Five Phytophthora isolates from avocado (Persea americana) were studied and compared with citricola phytofluoride. In cultivation, isolated avocados are very similar to P. citricola. Growth at different temperatures is also similar. The sporangia produced by these isolate products vary considerably in shape. The “typical” Phytophthorasporangia of avocado isolates is indistinguishable from that of genuine P. citricola isolates, including type culture.
They occur between the isolates of both groups, but there is a greater sporadic anomaly between the former. The sexual stage of avocado isolates appears to be almost identical to that of P. citricola, but the oogonia and oospores of avocado isolates are slightly smaller. The electrophoretic protein patterns of avocado isolates are similar to those of P. citricola.
Based on the similarities in all the characteristics studied, avocado isolate products are identified as P. citricola. Phytophthora citricola has limited pathogenicity to avocado roots, but can cause stem cancer when inoculated with wounds and cause rot in intact avocado fruit.
The effectiveness of various festyl-AI application methods in controlling Avocado strain disease, caused by Phytophthora citricola, was evaluated under greenhouse conditions. Festyl-AI was applied to the canal area as a single dye (0.4 g ai fosetyl-Al + 1.0 ml water), in combination with a sealing tree (0.4 g ai fosetyl-Al + 0.5 g Tree Seal + 0.5 ml of water) followed by a tree seal in a torn bark or bark cut in the shape of a fish (30 cm along the stem).
The use of festyl-AI as soil contaminant (3.2 g percent fosetyl-AI per liter) was also considered. The most effective method was either the use of festyl-AI: Tree seal: water formation in areas with intense drying of the stem or the application of festyl-AI only on the bark that was cut in the shape of a fish. Application of festyl-AI as soil contaminant was also effective in controlling stem cell disease, but to a lesser extent than the dye application method.
The anionic metabolite of festyl-AI in plants was quantified in the bark. Leaves and roots of processed avocado plants with high performance liquid chromatography following different application methods of fosetyl-Al. Application of festylo-AI formation: seal trees: water to areas with strongly dried stems resulted in the highest level of phosphonate residue in the cancer area. It was more effective in controlling the pathogenic strain. The phosphonate residue in the plant inhibits P. Citricola infection for about 6 months after application. There was a strong negative correlation (r = -0.978) between the phosphonate level in the bark of the stem and the size of the malignant stem caused by P. citricola. More info