Environmental group identification for upland rice production in central Brazil.

Upland rice (Oryza sativa L.) production is basically concentrated in four central Brazilian States, Mato Grosso, Goiás, Rondônia and Tocantins. To reduce the genotype and environment (G × E) interactions, the classification of environment groups was proposed. The goal of this study explores possibilities to adjust the upland rice regional breeding systems to optimally fit to the range of environments they are targeting, based on a historical yield data set of the Brazilian Geographic and Statistics Institute (IBGE, www.ibge.gov.br/home/) from 54 microregions. The specific objectives of this study were: (i) to identify and classify environmental groups in the Brazilian upland rice production area; (ii) to validate these environmental groups using yield data set from the upland rice multi-trial experiments (MTEs); (iii) and to identify the most representative site for each environmental group. For this the historical upland rice yield data from 54 microregions were detrented from the effects of technological advances and adjusted to the reference year, 2006. The adjusted yield data were used to build a matrix, which was submitted to a cluster analysis allowing the identification of three different environmental groups. These groups were classified as: highly favorable environment (HFE); favorable environment (FE); and less favorable environment (LFE). The HFE is less affected by inter-annual rainfall variability than the other two groups. The upland rice breeding programs must take into account the differences among the environmental groups to conduct their trials and suggest genotypes for the upland production area

Identification of mega environments in the Brazilian upland rice production area.

The goal of this study explores possibilities to adjust the upland rice regional breeding systems to optimally fit the range of environments they are targeting, based on a historical yield data set of the IBGE. The specific objectives of this study were: to identify and classify environment groups in the Brazilian upland rice (UPR) production area; to validate these environment groups using yield data set from the upland rice multi-trial experiments (MTEs); and to identify the most representative site for each environment group. For that, the historical upland rice yield data from 54 microregions were detrented from the effects of technological advances and adjusted to the reference year, 2006. A matrix was built with the adjusted yield data and submitted to a cluster analysis allowing to identify three different environment groups. These groups were classified as: high favourable environment (HFE); favourable environment (FE); and low favourable environment (LFE). The HFE has as characteristic being less affected by inter-annual rainfall variability than the other two. KEYWORDS: environment classification, cluster analysis, yield

Estimativa do saldo de radiação sobre um cultivo de videira BRS Clara com e sem tela de sombreamento.

O objetivo deste trabalho foi elaborar modelos de estimativa do saldo de radiação sobre videiras cultivadas na região noroeste de São Paulo a partir da radiação solar global.Resumo

Yield simulation for maize production maximization in the State of Goiás, Brazil, by using the Ceres-Maize model.

The aim of this study was to determine the best cultivar and sowing date to be use for maize in state of Goiás, to maximize the maize grain yield. It was used the Cropping System Model (CSM)-CERES-Maize, part of the DSSAT (Decision Support System for Agrotechnology Transfer) for yield simulation of two cultivars (DAS CO32 and DKB 333B) for seven sowing dates (01/11, 10/11, 20/11, 01/12, 10/12, 20/12 and 30/12), for eight locations in the state of Goiás. The meteorological data were obtained from SECTEC/SIMEHGO weather stations, for periods ranging from 5 to 27 years. The decision criteria used were the yield variability between the sowing dates, comparison of exceedance probability for yield and percentage of yield reduction due to water deficiency. The results showed that the highest simulated yield for the state of Goiás was obtained for DAS CO32 cultivar, for the sowing date of 10/12. This sowing date also showed the lowest percentage of yield reduction

Risco climático do consórcio milho com braquiária em Mato Grosso do Sul.

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Deficiência hídrica acumulada como índice de risco de incêndios florestais.

O trabalho analisa riscos de incêndios florestais em locais onde se dispõe apenas de dados de temperatura e chuva; apresenta os balanços hídricos climatológicos dos anos de 1999 e 2000, que caracterizam os períodos de maiores riscos de ocorrência de incêndios, comparando-os ainda ao balanço hídrico normal para Piracicaba-SP

Use of advisory systems and plastic covering in the control of downy mildew on vines of São Paulo, Brazil.

The Northwest region of the State of São Paulo is one of the main producers of table grapes in Brazil. However, the climate of this region is highly favorable for fungal diseases during the growing season. The use of disease advisory systems and plastic covers are promising alternatives for rationalize the use of fungicides for disease control. Thus, the objective of this study was to evaluate the efficacy of the combination of advisory systems and plastic covering in the control of downy mildew (Plasmopara viticola) on vineyards of the Northwest region of State of São Paulo, Brazil. The experiments were carried out at the EMBRAPA - Tropical Viticulture Experimental Station, located in Jales, SP, Brazil. Three rows of 120 m of the seedless grape cultivar ?BRS Morena? (Vitis vinifera), spaced with 3.0 m between plants were conducted during 2012 and 2013 growing seasons. Half of the vineyard was covered with braided polypropylene plastic film installed over a metallic arc-shaped structure and the other half with black screen, with 18% of shading. The experimental design was randomized blocks composed of five treatments, with six repetitions per covered environment. The treatments were defined by the different grapevine downy mildew management : (CO) Control (no sprays against downy mildew); (CA) Conventional control (calendar); (BA) Advisory system 'Rule 3-10'; (MA25) Advisory system with low-infection efficiency - i0 > 25%; and (MA75) Advisory system with high infection efficiency ? i0 > 75%. According to the results, the plastic cover alone was not effective in controlling downy mildew. Under plastic cover, all advisory systems tested were as effective as the control provided by treatment calendar (CA), however, with 75% less fungicide application (MA75) than CA.Resumo expandido

Evapotranspiration and CROP COEFFICIENTS of a Coffee Plantation in Southern Brazil.

Coffee plants have been cultivated in Brazil since 1727 and have a great importance for the economy of the country. Brazil has more than 2,400,000 ha of commercial plantations of coffee, and in the last 15 years they have been expanded to regions where drought is more intense and normally coincides with fruit expansion, what became irrigation very important and somewhat essential in such regions (Camargo, 1985). Currently, it is estimated that about 200,000 ha of coffee plantations are being grown under irrigation in the country. In spite of great advances in technologies for water supply and the economic importance of coffee crop, irrigation management have been made inadequately in the most Brazilian coffee regions due to the large amount of water applied, which normally exceeds the crop needs (Camargo, 2002). Regarding this point, Carr (2001) postulated that estimates of water requirements for irrigation purposes are still imprecise for this crop and, probably, subject to large errors depending on the local circumstances and the system of irrigation used. The objective of this study was to assess the water use by a drip-irrigated coffee plantation in Southern Brazil using different measurement techniques in order to determine the two components of crop coefficients (Kc), i.e. basal (Kcb) and evaporative (Kce) components. The study also evaluated the micrometeorological factors affecting transpiration, crop and reference evapotranspiration relationships and its implications on actual rates of water use and on irrigation management

Rice yield estimation based on weather conditions and on technological level of production systems in Brazil.

The objective of this work was to evaluate an estimation system for rice yield in Brazil, based on simple agrometeorological models and on the technological level of production systems. This estimation system incorporates the conceptual basis proposed by Doorenbos & Kassam for potential and attainable yields with empirical adjusts for maximum yield and crop sensitivity to water deficit, considering five categories of rice yield. Rice yield was estimated from 2000/2001 to 2007/2008, and compared to IBGE yield data. Regression analyses between model estimates and data from IBGE surveys resulted in significant coefficients of determination, with less dispersion in the South than in the North and Northeast regions of the country. Index of model efficiency (E1') ranged from 0.01 in the lower yield classes to 0.45 in higher ones, and mean absolute error ranged from 58 to 250 kg ha-1, respectively