Resumo
Over the last decades, stable fly (Stomoxys calcitrans) outbreaks associated with agricultural and/or livestock production systems have become a serious problem in some Brazilian locations. This article presents a survey on the history, evolution and mapping of such outbreaks in Brazil over five decades (1971-2020). Outbreaks (n= 579) were recorded in 285 municipalities from 14 states, mainly associated with by-products from the ethanol industry (82.7%), in natura organic fertilizers (12.6%) and integrated crop-livestock systems (3.1%). Few cases were reported until the mid-2000s, progressively increasing since then. Outbreaks associated with ethanol mills occurred in 224 municipalities, mainly in Southeast and Midwest states, while those associated with organic fertilizers (mainly poultry litter and coffee mulch) affected 39 municipalities, mostly in the Northeast and Southeast states. More recently, outbreaks in integrated crop-livestock systems during the rainy season have occurred in Midwest states. This survey highlights the magnitude of the problem of stable fly outbreaks in Brazil and its relationship with environmental public policies, agricultural production chains and regional trends. Specific public actions and policies are urgently needed to prevent their occurrence and impact in the affected regions.(AU)
Nas últimas décadas, surtos da mosca-dos-estábulos (Stomoxys calcitrans), associados a sistemas de produção agrícola e/ou pecuária, tornaram-se um grave problema em algumas localidades brasileiras. Este artigo apresenta um levantamento sobre a história, evolução e mapeamento desses surtos no Brasil ao longo de cinco décadas (1971-2020). Surtos (n= 579) foram registrados em 285 municípios de 14 estados, principalmente associados a subprodutos da indústria do etanol (82,7%), fertilizantes orgânicos in natura (12,6%) e sistemas de integração lavoura-pecuária (3,1%). Poucos casos foram registrados até meados dos anos 2000, aumentando progressivamente desde então. Surtos associados a usinas de etanol ocorreram em 224 municípios, principalmente no Sudeste e Centro-Oeste, enquanto surtos associados a fertilizantes orgânicos (principalmente esterco aviário e palha de café) afetaram 39 municípios, principalmente nos estados do Nordeste e Sudeste. Mais recentemente, surtos em sistemas de integração lavoura-pecuária, durante a estação chuvosa, têm ocorrido no Centro-Oeste. Este levantamento ressalta a magnitude do problema dos surtos da mosca-dos-estábulos no Brasil e sua relação com políticas públicas ambientais, cadeias produtivas agrícolas e tendências regionais. Ações e políticas públicas específicas são urgentemente necessárias para prevenir sua ocorrência e impacto nas regiões afetadas.(AU)
Assuntos
Animais , Muscidae , Monitoramento Epidemiológico/veterinária , BrasilResumo
Mulching use in agriculture has been known since 1802 as the practice of spreading dry leaves and straw on the soil to prevent erosion and water loss. Our study evaluated the mulch effectiveness in the establishment of regenerating seedlings and its contribution to the control of exotic grasses. The studies were carried out in an ecological restoration area in the municipality of Itapira-SP. The treatment with mulching consisted in chemical desiccation with glyphosate herbicide application, keeping the dry grass on the ground. In the control treatment, after chemical weeding, the grass was removed with manual mowing, exposing the soil. Eight months after implantation, we sampled all regenerating seedlings in 100 plots of 50 x 50 cm in each treatment. We considered as seedlings all individuals of tree species less than 100 cm tall. We calculated richness, abundance, similarity, and the relationship of the frequency of seedlings to the height of the mulch. We sampled eight species with 42 seedlings, with only one not identified. The highest abundance and species richness were found in the treatment with mulch (n = 34 individuals; eight species), the most abundant being Schinus terebinthifoliaRaddi (14 individuals) followed by Solanum mauritianumScop. (11 individuals), and Platypodium elegansVog. (three individuals). The presence of exoticgrasses was lower in the plots of the mulching (13%) compared to the control treatment (67%). The highest frequency of seedlings was obtained with mulch height from 21 to 37 cm. We suggest that adaptive management practices, such as the use of the mulching technique, can be implemented in ecological restoration areas, because they favor the natural regeneration of native seedlings and can contribute to the control of exotic grasses, but the height of the layer must be controlled.(AU)
Assuntos
Regeneração , Árvores , Erosão , Plântula , PoaceaeResumo
Banana is one of the most produced fruit crops in Brazil and has great economic, social and nutritional importance. Factors such as water availability and well-managed fertilization are fundamental to achieving profitable yields. The aim of this study was to examine the agronomic performance and water use efficiency of 'BRS Princesa' banana under combinations of irrigation systems, fertilization methods and mulching, during three production cycles. The experiment was laid out in a randomized-block design with four replicates. Treatments consisted of a combination of the localized irrigation system, fertilization strategy and mulching, as follows: Drip irrigation with manual fertilization; Micro-sprinkler irrigation with manual fertilization; Drip fertigation with mulch; Drip fertigation without mulch; Micro-sprinkler fertigation with mulch; and Microsprinkler fertigation without mulch. The plants were irrigated every three days, using three 4-L h-1 drippers per plant or a 64-L h-1 micro-sprinkler for every four plants. The following variables were analyzed: number of leaves, plant height, pseudostem circumference, number of hands, hand yield, water and nutrient (nitrogen and potassium) use efficiency and earliness. The micro-sprinkler system provided a greater pseudostem circumference without the presence of mulch. Plants under micro-sprinkler fertigation with mulching grew taller. The banana yield was higher when fertigation was used than with manual fertilization, regardless of the irrigation system. Plants grown in mulched soil were more productive than those grown in bare soil. The use of mulch increased water, nitrogen and potassium use efficiency when compared with cultivation in bare soil. Drip-irrigated plants showed earlier production than those irrigated with micro-sprinklers.(AU)
A bananeira é sendo uma das fruteiras mais produzidas no Brasil e possui grande importância econômica, social e alimentícia. Fatores como disponibilidade de água e adubação bem manejados são fundamentais para obtenção de produtividades rentáveis. Objetivou-se com este trabalho, avaliar o desempenho agronômico e a eficiência no uso da água da bananeira 'BRS Princesa' sob combinações de sistemas de irrigação, métodos de adubação e cobertura morta, durante três ciclos de produção. O delineamento experimental foi o de blocos casualizados, com quatro repetições. Os tratamentos consistiram na combinação do sistema de irrigação localizada, estratégia de adubação e uso de cobertura morta: a) Irrigação por gotejamento com adubação manual; b) Irrigação por microaspersão com adubação manual; c) Fertirrigação por gotejamento com cobertura morta; d) Fertirrigação por gotejamento sem cobertura morta; e) Fertirrigação por microaspersão com cobertura morta e f) Fertirrigação por microaspersão sem cobertura morta. As irrigações ocorreram a cada três dias, utilizando-se três gotejadores de 4 L h-1 por planta ou um microaspersor de 64 L h-1 para cada quatro plantas. As variáveis estudadas foram: número de folhas, altura da planta, perímetro do pseudocaule, número de pencas, produtividade, eficiência no uso da água e de nutrientes (nitrogênio e potássio) e precocidade. A microaspersão proporcionou maior circunferência do pseudocaule sem a presença da cobertura do solo. Plantas sob fertirrigação por microaspersão com cobertura do solo expressam maiores alturas. A produtividade da bananeira foi maior quando utilizada a fertirrigação em detrimento da adubação manual, independente do sistema de irrigação. As plantas cultivadas em solo coberto foram mais produtivas que aquelas cultivadas em solo descoberto. O uso da cobertura morta elevou a eficiência do uso da água, de nitrogênio e de potássio em relação ao cultivo em solo descoberto. As plantas irrigadas por gotejamento apresentaram produção mais precoce que irrigadas por microaspersão.(AU)
Assuntos
Usos da Água , Folhas de Planta , Produtos Agrícolas , Musa , Fertilização , NitrogênioResumo
The adjustment in the growing season associated with cultural practices can mitigate the negative effects of salinity on crop production. In this context, the objective of this study was to evaluate the production components of watermelon cv. Crimson Sweet under the effects of irrigation with saline water, soil cover and potassium doses in crops during dry and rainy seasons. The treatments were arranged in a split plot with 2 x 2 x 4 scheme, with the electrical conductivity of the irrigation water (0.3 and 3.0 dS m-1) in the main plot, and the combinations between soil mulch (without and with) and doses of potassium (0, 40, 80 and 120 kg ha-1 of K2 O) in the subplots, distributed in randomized blocks. Final stand, number of fruits per plant, average fruit weight, production per plant and yield were evaluated. The data were subjected to analysis of variance and potassium doses were evaluated by regression. In the rainy season, watermelon was more productive than in the dry season even under irrigation, with higher number of fruits and production per plant and yield. Irrigation using water with electrical conductivity of 3.0 dS m-1 should be used with moderation in watermelon crop, as it did not compromise yield. Potassium chloride application is not recommended in soil with intermediate potassium content, because it reduced the number of fruits per plant and yield. The use of mulch is recommended in watermelon cultivation, since it increased the number of fruits and production per plant.(AU)
A adequação na época de cultivo associada às práticas culturais pode mitigar os efeitos negativos da salinidade à produção agrícola. Nesse sentido, objetivou-se com esta pesquisa avaliar componentes de produção de melancia cv. Crimson Sweet sob efeitos da irrigação com água salina, cobertura do solo e doses de potássio nos cultivos em épocas de estiagem e chuvosa. Os tratamentos foram organizados em parcela subdividida no esquema 2 x 2 x 4, sendo a condutividade elétrica da água de irrigação (0,3 e 3,0 dS m-1) a parcela principal, e as combinações entre cobertura morta do solo (sem e com) e doses de potássio (0, 40, 80 e 120 kg ha-1 de K2 O) as subparcelas, distribuídos em blocos casualizados. Avaliou-se o estande final, número de frutos por planta, massa média dos frutos, produção por plantas e produtividade. Os dados foram submetidos as análises de variância e as doses de potássio avaliadas por regressão. Na época chuvosa, a melancieira foi mais produtiva que no período de estiagem mesmo sob irrigação, com maior número de frutos, produção por planta e maior produtividade. A irrigação com água de 3,0 dS m-1 de condutividade elétrica pode ser recomendada com moderação na cultura da melancieira, visto que não comprometeu a produtividade. A aplicação de cloreto de potássio não é recomendada em solo com teor médio de potássio, pois reduziu o número de frutos por planta e a produtividade. O uso de cobertura morta é indicado no cultivo de melancieira, uma vez que aumentou o número de frutos e a produção por planta.(AU)
Assuntos
Águas Salinas , 24444 , Estação Chuvosa , Citrullus , Produção AgrícolaResumo
ABSTRACT: Mechanical harvesting leaves in its wake a considerable amount of straw in the field, which can be effectively utilized to improve the soil condition and sugarcane yield. However, there is no specific information as to the quantity of straw mulch required to achieve such effects and as to whether it can be used in other sectors for bioelectricity and ethanol production. The aim of this research was to evaluate the effect of removing different amounts of straw from the field and its impact on the yield and industrial quality of sugarcane ratoons. The experiment was carried out on Rhodic soil where six treatments were evaluated including 0 %, 25 % (5 Mg ha1), 50 % (10 Mg ha1), 75 % (15 Mg ha1), 100 % (20 Mg ha1) straw on the soil surface and burned sugarcane (where 100 % of the straw was burned). The influence on yield and industrial quality was calculated using total soluble solids, Pol (Apparent sucrose content), apparent purity, total sugars, reducing sugars and fiber. Shifting the harvesting system from burned cane to growing under straw mulch improved crop yield as well as favoring sugar contents during water deficit conditions. The straw left on the soil did not affect industrial quality in any way during the trials; however, under drought conditions, treatments with 50 and 75 % of straw resulted in a 76 % higher yield compared to burned sugarcane, and 29 % more than the 0 %, 25 % to 100 % treatments of straw mulch thus favoring higher sugar production. The removal of 50 % of the straw caused no damage to the sugarcane crop.
Resumo
ABSTRACT: Mechanical harvesting leaves in its wake a considerable amount of straw in the field, which can be effectively utilized to improve the soil condition and sugarcane yield. However, there is no specific information as to the quantity of straw mulch required to achieve such effects and as to whether it can be used in other sectors for bioelectricity and ethanol production. The aim of this research was to evaluate the effect of removing different amounts of straw from the field and its impact on the yield and industrial quality of sugarcane ratoons. The experiment was carried out on Rhodic soil where six treatments were evaluated including 0 %, 25 % (5 Mg ha1), 50 % (10 Mg ha1), 75 % (15 Mg ha1), 100 % (20 Mg ha1) straw on the soil surface and burned sugarcane (where 100 % of the straw was burned). The influence on yield and industrial quality was calculated using total soluble solids, Pol (Apparent sucrose content), apparent purity, total sugars, reducing sugars and fiber. Shifting the harvesting system from burned cane to growing under straw mulch improved crop yield as well as favoring sugar contents during water deficit conditions. The straw left on the soil did not affect industrial quality in any way during the trials; however, under drought conditions, treatments with 50 and 75 % of straw resulted in a 76 % higher yield compared to burned sugarcane, and 29 % more than the 0 %, 25 % to 100 % treatments of straw mulch thus favoring higher sugar production. The removal of 50 % of the straw caused no damage to the sugarcane crop.
Resumo
Mechanical harvesting leaves in its wake a considerable amount of straw in the field, which can be effectively utilized to improve the soil condition and sugarcane yield. However, there is no specific information as to the quantity of straw mulch required to achieve such effects and as to whether it can be used in other sectors for bioelectricity and ethanol production. The aim of this research was to evaluate the effect of removing different amounts of straw from the field and its impact on the yield and industrial quality of sugarcane ratoons. The experiment was carried out on Rhodic soil where six treatments were evaluated including 0 %, 25 % (5 Mg ha1), 50 % (10 Mg ha1), 75 % (15 Mg ha1), 100 % (20 Mg ha1) straw on the soil surface and burned sugarcane (where 100 % of the straw was burned). The influence on yield and industrial quality was calculated using total soluble solids, Pol (Apparent sucrose content), apparent purity, total sugars, reducing sugars and fiber. Shifting the harvesting system from burned cane to growing under straw mulch improved crop yield as well as favoring sugar contents during water deficit conditions. The straw left on the soil did not affect industrial quality in any way during the trials; however, under drought conditions, treatments with 50 and 75 % of straw resulted in a 76 % higher yield compared to burned sugarcane, and 29 % more than the 0 %, 25 % to 100 % treatments of straw mulch thus favoring higher sugar production. The removal of 50 % of the straw caused no damage to the sugarcane crop.(AU)
Assuntos
Saccharum , Biomassa , Tratamento do Solo , 24444Resumo
The mechanisms of seeding machines to cut the mulch, mobilize the topsoil and deposit the seeds in the furrows modify soil properties and interfere in crop growth. This study sought to evaluate the effects of furrow openers and scarification on the attributes of a South Brazilian latosol (Bruno oxisol) and crop yields. The treatments were: double disc furrow opener (DD); shovel type furrow opener (S); shoe type furrow opener (SH); and scarification followed by double disc furrow opener (SC+DD). Samples were collected at 0-10, 10-20 and 20-40 cm and evaluated for soil physical (bulk density, total porosity, macro and microporosity), chemical (pH, Ca, Mg, K and P) and organic carbon content. The normality of data was tested, and the analysis of the variance was performed (F test, p 0.05), and the means was compared by Tukeys test (p=0.05). Soil attributes were analyzed for each layer separately. After four years it was observed that the bulk density is still affected by scarification, which reduces it. The successive use of DD in the winter for the implantation of the crops caused the homogenization of the soil, although with no differences on the other physical and chemical properties. In general, grain yield and dry mass were higher in the treatment that used scarification and the double disc during the summer, and the shoe type when compared to shovel type.
Os mecanismos das semeadoras para cortar os resíduos vegetais, mobilizar a camada superficial do solo e depositar as sementes nos sulcos modificam os atributos do solo e interferem no crescimento das culturas. Portanto, comparar os efeitos destes mecanismos é necessário. Este estudo objetivou avaliar o efeito de diferentes mecanismos sulcadores de semeadora-adubadoras, e da escarificação, sobre atributos de um Latossolo Bruno alumínico típico, e na produtividade de culturas. Os tratamentos avaliados foram: sulcadores tipo disco duplo (DD); sulcadores tipo guilhotina (GUI); sulcadores tipo facão (FA); e escarificação seguido de disco duplo (ESC+DD). Amostras de solo foram coletadas nas camadas de 0-10, 10-20 e 20-40 cm para avaliar atributos físicos (densidade, porosidade total, macro e microporosidade), químicos (pH, Ca, Mg, K e P) e conteúdo de carbono orgânico. Avaliou-se a matéria seca da parte aérea da soja e a produtividade das culturas em três safras distintas. Foi testada a normalidade dos dados, e realizada a análise da variância (teste F a p 0,05), e apresentando significância as médias foram comparadas pelo teste de Tukey a 5%. Os atributos de solo foram analisados para cada camada separadamente. Após quatro anos observou-se que a densidade do solo ainda é afetada pela escarificação, que a reduziu. A utilização sucessiva de DD no inverno para a implantação das culturas provocou homogeneização do solo, não diferindo as demais propriedades físicas e químicas. De maneira geral a produtividade de grãos e massa seca foram superiores no tratamento onde houve escarificação, utilização do disco duplo no verão e utilização do facão, em comparação a guilhotina.
Resumo
The mechanisms of seeding machines to cut the mulch, mobilize the topsoil and deposit the seeds in the furrows modify soil properties and interfere in crop growth. This study sought to evaluate the effects of furrow openers and scarification on the attributes of a South Brazilian latosol (Bruno oxisol) and crop yields. The treatments were: double disc furrow opener (DD); shovel type furrow opener (S); shoe type furrow opener (SH); and scarification followed by double disc furrow opener (SC+DD). Samples were collected at 0-10, 10-20 and 20-40 cm and evaluated for soil physical (bulk density, total porosity, macro and microporosity), chemical (pH, Ca, Mg, K and P) and organic carbon content. The normality of data was tested, and the analysis of the variance was performed (F test, p 0.05), and the means was compared by Tukeys test (p=0.05). Soil attributes were analyzed for each layer separately. After four years it was observed that the bulk density is still affected by scarification, which reduces it. The successive use of DD in the winter for the implantation of the crops caused the homogenization of the soil, although with no differences on the other physical and chemical properties. In general, grain yield and dry mass were higher in the treatment that used scarification and the double disc during the summer, and the shoe type when compared to shovel type.(AU)
Os mecanismos das semeadoras para cortar os resíduos vegetais, mobilizar a camada superficial do solo e depositar as sementes nos sulcos modificam os atributos do solo e interferem no crescimento das culturas. Portanto, comparar os efeitos destes mecanismos é necessário. Este estudo objetivou avaliar o efeito de diferentes mecanismos sulcadores de semeadora-adubadoras, e da escarificação, sobre atributos de um Latossolo Bruno alumínico típico, e na produtividade de culturas. Os tratamentos avaliados foram: sulcadores tipo disco duplo (DD); sulcadores tipo guilhotina (GUI); sulcadores tipo facão (FA); e escarificação seguido de disco duplo (ESC+DD). Amostras de solo foram coletadas nas camadas de 0-10, 10-20 e 20-40 cm para avaliar atributos físicos (densidade, porosidade total, macro e microporosidade), químicos (pH, Ca, Mg, K e P) e conteúdo de carbono orgânico. Avaliou-se a matéria seca da parte aérea da soja e a produtividade das culturas em três safras distintas. Foi testada a normalidade dos dados, e realizada a análise da variância (teste F a p 0,05), e apresentando significância as médias foram comparadas pelo teste de Tukey a 5%. Os atributos de solo foram analisados para cada camada separadamente. Após quatro anos observou-se que a densidade do solo ainda é afetada pela escarificação, que a reduziu. A utilização sucessiva de DD no inverno para a implantação das culturas provocou homogeneização do solo, não diferindo as demais propriedades físicas e químicas. De maneira geral a produtividade de grãos e massa seca foram superiores no tratamento onde houve escarificação, utilização do disco duplo no verão e utilização do facão, em comparação a guilhotina.(AU)
Resumo
ABSTRACT: The mysterious ancient Mesoamerican Indian crop chia (Salvia hispanica) is revived and expanding worldwide due to its richness of valuable nutraceuticals such as -linolenic acid (ALA), antioxidants, food fiber, gels, and proteins. We carried out a pilot experiment on chia planting in non-frost Sichuan Basin, at Hechuan Base (300 43 N, 1067 41 E, 216 m), Southwest University, Chongqing, China. The split-plot trial contained two factors, 3 spring-summer sowing times as main plots, and 6 densities as subplots, with 3 replicates. Phenological, botanical, adversity, yield, and seed quality traits were investigated. Plants were very tall, suffered from lodging, and flowered in mid-October. Sichuan Basin can be considered as a north edge for growing chia, with low yield (680 kg/hectare) because of insufficient seed filling and maturation in autumn-winter season (1000-seed weight of 1.14 g). However, its ALA content is 5 percent points higher than the seed-donor commercial bottle (65.06%/63.96% VS 59.35%/59.74% for black/white seeds), accompanied by decrease oleic and stearic acid, while linoleic acid and palmitic acid are equivalent. Considering its short-day habit, it is recommended to try sowing in middle summer (from late June to early August) to avoid too long growing period, excessive vegetative growth, and waste of field and climate resources caused by spring-summer sowing. Furthermore, winter sowing of chia with mulch cover could also be tried, with an expectation of harvesting in summer. Most importantly, only when the photoperiod-insensitive early flowering stocks are created, chia can be recommended as a low-risk crop to the farmers of this region.
RESUMO: A chia (Salvia hispanica) é cultivada em todo o mundo por sua riqueza de nutrientes nutracêuticos valiosos, tais como a-ácido linolênico (ALA), antioxidantes, fibras alimentares, géis e proteínas. Entretanto, não há informações sobre sua performance agronômica se cultivada aos 30N na China. Assim, realizou-se um experimento com o cultivo de chia na base Hechuan (30°043N, 106°741E, 216m, que não apresenta geada) da Southwest University, Chongqing, China. O delineamento em parcela subdividida contém dois fatores,três épocas de semeadura na primavera-verão como parcelas principais e seis densidades de sementes como subparcelas, com três repetições. Foram investigados os caracteres fenológicos, botânicos, de adversidade, rendimento e qualidade da semente. As plantas se tornaram altas, acamarame floresceram em meados de outubro. A bacia de Sichuan pode ser considerada como uma fronteira limítrofe norte para o crescimento da chia, com baixo rendimento (680kg ha-1) devido ao enchimento e amadurecimento insuficientes na estação outono-inverno (peso de 1000 sementes de 1,14g). No entanto, o seu conteúdo de ALA é de 5 pontos percentuais mais elevado do que a semente comercial, 65,06%/63,96% contra 59,35%/59,74% para as sementes pretas/brancas, respectivamente, acompanhado por diminuição de ácido oleico e ácido esteárico, enquanto que o ácido linoleico e o ácido palmítico são equivalentes. Considerando o seu hábito de dia curto, recomenda-se semear no meio do verão,de junho a início de agosto, para evitar um tempo de cultivo muito longo, desenvolvimento vegetativo excessivo e desperdício de recursos de campo e clima causados pela semeadura de primavera-verão. Além disso, a semeadura de inverno da chia com cobertura morta também poderia ser realizada, com expectativa de colheita no verão. Mais importante ainda, somente quando os estoques de floração precoce insensíveis ao fotoperíodo são criados, pode-se recomendar como uma cultura de baixo risco para os agricultores desta região.
Resumo
The mysterious ancient Mesoamerican Indian crop chia (Salvia hispanica) is revived and expanding worldwide due to its richness of valuable nutraceuticals such as α-linolenic acid (ALA), antioxidants, food fiber, gels, and proteins. We carried out a pilot experiment on chia planting in non-frost Sichuan Basin, at Hechuan Base (30 ̊0′ 43′′ N, 106 ̊7′ 41′′ E, 216 m), Southwest University, Chongqing, China. The split-plot trial contained two factors, 3 spring-summer sowing times as main plots, and 6 densities as subplots, with 3 replicates. Phenological, botanical, adversity, yield, and seed quality traits were investigated. Plants were very tall, suffered from lodging, and flowered in mid-October. Sichuan Basin can be considered as a north edge for growing chia, with low yield (680 kg/hectare) because of insufficient seed filling and maturation in autumn-winter season (1000-seed weight of 1.14 g). However, its ALA content is 5 percent points higher than the seed-donor commercial bottle (65.06%/63.96% VS 59.35%/59.74% for black/white seeds), accompanied by decrease oleic and stearic acid, while linoleic acid and palmitic acid are equivalent. Considering its short-day habit, it is recommended to try sowing in middle summer (from late June to early August) to avoid too long growing period, excessive vegetative growth, and waste of field and climate resources caused by spring-summer sowing. Furthermore, winter sowing of chia with mulch cover could also be tried, with an expectation of harvesting in summer. Most importantly, only when the photoperiod-insensitive early flowering stocks are created, chia can be recommended as a low-risk crop to the farmers of this region.(AU)
A chia (Salvia hispanica) é cultivada em todo o mundo por sua riqueza de nutrientes nutracêuticos valiosos, tais como a-ácido linolênico (ALA), antioxidantes, fibras alimentares, géis e proteínas. Entretanto, não há informações sobre sua performance agronômica se cultivada aos 30 ̊N na China. Assim, realizou-se um experimento com o cultivo de chia na base Hechuan (30°043N, 106°741E, 216m, que não apresenta geada) da Southwest University, Chongqing, China. O delineamento em parcela subdividida contém dois fatores,três épocas de semeadura na primavera-verão como parcelas principais e seis densidades de sementes como subparcelas, com três repetições. Foram investigados os caracteres fenológicos, botânicos, de adversidade, rendimento e qualidade da semente. As plantas se tornaram altas, acamarame floresceram em meados de outubro. A bacia de Sichuan pode ser considerada como uma fronteira limítrofe norte para o crescimento da chia, com baixo rendimento (680kg ha-1) devido ao enchimento e amadurecimento insuficientes na estação outono-inverno (peso de 1000 sementes de 1,14g). No entanto, o seu conteúdo de ALA é de 5 pontos percentuais mais elevado do que a semente comercial, 65,06%/63,96% contra 59,35%/59,74% para as sementes pretas/brancas, respectivamente, acompanhado por diminuição de ácido oleico e ácido esteárico, enquanto que o ácido linoleico e o ácido palmítico são equivalentes. Considerando o seu hábito de dia curto, recomenda-se semear no meio do verão,de junho a início de agosto, para evitar um tempo de cultivo muito longo, desenvolvimento vegetativo excessivo e desperdício de recursos de campo e clima causados pela semeadura de primavera-verão.(AU)
Assuntos
Salvia/crescimento & desenvolvimento , Ácido alfa-Linolênico , 24444 , ChinaResumo
In the Amazonian region, P is often a primary factor limiting sustainable agrosystems. We compared the efficiencies of local aluminous phosphate (ALP) and single superphosphate (SSP) under a cover of leguminous residues to determine the fate of P sources in an Amazonian soil with hardsetting characteristics. The experiment followed a randomized block design with four replications and the following treatments: ALPU, i.e. ALP plus urea (U); ALPL, i.e., ALP plus leucaena (L); SSPU, i.e., SSP plus urea; SSPL, i.e., SSP plus leucaena; and BS, i.e., bare soil (without residues). To assess the residual values of the P sources, we used a sequence of crops consisting of maize, cowpea and cassava. Both ALP and SSP exhibited low P efficiency in BS. The greatest amounts of P and N uptake in the plots where P sources and leucaena residues were added, as in those covered with leucaena residue, resulted in higher productivity levels. These differences are important for the adoption of beneficial soil management practices and the use of P sources to enhance efficiency in tropical soils. The use of residues increased the P use efficiency of both P sources, as it enhanced the uptake of both N and soluble P. The replacement of SSP with ALP may be advantageous in the second year of planting with high-demand crops, but the P of the SSP retained in the minus soluble fractions may be available if the SSP is used in P-depleting crops combined with no-tillage underneath a mulch of residues.
Assuntos
Fósforo , Solo , Compostos de Nitrogênio , FabaceaeResumo
In the Amazonian region, P is often a primary factor limiting sustainable agrosystems. We compared the efficiencies of local aluminous phosphate (ALP) and single superphosphate (SSP) under a cover of leguminous residues to determine the fate of P sources in an Amazonian soil with hardsetting characteristics. The experiment followed a randomized block design with four replications and the following treatments: ALPU, i.e. ALP plus urea (U); ALPL, i.e., ALP plus leucaena (L); SSPU, i.e., SSP plus urea; SSPL, i.e., SSP plus leucaena; and BS, i.e., bare soil (without residues). To assess the residual values of the P sources, we used a sequence of crops consisting of maize, cowpea and cassava. Both ALP and SSP exhibited low P efficiency in BS. The greatest amounts of P and N uptake in the plots where P sources and leucaena residues were added, as in those covered with leucaena residue, resulted in higher productivity levels. These differences are important for the adoption of beneficial soil management practices and the use of P sources to enhance efficiency in tropical soils. The use of residues increased the P use efficiency of both P sources, as it enhanced the uptake of both N and soluble P. The replacement of SSP with ALP may be advantageous in the second year of planting with high-demand crops, but the P of the SSP retained in the minus soluble fractions may be available if the SSP is used in P-depleting crops combined with no-tillage underneath a mulch of residues.(AU)
Assuntos
Fósforo , Solo , Fabaceae , Compostos de NitrogênioResumo
The objectives of the study were to analyze the effect of sawdust mulch on the: (1) soil characteristics; (2) growth and flower yield of the anthurium cv. 'Apalai'. Assay was conducted in a totally randomized design in subdivided plots, with five treatments and eight replications. The treatment consisted of five volumes of sawdust 0, 20, 40, 60 and 80L m-2, distributed over the bed, every three months. Soil, plants and flower stalks were evaluated during two years. Soil temperature, moisture, organic matter, bulk density and water retention conditions were improved, while the leaf area of plants and the yield of flower stalks were increased when the soil were mulched with sawdust. In addition to increasing soil organic matter, however, no change occurred in the level of nutrients in plants. Sawdust also improved the dimension of flower stalks. Application of 40L m-2 of sawdust every three months is recommended.
Objetivou-se analisar o efeito da serragem de madeira: (1) nas características do solo; (2) no crescimento e produção de hastes florais de anthurium cv. 'Apalai'. O ensaio foi conduzido em delineamento inteiramente casualizado em parcelas subdivididas, com cinco tratamentos e oito repetições. Os tratamentos consistiram em cinco volumes de serragem 0, 20, 40, 60 e 80L m-2, distribuídos sobre os canteiros, a cada três meses. O solo, as plantas e hastes florais foram avaliados por dois anos. A temperatura, a umidade, o teor de matéria orgânica, a densidade e a retenção de água do solo melhoraram, enquanto a área foliar e a produção de hastes florais aumentaram quando o solo foi coberto com serragem. Apesar do aumento do teor de matéria orgânica, não ocorreram modificações no teor de nutrientes nas plantas. A serragem também melhorou as dimensões das hastes florais. Recomenda-se aplicação de 40L m-2 de serragem a cada três meses.
Assuntos
Desenvolvimento Vegetal , Flores/crescimento & desenvolvimento , Madeira , Tratamento do SoloResumo
The objectives of the study were to analyze the effect of sawdust mulch on the: (1) soil characteristics; (2) growth and flower yield of the anthurium cv. 'Apalai'. Assay was conducted in a totally randomized design in subdivided plots, with five treatments and eight replications. The treatment consisted of five volumes of sawdust 0, 20, 40, 60 and 80L m-2, distributed over the bed, every three months. Soil, plants and flower stalks were evaluated during two years. Soil temperature, moisture, organic matter, bulk density and water retention conditions were improved, while the leaf area of plants and the yield of flower stalks were increased when the soil were mulched with sawdust. In addition to increasing soil organic matter, however, no change occurred in the level of nutrients in plants. Sawdust also improved the dimension of flower stalks. Application of 40L m-2 of sawdust every three months is recommended.(AU)
Objetivou-se analisar o efeito da serragem de madeira: (1) nas características do solo; (2) no crescimento e produção de hastes florais de anthurium cv. 'Apalai'. O ensaio foi conduzido em delineamento inteiramente casualizado em parcelas subdivididas, com cinco tratamentos e oito repetições. Os tratamentos consistiram em cinco volumes de serragem 0, 20, 40, 60 e 80L m-2, distribuídos sobre os canteiros, a cada três meses. O solo, as plantas e hastes florais foram avaliados por dois anos. A temperatura, a umidade, o teor de matéria orgânica, a densidade e a retenção de água do solo melhoraram, enquanto a área foliar e a produção de hastes florais aumentaram quando o solo foi coberto com serragem. Apesar do aumento do teor de matéria orgânica, não ocorreram modificações no teor de nutrientes nas plantas. A serragem também melhorou as dimensões das hastes florais. Recomenda-se aplicação de 40L m-2 de serragem a cada três meses.(AU)
Assuntos
Desenvolvimento Vegetal , Madeira , Tratamento do Solo , Flores/crescimento & desenvolvimentoResumo
Melon plants (Cucumis melo L.) are grown in the state of Rio Grande do Norte (RN), the largest producer of melons in Brazil, with plastic mulch and agrotextiles. Studies of crop evapotranspiration (ET) under these conditions are required to ensure adequate irrigation. This study aimed to determine the crop coefficients (Kc) of irrigated melon plants grown with mulch and agrotextiles in the region of Mossoró, RN, based on the Bowen Ratio Energy Balance (BREB) method. Two experiments were conducted at different times during the 2009/2010 season in a melon producing area (4°59'52" S, 37°23'09" W, and 54 m elevation) to define ET and Kc. Due to the plastic cover and reduced precipitation during the experiments, the Kc obtained by the BREB method was considered the basal Kc - KcbBREB. The results were compared with the Kcb from the FAO 56 Bulletin. There was close agreement between BREB and FAO ET measurements (12 % underestimation by the FAO method for the entire crop season), with sizeable differences only during the initial phenological stage. The mean KcbBREB values of the two field campaigns were 0.26, 0.96 and 0.63 for the initial, midseason and late stages, respectively. The high KcbBREB value in the initial growth phase may be related to the effect of the plastic mulch and agrotextiles on the energy balance at the surface. The relationship between KcbBREB and fc had high correlation, making possible an estimation of the melon Kcb based on the level of crop ground cover.
Assuntos
Cucumis melo , Evapotranspiração , Irrigação Agrícola , Zona SemiáridaResumo
Melon plants (Cucumis melo L.) are grown in the state of Rio Grande do Norte (RN), the largest producer of melons in Brazil, with plastic mulch and agrotextiles. Studies of crop evapotranspiration (ET) under these conditions are required to ensure adequate irrigation. This study aimed to determine the crop coefficients (Kc) of irrigated melon plants grown with mulch and agrotextiles in the region of Mossoró, RN, based on the Bowen Ratio Energy Balance (BREB) method. Two experiments were conducted at different times during the 2009/2010 season in a melon producing area (4°59'52" S, 37°23'09" W, and 54 m elevation) to define ET and Kc. Due to the plastic cover and reduced precipitation during the experiments, the Kc obtained by the BREB method was considered the basal Kc - KcbBREB. The results were compared with the Kcb from the FAO 56 Bulletin. There was close agreement between BREB and FAO ET measurements (12 % underestimation by the FAO method for the entire crop season), with sizeable differences only during the initial phenological stage. The mean KcbBREB values of the two field campaigns were 0.26, 0.96 and 0.63 for the initial, midseason and late stages, respectively. The high KcbBREB value in the initial growth phase may be related to the effect of the plastic mulch and agrotextiles on the energy balance at the surface. The relationship between KcbBREB and fc had high correlation, making possible an estimation of the melon Kcb based on the level of crop ground cover.(AU)
Assuntos
Cucumis melo , Evapotranspiração , Zona Semiárida , Irrigação AgrícolaResumo
The use of eco-friendly mulch materials as alternatives to the standard polyethylene (PE) has become increasingly prevalent worldwide. Consequently, a comparison of mulch materials from different origins is necessary to evaluate their feasibility. Several researchers have compared the effects of mulch materials on each crop variable through univariate analysis (ANOVA). However, it is important to focus on the effect of these materials on fruit quality, because this factor decisively influences the acceptance of the final product by consumers and the industrial sector. This study aimed to analyze the information supplied by a randomized complete block experiment combined over two seasons, a principal component analysis (PCA) and a cluster analysis (CA) when studying the effects of mulch materials on the quality of processing tomato (Lycopersicon esculentum Mill.). The study focused on the variability in the quality measurements and on the determination of mulch materials with a similar response to them. A comparison of the results from both types of analysis yielded complementary information. ANOVA showed the similarity of certain materials. However, considering the totality of the variables analyzed, the final interpretation was slightly complicated. PCA indicated that the juice color, the fruit firmness and the soluble solid content were the most influential factors in the total variability of a set of 12 juice and fruit variables, and CA allowed us to establish four categories of treatment: plastics (polyethylene - PE, oxo- and biodegradable materials), papers, manual weeding and barley (Hordeum vulgare L.) straw. Oxobiodegradable and PE were most closely related based on CA.
Assuntos
Análise Multivariada , Solanum lycopersicum , Plásticos Biodegradáveis , Polietileno , Qualidade dos AlimentosResumo
The use of eco-friendly mulch materials as alternatives to the standard polyethylene (PE) has become increasingly prevalent worldwide. Consequently, a comparison of mulch materials from different origins is necessary to evaluate their feasibility. Several researchers have compared the effects of mulch materials on each crop variable through univariate analysis (ANOVA). However, it is important to focus on the effect of these materials on fruit quality, because this factor decisively influences the acceptance of the final product by consumers and the industrial sector. This study aimed to analyze the information supplied by a randomized complete block experiment combined over two seasons, a principal component analysis (PCA) and a cluster analysis (CA) when studying the effects of mulch materials on the quality of processing tomato (Lycopersicon esculentum Mill.). The study focused on the variability in the quality measurements and on the determination of mulch materials with a similar response to them. A comparison of the results from both types of analysis yielded complementary information. ANOVA showed the similarity of certain materials. However, considering the totality of the variables analyzed, the final interpretation was slightly complicated. PCA indicated that the juice color, the fruit firmness and the soluble solid content were the most influential factors in the total variability of a set of 12 juice and fruit variables, and CA allowed us to establish four categories of treatment: plastics (polyethylene - PE, oxo- and biodegradable materials), papers, manual weeding and barley (Hordeum vulgare L.) straw. Oxobiodegradable and PE were most closely related based on CA.(AU)
Assuntos
Solanum lycopersicum , Análise Multivariada , Qualidade dos Alimentos , Polietileno , Plásticos BiodegradáveisResumo
Mulch materials of different origins have been introduced into the agricultural sector in recent years alternatively to the standard polyethylene due to its environmental impact. This study aimed to evaluate the multivariate response of mulch materials over three consecutive years in a processing tomato (Solanum lycopersicon L.) crop in Central Spain. Two biodegradable plastic mulches (BD1, BD2), one oxo-biodegradable material (OB), two types of paper (PP1, PP2), and one barley straw cover (BS) were compared using two control treatments (standard black polyethylene [PE] and manual weed control [MW]). A total of 17 variables relating to yield, fruit quality, and weed control were investigated. Several multivariate statistical techniques were applied, including principal component analysis, cluster analysis, and discriminant analysis. A group of mulch materials comprised of OB and BD2 was found to be comparable to black polyethylene regarding all the variables considered. The weed control variables were found to be an important source of discrimination. The two paper mulches tested did not share the same treatment group membership in any case: PP2 presented a multivariate response more similar to the biodegradable plastics, while PP1 was more similar to BS and MW. Based on our multivariate approach, the materials OB and BD2 can be used as an effective, more environmentally friendly alternative to polyethylene mulches.