Fusarium wilt of watermelon, caused by the fungal pathogen Fusarium oxysporum f. sp. niveum (FON), has been a serious threat for the watermelon production in the United States, including Georgia. We investigated the role of controlled micronutrient feeding [copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn)] on the induction of disease resistance genes (PR5, PR1, and NPR1) in watermelon against FON. Both high (2X) and low levels (0.5X) of micronutrients (X= recommended dose) were applied for 7-days in a hydroponics system. After 7-days of feeding, the plants were evaluated for the level of expression of disease resistance genes. Later, sub-set of plants were inoculated with FON and watermelon plants were reevaluated for the presence of expression of disease resistance genes. The results from this investigation indicate that micronutrient feeding for 7-days can induce disease resistance genes, (PR1, PR5 and NPR1) which are the key indicators of systemic acquired resistance (SAR).
