CONSUMO HÍDRICO E COEFICIENTE DE CULTIVO DA MAMONEIRA, CULTIVAR BRS ENERGIA

CONSUMO HÍDRICO E COEFICIENTE DE CULTIVO DA MAMONEIRA, CULTIVAR BRS ENERGIA JOSÉ MARCELO DIAS1; PEDRO VIEIRA DE AZEVEDO2; JOSÉ RENATO CORTEZ BEZERRA3; NAPOLEÃO ESBERARD DE MACÊDO BELTRÃO3; GERALDO DOS SANTOS OLIVEIRA3 E MARIA IDALINE PESSOA CAVALCANTI4 1Embrapa Produtos e Mercado, [email protected],2Centro de Tecnologia e Recursos Naturais – UFCG, [email protected] Algodão, [email protected]; [email protected] de Ciências Agrárias – UFPB, [email protected]. 1 Resumo O presente trabalho objetivou a determinação das exigências hídricas da mamoneira cultivada sob irrigação. Os experimentos de campo foram conduzidos na Estação Experimental da Embrapa Algodão, localizada em Barbalha – CE, nos anos de 2005 e 2006. A cultivar utilizada foi a BRS Energia, de ciclo precoce e porte baixo com 107 dias de ciclo, composto de 5 fases fenológicas: I - Germinação até 10% de cobertura do solo; II - Até inflorescência do 1º cacho; III - Até inflorescência do 2º cacho; IV - Maturação do 1º cacho; V - Maturação do 2º cacho, em uma área de 1 hectare. A estimativa da evapotranspiração da cultura (ETc), para as diferentes fases fenológicas, foi obtida pelo método do balanço de energia baseado na razão de Bowen. O coeficiente de cultivo (Kc) foi obtido pela relação entre a evapotranspiração da cultura (ETc) e a evapotranspiração de referência (ETo), estimada pelo método FAO-Penman-Monteith. A evapotranspiração média para os dois anos de cultivo foi de 565,1 mm, com um consumo mínimo de 47,4 mm na fase I e um máximo de 212.3 mm na fase IV. Os valores médios de Kc por fase fenológica foram de 0,74; 0,93; 1,00; 1,18 e 0,92. O Kc pode ser definido em função dos dias após a emergência, pela equação Kc = -0,0001DAE2 + 0,016DAE + 0,556. Palavras-chave: Ricinus communis, evapotranspiração, razão de Bowen. DIAS, J. M.; AZEVEDO, P. V. de; BEZERRA, J. R. C.; BELTRÃO, N. E.de M.; OLIVEIRA, G. dos S.; CAVALCANTI, M. I. P.WATER CONSUMPTION AND CROP COEFFICIENT OF CASTOR BEAN CROP, CV. BRS ENERGIA 2 ABSTRACT The objective of this study was to determine water requirement of castor bean under irrigation. Field experiments were conducted at the Experimental Station of Cotton Embrapa in Barbalha city, Ceará State, Brazil in 2005 and 2006. With early maturity and low height, cv. BRS Energia was used, 107-day cycle, consisting of five phenological phases: I- germination up to 10% soil covering; II- up to inflorescence of the first bunch; III- up to inflorescence of the second bunch; IV- up to maturation of the first bunch; V- up to maturation of the second bunch, in 1 hectare area. The estimate of crop evapotranspiration for the phenological phases throughout the crop cycle was obtained by the Bowen-ratio energy balance. Crop coefficient (Kc) was obtained by the ratio between crop evapotranspiration (Etc) and reference evapotranspiration (ETo), estimated by the FAO-Penmam-Monteith method. The mean evapotranspiration for the 2 year-cultivation period was 565.1 mm, being 47.4 mm minimum consumption in phase 1 and 212.3 mm maximum consumption in phase IV. Mean values of Kc by phenological phase were 0.74; 0.93; 1.00; 1.18 and 0.92. Kc was defined as a function of days after emergence (DAE) by the equation Kc = -0.0001DAE2 + 0.016DAE + 0.556. Keywords: Ricinus communis, evapotranspiration, Bowen ratio.

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Evapotranspiration, crop coefficient and water use efficiency of coriander grown in tropical environment

Horticultura Brasileira ◽

10.1590/s0102-053620180404 ◽

2018 ◽

Vol 36 (4) ◽

pp. 446-452 ◽

Cited By ~ 1

Author(s):

Vicente de PR da Silva ◽

Inajá Francisco de Sousa ◽

Alexandra L Tavares ◽

Thieres George F da Silva ◽

Bernardo B da Silva ◽

...

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Crop Production ◽

Field Experiments ◽

Growth Parameters ◽

Crop Coefficient ◽

Growing Season ◽

Tropical Environment ◽

Mean Values ◽

Use Efficiency

ABSTRACT The water scarcity is expected to intensify in the future and irrigation becomes an essential component of crop production, especially in arid and semiarid regions, where the available water resources are limited. Four field experiments were carried out at tropical environment in Brazil in 2013 and 2014, in order to evaluate the effect of planting date on crop evapotranspiration (ETc), crop coefficient (Kc), growth parameters and water use efficiency (WUE) of coriander (Coriandrum sativum) plants. The planting dates occurred during winter, spring, summer and autumn growing seasons. ETc was obtained through the soil water balance method and the reference evapotranspiration (ETo) through the Penman-Monteith method, using data collected from an automatic weather station located close to the experimental area. The results of the research showed that the mean values of coriander ETc and Kc were 139.8 mm and 0.87, respectively. Coriander water demand is higher in the summer growing season and lower in the winter; however, its yield is higher in the autumn and lower in the winter. Coriander has higher yield and development of its growth variables in the autumn growing season. The results also indicated that the interannual climate variations had significant effects on most growth variables, as yield, ETc and Kc of coriander grown in tropical environment.

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EVAPOTRANSPIRAÇÃO DE CULTURA: UMA ABORDAGEM DOS PRINCIPAIS MÉTODOS APLICADOS ÀS PESQUISAS CIENTÍFICAS E NA AGRICULTURA

Irriga ◽

10.15809/irriga.2019v24n4p719-746 ◽

2019 ◽

Vol 24 (4) ◽

pp. 719-746

Author(s):

Luan Peroni Venancio ◽

Fernando França Da Cunha ◽

Everardo Chartuni Mantovani ◽

Cibele Hummel Do Amaral ◽

Edvaldo Fialho Dos Reis

Keyword(s):

Remote Sensing ◽

Energy Balance ◽

Irrigation Management ◽

Vegetation Indices ◽

Remote Sensing Data ◽

Crop Coefficient ◽

Bowen Ratio ◽

Climatic Conditions ◽

Irrigated Agriculture ◽

Crop Evapotranspiration

EVAPOTRANSPIRAÇÃO DE CULTURA: UMA ABORDAGEM DOS PRINCIPAIS MÉTODOS APLICADOS ÀS PESQUISAS CIENTÍFICAS E NA AGRICULTURA LUAN PERONI VENANCIO1; FERNANDO FRANÇA DA CUNHA1; EVERARDO CHARTUNI MANTOVANI1; CIBELE HUMMEL DO AMARAL2 E EDVALDO FIALHO DO REIS3 1Departamento de Engenharia Agrícola, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, Campus Universitário, CEP: 36570-900, Viçosa, MG, Brasil, [email protected], [email protected], [email protected] 2Departamento de Engenharia Florestal, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, CEP: 36570-900, Viçosa, MG, Brasil, [email protected] 3Departamento de Engenharia Rural, Universidade Federal do Espírito Santo, Alto Universitário, s/nº, Guararema, CEP: 29500-000, Alegre, ES, [email protected] 1 RESUMO Existem muitas metodologias para medição ou estimativa da evapotranspiração de cultura (ETc). Essas metodologias apresentam grandes diferenças entre si, especialmente no que se refere à base de formulação (empíricos, físicos ou a combinação de ambos), ao nível tecnológico (equipamentos, sensores sofisticados, etc.), a necessidade de dados de entrada, a área de aplicação, custo e precisão. Esta diversidade está relacionada à complexidade envolvida na transferência de água do sistema solo-planta para a atmosfera, com as variadas condições climáticas ao redor do planeta e também com os diferentes tipos de vegetação estudados. Nesta revisão, os seguintes métodos foram descritos e revisados: lisimetria (LIS), balanço de água no solo (BAS), razão de Bowen - balanço de energia (RBBE), covariância de vórtices turbulentos (CVT), modelos de fluxo de seiva (MFS), sistema de câmaras (SC), e métodos baseados no coeficiente de cultura (MBKc). Por fim, os métodos baseados no balanço de energia das superfícies (SRBE) e em índices de vegetação (SRIV), calculados a partir de dados de sensoriamento remoto (SR). Esses métodos foram selecionados por serem considerados, dentro do seu tipo de abordagem (hidrológica, micrometeorológica, fisiológica, empírica e sensoriamento remoto), os mais difundidos entre a comunidade científica internacional, e na agricultura. Palavras-chave: agricultura irrigada, consumo hídrico, manejo da irrigação, coeficiente de cultura, sensoriamento remoto. VENANCIO, L. P.; CUNHA, F. F.; MANTOVANI, E. C.; AMARAL, C. H.; REIS, E. F. CROP EVAPOTRANSPIRATION: AN APPROACH TO MAIN METHODS APPLIED TO SCIENTIFIC RESEARCHES AND IN AGRICULTURE 2 ABSTRACT There are many methodologies for measuring or estimating crop evapotranspiration (ETc). These methodologies differ greatly from each other depending on the approach (empirical, physical or a combination of both), technological level, input dataset, application area, cost and accuracy. This wide diversity is related to the complexity involved in water transference from the soil-plant system to the atmosphere, within various climatic conditions around the Earth and also to the different types of vegetation. In this review, the following methods were described and reviewed: lysimeter (LIS), soil water balance (BAS), Bowen ratio - energy balance (RBBE), eddy covariance (CVT), sap-flow models (MFS), chamber system (SC) and, crop coefficient-based methods (MBKc). Finally, the methods based on surface energy balance (SRBE) and vegetation indices (SRIV) were estimated through remote sensing data (SR).These methods were selected because they are considered, within their type of approach (hydrological, micrometeorological, physiological, empirical and remote sensing), the most widespread among the international scientific community and in agriculture. Keywords: irrigated agriculture, water consumption, irrigation management, crop coefficient, remote sensing.

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Evapotranspiration, crop coefficient and water use efficiency of onion cultivated under different irrigation depths

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v26n3p219-225 ◽

2022 ◽

Vol 26 (3) ◽

pp. 219-225

Author(s):

Wendy K. Matsunaga ◽

Vicente de P. R. da Silva ◽

Victória P. Amorim ◽

Eliton S. G. Sales ◽

Sílvia M. Dantas ◽

...

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Field Experiments ◽

Crop Coefficient ◽

Northeastern Brazil ◽

Semiarid Region ◽

Crop Evapotranspiration ◽

Maturation Stages ◽

Use Efficiency ◽

Crop Coefficients

ABSTRACT This study aimed to determine crop evapotranspiration through the soil water balance, the crop coefficient and water use efficiency of the onion (Allium cepa L.) in a system with four irrigation regimes, cultivated in the semiarid region of northeastern Brazil. Two field experiments were carried out during the rainy and dry periods of the region in 2018, using the treatments of 100% (T1), 75% (T2), 50% (T3) and 25% (T4) of the reference evapotranspiration for daily water replacement and five replicates for each treatment. It was verified that crop evapotranspiration varies according to the water availability in the soil; however, the highest water use efficiency occurred for the T3 treatment. The T1 treatment obtained the highest estimated yield, 43.86 tons ha-1, while T4 obtained 13.47 tons ha-1, the lowest estimated yield among the treatments, and this difference was statistically significant (p ≤ 0.05) by F test. The crop coefficients obtained were 0.68, 0.89, 0.99 and 0.73 for the initial, vegetative, bulbing and maturation stages, respectively.

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Utilização do lisímetro de drenagem para obtenção do “Kc” da mamoneira em plantio adensado

Revista Verde de Agroecologia e Desenvolvimento Sustentável ◽

10.18378/rvads.v11i1.3915 ◽

2016 ◽

Vol 11 (1) ◽

pp. 08 ◽

Cited By ~ 3

Author(s):

W. L. Miranda ◽

L. G. Carvalho ◽

P. Castro Neto ◽

P. A. B. Santos

Keyword(s):

Water Deficit ◽

Castor Bean ◽

Considerable Increase ◽

Reference Evapotranspiration ◽

Irrigation Management ◽

Crop Coefficient ◽

Crop Evapotranspiration ◽

Crop Cycle ◽

Increase In Productivity ◽

Drainage Lysimeter

A cultura da mamona é considerada resistente a deficiências hídricas, no entanto, apresenta considerável incremento de produtividade quando submetida à irrigação. Para o adequado manejo da irrigação um dos critérios passíveis de serem adotados baseia-se na evapotranspiração da cultura (ETc) e para tanto torna-se necessário o conhecimento do valor do coeficiente de cultura (Kc). Com o presente trabalho objetivou-se determinar o Kc da mamoneira em plantio adensado, no período de safrinha, utilizando-se lisímetro de drenagem. Foram utilizados três lisímetros de drenagem, com dimensões de 1,2 m de comprimento, 1,4 m de largura e 1,2 m de profundidade. Nos lisímetros foram plantadas oito mudas de mamoneira da cultivar Al Guarany 2002 com espaçamento de 0,3 m entre plantas e 0,7 m entre linhas. A ETc foi contabilizada no intervalo de 5 a 12 dias, conforme se observou o fim da drenagem. A evapotranspiração de referência (ETo) foi estimada pela equação de Penman-Monteith-FAO. A partir da relação ETc/ETo obteve-se o Kc para os diferentes períodos ao longo do ciclo da cultura. Os valores de ETc encontrados nas fases inicial, de crescimento, intermediária e final foram 1,65; 3,07; 9,14 e 5,85 mm d-1 respectivamente. Os valores de Kc para as fases mencionadas foram 0,98; 1,41; 2,11 e 1,65 respectivamente.Use of drainage lysimeter for obtaining Kc of castor bean in dense plantationAbstract: Castor bean culture is considered resistant to water deficit. However, it presents considerable increase in productivity when submitted to irrigation. For the adequate irrigation management, one of the criterion considered is based on the crop evapotranspiration (ETc) and is necessary for finding the crop coefficient (Kc) value. With the present work, we aimed at determining the Kc of the castor bean in dense plantation, during the off-season, using a drainage lysimeter. Three drainage lysimeters, with dimensions of 1.2 m of length, 1.4 m of width and 1.2 m of depth, were used. In the lysimeters, eight castor bean seedlings, cultivar Al Guarany 2002 were planted with spacing of 0.3 m between plants and 0.7 m between lines. The ETc was calculated considering the interval from 5 to 12 days, according to the end of drainage. The reference evapotranspiration (ETo) was estimated by the Penman-Monteith-FAO equation. From the ETc/ETo relation, we obtained the Kc for the different periods over the crop cycle. The ETc values found in the initial, growing, intermediate and final phases were of 1.65; 3.07; 9.14 and 5.85 mm d-1, respectively. The Kc values for the mentioned phases were of 0.98; 1.41; 2.11 and 1.65, respectively.

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Evapotranspiration and Dual Crop Coefficient of Maize Second Season Intercropped with Crotalaria

Journal of Experimental Agriculture International ◽

10.9734/jeai/2020/v42i130460 ◽

2020 ◽

pp. 142-157

Author(s):

Diego Fernando Daniel ◽

Rivanildo Dallacort ◽

João Danilo Barbieri ◽

Marco Antônio Camillo de Carvalho ◽

Santino Seabra Júnior ◽

...

Keyword(s):

Developmental Stages ◽

Crop Coefficient ◽

The State ◽

State University ◽

Crop Evapotranspiration ◽

Maize Crop ◽

Evaporation Coefficient ◽

Mato Grosso ◽

Weight Variation ◽

Phenological Phases

The objective of this work was to determine the dual coefficient of culture (Kc) of maize in monoculture and intercropping systems, as well as to evaluate the influence of intercropping on evapotranspiration and productive characteristics of maize second season. The experiment was carried out in the experimental field of the State University of Mato Grosso - UNEMAT in 2018, with three treatments: T1 - maize monoculture; T2 - Crotalaria monoculture and T3 - maize + Crotalaria. The crop evapotranspiration (ETc) of maize, Crotalaria, and maize + Crotalaria intercropping was determined daily by weight variation of weighing lysimeters, converted into mm day-1. The methodology used was that of dual Kc - FAO 56, dividing the crop coefficient (Kc), in soil evaporation coefficient (Ke), determined in microlysimeters, and basal crop coefficient (Kcb), determined in weighing lysimeters. The phenological phases of the maize crop were observed to determine the coefficients in the different developmental stages, being the Kc, Kcb, Ke in the phases: Initial (I), Development (II), Intermediate (III) and Final (IV). The accumulated culture evapotranspiration was 312.00; 436.16 and 422.38 mm and daily averages of 2.86; 4.00- and 3.88-mm d-1, respectively for monoculture maize, for Crotalaria and for intercropping. The Kc values for each phase of maize development in intercropping with crotalaria were: I (1.46); II (1.48); III (1.59) and IV (0.94). For maize monoculture, dual Kc values were: I (1.24), II (1.30), III (1.00) and IV (1.11) and for Crotalaria monoculture were: I (1.77), II (1.59), III (1.56) and IV (1.05).

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Estimating Water Use and Irrigation Requirements of Coffee in Hawaii

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.119.3.652 ◽

1994 ◽

Vol 119 (3) ◽

pp. 652-657 ◽

Cited By ~ 24

Author(s):

Marco V. Gutiérrez ◽

Frederick C. Meinzer

Keyword(s):

Crop Coefficient ◽

Bowen Ratio ◽

Crop Evapotranspiration ◽

Area Index ◽

Canopy Development ◽

Severe Water Deficit ◽

Balance Technique ◽

Irrigation Requirements ◽

Ratio Energy ◽

Exchange Activity

Crop evapotranspiration (ETc) was measured as evaporative heat flux from drip-irrigated coffee (Coffea arabica L. cv. Yellow Catuai) fields at different stages of canopy development using the Bowen ratio-energy balance technique. Irrigation requirements were determined by comparing the ETc values obtained against reference values (ET0) derived from a modified Penman equation, and expressed as the ETc/ET0 ratio, or crop coefficient (Kc). In 1991, the average Kc was 0.75 to 0.79 for fields containing 2- to 4-year-old plantings. This ratio was 0.58 for a field containing a 1-year-old planting. Crop coefficient was 30% lower in 1992 due to higher ET0 values and lower stomatal conductance. Measurements made between July and August and again between September and November 1991 suggested that Kc may vary seasonally. Crop transpiration (T), determined with the stem heat balance technique, comprised from 40% to 95% of ETc as the leaf area index increased from 1.4 to 6.7. Behavior of Kc and T during a 25-day soil drying-reirrigation cycle indicated that the crop was able to maintain relatively high levels of gas-exchange activity during periods of severe water deficit.

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EVAPOTRANSPIRAÇÃO DA CULTURA DO GERGELIM IRRIGADA NA REGIÃO DA CHAPADA DO APODÍ-RN

Irriga ◽

10.15809/irriga.2017v22n3p497-511 ◽

2017 ◽

Vol 22 (3) ◽

pp. 497-511

Author(s):

Alécio Rodrigues Pereira ◽

PEDRO VIEIRA DE AZEVEDO ◽

ELLOISE RACKEL COSTA LOURENÇO ◽

LUCIANO MARCELO FALÉ SABOYA ◽

JOSÉ RENATO CORTEZ BEZERRA

Keyword(s):

Stage Iv ◽

Crop Coefficient ◽

Rio Grande ◽

Bowen Ratio ◽

Reproductive Development ◽

Sesamum Indicum ◽

Phase Iii ◽

Crop Evapotranspiration ◽

Average Value ◽

E Mail

EVAPOTRANSPIRAÇÃO DA CULTURA DO GERGELIM IRRIGADA NA REGIÃO DA CHAPADA DO APODÍ-RN ALÉCIO RODRIGUES PEREIRA1; PEDRO VIEIRA DE AZEVEDO2; ELLOISE RACKEL COSTA LOURENÇO3; LUCIANO MARCELO FALÉ SABOYA4 E JOSÉ RENATO CORTEZ BEZERRA5 1Mestre em Meteorologia; Universidade Federal de Campina Grande, Programa de Pós Graduação em Meteorologia; Campina Grande –PB, Av. Aprígio Nepomuceno, 882, CEP: 58109-970, Brasil; Fone: (83) 2110 – 1000. E-mail: [email protected] 2Prof. Dr. da Universidade Federal de Campina Grande, Centro de Tecnologias e Recursos Naturais, Departamento de Ciências Atmosféricas, Campina Grande –PB, Av. Aprígio Nepomuceno, 882, CEP: 58109-970, Brasil; Fone: (83) 2110 – 1000. E-mail: [email protected] 3Doutoranda em Geografia, Universidade Federal da Paraíba, Departamento de Geociências, Centro de Ciências Exatas e da Natureza, João Pessoa, Cidade Universitária, s/n – Castelo Branco III, CEP: 58051-085, Brasil; Fone: (83) 3216 – 7750. E-mail: [email protected] 4 Prof. Dr. da Universidade Federal da Paraíba, Centro de Tecnologias e Recursos Naturais, Unidade Acadêmica de Engenharia Agrícola, Campina Grande, Av. Aprígio Nepomuceno, 882, CEP: 58109-970, Brasil; Fone: (83) 2110 – 1000. E-mail: [email protected] 5Pesquisador da Empresa Brasileira de Pesquisa Agropecuária, EMBRAPA Algodão, Campina Grande-PB, Rua Osvaldo Cruz, 1143; CEP: 58428 – 095, Brasil; Fone: (83) 3182 – 4300. E-mail: [email protected] 1 RESUMO O experimento foi conduzido na Chapada do Apodi, na estação experimental da Empresa de Pesquisa Agropecuária do Rio Grande do Norte (EMPARN), localizada no município de Apodi-RN. O objetivo da pesquisa foi determinar as necessidades hídricas do gergelim (Sesamum indicum L.), cultivar BRS ANAHÍ, durante a estação seca de 2015, entre os meses de agosto, setembro e outubro. A evapotranspiração da cultura (ETc) e o coeficiente de cultivo (Kc) foram obtidas pelo método do balanço de energia baseado na razão de Bowen (BREB), enquanto que a evapotranspiração de referência (ET0) foi estimada pelo método de Penman-Monteith. Os resultados evidenciam que, em relação ao saldo de radiação (Rn), os fluxos de calor latente (LE), calor sensível (H) e calor no solo (G) corresponderam a 81,3%, 17,7% e 0,4%, respectivamente. A ETc acumulada ao longo da estação de cultivo foi de 566,2 mm, correspondendo a uma média de 6,9 mm dia-1. A Fase III (desenvolvimento reprodutivo da cultura) apresentou maior demanda hídrica, com média de 8,0 mm dia-1. Os valores do Kc foram: 0,6 no estágio inicial, 0,9 no estágio médio e 0,8 no estágio final. O valor do Kc médio determinado experimentalmente foi inferior àquele recomendado pela FAO-56 nas Fases: I (emergência), II (desenvolvimento vegetativo) e III (desenvolvimento reprodutivo), enquanto que na Fase IV (frutificação e maturação) foi superior. Palavras Chave: razão de bowen, evapotranspiração da cultura, coeficiente de cultivo. PEREIRA, A. R.; AZEVEDO, P. V.; LOURENÇO, E. R. C.; SABOYA, L. M. F.; BEZERRA, J. R. C. IRRIGATED SESAME CROP EVAPOTRANSPIRATION IN THE APODÍ, RN TABLELAND 2 ABSTRACT The experiment was conducted on the Apodi Tableland at the experimental station of Empresa de Pesquisa Agropecuária do Rio Grande do Norte (EMPARN), located in the municipality of Apodi, RN. The objective of the research was to determine the water requirements of irrigated sesame (Sesamum indicum L.), BRS Anahi cultivar, during the dry season of 2015, over the months of August, September and October. The crop evapotranspiration (ETc) and crop coefficient (Kc) were obtained by the method of Bowen ratio energy balance (BREB), while the reference evapotranspiration (ET0) was estimated by the Penman-Monteith method. The results show that, in comparison to net radiation (Rn), the latent heat (LE), sensible heat (H) and heat to the ground (G) accounted for 81.3%, 17.7% and 0, 4%, respectively. The accumulated ETc over the growing season was 566.2 mm, corresponding to a 6.9 mm.day-1. Phase III (crop reproductive development) showed higher water demand, with 8.0 mm.day-1. The values of Kc were 0.6 in the initial stage, 0.9 on the middle stage and 0.8 in the final stage. The average value of Kc experimentally determined was lower than that recommended by the FAO-56 in Phase I (emergency), II (vegetative growth) and III (reproductive development) while Stage IV (fruit set and ripening) was higher. Keywords: Crop evapotranspiration, crop coefficient, Bowen ratio

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

Cropp Breeding and Applied Biotechnology ◽

10.1590/s1984-70332012000400006 ◽

2012 ◽

Vol 12 (4) ◽

pp. 269-276

Author(s):

Inocencio Junior de Oliveira ◽

Maurício Dutra Zanotto ◽

Milton Krieger ◽

Roland Vencovsky

Keyword(s):

Inbreeding Depression ◽

Castor Bean ◽

Recurrent Selection ◽

Ricinus Communis ◽

Inbred Lines ◽

Open Pollination ◽

Mean Values ◽

Ricinus Communis L ◽

Mother Plants ◽

Broad Variation

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.

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