| Popis: |
The aim of the present study is to evaluate the relative disease severity of chickpea wilt in the most important chickpea growing areas in North Algeria and their relationship to soils properties. The physicochemical and biological parameters of 14 soils were analyzed and correlated to the disease index severity (Dis). Soil physicochemical factors were determined as a means of particle size distribution, pH, Electrical Conductivity (EC), CaCO3 content, total Nitrogen (Total-N), Olsen-P and biological factors including Foc inoculum density (ID-Foc), Trichoderma spp propagule number (TrPn), Pseudomonas spp and Bacillus spp. The results revealed that the spread of the disease was evident in all prospected areas and recorded as low to medium with values ranging from 2.05 to3 9.8. The disease severity was positively correlated with EC (r=0.62), Total-N (r= 0.79), and ID-Foc (r=0.72), whereas negatively correlated with Olsen-P (r=-0.67), TrPn (r=-0.70) and Pseudomonas spp (r=-0.89). There was no correlation between Dis and soil physical (clay, loam and sand), chemical (pH, CaCO3 content) and biological factors (Bacillus spp). As well, ID-Foc was positively correlated with Total-N and negatively correlated with Olsen-P. The results indicated that TrPn and Pseudomonas spp were positively correlated, whereas both were negatively associated with ID-Foc and Dis. Our finding pointed out the critical role of some physicochemical and biological soil characteristics in the epidemic development of chickpea wilt under field conditions. |
