage is noticed. The characteristic egg can be seen near the veins beneath the leaf as a translucent, flat oval with a stippling of white dots. The mite itself is flat but is less easily identified than its egg.

Control methods
Chemical
Apply 2 miticide sprays 10 to 14 days apart. Good coverage is essential. Affected plants usually recover and specific control measures are not normally required in northern districts.

Nutrient Profiling

Nutrient profiling is a means of presenting a nutrient solution with its worth given in terms of its elemental makeup for elements essential to plant growth, and some beneficial elements. Because this is a common language spoken by all nutrient solutions and fertilizer products, when it's known, a nutrient mix can be tailored using the guaranteed analysis from a variety of fertilizer products. In this way, a nutrient solution mixed from one assortment of fertilizer products can be reproduced by someone using a completely different assortment of products. For example, a solution made from liquid premixed products can be reproduced by someone using dry raw chemical compounds, and vice versa.

This method of communicating nutrient solutions has been used by researchers and professionals because it leaves no doubt as to the nutritive worth to be targeted when mixing fertilizers with water. When a profile target is given, instead of the measures for a specific fertilizer or fertilizer brand used to mix the profile, it effectively becomes a generic formula that can be used by anyone even if they don't have the same fertilizers or brand name products used by the originator of the profile.

A Grower's Project
Several years ago I undertook a project to find which hydroponic nutrient profile(s) produced the highest yield. The project ended after 10 years and more than 25 crops. I was that convinced of the control nutrients gave me, and just as determined not to let the project end until I proved it to myself. That never happened. As a starting point I set out to collect as many published cannabis nutrient profiles as I could find. To my surprise I could only find two sets of recommended profiles, one published by Mel Frank in his Grower's Insider's Guide, the other by pH Imbalance (no relation to myself) in his Growers Handbook, both are shown further below.

Stage of Growth
The first thing you'll notice about the profiles is that they change according to the stage of growth for the crop, three stages for those in the Grower's Insider's Guide, and four for those in the  Growers Handbook. While three or four reservoir changes aren't unusual for a hydroponic grower to endure, I've seen many stage of growth schedules recommended by individuals and fertilizer manufacturers that called for more, some as often as every week (for a typical 90 day crop that's 13 reservoir changes). A nutrient solution is generally changed for two reasons. Primarily, to prevent its profile from becoming dangerously depleted or out of balance from overuse, secondly, because the grower simply wanted to change the nutrient profile in order to follow a certain stage of growth schedule even if the solution still has the better part of its life remaining.

A grower should be aware that anyone recommending a reservoir change every week without knowing the size of the reservoir and the area of growth it supports is probably playing it safe at the grower's expense for both labor and fertilizer costs (for more information on reservoir changes see this nutrient solution management article). Going on the assumption that the stage of growth recommendations produced acceptable results, the project included as many as twelve reservoir changes and as few as three (including the initial first mix) even though the size of the reservoir and the growth it supports dictate that only three changes were required. I found no difference in yields, but I did spend more time working harder and using more fertilizer than I needed to whenever more than three reservoir changes were made.

More is Better?
The second thing you'll notice about the profiles is that some are much stronger than others, with the growth stage formulas being the strongest. However, even within the same stage of growth the authors don't seem to be of the same mind. This suggests that plants produces equally well under a wide range of nutrient strengths and profiles, and that using more is not necessarily better when using less gives the same results as using more.

The nutrient profiles used during this project varied according to Mel Frank's recommendations for both moderate and strong light gardens. It was discovered that using 250ppm N during the growth stage produced no faster growth nor higher yields than using the 100ppm N found in his flowering profile (the one highlighted red in the For Flowering section below), and that the same flowering profile could also be used during the first two weeks of growth. It became apparent that using growth stage as a prerequisite for managing a cannabis crop's nutrient profile was not only overstated, but strengths and profiles were overstated as well. While this may not be the case with other hydroponically grown crops such as tomatoes, it does suggest that flowers have simpler needs than many people and fertilizer manufactures advocate. In fact, using his 100N-100P-200K-60Mg flowering profile for all stages of growth with just three reservoir changes produced the same yields as twelve reservoir changes and stronger profiles did. Doing less and using less produced the same results as doing more and using more.

Recommended Profile Target
Where the 100N-100P-200K-60Mg target profile relates to General Hydroponics Flora Series 3 part liquid fertilizer products, the same profile can be mixed without using any of the GH Grow component. If one carefully reads the labels, he'll find the Micro component actually contains more N than the Grow, and the Grow component contains nothing else that isn't already contained in the Micro and Bloom components. Substituting a little more of the Micro component to make up for the missing Grow precludes the use of the Grow component altogether.

Deviations from a given target are to be expected when using any premixed fertilizer, even 3 part products, due to the pre-determined ratio between elements contained in each part. More often than not, increasing the content of one element to match its target perfectly causes other elements to move off-target. Given flowers' apparent immunity to a wide range of profiles, small compromises from the target are of no consequence, but often annoying. The profile arrived at during the project used just the Micro and Bloom GH Flora components at a convenient 1:2 usage rate, though any comparable fertilizer product(s) could be used to reproduce the profile. It translates into the following formula...

N-P-K-Mg ppm	ml/US Gallon GH Flora	Est TDS@.7	Est Cost/ResGal
122-99-171-68	7.5M-15B-0G	1251	$0.15

This formula has proven itself to be one that can be used for all stages of growth, under HID lighting of various intensities, and when using a variety of hydroponic systems with a reasonably good quality source water. What is most notable, however, is in the interest of efficiency, low maintenance, ease of use, fewer products to purchase, equally high yields and equally healthy plants. For expedience, that GH formula was rounded to 8M-16B-0G, which has become widely known in Internet flower circles as the Lucas formula.

About The Published Nutrient Profiles
The published profiles are shown here for those wishing to use them as a starting point for their own project. And though directly below each given set of ranges, in italics, are mixes for the General Hydroponics Flora Series brand of fertilizer, you can use the Profile Calculator below to match your brand of fertilizer with a profile. The mixes were designed to match, as closely as possible, the high end of the recommended ranges. In normal reservoir maintenance, where only plain water is added back to the solution, mixes can be made nearer the high end of the recommended ranges. This will account for the normal attrition of elements occurring over the life of the solution, and by the time the solution is ready to be replaced its content should be nearer the low end of the range.

Mixes are shown in the format ml/gal M-B-G to indicate the milliliters per US gallon for General Hydroponics Flora Micro, Bloom, and Grow components respectively (Hard Water Micro is not used here). The number accompanying each component (for example 1M-1B-1G) indicates the milliliters per US Gallon to be used for that component. Following each mix is its primary nutrient content in elemental ppm for N-P-K-Mg, as well as the metered TDSppm@.7 for the mix, and the cost per reservoir gallon for the mix.