the tenacity of a graph g, t(g), is dened by t(g) = min{[|s|+τ(g-s)]/[ω(g-s)]}, where the minimum is taken over all vertex cutsets s of g. we dene τ(g - s) to be the number of the vertices in the largest component of the graph g - s, and ω(g - s) be the number of components of g - s.in this paper a lower bound for the tenacity t(g) of a graph with genus γ(g) is obtained using the graph's...

let $r$ be a commutative ring with identity. an ideal $i$ of a ring $r$is called an annihilating ideal if there exists $rin rsetminus {0}$ such that $ir=(0)$ and an ideal $i$ of$r$ is called an essential ideal if $i$ has non-zero intersectionwith every other non-zero ideal of $r$. thesum-annihilating essential ideal graph of $r$, denoted by $mathcal{ae}_r$, isa graph whose vertex set is the set...

Abstract Insecticides applications are one of the components to control brown planthoppers pest that applied in large scale by farmers. In field, some farmers mix different active ingredients insecticides planthoppers. This study was aimed find out efficacy mixed plant hoppers and effect on natural enemies field. The research carried Pemalang Regency, Central Java, 2016/2017 rice planting seaso...

Abstract Jajar legowo (Jarwo) is a rice planting system that widely practiced by farmers, but information regarding its effects on pests and natural enemies limited. This study aimed to identify how the Jarwo affects population damage intensity of yellow stem borer ( Scirpophaga incertulas ) predators. The research was conducted in Wonosari-Klaten, Central Java, during dry season 2020. 2:1 used...