WATER MANAGEMENT, DISEASE DEVELOPMENT, AND POTATO PRODUCTION

The increased use of high frequency, sprinkler irrigation programs, particularly those with early season requirements for maintenace of high soil moisture levels, can mean increased tuber yields and quality, and reduced incidences of common scab. However, such programs may lead to increased incidences of brown center (and hollow heart) and powdery scab. More importantly, with respect to most of the currently important diseases of potato in the United States (i.e., late blight, early blight, white mold, bacterial stem rot, early dying, bacterial ring rot), growers using such programs face serious and complicated disease management problems because of the effects of more favorable canopy and soil moisture and temperature regimes on pathogen infection, growth, reproduction, dispersal, and survival. This means that today's potato grower needs to devote attention to better integration of disease and irrigation management strategies. For example, irrigations must be carefully timed, so that water is applied only when crop demands warrant while minimizing the duration of leaf wetness. This will require use of potato crop irrigation scheduling programs based on calculations of crop evapotranspiration. Such programs will have to have their crop coefficients (17) adjusted for reductions in leaf area caused by foliar diseases so as to reduce the likelihood of applying excessive water and ending up with additional problems of haulm or tuber rot. © 1990 Springer.