Health & Environmental Research Online (HERO)


Print Feedback Export to File
503531 
Journal Article 
Effect of nitrogen fertilization on the expression of slow-blasting resistance in rice 
Mukherjee, AK; Mohapatra, NK; Rao, AVS; Nayak, P 
2005 
Yes 
Journal of Agricultural Science
ISSN: 0021-8596
EISSN: 1469-5146 
143 
385-393 
English 
The development of rice blast disease in four slow-blasting (SB) genotypes was compared with that in the fast-blasting (FB) genotype Karuna, under natural field epidemics over a period of 3 years at five levels of nitrogen, in order to determine if the application of high doses of nitrogen influenced the expression of disease progress in the SB types. The treatment effects were compared through estimation of nine parameters viz. (i) lesion number (LN); (ii) area under disease progress Curve (AUDPC), (iii) relative area under disease progress Curve (RAUDPC; (iv) logistic apparent infection rate (r); (v) Gompertz apparent infection rate (k); (vi) logit line intercept (logit-a); (vii) gompit line intercept (gompit-a); (viii) time required for the disease to reach 0(.)25 severity in logistic (T-25r); and (ix) Goinpertz (T-25k) models. There was a significant increase in LN, AUDPC, RAUDPC, r and k with increased levels of nitrogen application in all genotypes, but the rate of increase in disease Was Much lower in SB genotypes than the FB one and did not lead to breakdown of severity resistance in the SB genotypes, since severity level Was Much below the economic injury level. Among the nine derived parameters for evaluation of resistance LN, AUDPC, RAUDPC, r and k were best. The AUDPC and RAUDPC had lower degrees of error variance compared with the other parameters and hence were considered superior Measures for characterization of disease progress Curves. 
disease progress; cultivars; wheat