The Eum tree (Pistachios racemosa) is an exotic species that has been widely cultivated for its essential oil. It has also been naturalized in Benin and some Pacific islands, and is considered a potentially invasive plant due to its ability to suffocate vines and other plants with dense crowns. The presence of this tree could limit crop production and impose additional costs to wine growers in these regions. It has been recommended as an ornamental in Florida and has a potential for intentionally introduction to other countries because of its high value as an essential oil source.
The sensitivity of vineyard pruning wounds to infection by the fungal pathogen Eutypa lata was evaluated. A simple method for detection of Eutypa lata DNA in grapevine wood was developed using nested multiplex polymerase chain reaction. This procedure was compared with other detection methods, and proved to be the most accurate. The results showed that the detection of Eutypa lata DNA by nested PCR is possible and that it allows a reliable identification of the fungus in grapevine wood samples.
Two-year own-rooted Vitis vinifera L. cv. Ecolly grapevines were planted in Lou soil (Eum-Orthic Anthrosol in FAO soil taxonomy) in the College of Enology at Northwest A & F University, Palmerston North, New Zealand. The plantations were sprayed every week with either fungicide (Daconil or thiophanate-methyl), or the fungus-inhibiting microbes Agrobacterium rhizogenes and Bacillus pumilus. All treatments were able to significantly reduce the incidence of silverleaf disease.
Agrobacterium rhizogenes significantly reduced the severity of disease in the plants. The fungus-inhibiting microbes also reduced the severity of disease to some extent, but not to the same degree as Agrobacterium rhizogenes.
Mycorrhizal grapevines displayed higher chlorophyll a content than non-mycorrhizal plants under drought stress and in well-watered conditions. The differences in chlorophyll a content were attributed to improved photosynthesis capacity and gas-exchange performance of the mycorrhizal grapevines.
Rhizoremediation of petroleum hydrocarbons in soils depends on a complex interaction among plants, bacteria, and fungi. The effectiveness of different vegetation types for this purpose varies, with trees being used more often than grasses to remediate BTEX and PAHs, while grasses are more commonly employed for the remediation of total petroleum hydrocarbons. The study reviewed the literature on this topic and found that the rooting depth of trees provides a greater potential for the absorption of soluble hydrocarbons than that of grasses.