Efficacy of selected chicken manure charged biochar on management of bacterial wilt (ralstonia solanacearum), growth and yield of potato (solanum tuberosum l.)

Abstract

Potato (Solanum tuherosum L.) is a vital staple crop globally but its production is highly restricted by bacterial wilt caused by Ralslonia solanacearum responsible for significant losses of yield. The aim of this study was to investigate the efficacy of chicken manure charged biochar in management of bacterial wilt and performance of potato. In vitro experiment was carried out at Biotechnology laboratory of Egerton University to determine the antibacterial activity of selected chicken manure charged biochar extracts on growth of Ralstonia solanacearum in vitro. Pot and field experiments aimed to determine the effect of selected chicken manure charged biochar on bacterial wilt incidence and severity, growth and yield of Shangi potato variety. Field experiment was conducted in Mau-Narok and Egerton, arranged in randomized complete block design (RCBD) with three replicates. The feed stocks started include: maize cobs (MC), Maize straw (MS), rice husk (RH), bean waste (BW) and eucalyptus branches (EU). Data collected for in vitro experiment was number of colony forming units from each plate while for pot and field experiments data was on disease incidence, severity, growth and yield. Data was analyzed using R software version 4.4.3, general linear model (GLM) technique was used to conduct ANOVA and means separated using Fisher’s least significant difference (LSD) test at 5%. Results revealed that all charged biochar were alkaline with maize straw charged (MSCB) highest at 10.4 while plain rice husk was acidic at 5 .4. Charged biochar exhibited higher nitrogen content with bean waste charged (BWCB) highest at 1.5% N and plain eucalyptus (EUPB) lowest at 0.4% N. Maize cobs charged biochar (MCCB) had the highest available phosphorus at 1846 mg/kg while the lowest was 671.5 mg/kg for rice husk charged biochar (RHPB). MCCB had the highest organic carbon at 74.2% while EUPB was lowest at 23.5%. Biochar extracts inhibited the growth of the pathogen by 100% for eucalyptus followed by 98% for bean waste while the least was 2.3% exhibited by plain maize stalk. The treatments reduced disease incidence and severity and the highest were EUCB followed by BWCB at 91.8% and 75.3%, respectively. EUCB increased plant height by 63.5% which was highest in pot experiment while BWCB was highest at 34.5% for in field experiment. Treatments increased yield by 64.6%, 56.7% and 51.4% for bean waste, eucalyptus and rice husk charged biochar, respectively. This study demonstrated that charged biochar has potential in control of bactenal wilt and improving potato yield