Re: Cold weather & pests
Very interesting information. I have heard about using humic acid and
fulvic acid as a mild bio-growth stimulant, had any one else heard this/have
any info?
Chris
-----Original Message-----
From: Wim Van Loock <EYES_T@bigfoot.com>
To: pumpkins@mallorn.com <pumpkins@mallorn.com>
Date: 08 January 2001 07:33
Subject: Re: Cold weather & pests
>This is the most comprehensive article I found so far.
>It's over 10 years old, but gives a good idea of what to
>expect and what not.....
>
>Greetings from Belgium!!
>
>Wim Van Loock
>///////////////////////////////////////////////////////////////////////////
/
>///////////////////////////
>A Realistic Look at Mycorrhizae
>R. M. Augé
>UT Ornamental Horticulture
>Tennessee Flower Growers Newsletter 4(5): 2-3. 1990.
>
>Over the past few years there has been interest in using beneficial soil
>microorganisms in horticulture. This interest continues to grow, as there
is
>no doubt that certain soil fungi and bacteria can help plants scavenge
>nutrients and possible water when these elements are in short supply.
>Mycorrhizal fungi have been investigated as growth and quality enhancers on
>a number of horticultural crops. Reported benefits to plants include larger
>size and enhanced foliar quality, more profuse and earlier flowering, and
>greater resistance to disease and drought and salt stress.
>
>What are Mycorrhizal fungi?
>Mycorrhiza literally means "fungus root". The term was coined a century ago
>to describe the association of plant roots and certain fungi. This
>association is referred to as symbiotic, which means both the plant and the
>fungus benefit from the relationship.
>There are several types of mycorrhizal fungi. Orchids and plants such as
>azaleas and rhododendrons have their own particular types, but those which
>colonize most floricultural commodities are referred to as
>vesicular-arbuscular (VA) fungi (which are the kind described in this
>article).
>Mycorrhizal fungi have been colonizing the root systems of plants
>essentially ever since plants have grown on land. The fungus extends from
>the root like tiny pipes into the soil or potting medium, greatly enhancing
>the absorptive surface area of root systems. Because of the use of
>fungicides, high rates of fertilization and pasteurized, soilless,
>"fungus-less" media, many of our important greenhouse crops do not have the
>opportunity to form this symbiotic association in the greenhouse.
Scientists
>are now studying the effects of reintroducing this beneficial soil organism
>to greenhouse cropping situations. Reports range from lukewarm to
fantastic.
>
>Plant benefits
>What is the "mycorrhizal advantage" to a plant? The most consistent and
>dramatic improvement in host plant growth results from the ability of the
>fungus to increase phosphorus uptake. This effect is most conspicuous in
>situations where the soil phosphorus level is low enough to limit growth.
>Increases in growth on the order of five-to-10-and even 40-fold are
possible
>in these situations.
> Specific studies using mycorrhizal fungi found:
> In greenhouse trials, heliotrope and fuchsia inoculated with
>mycorrhizal fungi produced more flowers and bloomed earlier than
>non-inoculated plants. Inoculated unrooted cuttings of chrysanthemum,
>fuchsia and benjamin fig produced more roots that noninoculated cuttings.
> Inoculation of poinsettia cuttings in the mist bed increased
cutting
>survival, leaf retention and subsequent plant growth. In another study,
>mycorrhizal fungi slightly reduced the incidence of Pythium root rot in
>poinsettia.
> Growth has been increased by mycorrhizal symbiosis in several
>studies. Examples include the following: Easter lily, marigold, geranium,
>bell pepper, rose, petunias and chrysanthemum.
> 'Samantha' rose plants inoculated with mycorrhizal fungi were more
>resistant to drought that noninoculated plants. Plants appeared to maximize
>soil water extraction and harden to drought more effectively when their
>roots were colonized by mycorrhizal fungi. Leaf conductance (a measure of
>stomatal openness and thus of a plant's ability to photosynthesize) was
>about twice as great during drought in those roses colonized by the
>mycorrhizal fungus Glomus intraradices. Leaf water potential (a measure of
>plant water stress) also indicated this fungus was helping the plant during
>drought.
>In most (but not all) cases, these benefits are the result of improved
plant
>nutrition; mycorrhizal plants performed much better when compared with
>undernourished nonmycorrhizal plants.
>
>Free benefits?
>Mycorrhizal fungi do come with a price tag, though it is usually not a
large
>one. In exchange for possible positive effects on host plant growth, the
>fungus takes from the plant the carbon compounds (food) it requires. It has
>been estimated that approximately 10 to 25 percent of the carbohydrates
made
>by the plant's foliage ultimately wind up nourishing the mycorrhizae. In
>some instances, particularly during the fungal establishment phase in young
>seedlings or cuttings, growth of mycorrhizal plants may lag slightly behind
>that of plants which do not have to "feed" a fungal partner. This reduction
>of growth by mycorrhizal fungi does not always occur, however, and is
>usually short-lived when it does occur. Growth of mycorrhizal plants in
>phosphorus-deficient media typically rapidly matches and then usually
>greatly exceeds that of nonmycorrhizal plants.
>
>Should I use them?
>Would a grower notice an effect from using mycorrhizal fungi? If you were
>late in watering, it's possible that those plants with mycorrhizae might
not
>wilt as soon. Definitely, if phosphorus levels in your medium became
>deficient for any length of time, the mycorrhizal plants would fare much
>better. Since these "ifs" seldom occur in a well-managed greenhouse, it
>would probably not be worth the effort to most growers at this time to
>inoculate plants.
>Would a consumer realize any extra benefit from possessing a mycorrhizal
>product? Maybe. During shipping and marketing, most plants do not receive
>the ideal conditions they received in the greenhouse. Under stress, a
>mycorrhizal product is likely to outperform its nonmycorrhizal counterpart
>and will often look better longer when fertilization and regular water
>cease. However, as many of our greenhouse crops are annuals, this
>competitive "mycorrhizal edge" may not become evident in a single season.
>
>How to inoculate?
>Ease in application is of course important to growers. Because mycorrhizal
>fungi are alive, there is a bit more involved than simply adding it to the
>medium at potting time, but not much more. We are pretty much in the
>"grow-your-own" phase right now with mycorrhizal fungi. However, a Utah
firm
>(NPI Nutri-link, 417 Wakara Way, Salt Lake City, Utah 84108) markets a
>commercially available inoculum (a batch of mycorrhizal fungi propagules
>which gets the symbiosis going). This inoculum can simply be measured out
>and worked into a potting mix. Thus, it is easy to inoculate plants at
>seeding. At transplanting, the fungus moves into the new container or plug
>along with the colonized roots. Those conditions which promote good root
>growth generally encourage growth of the mycorrhizal fungi, with the
>exception of phosphorus fertilization. For many, if not most crops, the
>amount of phosphorus applied to plants must be limited to about one-third
to
>one-tenth of that normally applied. Higher rates of phosphorus often
>discourage colonization of the fungi.
>
>Future use
>Is it likely that growers of the future will realize significant economic
>benefits from these fungi? There is probably no compelling reason for the
>greenhouse manager of today to worry about mycorrhizal symbiosis, but as
our
>resources diminish in the future and the costs of fertilizers escalate, it
>is likely that these soil fungi will prove to be of economic advantage. An
>additional consideration may be environmental quality. As restrictions
>tighten concerning the contamination of runoff water, for instance, a soil
>amendment which allows growers to apply less fertilizer would result in
>cleaner leachate. Even right now, though, to a grower who is concerned
about
>survival and quality of his/her product after it leaves the greenhouse,
>mycorrhizal fungi might give a competitive edge to some plants.
>More research is required, but the indications are that certain mycorrhizal
>fungi can assist plants growing under saline conditions. The amount of salt
>a plant can tolerate is limited, and mycorrhizal fungi may extend somewhat
>the range a plant can endure. As water quality becomes more an more of a
>concern to growers, both because clean water is getting harder to find and
>because we are becoming increasingly aware of the effects our irrigation
>water has on our crops, growers may begin to use this benefit of
mycorrhizal
>symbiosis.
>
>In summary
>Many benefits of mycorrhizal symbiosis in horticultural production systems
>have been suggested and researched: reduced time to flowering, enhanced
>rooting of cuttings, resistance to water and salt stress, resilience to
>heavy metal and other pollutant toxicity, reduction of transplant shock and
>incidence of disease. Yet a real, calculable, economic advantage remains
>elusive, especially when plants are pampered as they are in most
>greenhouses.
>The future, though, may likely see a typical grower incorporating a
>mycorrhizal inoculum into greenhouse media. As is becomes increasingly
vital
>that production be both in equilibrium with our resources and
>environmentally compatible, mycorrhizal fungi may very well find
significant
>roles. For now, at least, they continue to be an interesting and hopeful
>target of horticultural research.
>
>
> \\ -- //
> ( @ @ )
> ----oOOo--(_)--oOOo---------
>----- Oorspronkelijk bericht -----
>Van: "andy wolf" <farm@eznet.net>
>Aan: <pumpkins@mallorn.com>
>Verzonden: maandag 8 januari 2001 5:40
>Onderwerp: Re: Cold weather & pests
>
>
>> well, I'll add what I can. I tried it this past season, and wasn't
>> overwhelmed with results. Could have been many things, such as the
>weather,
>> genetics, soil, ect... I'm waiting to hear from a few other growers out
>> there I know have tried it, maybe we can figure some things out. I'm
>> planning on trying it again next season on only one plant, just to see
>what
>> happens again. Word of caution, if you want the good stuff, it's
>expensive.
>> Most should stick with the everyday good gardening practices until we see
>> significant results from this stuff. I did do a lot of research on this
>> mycorrhizal fungi on the internet before buying, and it's possibilities
>are
>> impressive, but not tested on competition AG's extensively enough by us.
>If
>> you want to check it out, here are some links:
>>
>> http://mycorrhiza.ag.utk.edu/
>> http://dmsylvia.ifas.ufl.edu/
>> http://www.cof.orst.edu/cof/teach/for442/sec8/more3.htm
>> http://www.treemail.nl/eurobio/inform/mycart.htm
>> http://www.soilfoodweb.com/index.html
>>
>> These were just what i had bookmarked, I'm sure there's a lot of new ones
>> since i started looking.
>>
>> Andy Wolf
>> best: 535* uow
>> farm@eznet.net
>> http://home.eznet.net/~farm
>>
>>
>>
>>
>> -----Original Message-----
>> From: BILL J. SADOWSKI <BSADOWSKI@CompuServe.COM>
>> To: INTERNET:pumpkins@mallorn.com <pumpkins@mallorn.com>
>> Date: Sunday, January 07, 2001 10:49 PM
>> Subject: Re: Cold weather & pests
>>
>>
>> >Message text written by INTERNET:pumpkins@mallorn.com
>> >>on the subject of Endomycorrhizal fungi. Fascinating subject....<
>> >
>> >I deal with another person on another garden chat line. She is a PhD
>from
>> >Berkley University and speaks highly of the fungi.........which is a
>growth
>> >stimulant for the roots? I have some info on this, but I have to find
>it.
>> > It is something worth trying. Let me research my files.
>> >
>> >Bill Sadowski......finally hit over 30 degrees in Ohio
>> >
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>> >
>>
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>>
>
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