ABSTRACT The environment is vital to the agricultural sector since it can cause adversities throughout the entire productive chain. This study evaluated the geographical distribution of zebu breeds in Brazil and correlated their occurrence with environmental variables and the human development index. Herds of purebred zebu cattle (Bos indicus) in Brazil were classified as beef, dairy, and dual-purpose breeds, and all breeds were spatialized in the ArcGIS program. Environmental (precipitation, temperature, relative humidity index) and the human development index (HDI) were examined. We conducted regression and logistic analyses. Zebu cattle showed a lower distribution in the Northeastern states compared to other locations, possibly due to harsh weather conditions, namely long periods of high temperatures and lower precipitation, directly affecting local livestock. Beef breeds were evenly spread throughout the country in regions influenced by environmental variables of higher precipitation, normalized difference vegetation index (NDVI), temperature, relative humidity (RH), and temperature humidity index (THI), as well as properties without smallholder farmers and rivers and streams with riparian vegetation. The regions for dual-purpose and dairy breeds were predominantly cultivated with cutting forages (e.g., sugarcane - Saccharum officinarum), with the integration of crops, livestock and/or forestry (i.e., combining different activities in the same area) and areas with a rotational grazing system (i.e., grazing management), indicating a higher occupation in fertile lands. The Gir breed, the only dairy breed evaluated in this study, was seen in establishments with smallholder farmers, characterized by small to medium farms, and in regions at higher altitudes.

Resumo O trabalho objetivou verificar se a rustificação por flexões caulinares e a pulverização foliar com ácido jasmônico (JA) induz lignificação e altera o desenvolvimento pós-plantio. O experimento iniciou em ambiente protegido seguindo um delineamento inteiramente ao acaso com sete tratamentos (T1) testemunha; (T2) 2,0 μmol L-1 de JA; (T3) 4,0 μmol L-1 de JA; (T4) 6,0 μmol L-1 de JA; (T5) 8,0 μmol L-1 de JA; (T6) 20 flexões; (T7) 40 flexões e cinco repetições. Ao final da aplicação dos tratamentos, avaliaram-se os incrementos na altura, no diâmetro do coleto e número de folhas, assim como o teor de lignina dos tecidos caulinares, das raízes e a rigidez flexural. Em seguida, as mudas rustificadas foram plantadas a campo em delineamento em blocos ao acaso com três mudas por repetição. Aos 90 e 150 dias, avaliaram-se os incrementos na altura e no diâmetro do caule. Mudas dos tratamentos T5 e T6 apresentaram maior resistência à curvatura (0,2885 e 0,3005 N cm-1, respectivamente). O teor de lignina no caule aumentou com aplicações de JA acima de 6,0μmol L-1 e imposição de flexões caulinares. As menores doses de JA (T2, T3 e T4) e o tratamento com 20 flexões caulinares (T6) resultaram em mudas com aumento no incremento no diâmetro do caule. A interpretação da análise de trilha demonstrou que houve aumento na rigidez do caule acompanhado com o aumento no teor de lignina e que estes possuem um maior efeito direto inversamente proporcional com o incremento médio em altura e com o diâmetro do caule após o plantio.

Abstract The objective of this work was to verify if hardening by stem bending and foliar spray of jasmonic acid (JA) induced lignification and if it altered the post-planting development. The experiment was initially conducted in a shade house following a completely randomized design with treatments as (T1) control; (T2) 2.0 μmol L-1 of JA; (T3) 4.0 μmol L-1 of JA; (T4) 6.0 μmol L-1 of JA; (T5) 8.0 μmol L-1 of JA; (T6) 20 stem bending; (T7) 40 stem bending and five replicates. At the end of the imposed treatments, we calculated the increments in height, stem diameter, number of leaves, root and shoot dry biomasses, as well as the lignin content of shoots and roots and the stem stiffness. Afterwards, seedlings were planted following a randomized block design with three seedlings per replicate. At 90 and 150 days after planting, we quantified increments in height and stem diameter. Treatments T5 and T6 showed higher bending strength (0.28885 and 0.3005 N cm-1, respectively). Seedlings submitted to doses above 6.0 μmol L-1 of JA (T5) and imposition of stem bending (T6 and T7) resulted in a higher stem lignin content. The smaller doses of JA (T2, T3 and T4) and 20 stem bending (T6) resulted in seedlings with a relative increase in diameter. The interpretation of path analysis showed weak multicollinearity, that is, the variables under study are not highly correlated and there was a greater direct correlation between the lignin content of the stem with the mean increase in height and diameter of the seedlings after planting.

Abstract This study aimed to quantify the effects of water management during hardening on seedlings of Gallesia integrifolia (Spreng.) Harms, evaluating leaf temperature, morphometric variables, and their performance after hardening in sandy and clayey soil. Water regimes included irrigation for four weeks (daily, every two, three, and four days). Leaf temperature was recorded at the end of each irrigation cycle. Increases in height, root collar diameter, root dry mass, and aerial part dry mass were measured at the end of the hardening period. The seedlings irrigated every two and three days did not significantly differ (p > 0.05) from those irrigated daily. Irrigation every four days reduced the speed of aboveground growth and increased leaf temperature. The seedlings irrigated every three and four days were more resistant to water deficit than those from other treatments, showing severe symptoms of water deficit later.

Resumo Este trabalho objetivou investigar as respostas fotossintéticas em mudas de híbrido 1528 de Eucalyptus urophylla x Eucalyptus grandis submetidas à aplicação de ácido jasmônico (JA) e flexões caulinares. O experimento foi conduzido em casa de sombra utilizando delineamento inteiramente ao acaso com cinco repetições de 20 mudas, com os seguintes tratamentos: T1: controle, T2: 8,0 µmol de JA e T3: 40 flexões caulinares. A taxa de assimilação líquida de CO2 (A), condutância estomática (gs), concentração interna de CO2 (Ci), taxa de transpiração da folha (E), eficiência do uso de água (WUE), eficiência intrínseca do uso de água (iWUE) e eficiência de carboxilação (Fc) foram mensuradas com o auxílio do IRGA. A dose de JA aplicada nas mudas foi insuficiente para alterar as respostas fotossintéticas em relação ao tratamento-controle. Estímulos mecânicos induzidos através de flexões caulinares em mudas do híbrido 1528 de eucalipto promoveram incremento da capacidade fotossintética máxima e máxima assimilação de CO2. Porém, as mudas apresentaram redução na eficiência do uso da água, ou seja, menor eficiência fotossintética quando comparado com as mudas submetidas aos demais tratamentos. Mudas do híbrido 1528 de eucalipto submetidas aos estímulos mecânico e ácido jasmônico apresentaram maior respiração sob níveis baixos de fluxo de fótons fotossinteticamente ativos.

Abstract This work aimed to investigate the photosynthetic responses of Eucalyptus urophylla x Eucalyptus grandis hybrids 1528 submitted to the application of jasmonic acid (JA) and stem bending. The experiment was conducted in a shade house using a completely randomized design with five replicates of 20 seedlings, with the following treatments: T1: control, T2: 8.0 µmol of JA and T3: 40 stem bending. The net assimilation rate of CO2 (A), stomatal conductance (gs), internal CO2 concentration (Ci), leaf transpiration rate (E), water use efficiency (WUE), intrinsic efficiency of use of Water (iWUE) and carboxylation efficiency (Fc) were measured with an IRGA. The dose of JA applied to the seedlings was insufficient to alter the photosynthetic responses in relation to the control treatment. Mechanical stimuli induced by stem bending in eucalyptus hybrid 1528 seedlings promoted an increase in the maximum photosynthetic capacity and maximum assimilation of CO2, but the seedlings presented a reduction in the efficiency of the water use, that is, lower photosynthetic efficiency when compared to the seedlings submitted to other treatments. Seedlings of eucalyptus hybrid 1528 submitted to mechanical stimuli and jasmonic acid show greater respiration under low flow levels of photosynthetically active photons.

RESUMO Para o sucesso do plantio a campo e o êxito de um povoamento florestal, faz-se necessário o uso de mudas florestais que apresentem bom desempenho após o plantio. Este estudo objetivou avaliar a qualidade de mudas de eucalipto, após rustificação com aplicação de ácido jasmônico (JA) e flexões caulinares. O experimento foi realizado em duas etapas, sendo a primeira desenvolvida em ambiente protegido e a segunda realizada a campo. O delineamento experimental foi inteiramente ao acaso, com sete tratamentos (testemunha; 2,0; 4,0; 6,0 e 8,0 μmol L-1 de JA, aplicados semanalmente, por quatro semanas; 20 e 40 flexões caulinares diárias, por quatro semanas), com cinco repetições. Após as quatro semanas de aplicação dos tratamentos, foram determinados os incrementos de altura, de diâmetro do coleto e de número de folhas, de massas de matérias secas das raízes e da parte aérea, de potencial de regeneração de raízes e de índice SPAD. Aos 90 dias após o plantio, foram avaliados os incrementos de altura e de diâmetro do coleto e a relação altura/diâmetro das mudas. A análise de agrupamento por UPGMA evidenciou a formação de três grupos: grupo 1 (testemunha, 2,0; 4,0 e 6,0 μmol L-1 de JA); grupo 2 (8,0 μmol L-1 de JA) e grupo 3 (flexões caulinares). Mudas que apresentaram maior incremento de altura e de número de folhas (grupos I e II), durante a fase de rustificação, apresentaram maiores incrementos de altura e de diâmetro do coleto a campo, aos 90 dias após o plantio. Parâmetros como incrementos de diâmetro do coleto, de potencial de regeneração de raízes e de SPAD, quantificados durante a rustificação de mudas no viveiro, não são preditivos de maior desempenho a campo.

ABSTRACT The objective of this work was to evaluate the quality of seedlings of clone 1528 of eucalyptus after hardening with application of jasmonic acid (JA) and stem bending. The experiment conducted in two stages, the first in protected environment and the second in the field. A completely randomized experimental design with seven treatments (control, 2.0, 4.0, 6.0 and 8.0 μmol L-1 of JA applied weekly for 4 weeks, 20 and 40 daily push-ups for 4 weeks), with five replicates of twenty seedlings. At the end of the treatments, the increase in height (IA), collection diameter (IDC), number of leaves (NF), dry masses of roots and shoot and relative chlorophyll index (SPAD) were determined. At 90 days after planting (field), the increases in height, the collection diameter, and the height / diameter ratio of the seedlings were evaluated. A clustering analysis by UPGMA showed a formation of three groups: group 1 (control, 2.0, 4.0 and 6.0 μmol L-1 of JA); Group 2 (8.0 μmol L-1 of JA) and group 3 (stem bending). Seedlings that showed the greatest increase in height and number of leaves (groups I and II) during the rustification phase obtained to greater increase in height and in the diameter of the field collection at ninety days after planting. Parameters such as increment in collection diameter, root regeneration potential and SPAD quantified during the rustification of seedlings in the nursery are not predictive of higher field performance.

Este trabalho objetivou quantificar os efeitos do manejo hídrico durante a rustificação de mudas de Handroanthus impetiginosus, por meio da termometria foliar e por parâmetros morfométricos de qualidade. Os tratamentos foram: irrigação diária (controle), a cada dois, três e quatro dias, em 60 mudas por tratamento, durante quatro semanas. As mensurações envolveram a medição da temperatura foliar (TF), os incrementos na altura, no diâmetro de colo e na massa seca radicular. As quantificações da TF ocorreram ao final do ciclo de cada manejo de irrigação e, para as demais variáveis, realizaram-se as análises no início e no final da rustificação. Mudas de H. impetiginosus irrigadas diariamente apresentaram maior incremento em diâmetro em relação às irrigadas a cada três dias e as mudas irrigadas a cada quatro dias apresentaram maior crescimento do sistema radicular e redução no crescimento aéreo. Contudo, o uso da termometria infravermelho permitiu aferir a TF em mudas de H. impetiginosus durante a rustificação, verificando que, com o prolongamento do período de estresse hídrico, houve o aumento gradativo da temperatura foliar, sendo a maior delas observada em mudas irrigadas a cada quatro dias.

The present study aimed to quantify the effects of hydric management during the hardening process of Handroanthus impetiginosus seedlings by means of foliar thermography and morphometric parameters of quality. Irrigation treatments of 60 seedlings each were carried out at the following frequencies: daily (control), and every two, three, and four days for four weeks. Measures of leaf temperature (LT), height increment, collar diameter, and root dry mass were performed. Quantification of LT occurred at the end of each irrigation management cycle and analysis of the other variables studied was performed at the beginning and end of the hardening process. Seedlings of H. impetiginosus irrigated daily presented higher diameter increment in relation to those irrigated every three days, and the seedlings irrigated every four days showed higher root system growth and reduction of aerial part growth. The use of infrared thermometry allowed LT assessment in seedlings of H. impetiginosus during hardening. It was possible to verify that the longer the water stress period, the higher the leaf temperature, with the highest temperature observed in seedlings irrigated every four days.

This study examined the effects of crossbreeding low genetic potential cows of Bos indicus origin characterized by Gyr crossed with Holstein-Friesian and Simmental bulls to produce animals in a low input dual purpose system. The farm is situated near Brasilia, in the savannah region of Brazil. The climate of the region is classified as Aw by Köppen. Data was available on 1580 calvings and completed lactations of cows with three genetic types: Gyr, Holstein-Friesian × Gyr and Simmental × Gyr. The bulls ran with the cows all year round and the diet comprised of pasture (mainly Brachiaria and Andropogon) during the summer (rainy season) and milled sugar cane with added urea during the winter (dry season). A mineral salt mixture was available ad libitum. Data was analysed using Statistical Analysis System. The results show that, under low input management conditions, the crossbred cows produce approximately twice the volume of milk per lactation, calve at a younger age and have a shorter open period, but there are no significant differences between crosses for growth rates of the calves or body condition of the cows. In this system, crossbred cows had production higher indices than zebu cattle. The best indices were found for cows calving in the rainy season (September to December) and thinner cows (with body condition 3-5 on a scale of 9).