Time of arrival during plant disease progression and humidity additively influence <i>Salmonella enterica</i> colonization of lettuce

Bacterial leaf spot of lettuce caused by <i>Xanthomonas hortorum</i> pv. vitians is a common threat to leafy green production. The global impact caused by phytopathogens, including <i>X</i>. <i>vitians</i>, is likely to increase with climate change. We found that even under a scenario where increased humidity did not enhance plant disease, high humidity had a substantial effect on facilitating <i>Salmonella enterica</i> growth on <i>Xanthomonas</i>-infected plants. High humidity climates may directly contribute to the survival of human enteric pathogens in crop fields or indirectly affect bacterial survival via changes to the phyllosphere brought on by phytopathogen disease.