Tecnologia de aplicação de SfMNPV-6nd no controle da lagarta-do-cartucho

The objective of this work was to evaluate the application technology and the compatibility of the SfMNPV-6nd baculovirus with surfactants and markers in the mortality of Spodoptera frugiperda second‑instar larvae. The compatibility studies were carried out with the brilliant blue (BB) dye and copper oxychloride (CO) markers and with the polyalkylene oxide heptamethyltrisiloxane (PH) and ethoxylated alkylphenol (EA) surfactants mixed with the SfMNPV-6nd biological insecticide. Droplet dispersion was assessed by spraying a SfMNPV-6nd solution on corn plants using flat fan and hollow cone nozzles. The evaluated parameters were: spray deposits, volumetric median diameter (VMD), droplet size, pH of spray solution, and mortality of second-instar S. frugiperda larvae. The PH and EA surfactants present synergism with SfMNPV-6nd and increase S. frugiperda control. The addition of the EA and CO surfactants to the SfMNPV-6nd solution reduces pH values. Droplet density, VMD, spray deposition of the SfMNPV-6nd solution, and mortality of S. frugiperda second-instar larvae do not differ among treatments regardless of the type of nozzle used.O objetivo deste trabalho foi avaliar a tecnologia de aplicação e a compatibilidade do baculovírus SfMNPV-6nd com surfatantes e marcadores na mortalidade de larvas de segundo instar de Spodoptera frugiperda. Os estudos de compatibilidade foram realizados com os marcadores corante azul brilhante (AB) e oxicloreto de cobre (OC) e com os surfatantes heptametiltrisiloxano óxido de polialquileno (HP) e alquilfenol etoxilado (AE) misturados ao inseticida biológico SfMNPV-6nd. Avaliou-se a dispersão de gotas por meio da pulverização de solução de SfMNPV-6nd em plantas de milho, com uso de pontas de jato plano e cônico vazio. Os parâmetros avaliados foram: depósito da pulverização, diâmetro mediano volumétrico (DMV), tamanho de gotas, pH da solução e mortalidade de larvas de segundo instar de S. frugiperda. Os surfactantes HP e AE apresentam sinergismo com SfMNPV-6nd e aumentam o controle de S. frugiperda. A adição dos surfactantes AE e OC na solução de SfMNPV-6nd reduz os valores de pH. Densidade de gotas, DMV, depósitos da pulverização da solução de SfMNPV-6nd e mortalidade de larvas de segundo instar não diferem entre os tratamentos, independentemente do tipo de ponta utilizado

Initial growth of Schizolobium parahybae in Brazilian Cerrado soil under liming and mineral fertilization

ABSTRACT High prices and the scarcity of hardwoods require the use of alternative wood sources, such as the Guapuruvu (Schizolobium parahybae), an arboreal species native to the Atlantic Forest, which has fast growth and high market potential. However, there is no information on its cultivation in the Brazilian Cerrado. Thus, this study aimed to analyze the contribution of mineral fertilization and liming in a Cerrado soil on the initial growth of Schizolobium parahybae. The experiment was set in a randomized block design, with 4 treatments (Cerrado soil; soil + liming; soil + fertilizer; and soil + fertilizer + liming) and 15 replicates. The following variables were analyzed: plant height, stem diameter, number of leaves, total, shoot, leaf, root and stem dry matter, and root/shoot ratio. The obtained data were subjected to the analysis of variance, Tukey test and regression analysis. During the initial growth, Schizolobium parahybae can be cultivated in a Brazilian Cerrado soil only under mineral fertilization, with no need for soil liming