Aspectos biológicos e dano de Diatraea saccharalis (fabr., 1794) (Lepidoptera: Pyralidae) em sorgo cultivado sob diferentes doses de nitrogênio e potássio

Abstract

O presente trabalho teve como objetivo avaliar a influência da adubação da cultura do sorgo Sorghum bicolor (L.) Moench, na biologia da broca da cana-de-açúcar Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Pyralidae). Para isso foi utilizado sorgo da cultivar Rubi-Asgrow, plantado em vasos utilizando-se diferentes doses de fertilizantes e mantidos em casa-de-vegetação. Os tratamentos utilizados (doses de NK) foram: N1 = 0-200 ppm; N2 = 50-200 ppm; N3 = 100-200 ppm; N4 = 200-200 ppm; N5 = 400-200 ppm; K1 = 200-0 ppm; K2 = 200-50 ppm; K3 = 200-100 ppm; K4 = 200-200 ppm; e K5 = 200-400 ppm. De modo geral, pode-se concluir que doses de 50 a 200 ppm de N promoveram o desenvolvimento normal das larvas de D. saccharalis, sendo que as menores porcentagens de dano foram verificadas nas menores doses; para o potássio, quanto maior a dose, menor foi o dano causado pelas lagartas, apesar de favorecer o desenvolvimento da mesma.

Brachiaria ruziziensisResponses to Different Fertilization Doses and to the Attack ofMahanarva spectabilis(Hemiptera: Cercopidae) Nymphs and Adults

“…Nevertheless, within the density of 10 adults, injuries on the nonfertilized plants were observed (control group) in more than 68% of the leaf area (3.9 on the damage score), reducing significantly the damage verified on fertilized plants with the recommended dose, or half of this one. These results confirm those from Scanavachi et al [ 34 ] and De Bortoli et al [ 35 ], who observed higher damage when there was no fertilization in corn and sorgo, exposed to its main pests. In this study, when the plants were fertilized, the damage averages were not higher than 50% (2.7 on the damage score) ( Table 1 ).…”

Research Article ITS2 as a molecular marker for the identification of Diatraea saccharalis and D. flavipennella and possible infection with Cotesia spp.

“…D. saccharalis, D. flavipennella, D. grandiosella, and O. nubilalis are among the crambids affected by that parasitoid (Hall et al, 1991;Alleyne and Wiedenmann 2001a,b;Bortoli et al, 2005;Araújo et al, 2010). When the host is parasitized by Cotesia the host's immune system applies some defensive strategies to combat those parasitoids by humoral (production of antimicrobial peptides, reactive intermediates of oxygen and nitrogen, coagulation, or melanization) and cellular defenses (defenses mediated by hemocytes through phagocytosis, nodulation, and encapsulation) (Strand and Pech, 1995;Gillespie et al, 1997;Lowenberger, 2001;Vass and Nappi, 2001;Schmidt et al, 2001).…”

“…Diatraea saccharalis (Fabricius, 1794) and D. flavipennella (Box, 1931), most known as the little sugarcane moth borer, are widespread in the Brazilian territory, and can occur in other cultures as maize, sorghum, and rice (Hall et al, 1991;Bortoli et al, 2005;Araújo et al, 2010).…”

Interaction between N-fertilizer and water availability on borer-rot complex in sugarcane

“…Nitrogen fertilization favors infestation by several insect species because it increases the levels of soluble nitrogen, mainly as free amino acids, resulting from alterations in the quantity and quality of nitrogen present in the plant and facilitates nitrogen assimilation by insects (Bortoli et al, 2005).…”