Maurício Dutra Zanotto

Espaçamento e população de plantas de mamoneira de porte baixo para colheita mecanizada

The objective of this work was to evaluate the effect of row spacing and plant population on yield and others agronomic characteristics of low-height castor bean, for mechanical harvest, in the summer cropping season. The experiment was carried out during the 2007/2008 and 2008/2009 growing seasons, on a Haplorthox soil, in Botucatu, Sao Paulo State, Brazil, using the cultivar FCA-PB. A randomized complete block design in a split-plot arrangement with four replicates was used. The plots consisted of four row spacings (0.45, 0.60, 0.75, and 0.90 m), and the subplots of four initial plant populations (25,000, 40,000, 55,000, and 70,000 plants per hectare). Increases in plant population, decreased plant survival, stem diameter, number of racemes per plant and number of fruits per raceme, regardless of row spacing. The highest grain and oil yields of castor bean FCA-PB are obtained with initial plant populations between 55,000 and 70,000 plants per hectare, with the rowspacing from 0.45 to 0.75 m.

Eficiência da seleção recorrente para redução da estatura de plantas em mamoneira (Ricinus communis L.)

The aim of this work was to evaluate the recurrent selection efficiency for reduction of stature of the castor bean plants of the Guarani cultivar (Ricinus communis L.), turning it with appropriate strucuture to facilitate the manual and/or mechanic harvest. Four cycles of recurrent selection were accomplished through the utilization of self-pollinated progenies in the Guarani cultivar for reduction of plants stature, in edaphclimatic conditions of Sao Manuel-SP, Botucatu-SP and Penapolis-SP towns. The evaluations of plants stature and yield (kg.ha-1) of the four selection cycles and the original cycle (cycle 0) were accomplished in Sao Manuel-SP, Botucatu-SP and Penapolis-SP, under a randomized block design with five repetitions and useful parcels of 30 m2. The analysis of variance for the characteristics plant stature and yield was made apart to each environment and together for the three environment and, afterwards one performed the average comparison by the Tukey test using 5% of probability. One estimated for the three environments, by the regression analysis, the genetic gains of the four selection cycles for plant stature. One concluded that the recurrent selection was efficient to the reduction of plant stature and that Guarani castor bean cultivar could create genetic variability for this characteristic and the yield was not influenced by the reduction of plants stature.

Custos de produção e lucratividade de cultivares de mamona em diferentes arranjos de plantas

The optimal combination between row spacing and plant population can lead to the economic maximization of castor bean yield. This study aimed to analyze the production cost and profitability per hectare of two castor bean cultivars (IAC 2028 and FCA-PB), under eight different plant arrangements, in the summer of 2007/2008 and 2008/2009, in Botucatu, Sao Paulo State, Brazil. The best economic results were obtained when using narrower row spacing (0.45 m). The highest production cost occurred in 2007/2008, for the 70,000 plants ha -1 population, due to the use of a higher amount of seeds and fungicide applications, when compared to 2008/2009. The FCA-PB cultivar showed the highest profitability index (27.46%), with the combination of 0.45 m row spacing and 55,000 plants ha -1 , in 2007/2008, with operational profit of US

Seletividade e eficácia de herbicidas inibidores da enzima accase na cultura da mamona

655.47 ha -1 .

Agronomic characteristics of the castor bean as affected by cultivation method and planting density

Universidade Estadual de Maringa (UEM) CCA UEM, Dep Ciencias Agron, BR-87507190 Umuarama, PR, Brazil

Avaliação de fungicidas, óleos essenciais e agentes biológicos no controle de Amphobotrys ricini em mamoneira (Ricinus communis L.)

A cultura da mamona possui grande potencial para o cultivo em condicoes brasileiras, contudo, deve-se buscar metodos cada vez mais eficientes de manejo da cultura, a fim de atingir altas produtividades e introduzir de modo definitivo a cultura no sistema agricola nacional. O objetivo do presente estudo foi avaliar as caracteristicas agronomicas e a produtividade da mamoneira em funcao do metodo de conducao de plantas e da densidade de cultivo. O estudo foi conduzido em condicoes de campo no ano agricola de 2010, utilizando a cultivar IAC 2028, em delineamento experimental de blocos casualizados em esquema fatorial 2x3 com quatro repeticoes. O primeiro fator foi composto por duas densidades de semeadura (26666 e 111111 plantas ha-1), enquanto o segundo fator foi composto por tres metodos de conducao de plantas (testemunha, poda parcial e poda+desbrota). Ao final do desenvolvimento da cultura, foram determinadas as caracteristicas agronomicas das plantas, os componentes da producao e a produtividade. A poda + desbrota proporcionou melhoria dos caracteres agronomicos, sem afetar a produtividade e reduziu o ciclo da cultura em ate 30 dias. Este comportamento, aliado a maturacao uniforme, pode proporcionar a colheita mecanizada da cultura, alem de proporcionar o cultivo da mamoneira em janelas de cultivo na safrinha, sem prejudicar a implantacao da safra seguinte. O cultivo adensado de plantas de mamona limitou a emissao de ramos produtivos secundarios sem afetar a produtividade, revelando elevada plasticidade fenotipica no desenvolvimento da cultura.

Nutrient extraction and exportation by castor bean hybrid lyra

The castor bean (Ricinus communis L.) is a tropical oilseed species, and the oil extracted from its seeds is one of the most versatile oils in the nature, showing various industrial uses. Even though it is a rustic species, the castor bean is subjected to several diseases such as the gray mold, caused by the fungus Amphobotrys ricini. Genetic breeding would be the best alternative for the disease control, but a long time is required to obtain resistant cultivars. Thus, the use of control strategies based on chemical, alternative or biological methods shows viable in the short term. The aim of this study was to investigate gray mold control efficiency, in castor bean crop, using chemical, alternative and biological methods. The pathogen control efficiency was evaluated both in vitro and in vivo using fungicides, essential oils and biological control agents. As regards the in vitro inhibition of the pathogen mycelial growth, the best treatments with essential oils were those based on C. martini and C. zeylanicum at all five tested concentrations. For both oils, the average diameter of colonies was 0.7 cm against 4.79 cm for the control treatment. For the fungicides, at all four tested levels, the most efficient active ingredients were methyl tiophanate, carbendazim, tebuconazole and iprodione. The ED50 of these fungicides was <1uL/L, yielding 100% mycelial growth inhibition at all concentrations. As to the inhibition of A. ricini conidium germination, the fungicides tebuconazole and chlorotanolyl were the best at all tested concentrations, and the average of germinated conidia with these fungicides was 0.0 and 0.15%, respectively, against 100% for the control treatment. In the field, treatment with the fungicide iprodione was the best for the disease control when compared to biological and alternative treatments. Under field conditions, the average disease severity for the treatment with iprodione was 15.76% against 95.81% for the inoculated control.

Inbreeding depression in castor bean (Ricinus communis L.) progenies

Information about nutrient extraction and exportation by crops, as well as the periods of highest nutrient demand is important for an adequate fertilization management. However, there are no studies on the nutrient uptake of short-stature hybrid castor bean. Therefore, the purpose of this study was to evaluate nutrient extraction and exportation by short-stature castor bean hybrid Lyra, in the spring-summer and fall-winter growing seasons. The experiments were conducted in the 2005/2006 spring-summer and 2006 fall-winter growing seasons on an Oxisol, in Botucatu, SP, in a randomized block design, with four replications. The plots consisted of plant samplings, which occurred 17, 31, 45, 59, 73, 97 and 120 days after emergence (DAE) in the spring-summer and 17, 31, 45, 59, 80, 100 and 120 DAE in fall-winter growing season. The growth of hybrid Lyra was slow and nutrient uptake lowest between emergence and the beginning of flowering. The period of highest dry matter (DM) accumulation rates and highest nutrient demand were observed 40 to 80 DAE, in both growing seasons. The order of nutrient extraction by the plants in the spring-summer growing season was: N>K>Ca>Mg>S>P>Fe>Mn>Zn>B>Cu>Mo. In fall-winter, S was more absorbed than Mg. Seed yield was higher in the spring-summer (2.995 kg ha-1), but nutrient extraction and exportation per ton of seed were similar in both growing seasons. Around 58 % of N and 84 % of P, and approximately half of the S and B absorbed throughout the cycle were exported with the seeds. However, most of the other nutrients accumulated in the plants returned to the soil in plant residues.

Melhoramento genético da mamona visando incremento de flores femininas

The purpose of this study was to investigate inbreeding depression (DE) in castor bean. From a population derived from the Guarani cultivar, 60 mother plants were sampled. Three types of progenies were obtained from each one: from self-pollination (AU), from crosses (CR) and from open pollination (PL). Grain yield of the progenies was evaluated in two locations. There was a strong interaction of progenies x locations, which led to obtaining estimates within each location. Broad variation was observed in inbreeding depression, with mean values of 6.7% and 13.4%, comparing AU progenies with PL progenies. It was observed that the population has high potential for selecting promising inbred lines. The frequency of mother plants generating progenies with simultaneous high general combination capacity and low inbreeding depression was low. Recurrent selection will increase the occurrence of parent plants associating these two properties, which is necessary for obtaining superior synthetic varieties.

Agronomic performance of Safflower genotypes (Carthamus tinctorius L.) under different soil bulk density levels in the Oxisol of the Cerrado

O objetivo deste trabalho foi testar metodos de selecao visando ao aumento de flores femininas na populacao FCA-UNESP-PB de mamona (Ricinus communis L.). A selecao foi realizada no municipio de Botucatu (SP), na safrinha de 2007. Por meio de selecao massal, foram selecionadas plantas com racemo primario estritamente feminino. Destas plantas, as que tinham reversao sexual foram autofecundadas. As avaliacoes foram realizadas na safrinha de 2008 em Botucatu e Sao Manuel (SP), onde foram comparados os tratamentos: metodo de selecao massal; metodo de selecao massal com autofecundacao e testemunha (racemos de plantas colhidos ao acaso, sem selecao). Foram avaliados: porcentagem de flores femininas do racemo primario (%), produtividade de graos (kg ha-1) e teor de oleo das sementes (%). O delineamento experimental utilizado foi o de blocos casualizados com 30 repeticoes. Os dados foram submetidos a analise de variância individual para cada local e conjuntamente para os dois locais, pelo teste F a 1% de probabilidade. Mediante os resultados conclui- se que o metodo de selecao massal com autofecundacao foi aquele que proporcionou maiores valores de porcentagem de flores femininas no racemo primario, com ganho fenotipico realizado de 18% em Botucatu e 29% em Sao Manuel (SP). Por meio dos metodos de selecao, notou-se comportamento diferencial em relacao aos locais para a caracteristica produtividade de graos, e o metodo selecao massal com autofecundacao proporcionou a menor produtividade. No teor de oleo nao houve diferencas significativas entre os metodos e os locais avaliados.