土壤添加物AR3- 2S防治菜豆白絹病的效果

Abstract

以AR3- 2土壤添加物為基礎，菜豆施肥推荐量為依据，合成一 AR3- 2S土壤添加物(組成分重量比為牛糞堆肥：米糠：蟹殼粉：尿素：過磷酸鈣：氯化鉀：矽酸爐渣＝10: 20: 10: 6: 20: 4: 30)作為防治菜豆白絹病之用，並比較兩者與氰氮化鈣(烏肥，Calcium cyanamide)之防病效果。於台中縣新社鄉之菜豆栽培田進行小區域(1×4公尺/區)防病試驗，試區採逢機區集設計，於菜豆植前二星期，每分地土壤分別處理200公斤AR3- 2、AR3- 2S及25公斤氰氮化鈣，並以不施用任何添加物者為對照組。試驗結果顯示，無論作覆蓋處理與否，施用三種添加物皆可明顯降低單位土壤中的菌核數目及減少病害的發生。於大面積(10×4公尺/區)進行田間試驗之結果亦證明AR3- 2S可有效防治菜豆白絹病。於農試所罹病菜豆試驗田測試土壤添加物AR3- 2S處理植穴之防治效果，結果顯示添加物可有效降低土壤中的菌核數目，並抑制白絹病的再發生。 The effect of a soil amendment (AR3-2S) treatment on the control of snap bean southern blight caused by Sclerotium rolfsii was assessed. The AR3-2S amendment was modified from a previously described AR3-2 amendment designed for the control of lily southern blight. The content of AR3-2S amendment includes 10 % (W/W) of cattle manure, 20 % of rice chaff, 10 % of crab shell meal, 6 % of urea, 20 % of calcium superphosphate, 4 % of potassium chloride, and 30 % of mineral ash. During field trials, the effect of AR3-2S was evaluated together with AR3-2 amendment and calcium cyanamide treatment. Two weeks before sowing snap bean seeds, 2000 kg/ha of amendments but only 250 kg/ha of calcium cyanamide were machinely mixed into natural infested soils. Each treatment was further divided into mulching and nonmulching for two weeks and the results showed that all treatments not only increased the sclerotial mortality but also significantly reduced the disease incidence of southern blight in either with mulching or nonmulching treatments. In the following large-scale field trials, amendment AR3-2S consistently showed its potential in the suppressing of southern blight both in seedling and mature stages of snap bean. Furthermore, AR3-2S could also be applied in treating the infested soil of a previous diseased plant by 20 g per sowing hole, 10 days before seeding another fresh snap beans, and obtained significant control effect on reducing the number of sclerotia and suppressing disease incidence.