Methods of application and dosages of insecticides forAphis gossypii(Glover) (Hemiptera: Aphididae) in the yellow melon

Abstract

Formas de aplicação e doses de inseticidas sobre Aphis gossypii(Glover) (Hemiptera: Aphididae) em melão amarelo RESUMO -Para aperfeiçoar o manejo fitossanitário de pragas na cultura do melão (Cucumis melo L.), objetivou-se avaliar os efeitos de formas de aplicação e doses de inseticidas sobre a eficiência de controle químico do pulgão A. gossypii. O experimento foi realizado em 2010, na cidade de Fortaleza, Ceará, com melão amarelo cultivado em condições de campo. O delineamento experimental foi em blocos ao acaso, arranjo fatorial 2 x 4, com quatro repetições e parcelas de seis plantas. Os tratamentos foram duas formas de aplicação (pulverização costal manual e insetigação por gotejamento) e quatro doses de inseticida (0; 50; 100; 200% da dose recomendada pelo fabricante). Os inseticidas acefato e tiametoxam, testados separadamente, foram aplicados em manejo de rotação de grupos químicos. A eficiência de controle foi avaliada sete dias após o uso de cada inseticida. O acefato não apresentou diferença significativa entre as formas de aplicação, atingindo eficiências de controle de 88,95 e 84,09% com 100 e 200% da dose recomendada, respectivamente. O tiametoxam não diferiu significativamente quanto às formas de aplicação e doses testadas, apresentando eficiência de 100% em todos os tratamentos. Atualmente, no Brasil, a utilização de acefato no melão está limitada à aplicação mecanizada devido ao risco de contaminação. Diante dessa limitação, o controle do pulgão em meloeiro amarelo pode ser realizado via insetigação por gotejo ou pulverização costal manual, devendo-se empregar, preferencialmente, 100% da dose recomendada de tiametoxam. Palavras-chave:Cucumis melo L.. Pulgão. Pulverização foliar. Quimigação.ABSTRACT -In order to perfect the phytosanitary management of pests in the melon crop (Cucumis melo L.), the aim here was to evaluate the effects of different methods of application and dosages of insecticides on the effectiveness of chemical control of the aphid A. gossypii. The experiment was carried out in 2010, in Fortaleza, in the state of Ceará, Brazil, with yellow melon grown under field conditions. The experimental design was of randomised blocks in a 2 x 4 factorial arrangement, with four replications and lots of six plants. Treatments consisted of two methods of application (manual backpack spray and drip insectigation) and four dosages of insecticide (0, 50, 100 and 200% of the dosage recommended by the manufacturer). The insecticides acephate and thiamethoxam, tested separately, were applied in a rotating management of chemical groups. Efficiency of the control was evaluated seven days after the use of each insecticide. The acephate showed no significant difference between the forms of application, reaching control efficiencies of 88.95 and 84.09% with 100 and 200% of the recommended dose respectively. The thiamethoxam did not differ significantly for the application methods and dosages under test, giving 100% efficiency in all treatments. Currently in Brazil the use of acephate in the melon is limi...

Effect of a synthetic insecticide and a botanical on pests, natural enemies and melon productivity

“…Experiments carried out to establish the effectiveness in the control of A. gossypii showed differences in the levels of control according to the insecticides sprayed. The number of A. gossypii individuals ranged from 3.17 and 47.38 aphids.leaf -1 in untreated plots of yellow melon in a field trial (Bomfim et al 2015). In that experiment, populations declined to zero individuals, seven days post-application of a commercial formulation of thiamethoxam at all doses evaluated (Bomfim et al, 2015).…”

“…The number of A. gossypii individuals ranged from 3.17 and 47.38 aphids.leaf -1 in untreated plots of yellow melon in a field trial (Bomfim et al 2015). In that experiment, populations declined to zero individuals, seven days post-application of a commercial formulation of thiamethoxam at all doses evaluated (Bomfim et al, 2015). Populations of A. gossypii decreased from 81.3 to 10.6 individuals.leaf -1 at 336 hours post-application in plots sprayed with azadirachtin on a hydroponic cucumber (Saleem et al, 2019).…”

Control of Brevicoryne brassicae (Hemiptera: Aphididae) with extracts of Agave americana var. Marginata Trel. in Brassica oleracea crops

“…The application of chemical insecticides in vegetable crops presents many problems, such as the contamination of food, water and soil (Bai et al, ; Sarwar, ). Moreover, these products are capable of eliminating entire populations of non‐target organisms (Sarwar, ) that are part of a complex and diverse agroecosystem (Balvanera et al, ; Benton, Vickery, & Wilson, ; Bomfim, Azevedo, de Araujo Viana, Manzano, & Vasconcelos, ; Rusch et al, ). Hence, the insecticides in horticulture must be used responsibly, and efforts are needed to make feasible control methods without risking the health of farmers and the environment (Bomfim et al, ; Enserink, Hines, Vignieri, Wigginton, & Yeston, ; Gangwar, Singh, Tyagi, Kumar, & Sharma, ).…”