Soil amendment with raw rice hull as a source of silicon in enhancing anthracnose disease resistance, plant growth and fruit qualities of chili pepper (Capsicum annuum L.)

Abstract

This study was conducted to investigate the effect of soil incorporation of raw rice hull (RRH) as a source of silicon on plant growth, yield and anthracnose disease development of Capsicum annuum L. ‘Muria F1’. Experiment was conducted using five different ratios of RRH:soil:sand (T₁-3:2:0, T₂-3:0:2, T₃-3:1:1, T₄-2:3:0, T₅-1:1:3) in the first 5 treatments and applying potassium silicate (PS) as a Si source at the rate of 75 mg/L to the soil replacing RRH in the 6^th (positive control). The plants grown in soil medium with no addition of a silicon source were used as the negative control. All treatments were arranged in a completely randomized design with 4 replicates. Anthracnose disease development was assessed as number of days for the appearance of symptoms and the mean lesion areas by challenge inoculation with Colletotrichum gloeosporioides on fruits. The highest reduction of disease severity (61%) was observed in crops grown in soils amended with RRH (T₁) compared to control plants. The disease reduction observed in fruits from plants provided with potassium silicate was only about 15%, compared to that of Si-free plants. It was concluded that incorporation of rice hull (60% of the media) in the growing substrate would be an effective solution against anthracnose disease of chili pepper plants.  

Keywords. Capsicum annuum, silicon, rice hull, soil amendment