Profitability and risk of production systems of grains combined with winter pastures

O objetivo deste trabalho foi avaliar a lucratividade e o risco de quatro sis-temas de produção de grãos combinados com pastagens de inverno, em sis-tema de plantio direto. O experimento foi realizado em Passo Fundo, RS, no período de 1990 a 1995. Os sis-temas foram: sis-tema I (trigo/soja, aveia-preta pastejada/soja, e aveia-preta pastejada/soja); sis-tema II (trigo/soja e aveia-preta + ervilhaca pastejadas/milho); sis-tema III (trigo/soja, aveia-preta + ervilhaca pastejadas/soja e aveia-preta + ervilhaca pastejadas/milho); e sis-tema IV (trigo/soja, aveia-branca/soja e aveia-branca/soja). O delineamento experimental foi em blocos ao acaso, com três repetições, e parcelas totalizando 500 m2. Foram aplicados três tipos de análise à receita líquida dos sis-temas: análise da média variância, da distribuição de probabilidade acumulada e da dominância estocástica. Pela análise da média variância, não houve diferença significativa entre os sis-temas estudados. Pela distribuição de probabilidade acumulada, a escolha da alternativa depende única e exclusivamente do nível de risco escolhido pelo tomador de decisão. Pelo método da dominância estocástica, o sis-tema II mostrou ser a melhor alternativa de produção a ser oferecida aos agricultores, dos pontos de vista de rentabilidade e de menor risco.The objective of this work was to evaluate the profitability and risk of grain production systems combined with annual winter pastures, under no-tillage system. The experiment was carried out in Passo Fundo, RS, Brazil, in a six-year period (1990-1995). The systems were: system I (wheat/soybean, grazed black oats/soybean, and grazed black oats/soybean); system II (wheat/soybean and grazed black oats + grazed common vetch/corn); system III (wheat/soybean, grazed black oats + grazed common vetch/soybean, and grazed black oats + grazed common vetch/corn); and system IV (wheat/soybean, white oats/soybean, and white oats/soybean). An experimental design in blocks at random, with three replications and plots with 500 m2, was used. Three types of analysis were applied to the net return of systems: mean-variance analysis, distribution of accumulated probability, and stochastic dominance. When mean-variance analysis was used no significant differences were observed in the systems studied. By the distribution of accumulated probability, the selection of an alternative depends solely and exclusively on the level of risk chosen by the decision-maker. By the stochastic dominance method, system II showed to be the best production alternative to be offered to farmers from both profit and lower risk standpoints

Economic analysis of grain production systems with annual winter pastures, under no-tillage

Durante seis anos (1990 a 1995), foram avaliados, no CEPAGRO-Centro de Extensão e Pesquisa Agronômica, da Faculdade de Agronomia da Universidade de Passo Fundo (UPF), em Passo Fundo, RS, quatro sistemas de produção de grãos com pastagens anuais de inverno. Os sistemas foram constituídos por: sistema I (trigo/soja, aveia-preta pastejada/soja e aveia-preta pastejada/soja); sistema II (trigo/soja e aveia-preta + ervilhaca pastejadas/milho); sistema III (trigo/soja, aveia-preta + ervilhaca pastejadas/soja e aveia-preta + ervilhaca pastejadas/milho); e sistema IV (trigo/soja, aveia-branca/soja e aveia-branca/soja). O delineamento experimental foi em blocos ao acaso, com três repetições, e parcelas totalizando 500 m2. Na média dos seis anos, o sistema II mostrou maior receita líquida (R$432,71/ha) do que o sistema IV (R$ 322,93/ha). Por sua vez, o sistema II não diferiu significativamente dos sistemas I (R$377,93/ha) e III (R$ 400,27/ha). A integração lavoura pecuária sob sistema de cultivo plantio direto foi viável tanto para as culturas de inverno e de verão como para a engorda de bovinos no período invernal.During six years (1990 to 1995), at the CEPAGRO-Centro de Extensão e Pesquisa Agronômica, of the Faculdade de Agronomia da Universidade de Passo Fundo, in Passo Fundo, RS, Brazil, the effects of grain production systems and annual winter pastures were assessed. The economic analysis on that period is presented in this paper. Four production systems were evaluated: system I (wheat/soybean, grazed black oats/soybean, and grazed black oats/soybean); system II (wheat/soybean and grazed black oats + grazed common vetch/pasture/corn); system III (wheat/soybean, grazed black oats + grazed common vetch/soybean, and grazed black oats + grazed common vetch/corn); and system IV (wheat/soybean, white oats/soybean, and white oats/soybean). An experimental design in blocks at random, with three replications and plots with 500 m2, was used. In the average of six years, system II showed a higher net return (R$432.71/ha), as compared to system IV (R$ 322.93/ha). System II showed no significant differences in relation to systems I (R$377.93/ha) and III (R$ 400.27/ha). The integration crop-livestock under no-tillage was viable for both winter and summer crops, as well as for fattening beef cattle during winter time

In vitro mycelial sensitivity of Macrophomina phaseolina to fungicides

Black root rot, caused by Macrophomina phaseolina (Tass.) Goid., is the most common root disease in soybean fields. This study aimed to determine the in vitro mycelial sensitivity, measured by the IC50 (concentration to inhibit 50% of the fungus mycelial growth) of a M. phaseolina isolate obtained from soybean, to different fungicides (thiram, iprodione, carbendazim, pyraclostrobin, fluquinconazol, tolyfluanid, metalaxyl and penflufen + trifloxystrobin), at six concentrations (0.01 mg L-1, 0.10 mg L-1, 1.00 mg L-1, 10.00 mg L-1, 20.00 mg L-1 and 40.00 mg L-1 of the active ingredient). The 0.00 mg L-1 concentration represented the control, without fungicide addition. The mycelial growth evaluation was performed with the aid of a digital pachymeter, by measuring the colonies diameter, when the fungus growth in the control treatment reached the Petri dish edge. The experimental design was completely randomized, with four replications. Concerning the fungitoxicity of active ingredients, a variation from non-toxic to highly fungitoxic was observed to the M. phaseolina isolate, with IC50 values ranging from 0.23 mg L-1 to > 40.00 mg L-1, being carbendazim the most efficient one (IC50 = 0.23 mg L-1). The fungus showed insensitivity to the active ingredients of fluquinconazole, metalaxyl, thiram and tolyfluanid

Conversão e balanço energético de sistemas de produção de grãos com pastagens sob plantio direto

Data obtained from experiments conducted, from 1990 to 1995, at the Universidade de Passo Fundo, Rio Grande do Sul State, Brazil, were evaluated with the objective to study the energy conversion and balance of four grain production systems with annual winter pastures. Four grain production systems were evaluated: system I (wheat/soybean, black oats/soybean, and black oats/soybean); system II (wheat/soybean and black oats + common vetch/corn); system III (wheat/soybean, black oats + common vetch/soybean, and black oats + common vetch/corn); and system IV (wheat/soybean, white oats/soybean, and white oats/soybean). Both winter and summer crops were grown under no-tillage. The trial was set up blocks at random, with three replications and plots with 500 m2. Systems II and III showed higher energy conversion (5.78 and 5.44) and balance rates (23,728 and 21,741 kg/Mcal), as compared to systems I (3.79 and 11,553 kg/Mcal) and IV (4.33 and 12,879 kg/Mcal), respectively. It was evident that the integration crop-livestock under no-tillage is a viable system, since the energetic conversion and balance showed positive results; actually, these rates were significantly higher in the systems including corn crop.Foram avaliados dados obtidos de experimentos conduzidos, no período de 1990 a 1995, na Universidade de Passo Fundo, RS, objetivando estudar a conversão e o balanço energético de quatro sistemas de produção de grãos com pastagens anuais de inverno. Os quatro sistemas foram constituídos por: sistema I (trigo/soja, aveia-preta/soja e aveia-preta/soja); sistema II (trigo/soja e aveia-preta + ervilhaca/milho); sistema III (trigo/soja, aveia-preta + ervilhaca/soja e aveia-preta + ervilhaca/milho); e sistema IV (trigo/soja, aveia-branca/soja e aveia-branca/soja). As culturas, tanto de inverno como de verão, foram estabelecidas sob sistema plantio direto. O delineamento experimental foi em blocos ao acaso, com três repetições, e parcelas totalizando 500 m2. Os sistemas II e III apresentaram conversão energética (5,78 e 5,44) e balanço energético (23.728 e 21.741 kg/Mcal) superiores aos sistemas I (3,79 e 11.553 kg/Mcal) e IV (4,33 e 12.879 kg/Mcal), respectivamente. Ficou evidenciado que a integração lavoura-pecuária sob sistema plantio direto foi viável, pois a conversão e o balanço energético foram positivos, tendo sido significativamente maiores nos sistemas que incluíram a cultura de milho

Análise econômica de sistemas de produção de grãos com pastagens anuais de inverno, em sistema plantio direto Economic analysis of grain production systems with annual winter pastures, under no-tillage

Durante seis anos (1990 a 1995), foram avaliados, no CEPAGRO-Centro de Extensão e Pesquisa Agronômica, da Faculdade de Agronomia da Universidade de Passo Fundo (UPF), em Passo Fundo, RS, quatro sistemas de produção de grãos com pastagens anuais de inverno. Os sistemas foram constituídos por: sistema I (trigo/soja, aveia-preta pastejada/soja e aveia-preta pastejada/soja); sistema II (trigo/soja e aveia-preta + ervilhaca pastejadas/milho); sistema III (trigo/soja, aveia-preta + ervilhaca pastejadas/soja e aveia-preta + ervilhaca pastejadas/milho); e sistema IV (trigo/soja, aveia-branca/soja e aveia-branca/soja). O delineamento experimental foi em blocos ao acaso, com três repetições, e parcelas totalizando 500 m². Na média dos seis anos, o sistema II mostrou maior receita líquida (R$432,71/ha) do que o sistema IV (R$ 322,93/ha). Por sua vez, o sistema II não diferiu significativamente dos sistemas I (R$377,93/ha) e III (R$ 400,27/ha). A integração lavoura pecuária sob sistema de cultivo plantio direto foi viável tanto para as culturas de inverno e de verão como para a engorda de bovinos no período invernal.<br>During six years (1990 to 1995), at the CEPAGRO-Centro de Extensão e Pesquisa Agronômica, of the Faculdade de Agronomia da Universidade de Passo Fundo, in Passo Fundo, RS, Brazil, the effects of grain production systems and annual winter pastures were assessed. The economic analysis on that period is presented in this paper. Four production systems were evaluated: system I (wheat/soybean, grazed black oats/soybean, and grazed black oats/soybean); system II (wheat/soybean and grazed black oats + grazed common vetch/pasture/corn); system III (wheat/soybean, grazed black oats + grazed common vetch/soybean, and grazed black oats + grazed common vetch/corn); and system IV (wheat/soybean, white oats/soybean, and white oats/soybean). An experimental design in blocks at random, with three replications and plots with 500 m², was used. In the average of six years, system II showed a higher net return (R$432.71/ha), as compared to system IV (R$ 322.93/ha). System II showed no significant differences in relation to systems I (R$377.93/ha) and III (R$ 400.27/ha). The integration crop-livestock under no-tillage was viable for both winter and summer crops, as well as for fattening beef cattle during winter time