Search

A intensidade das doenças e a densidade populacional das pragas variam em função das condições meteorológicas, que afetam tanto patógenos e pragas quanto a sua interação com a planta hospedeira. Para muitas doenças fúngicas, as condições de favorabilidade ao ciclo da doença dependem de um binômio entre temperatura e disponibilidade de água livre.

A inteligência digital, pelas mais variadas formas, chegou ao campo. O uso de tecnologias da informação e da comunicação (TIC) é realidade no meio rural brasileiro. Em maior ou menor grau, produtores rurais, assistentes técnicos e gestores de empresas do setor agrícola são usuários e demandam cada vez mais novos produtos e serviços que envolvem a integração digital. São partes desse segmento: canais online/plataformas para compra de insumos (sementes, fertilizantes agroquímicos, etc.), máquinas e equipamentos e de comercialização da produção; sistemas de planejamento e gestão financeira e de riscos dos empreendimentos rurais; e uso de ferramentas de Agricultura de Precisão.

Our objective was to measure alterations in the micrometeorological conditions surrounding canola seedlingsduring frost periods, and to quantify seedling mortality as a function of straw distribution on the ground surface. The data was acquired from 15 frosts in 2014. We used four treatments, comprising ground surface without straw (SWS), ground surface entirely straw-covered (SEC), sowing line without straw (SLW), and soil with preexisting surface straw (SES), over three experiments. Net radiation (NR), soil heat flux (G), air (Ta), leaf (Lf), rosette (Tr), and surface temperature (Ts), and plant mortality were evaluated. NR was higher in the SEC treatment and lower in the SLW treatment, whereas G was higher on straw-covered ground; Ts and Ta were lower in the SEC than in the other treatments during the most intense frosts. On 06/19, Tr in the SEC and SLW treatments was -0.66 °C and 0.42 °C, respectively; on 08/14, Lf was -3.62 °C and -2.88 °C in the SEC and SLW treatments, respectively. Plant mortality due to the frost on 06/19 was 30% in the SEC treatment, but 0% in the SLW treatment; the frost of 08/14 caused 33.8% mortality in the SEC treatment and 1.25% in the SLW treatment. This therefore showed that removing straw from the sowing line improved the microclimate around the plants, thus reducing canola mortality at the beginning of the growth cycle, which is when frost events most frequently occur. Keywords: air temperature, Brassica napus L., freezing, leaf temperature, microclimate Made available in DSpace on 2021-02-11T19:18:34Z (GMT). No. of bitstreams: 1 Kovaleski-2020-v11.pdf: 1711622 bytes, checksum: 5f3a603669605bfa727cd1d3451ebdef (MD5) Previous issue date: 2020

Made available in DSpace on 2019-12-18T00:37:43Z (GMT). No. of bitstreams: 1 ID448332019v65p7AWN.pdf: 485272 bytes, checksum: c23daec7283beb33479bcf322430f6a3 (MD5) Previous issue date: 2019

Improving rainfed wheat cultivation in central Brazil, where the Cerrado biome (Brazilian savanna) is predominant, remains a bottleneck for future increases in domestic wheat production. In the Cerrado, the limited water availability during the wheat-growing season is an obstacle to increase wheat yield. To address this issue, the physiological and molecular drought response of wheat and the environmental conditions of this region must be better understood. In this review, we characterized the impact of drought on rainfed wheat production in the Cerrado. Based on the peculiarities of this environment, we suggest that certain traits should be prioritized in selection. These traits and their molecular basis are important to raise wheat yields in the Cerrado and also to improve food security in Brazil, one of the top wheat-importing countries in the world. Made available in DSpace on 2020-01-08T18:21:25Z (GMT). No. of bitstreams: 1 ArtigoJorgeCBABImproved.pdf: 1072294 bytes, checksum: 0a575d658535c773bcfa7ae64b91d7c5 (MD5) Previous issue date: 2019

O objetivo deste trabalho foi determinar o número de folhas e o filocrono de genótipos de canola, em resposta a variações térmicas associadas com datas de semeadura. Foram realizados dois experimentos, em delineamento de blocos ao acaso, com arranjo fatorial de genótipos por datas de semeadura (5x2, em 2009, e 2x3 em 2010) e quatro repetições. O número de folhas do caule principal e do primeiro ramo foi determinado três vezes por semana. O filocrono foi estimado pelo inverso do coeficiente angular entre a soma térmica e o número de folhas, para os subperíodos da roseta e do alongamento do caule. O número de folhas no caule variou de 11,5 a 16,4; nos ramos, este número foi, em média, 70% menor. O número de folhas no caule foi maior em semeaduras precoces, e o inverso ocorreu no ramo. O filocrono foi maior no subperíodo da roseta e variou entre 21,4 e 52,9 graus‑dia por folha conforme o genótipo e a data de semeadura. Semeaduras tardias aumentaram o filocrono. Genótipos de ciclo precoce apresentam número de folhas e filocrono menores que genótipos de ciclo médio ou longo, e a variabilidade entre os genótipos acentua-se em semeaduras tardias. The objective of this work was to determine the number of leaves and phyllochron of canola genotypes, in response to thermal variations associated with sowing dates. Two experiments were conducted in a randomized block design, with a factorial arrangement of genotype by sowing date (5x2, in 2009, and 2x3 in 2010), and four replicates. The number of leaves on the main stem and first branch was determined threefold a week. Phyllochron was estimated by the inverse of the slope between the thermal time and the number of leaves, at the rosette stage and at stem elongation. The number of leaves on the main stem ranged from 11.5 to 16.4; this number was on average 70% lower in the first segment. The number of leaves on the main stem was higher in early sowing, and the opposite occurred in the first segment. The phyllochron was higher in the rosette stage, and values ranged from 21.4 to 52.9 degree‑days per leaf, according to genotypes and sowing dates. Late sowing dates increased the phyllochron. Early genotypes have lower number of leaves and phyllochron than medium and late genotypes, and the variability between them increase in late sowings.

El Niño, La Niña e Oscilação Sul. Mecanismos do ENOS. O fenômeno El Niño - Oscilação Sul e a probabilidade de chuvas no sul do Brasil. fenômeno El Niño - Oscilação Sul e a probabilidade de chuvas no nordeste do Brasil. Estratégias de manejo de cultivos com bases em previsões do fenômeno ENOS. Orientações gerais - chuva acima do normal. Orientações gerais - chuva abaixo do normal. Considerações finais. Sugestão de leituras. Made available in DSpace on 2012-02-09T00:03:28Z (GMT). No. of bitstreams: 1 elnino.pdf: 2424971 bytes, checksum: e943527d8a4a92d3a7b0897623fe6fbe (MD5) Previous issue date: 2012-02-08

Made available in DSpace on 2021-08-18T12:09:55Z (GMT). No. of bitstreams: 1 2011revistaplantiodiretov20n126p8.pdf: 2665699 bytes, checksum: 2ce4d6f39c3ffd1f82fbded8e94f7d6b (MD5) Previous issue date: 2011

Made available in DSpace on 2017-09-02T06:09:57Z (GMT). No. of bitstreams: 1 CNPTID10716.pdf: 2113255 bytes, checksum: 287bafb3ef880235c52dfe59d8a37100 (MD5) Previous issue date: 1994-07-21

Made available in DSpace on 2019-06-06T00:30:39Z (GMT). No. of bitstreams: 1 ID445792019v29n168p33PlantioDireto.pdf: 4692423 bytes, checksum: a7785bcf96b2ad64f90aafab50f5085b (MD5) Previous issue date: 2019