Concentração eficiente e econômica de caulim para a proteção de algodoeiro contra o bicudo

Abstract

Resumo:O objetivo deste trabalho foi determinar a concentração de caulim mais eficiente e econômica para a proteção de algodoeiro contra os danos causados pelo bicudo-do-algodoeiro (Anthonomus grandis). Utilizou-se o delineamento experimental de blocos ao acaso, com cinco tratamentos de pulverizações com caulim nas concentrações: 20, 40, 60, 80 e 100 g L-1. Determinaram-se os seguintes parâmetros: percentagem de botões florais com orifícios de oviposição por fêmeas do bicudo; resíduos de caulim depositados sobre as folhas e as brácteas do algodoeiro; média da produção; e receita líquida do algodão, por hectare, a partir da pesagem da pluma de algodão com caroço. As percentagens de botões florais com orifício de oviposição variaram de 13,6 a 30,8%; o resíduo médio de caulim depositado nas folhas, de 0,0010 a 0,0034 mg mm-2, e nas brácteas, de 0,0010 a 0,0034 mg mm-2; a produção variou de 348,1 a 717,8 kg ha-1; e a receita líquida de algodão de R$ 1.033,88 a R$ 2.098,86 por hectare. As concentrações de caulim mais eficientes para a proteção de algodoeiro contra o bicudo são as de 60, 80 e 100 g L-1; no entanto, a de 60 g L-1foi a mais econômica.

Influence of Mineral Particle Films and Biomaterials on Guava Fruits and Implications for the Oviposition of Anastrepha obliqua (Macquart) (Diptera: Tephritidae)

“…These results corroborate those of studies on kaolin applications that inhibited the oviposition of C. capitata in apples [ 54 ] and citrus fruits [ 31 ] at a concentration of 30 g L −1 in the laboratory and with those conducted in citrus orchards [ 32 , 65 ] and apples [ 66 ] sprayed with 50 g L −1 Surround ® kaolin. However, the increase in the number of treatments with fewer postures of A. obliqua , both for mineral particles and for biomaterials in the fruits treated at a concentration of 200 g L −1 can be attributed to the uniform coating of the fruits provided by the higher concentration of these products [ 67 ].…”

Survival, development and reproduction of Phenacoccus solenopsis (Hemiptera: Pseudococcidae) on kaolin-treated cotton

“…New insecticide formulations have been developed with effective physicochemical properties against P. solenopsis including natural products with potential to substitute conventional chemical insecticides (Silva and Ramalho, 2013;Silva and Silva, 2015). These products need to be biodegradable and selective, characteristics largely found in plant extracts or in minerals.…”

Spatial and temporal distribution of cotton squares and small cotton bolls fallen on ground after damage by boll weevil and the efficiency of the equipment used to collect them

“…The boll weevil is mainly controlled by application of chemical insecticide during the flowering period to protect cotton squares (SILVA & RAMALHO, 2013;SILVA & SILVA, 2015). Important alternatives to cotton insecticides include various types of cultural control tactics, as suggested elsewhere (GREENBERG et al, 2010).…”

“…Among these, the boll weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) is a key pest of cotton in the new world (SALVADOR et al, 2014). This insect has spread throughout the cotton-producing regions of Brazil, which has led to a severe increase in the cost of production due to economic losses arising from the insect feeding behavior and oviposition on the cotton squares and bolls (SILVA & RAMALHO, 2013).The boll weevil is mainly controlled by application of chemical insecticide during the flowering period to protect cotton squares (SILVA & RAMALHO, 2013;SILVA & SILVA, 2015). Important alternatives to cotton insecticides include various types of cultural control tactics, as suggested elsewhere (GREENBERG et al, 2010).…”