Plant Growth Responses to Vesicular‐arbuscular Mycorrhiza

Abstract

Summary Onion and Coprosma plants were grown in a range of soils mostly containing very little available phosphate. Very large increases of shoot dry weight (up to eighteen‐fold with Coprosma and nineteen‐fold with onion) were obtained by adding phosphate. Similar increases (up to fifteen‐fold with Coprosma and twelve‐fold with onion) were obtained by mycorrhizal inoculation. The response to phosphate equalled or slightly exceeded the response to mycorrhiza, except in two soils rich in phosphate in which there was no response to either, and in one soil in which the mycorrhizal onion and Coprosma plants were twice as heavy as those given phosphate. The greatly increased growth from either treatment was associated with a large increase in the uptake of phosphorus. The probability of such growth responses, but not their size, was usually predictable in soils containing very little phosphorus soluble in CaCl2. In all soils with inoculum mycorrhizal infection was extensive. The sources of phosphorus available to mycorrhizal roots but not to non‐mycorrhizal roots differed in the various soils. In some inhibitory factors might make vesicular‐arbuscular mycorrhiza less effective in promoting the growth of the host plants.

VESICULAR‐ARBUSCULAR MYCORRHIZA IN SOME NIGERIAN SOILS AND THEIR EFFECT ON THE GROWTH OF COWPEA (VIGNA UNGUICULATA), TOMATO (LYCOPERSICON ESCULENTUM) AND MAIZE (ZEA MAYS)

“…Some plants have been observed to exhibit enhanced phosphorus uptake when inoculated with endogonaceous spores forming VA mycorrhiza (Hayman and Mosse, 1971;Baylis, 1959;Gerdemann, 1965;Ross and Harper, 1970). Most of these results were obtained from spores collected in temperate regions.…”

Managing arbuscular mycorrhizal fungi in cropping systems

“…This growth-stimulating effect, referred to as 'mycorrhizal dependency' (MD) (Gerdemann 1975), is highly variable (Sanders et al 1977) and is influenced by several factors such as plant species (Gerdemann 1968), soil fertility (Hayman and Mosse 1971), and fungal strain . From an agronomic point of view, this makes it necessary to examine the mycorrhizal dependency of plants under field conditions.…”

“…Arbuscular mycorrhizae can also provide many non-nutritional benefits to crops, including: alleviation of water (Safir et al 1971;Allen and Boosalis 1983) and salt (Ruizlozano et al 1996) stress, protection against some soil-borne pathogens (Baltruschat and Schönbeck 1972;Roncadori and Hussey 1977) and improvements to soil structure (Hamel et al 1997;Schreiner and Bethlenfalvay 1995). Since the pioneering work of Baylis (1959), Daft and Nicolson (1966), Gerdemann (1968), and Hayman and Mosse (1971), the scientific community has advocated greater use of AM fungi in agricultural practices (Gianinazzi and Schüepp 1994;Harrier and Watson 2003), particularly to reduce the use of P fertilizers, but so far this has not happened. The intensive agriculture that developed from the mid-20th century was based on new cultivars and an increased use of fertilizers and biocides.…”

“…Phosphorus is the most common nutrient that is translocated from the soil to plants through hyphae; hyphae can bridge the depletion zone that occurs around plant roots for immobile elements, such as phosphorus (Hatting et al 1973). This mechanism is particularly important for the many soil types that have low levels of bioavailable phosphorus (Hayman and Mosse 1971. Arbuscular mycorrhizae can also provide many non-nutritional benefits to crops, including: alleviation of water (Safir et al 1971;Allen and Boosalis 1983) and salt (Ruizlozano et al 1996) stress, protection against some soil-borne pathogens (Baltruschat and Schönbeck 1972;Roncadori and Hussey 1977) and improvements to soil structure (Hamel et al 1997;Schreiner and Bethlenfalvay 1995).…”

Factorial Analysis on Flooded Soil Recovery Using Soil Containing Arbuscular Mycorrhizal Fungi

“…AMF enlarges the soil volume from which nutrients can be taken up, via an extensive mycelium network, enabling host plants to access more resources. As a consequence, AMF enhances uptake of nutrients, particularly phosphorus [3], and may allow for a reduction of the amount of fertilizers applied [4]. Hence, this study attempts to manipulate the ability of AMF in facilitating nutrient uptake to recover the infertile flooded soil with the help of onion plant as a host.…”