• Potential Yield Increase by Grafting for Watermelon Production in Arizona

      Kroggel, Mark; Kubota, Chieri (College of Agriculture, University of Arizona (Tucson, AZ), 2017-01)
      Grafting cucurbits onto rootstocks resistant to diseases and abiotic stresses can be a methodto overcome limited availability of effective pre-plant fumigants or land to rotate and to allowearlier planting. Commonly used rootstocks for cucurbits have resistance to Fusarium (race1&2) as well as cold tolerance, among other favorable traits like increased vigor of the scion. Grafting of cucurbits was developed in Asia primarily to allow production without rotation, because arable land is so limited. In the US, crop rotation schedules for seedless watermelon can be 3 years or longer reducing the amount of watermelon a grower can produce in a season. We have been growing grafted and non-grafted seedless watermelon on the same field/plot for 4 years, with no fumigation or off-season rotation of other crops. During the last 2 years, we planted early (March 1) to determine if grafting could overcome low night temperatures in addition to disease pressures. Treatments included grafted and non-grafted plants, covering with frost protection and non-covered. The results of the last 2 years indicate that grafted plants yielded nearly twice as much as non-grafted plants, suggesting that grafting can be a promising technology for Arizona watermelon producers.