Abstract

                                The effects of three doses (0, 60 and 100 kg N/ha) of Nitrogen in the form of Uras and four plant spacings on the bacterial leaf blight (Xanthomonas campestris PV. oryzae) severity of five rice varieties/mutants (BR 4, Nizersail, Mut NS 1, Mut NS 2 and Mut NS 3) were determined under natural field conditions at the Institute of Nuclear Agricultural farm, Mymensingh during cropping season of 1982. The results indicated that there was no significant increase of bacterial leaf blight severity at all doses of nitrogen used. Closest plant spacing showed significant increase of disease severity than wider plant spacings. The interaction effect of the nitrogen doses applied and plant spacing was significant. The variety BR 4 showed significantly lowest disease severity followed by mutant NS 5, NS 2, NS 1 and Nizersail.

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