APS Homepage

Poster: Biology & Disease Mgmt: Integrated Pest Mgmt


Response of grafted seedless watermelon to root regeneration and inoculation with Fusarium oxysporum f.sp. niveum
Q. Liu (1), X. Zhao (1), T. Sanchez (1), Z. Black (1), N. Dufault (1), Q. Liu (1) (1) University of Florida, U.S.A.

Grafting can be a successful tool in an integrated approach to manage soilborne diseases such as Fusarium wilt of watermelon caused by Fusarium oxysporum f. sp. niveum (FON). In cucurbit grafting, excision and regeneration of grafted seedling roots is often practiced by nurseries. The objectives of this greenhouse experiment were to assess the performance of grafted seedless watermelon plants under inoculation with FON, and compare grafted plants with original rootstock roots and with root regeneration. ‘Melody’ watermelon was grafted onto two squash rootstocks including ‘Marvel’ and ‘Super Shintosa’. Various plant growth parameters were measured. All the plants were plated on PDA to confirm the presence of FON colonies 32 days after transplanting. Non-grafted watermelon plants showed a significantly (P ≤ 0.05) higher percentage of recovered FON colonies (75%) compared to grafted treatments (0-8%). Plant growth measurements indicated less vigorous growth for non-grafted plants when compared to the grafted treatments. Root regeneration treatments had a numerically higher percentage of FON colonies (0-8%) compared with the regular grafting treatments (0-3%), while no differences were observed in plant growth measurements. These results showed that grafting can effectively prevent FON colonization in seedless watermelon, and supported the use of this practice as part of a watermelon production integrated management program.