危害和病症甜菜褐斑病遍及全国各甜菜产区,是甜菜的主要病害。在甜菜生长季节多雨和气温较高的地区褐斑病发生严重,一般可使甜菜块根产量减低10—20%,含糖降低1度左右,发病严重的地区或年份,块根减产30—40%,含糖量降低2—3度。原料甜菜和采种甜菜都能感病,感病部位主要是叶片、叶柄,种球也能受到侵染。 Hazard and illness Beet leaf brown spots throughout the country each beet production areas, beet is the main disease. Occurred in rainy and high temperature beet season brown spot disease serious occurrence can generally reduce beet root yield 10-20%, reduce sugar about 1 degrees, the incidence of severe areas or years, 30-40% reduction in tuberous roots, Reduced sugar content of 2-3 degrees. Raw beets and sugar beet seed can be susceptible, the main part of the diseased leaves, petiole, bulbs can also be infected.