Cost benefit analyses of using grafted watermelon transplants for Fusarium wilt disease control

Authors: TAYLOR, MERRITT - OSU, LANE, OK; Bruton, Benny; Fish, Wayne; ROBERTS, WARREN - OSU, LANE, OK

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2007
Publication Date: 2/1/2008
Citation: Taylor, M.J., Bruton, B.D., Fish, W.W., Roberts, W. 2008. Cost benefit analyses of using grafted watermelon transplants for Fusarium wilt disease control. Acta Horticulturae. 782:343-350.

Interpretive Summary: Soil-borne diseases such as Fusarium wilt continue to plague watermelon growers in intensive production areas where land resources are scarce and rotation of various crops is limited. Risk management alternatives, available to the farmer, have been reduced by the loss of soil fumigation chemicals such as methyl bromide. Fusarium wilt is generally observed in farmer’s fields during the latter stages of production when most of the costs have been incurred. In a cooperative research project between Oklahoma State University and Agricultural Research Service, the economics of grafting watermelon onto gourd rootstock for the control of Fusarium wilt was evaluated. We estimate that the cost to purchase a grafted seedling plant from a seedling supplier currently would be $ US 0.75, which would include the cost of the seed and the grafting operation. Non-grafted seedless plants cost approximately $ US 0.28 per plant. Assuming 1,500 plants per acre, grafted seedless transplants would cost approximately $ US 705 per acre more than the non-grafted plants. A more practical question facing a farmer is the potential of losing all or part of the crop after the entire costs of production have been expended. In most cases of an outbreak of Fusarium wilt, the plants begin to decline late in the production season after virtually all production costs have been spent. This is one of the conditions frequently faced by a farmer when symptoms of Fusarium wilt are observed. Determining when a farmer should consider using the more expensive grafted watermelon plants is a dynamic question given that future yields and prices are unknown at planting time. Therefore, a farmer’s production history becomes a critical decision factor along with the history of the specific field. If a farmer has consistently had high yields over several years with certain fields there is a high probability that his experience will enable him to continue to produce at a high level in the next season. Prices are less predictable but historical price “ranges” at harvest time can generally be expected. If the expected breakeven price for the farmer falls within that range there is a fairly high probability of a profitable crop.

Technical Abstract: Soil-borne diseases such as Fusarium wilt continue to plague watermelon growers in intensive production areas where land resources are scarce and rotation of various crops is limited. Risk management alternatives, available to the farmer, have been reduced by the loss of soil fumigation chemicals such as methyl bromide. Fusarium wilt is generally observed in farmer’s fields during the latter stages of production when most of the costs have been incurred. Depending on weather conditions, resistance of the cultivar, and inoculum density, disease can appear as early as the seedling stage drastically reducing survival of the plants and forcing the farmer to make risk management decisions regarding costs and returns. Research on grafted watermelon transplants at the Lane Agricultural Research and Extension Center in Lane, Oklahoma provided data for the cost benefit analyses performed in this work. Grafting of watermelon onto resistant rootstock was found to provide effective resistance to Fusarium wilt but at an increased cost of production. The resistance of these plants to several soil-borne diseases provides the farmer a viable risk management strategy and as an alternative to methyl bromide as a means of disease control.