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henry_kuska

mulch for blackspot supression

henry_kuska
10 years ago

There has been a recent thread with a subthread about mulch for blackspot prevention.
http://forums2.gardenweb.com/forums/load/roses/msg0510234627929.html?84
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Manure was reported as being useful in depressing blackspot.

This thread is being open to alert the readers that manure may help suppress blackspot by another mechanism than discussed in that thread. There are friendly fungi that compete with the blackspot fungi. It appears that a manure mulch encourages the growth of these friendly fungi.

"Trichoderma as a potent fungal biocontrol agent against
a range of plant pathogens has attracted considerable
scientific attention (e.g., Tewari and Mukhopadhyay,
2001; Rini and Sulochana, 2007). Different organic
media like neem cake, coir pith, farmyard manure, and
decomposed coffee pulp also have been suggested for
its multiplication (Saju et al., 2002)."

http://www.jtropag.in/index.php/ojs/article/viewFile/291/182
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Background friendly fungi article:

Title: "Influence of phylloplane colonizing biocontrol agents on the black spot of rose caused by Diplocarpon rosae"

Published in: Journal of Plant Interactions, Volume 2, Issue 4, pages 225-231, (2007)

Authors: Muthusamy Karthikeyana*, Ramanujam Bhaskarana, Subramanian Mathiyazhagana & Rethinasamy Velazhahana


Abstract: "An attempt was made to study the biocontrol efficacy of antagonistic microorganisms in phylloplane of rose cv. Edward to manage the black spot (Diplocarpon rosae) disease. Eight antagonistic microorganisms were tested in vivo against the black spot pathogen. Among these, Trichoderma viride and Pseudomonas fluorescens pf1 reduces the mycelial growth significantly. These two biocontrol agents were evaluated for their ability to induce defense-related enzymes and chemicals in plants. Increased activity of phenylalanine ammonia lyase (PAL), peroxidase (PO), polyphenoloxidase (PPO) and total phenolics were recorded in all the biocontrol agents treated leaves. P. fluorescens Pf1 recorded early and increased synthesis of the entire defense-related enzymes and total phenol within 6 days. The application of biocontrol agents induced the defense-related enzymes involved in phenyl propanoid pathway in addition to direct antagonism, which collectively contribute for enhanced resistance against invasion of Diplocarpon rosae in rose."

Here is a link that might be useful: link for manure encourages friendly fungi scientific article

Comments (4)

  • roseseek
    10 years ago

    Thanks Henry. A deep horse manure mulch works wonders. I had nearly no diseases in the old Newhall garden, even with copious overhead watering, as long as I maintained deep horse manure mulches. That stuff conditioned the soil so water actually penetrated into it, rather than running off it as is normal for our "soils".

    Horse manure has also been used to help fight off Oak Root Fungus outbreaks here. Once it's started, there is little you can do to save affected plants. Generous use of horse manure as a mulch around plants which have been attacked by the fungus helps keep the plants from dying off as quickly and actually seem to recover. Whatever that action is, horse manure is worth the effort to get it! Kim

  • KarenPA_6b
    10 years ago

    Is fresh horse manure ok to use as mulch around the roses? Does it have to be composted?

  • roseseek
    10 years ago

    I won't presume to advise that in every climate, soil and situation it makes little difference. I will state that in my zones 9 and 10 gardens, the main difference fresh over composted made was temporary chlorosis and some vegetative centers. Both of which rather quickly dissipated. I watered copiously prior to applying the manure. I kept it just under the drip zone (away from the shanks, trunks and crowns of the plants) and over the rest of the entire surface of the beds. I watered copiously afterwards. The drainage was good in most of that garden, with a few spots where the soil was a bit too "loving". With that heat, two to three inches of horse manure, kept regularly moist with overhead, oscillating sprinklers, became a thin layer of earthworm castings like material in three months. There were spots I had to make the original planting holes with a large power auger. After keeping it mulched with horse manure for a summer, I could sink my shovel in to the handle digging holes. Soil which initially resisted water (it rolled right off) became easy to water. It just soaked right in.

    I witnessed others attempting to duplicate those efforts along the coast where the temps were many degrees lower and the humidity many percentage points higher. Kept regularly wet, it didn't "digest" as it did in the valley heat. I had no mushrooms or other fungal fruiting bodies. In the "Perma Fog", there were many mushrooms and the manure took months longer to disappear. A much thinner layer performed much better in those conditions. Kim

  • susan4952
    10 years ago

    A frosting of well rotted manure is in my clean up, prune routine. If it is too thick it forms a crust that may keep water and food away from the rose. I try to form a berm so spring rain will wash it into the drip line. It keeps weeds down. Eventually , when broken down, I cover it with decorative bark chips. My roses love this. I do not have a huge BS problem. Next year I plan to mix Dr. earth in the manure application. This sounds so yummy. C :

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