ive used it several times.
i did a papaya trail, with and without, and there was a huge difference.
but, mainly i think on soil-less media and potting soil.
In the ground there was little difference, and the difference i did see, may have been because
of the humic acid and other bacteria in the mix (Paul Stamets myco-grow)
To me, there is no question they work, but, i have read some companies
have poor quality control, and the number of colonies can be quite low.
i had done some reading, and Glomus I. and Glomus Mosseae
are 2 that work well with papaya.
i am guessing i have those in my (outdoor) soil, in large enough amounts.
My potting soil was obviously lacking these in sufficient quantities.
It should be noted, that AMF have a harder time increasing
if there are high levels of phosphorus in the soil
soils are different though.
while many soils have many types
If a species of plant that normally live in the forest, is put into a sandy soil,
those Mychorizae may not be present, because there were no indigenous plants that used them,
so, if they were ever present, they could have died out.
In that case, it certainly makes sense to spend $5 or whatever, to put them in the soil.
This is also one reason i NEVER use an anti-fungal.
One study showed that the fungi travel in the soil at about 18 inches per year
so, if you have a large area that is devoid, it can take a long time
for natural processes to work their way in.
i have also gone to a wooded area near my house
and added a few handfuls of soil from there to each plant.
i had gotten a 3-cubic ft load of soil.
When it gets loaded, moved in a truck etc...
the soil is exposed to the sun, and turned over
often killing most of the soil life.
Mixing in my own soil, and that of the local woods, i think helped a lot.
there is a ton of info online almost all ive seen, show it as a benefit.
here are a couple from my files...
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Effect of Glomus mosseae and Entrophospora colombiana on plant growth, production, and fruit quality of ‘Maradol’ papaya (Carica papaya L.)
The effect of inoculating ‘Maradol’ papaya plants with arbuscular mycorrhizal fungi (AMF) Glomus mosseae (GM) and Entrophospora colombiana (EC) was assessed. The results showed that both mycorrhizae species increased the number of fruits and yield in papaya plants by 41.9 and 105.2% for GM and 22.1 and 44.1% for EC, respectively, with respect to control plants. GM significantly increased plant height. Sugar content, firmness, color (°Hue), and ripening process of mycorrhized plant fruits were similar to those of the control. Weight loss of mycorrhized plant fruits was considerably less than that of the control. Inoculation of papaya with AMF is recommended, particularly with GM since it increases yield, and fruit weight (45.1%), furthermore, it reduced fruit weight loss during ripening.
http://www.sciencedirect.com/science/article/pii/S030442381100046X---------------
Arbuscular mycorrhizal fungi benefit mango (Mangifera indica L.) plant growth in the field
Abstract
The rhizospheres of three year old-mango (Mangifera indica L.) rootstocks namely, Vellakulamban, Bappakai, Olour, Chandrakaran, Necker, Peach, Totapuri and Vellakulamban were studied for the spore load of arbuscular mycorrhizal (AM) fungi and root colonization at 15 cm, and 30 cm depths. Mycorrhizal spores were highest in Totapuri followed by Bappakai, Olour and Peach and Vellakulamban at 15 cm depth. Spores belonged to the genera Glomus and Acaulospora and few other genera, the predominant ones being Glomus fasciculatum and Glomus mosseae as identified by their morphology. The colonization of the root was higher in Vellakullamban and Totapuri rootstocks. Frequently occurring AM species were initially multiplied on finger millet (Eleucine coracona L.) in paper cups filled with soilrite and then in 12 in. pots that contained 1:1 sand soil mixture. The rootstock cultivars predominantly used for grafting mango scions in southern India were screened for their response to AM inoculation in pot culture. All the rootstock seedlings responded to mycorrhizal inoculations showed varied intensity of root colonization and improved plant height, growth and nutrient content compared to non-mycorrhizal in pot culture. Under field conditions, rootstock cv Totapuri inoculated with AM fungi and scions of mango hybrids Arka Aruna and Arka Puneeth grafted on them produced shoots earlier compared to non-mycorrhizal plants. Within two years of application of AM fungi yearly, clear difference in growth performance of mycorrhizal and nonmycorrhizal plants was observed. Plant growth studied in terms of number of branches, available soil P, leaf P, Zn and Cu improved significantly in AM colonized plants compared to uninoculated plants. This trend continued in the 8th year of sampling. The root acid and alkaline phosphatase activity was higher in six month old Arka Puneeth grafted on AM colonized Totapuri rootstock. Mycorrhizal inoculums can be easily multiplied on-farm on finger millet and applied yearly for desired results.
http://www.sciencedirect.com/science/article/pii/S0304423812002610African farmers are increasingly adopting sustainable agricultural practices including use of native shrub
intercropping approaches. In one village of Sénégal (near Thiès) it was reported that farmers planted
mango (Mangifera indica) seedlings within the canopies of a native shrub (Piliostigma reticulatum).
Anecdotal information and qualitative observations suggested that the presence of P. reticulatum
promoted soil quality and a competitive advantage for establishing mango plantations. We hypothesized
that soil chemical and microbial properties of mango rhizosphere soil growing in the presence of P.
reticulatum would be significantly improved over soils associated with mango growing outside the
influence of P. reticulatum. The results showed that mango-shrub interplanting significantly lowered pH,
and increased arbuscular mycorrhizal fungi (AMF) colonization of mango roots, enzyme activities, and
microbial biomass compared to mango alone. Phylogenetic analyses by PCR-denaturing gradient gel
electrophoresis (DGGE) showed that community structures of fungi, bacteria, and bacterial genes
responsible for denitrification (nirK) of the soil from the rooting zone of the mango-shrub intercropping
system were distinct from all other soil outside the influence of P. reticulatum. It is concluded that P.
reticulatum enhances soil biological functioning and that there is a synergistic effect of intercropping
mango with the native shrub, P. reticulatum, in soil quality with a more diverse community, greater AMF
infection rates, and greater potential to perform decomposition and mineralize nutrients
http://static1.squarespace.com/static/524fa55ee4b04b668ead159f/t/5509b1b8e4b02b7f525300ea/1426698680186/Hernandez+et+al.+2015+AE%26E+Mango+Shrub.pdf