Interaction between Pratylenchus sp. and Fusarium solani, causes of yellow leaf and root rot disease of citrus (Citrus reticulata Blanco cv. Hong)

Interaction between the plant parasitic nematode Pratylenchus sp. and the fungus Fusarium solani, causing yellow leaf and root rot disease on Hong mandarin was investigated under net house conditions, from July to September 2020 at the
Department of Plant Protection, Faculty of Agriculture, Can Tho University. The experiment was arranged in a completely randomized design with two factors: (P) densities of Pratylenchus sp. (0, 1, 2, 5 individuals/g soil); (F) densities of F. solani (0, 10³, 10⁶ spores/g soil). Fungal and nematode inoculation were performed at thirty days after planting, by applying inoculum suspensions to the potting medium, around the root zone. Experimental results evaluated at the time of 20, 30 and 40 days after inoculation by recording an average increase in plant height in 10 days in the treatment of 10³ fungal spores/g soil combined with nematode density of 2 individuals/g of soil (F3P2) was significantly lower than treatments only applied with 10³ fungal spores/g of soil (F3) or 2 nematodes/g of soil (P2) and the total height increase after 60 days were 50.58% (F3P2), 0.58% (F3), 4.98% (P2), respectively, lower compared with the uninoculated control (8.64 cm). This result shows that there is an interaction between Pratylenchus sp. and F. solani, when the nematodes present in rhizosphere leading disease severity of yellow leaf and root rot on Hong mandarin were more severe.
Keywords: citrus, Hong mandarin, Fusarium solani, Pratylenchus sp., soilborne disease.