Effect of Nitrogen Fertilization on the Productivity and Sensitivity of Two Sweet Sorghum Varieties to Pink Stem Borer (Sesamia cretica led.) Infestation

Abstract

Two field experiments were conducted at Agriculture Faculty farm of Demo (29°17 N; 30°53 E) El-Fayoum University, Egypt, during 2013 and 2014 to study the effect of three nitrogen rates, i.e. 80, 100 and 120 kg N/fed. on the damage cause by pink stem borer infestation [Sesamia cretica Lederer (Lepidoptera: Noctuidae)] under natural infestation, on stem characteristics, quality and yield traits. In addition to theoretical ethanol production of two sweet sorghum varieties (Brandes and Honey).Data obtained revealed that: Brandes variety is more tolerant to pink stem borer attack which recorded less damage sings measured in this study by many damage expressions. Moreover, Brandes exhibited better productivity traits (stalk, juice, syrup, grain, forage and ethanol yields) as well as quality traits (TSS, sucrose, reducing sugars, Total fermentable sugars and purity).The results also showed that application of the highest nitrogen rate (120 kg N/fed.) increased all borer infestation features, productivity and quality traits.The interaction between both variables markedly affected most studied traits, but in general, Brandes variety fertilized by the highest N rate exhibited the higher productivity and quality traits and the lower damage signs or to some extend characterized as moderate tolerance to pink borer infestation.