اثر خاک‌ورزی حفاظتی بر عملکرد محصول و شدت بیماری جرب باکتریایی سیب زمینی

Conservation tillage, unlike the plowing with a moldboard plow (conventional method) reduces soil erosion, it is feared that in the early years it will reduce crop yield and increase plant diseases. Common scab (Streptomyces scabies) is a severe disease of the potato, which can seriously reduce the commercial value of tuber. In order to study the effect of different tillage methods on potato yield and the severity of infection of the common scab disease of potato in three years of experiment. An experiment was conducted in the form of a strip plot statistical design based on completely randomized blocks with three replications, where the horizontal factor includes tillage methods: plowing with a moldboard plow (conventional method in Shahrood region), reduced tillage with a pen plow, plowing with a disc plow and reduced tillage with a chisel packer, and the vertical factor included two treatments: collection and preservation of plant residues. Scale of James was used to the severity of tuber contamination. The results showed that the effect of tillage methods on crop yield was not constant in three years of experiment. So that in the first year, the highest yield of potatoes related to conventional tillage method. However, in the third year of the experiment, the highest yield of potatoes was related to the reduced tillage method with a chisel packer. The effect of tillage methods on common scab disease was obtained in such a way that the lowest severity of the disease was for pen plow 10/8,% respectively, chisel packer was 10/13 %, disc plow was 11/13 % and moldboard plow was 12/4 %. Common scab severity was not significant in the treatment of preservation and collection of plant residues. According to the results of reduced tillage compared to the conventional tillage method, not only did it not reduce the yield of the crop and increase the common scab disease of potatoes, but it also caused a decrease in the field traffic, operation time and fuel consumption. Therefore, it is suggested that the reduced tillage with a chisel packer replaces the conventional tillage with a moldboard plow