First report of wilt and necrosis caused by Diplodia seriata on cowpea in Tennessee, USA

Molecular identification was performed with genomic DNA (Extract-N-Amp“ Kit, Sigma-Aldrich, USA) of fungal mycelia, PCR amplification of internal transcribed spacer (ITS) regions with primers ITS1 and ITS4 (White et al., 1990), followed by amplicon sequencing. Inoculated and control plants (n = 10, sprayed with sterile water) were individually covered with clear plastic bags for four days, after which they were uncovered and incubated in a growth chamber for three weeks at 25°C. Leaf discolouration and wilting were evident in all inoculated plants in the first trial after one week, and in eight of ten plants in the second trial. Figure 5 Diplodia seriata infects a wide range of woody plant species with varying severity (Díaz et al., 2019; Elena et al., 2015; Phillips et al., 2013) and in the case of cowpea, the pathogen can affect both leaf and stem tissue causing wilt, discolouration, and significant leaf loss.