Objetivando reduzir custos foi calculada a eficiência agroeconômica (> produtividade < custo) de cinco tratamentos de controle de plantas daninhas em ensaio conduzido de 27/03/05 a 23/02/07 na Fepagro, Maquiné, RS, delineado em blocos casualizados, cinco repetições dos tratamentos: T1-Capina; T2-Glyphosate (2,5 L i.a. ha-1); T3-Diuron(2,4 L i.a. ha-1) T4-Diuron+Glyphosate (2,4 + 2,5 L i.a. ha-1); T5-Atrazine+ Simazine (3,0 L i.a. ha-1). Calculou-se o custo da capina a partir da remuneração diária do operário, do preço, em g mL-1, dos princípios ativos e da receita bruta (no frutos x preço na região) de cada tratamento. O preço do g mL-1 do atrazine+simazine variou 25 %, do glyphosate, 32% e do diuron, 107 %. O custo dos tratamentos foi: T1 = R$ 2736,00; T5= R$ 653,00; T2 = R$ 629,00; T4= R$ 621,00 e T3= R$ 468, 00 ha-1 ano-1, respectivamente, 9, 3, 6, 5 e 2 % da receita. O controle de plantas daninhas com herbicidas custou 22 % do montante gasto com capinas-T1C e o diuron-T3D, aplicado a intervalos de 55 dias, foi o tratamento mais barato, custou 74 % do preço médio dos demais tratamentos com herbicidas.
Aiming to reduce production costs we studied the agroeconomic efficiency (> productivity, < cost) of weed control treatments in an experiment lead since 27 Mar 05 to 23 Jul 07 at Fepagro Litoral Norte, Maquiné, RS, in a randomized complete block design, five repetitions of the weed control treatments: T1-Weeding; T2-Glyphosate (2,5 La.i. ha-1); T3-Diuron (2,4 L a.i. ha-1) T4-Diuron+Glyphosate (2,4 + 2,5 L a.i. ha-1); T5-Atrazine+Simazine (3,0 L a.i. ha-1).The cost of T1-W was calculated based on daily payment of a worker and T2, T3, T4 and T5 from the average price of g mL-1 of the active ingredients of the used herbicides, and the gross income was calculated from commercial fruits and price. The price of g mL-1 of atrazine + simazine varied 25 %, glyphosate 32 % and diuron 107 %. The treatments costs was: T1= R$ 2736,00; T5= R$ 653,00; T2= R$ 629,00; T4= R$ 621,00 and T3= R$ 468,00 per hectare per year,respectively 9, 3, 6, 5 and 2 % of the income. The weed control in the pineapple culture with herbicides costed 22 % of the T1-W cost. The T3-D (diuron), applicated by 55 days intervals, was the treatment of higher agroeconomic efficiency and costed 74 % of the average price of the other treatments with herbicides.