Effect of the herbicide MCPA on VA mycorrhizal infection and growth of Pisum sativum

Abstract

The effect of the hormonal herbicide MCPA on VA mycorrhizal infection and on pea plant growth was examined. Plant growth was decreased by MCPA applied at the rate of 120 ppm. The VA infections of pea roots inoculated with G. mosseae was decreased by the MCPA when applied at high dosis (120 ppm), but those of indigenous endophytes were decreased at the rate of 12 and 120 ppm. MCPA applied to VA inoculated pots eight weeks before pea planting also decreased the VA infection of these plants. These results suggest that VA mycorrhizas was affected not only through the plant but also directly by the application of the herbicide. Glomus mosseae may help plants recover from the deleterious effect of MCPA when applied at intermediary (12 ppm) but not at high dosis (120 ppm).

Receptivity of various wheat cultivars to infection by VA-mycorrhizal fungi as influenced by inoculum potential and the relation of VAM-effectiveness to succinic dehydrogenase activity of the mycelium in the roots

“…As all cultivars tested showed the characteristic morphological structures of VAM, the nonreceptivity of Negrillo and Champlein does not seem to be a cultivar-specific feature, but rather appears to be dependent on the form of inoculation or the amount of inoculum. The amount of VAM-fungus inoculum in the soil can determine the efficiency of the fungus (Adelman and Morton, 1986;Garcia-Romera and Ocampo, 1988;Haas and Krikum, 1985). The different receptivities seen in the two experiments might also be due to increased inoculum, but the effect of consecutive inoculation can not be discarded.…”

Differences in Mycorrhizal Colonization of Rye (Secale cereale L.) Grown in Conventional or Organic (Biological‐dynamic) Farming Systems

“…It is well known that infection with VA mycorrhizal fungi can be beneficial to the host plant, especially under conditions of low P availability (HARLEY and SMITH 1983). The application of fertilizers (KRUCREL-MANN 1975, JENSEN andJAKOBSEN 1980) and herbicides LEIHNER 1984, GAR-ciA-RoMERA andOCAMPO 1988), the duration of the fallow period (THOMPSON 1987) and host/ non-host plant interactions (OCAMPO et al 1980) all influence the number and viability of infective propagules in arable soils.…”

Soil Fungi-Plant Interaction

“…Phosphorus influxes into mycorrhizal roots are quickly reduced after the application of systemic fungicides (Hale & Sanders, 1982), such as benomyl [methyl 1-(btylcarbamoyl)-2-benzimidazole carbamate]. According to the literature, alterations induced by fungicides on the health and physiology of plants have significant effects on symbionts (Garcia-Romera & Ocampo, 1988;Schwab et al, 1982). The response of mycorrhizal fungi to chemical treatments can be influenced by the different species of host plants, the variety of compounds used, their modes of action, different application methods and rates, the growth phases of mycorrhizal fungi, environmental conditions (Giovannetti et al, 2006;Jalali & Domsch, 1975).…”