Resumo em Português:

RESUMO A sensibilidade às variações ambientais observada na cultura do trigo implica na interação genótipo (G) × ambiente (A) (IGA) significativa. Objetivamos com o presente estudo comparar metodologias estatísticas para a análise da adaptabilidade e estabilidade de genótipos de trigo em ensaios de valor de cultivo e uso (VCU). Foram utilizados dados de desempenho produtivo de 22 genótipos de trigo avaliados em 3 locais (Guarapuava, Cascavel e Abelardo Luz), nas safras agrícolas de 2012 e 2013. Em cada ensaio, foi empregado o delineamento de blocos completos casualizados, com 3 repetições. Na avaliação da IGA, foram utilizadas metodologias baseadas em modelos mistos, análise de variância, regressão linear, análises multivariadas e não paramétricas. Para verificar semelhanças na seleção dos genótipos pelas diferentes metodologias, utilizou-se o coeficiente de correlação de postos de Spearman. As metodologias Annicchiarico, Lin e Binns modificada, bem como a média harmônica dos valores genéticos (MHVG) permitem identificar genótipos estáveis e, ao mesmo tempo, mais produtivos. A magnitude do rendimento de grãos não é associada às estimativas de estabilidade de Wricke, de Eberhart e Russell, escores do primeiro componente principal do método AMMI1 e a estabilidade pela análise GGE biplot, indicando que genótipos estáveis não necessariamente são mais produtivos. Para os dados analisados neste estudo, os métodos AMMI1 e GGE biplot mostraram-se equivalentes em relação ao ordenamento dos genótipos pela estabilidade e adaptabilidade.

Resumo em Inglês:

ABSTRACT The sensitivity of wheat crop to environmental variations frequently results in significant genotype (G) x environment (E) interaction (GEI). We compared statistical methods to analyze adaptability and stability of wheat genotypes in value for cultivation and use (VCU) trials. We used yield performance data of 22 wheat genotypes evaluated in three locations (Guarapuava, Cascavel, and Abelardo Luz) in 2012 and 2013. Each trial consisted of a complete randomized block design with three replications. The GEI was evaluated using methodologies based on mixed models, analysis of variance, linear regression, multivariate, and nonparametric analysis. The Spearman’s rank correlation coefficient was used to verify similarities in the genotype selection process by different methodologies. The Annicchiarico, Lin and Binns modified methodologies, as well as the Harmonic Mean of the Genetic Values (HMGV) allowed to identify simultaneously highly stable and productive genotypes. The grain yield is not associated with Wricke, Eberhart and Russell stability parameters, scores of the first principal component of the AMMI1 method, and GGE biplot stability, indicating that stable genotypes are not always more productive. The data analyzed in this study showed that the AMMI1 and GGE biplot methods are equivalent to rank genotypes for stability and adaptability.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate the effect of the high and low molecular weight glutenin subunits on the grain traits of sixteen Brazilian wheat genotypes. Grain hardness index, milling traits, physicochemical and rheological properties of the flour, and specific volume and firmness of the bread were evaluated. Physicochemical properties of the flour were not influenced by glutenin subunits. Genotypes with subunits at the Glu-B1 (17+18 or 7+8), Glu-D1 (5+10), and Glu-A3 (b) were associated with strong flours and bread with high specific volume and low firmness. The subunits at the Glu-A1 and Glu-B3 had no effect on the rheological properties of the dough and bread quality, while the subunit 2+12 at Glu-D1 negatively affected the resistance to extension, and specific volume and firmness of the bread. Specific volume and firmness of the bread were influenced by the rheological properties of the dough, while the flour protein content was not important to define wheat quality. The identification of glutenin subunits at different loci along with the rheological tests of the flour are fundamental in estimating the potential use of different materials developed in wheat breeding.

Resumo em Português:

RESUMO A produção de batatas-semente de qualidade em sistemas hidropônicos, como a aeroponia, demanda estudos sobre o manejo nutricional e cultural devido à recente introdução no Brasil. Assim, o objetivo do trabalho foi avaliar a influência da condutividade elétrica da solução nutritiva e da densidade de plantas sobre a produção de minitubérculos de batata-semente em aeroponia, cultivares Ágata e Asterix, em condições tropicais de cultivo (inverno/primavera), sob ambiente protegido. O delineamento experimental utilizado foi o de blocos casualizados em esquema de parcela subsubdividida, sendo a parcela constituída por 4 condutividades elétricas da solução nutritiva (1,0; 2,0; 3,0 e 4,0 dS∙m−1); a subparcela, por 4 densidades de plantio (25; 44; 66 e 100 plantas∙m−2); e a subsubparcela, pelas cultivares de batata (Ágata e Asterix), num total de 4 blocos. As condutividades elétricas da solução nutritiva que proporcionaram a maior produtividade de minitubérculos de batata-semente, independentemente da densidade de plantas, foram as de 2,2 e 2,1 dS∙m−1, para as cultivares de batata Ágata e Asterix, respectivamente. Quanto à densidade de plantas, para ambas as cultivares, melhor desempenho produtivo foi obtido na densidade de 100 plantas∙m−2.

Resumo em Inglês:

ABSTRACT The recent introduction in Brazil of production of quality seed potatoes in hydroponic systems, such as aeroponics, demands studies on the nutritional and crop management. Thus, this study evaluated the influence of electrical conductivity of the nutrient solution and plant density on the seed potato minitubers production in aeroponics system. The Agata and Asterix cultivars were produced in a greenhouse under tropical conditions (winter/spring). The experimental design was a randomized block in a split-split plot design. The plot consisted of 4 electrical conductivities of the nutrient solution (1.0; 2.0; 3.0; and 4.0 dS∙m−1); the subplot, of 4 plant densities (25; 44; 66; and 100 plants∙m−2); and the subsubplot, of the 2 potato cultivars (Ágata and Asterix), totaling 4 blocks. The 2.2 and 2.1 dS∙m−1 electrical conductivities yielded the highest productivity of seed potato minitubers, for Ágata and Asterix cultivars, respectively, regardless of plant density. For both cultivars, the highest yield was observed for the 100 plants∙m−2 density.

Resumo em Inglês:

ABSTRACT The maturing of drift used in the culture of sugar cane can have harmful effects on other crops grown in the vicinity of sugar cane plantations. Among these, sunflower grown in the off-season can have its growth and productivity affected by drift. The objective of this research was to evaluate whether the drift of trinexapac-ethyl and glyphosate promotes changes in the photosynthetic metabolism of sunflower plants. Two trials were carried out to evaluate the effects of these products on gas exchange, chlorophyll fluorescence, chloroplastid pigments, membrane permeability, sugar content, as well as shikimic acid and malondialdehyde concentration in the treated plants. In the first experiment, we tested glyphosate in doses of 0 (control); 3.6; 7.2; 14.4; 28.8; and 86.4 g a.e.∙ha−1 and in the second, trinexapac-ethyl at doses of 0 (control) 3.12; 6.25; 12.50; 25, and 75 g a.i.∙ha−1. The growth regulator trinexapac-ethyl did not change the photosynthetic metabolism of plants. However, glyphosate caused damage to the photosynthetic apparatus and a reduction in the carbohydrate concentration and chloroplastid pigments, with casual damage to cell membranes; these effect were more intense at increased doses. The effects of glyphosate were evidenced by the increased concentration of shikimic acid, derived from its mechanism of action. Concludes that, the photosynthetic metabolism of sunflower plants is not affected by the growth regulator trinexapac-ethyl, unlike to the evident effects after application of glyphosate.

Resumo em Português:

RESUMO Os objetivos deste trabalho foram determinar o tamanho de amostra necessário para a estimação da média de caracteres e avaliar as relações lineares existentes entre caracteres de plantas de Crotalaria spectabilis. Foi conduzido um experimento com C. spectabilis na safra 2014/2015, sendo os seguintes caracteres avaliados em 100 plantas: altura da planta (AP), número de ramos produtivos (NRP), massa seca da parte aérea (MSPA), massa seca de vagens (MSVG), número de vagens (NVG), peso médio de cada vagem (PMVG), número de sementes (NS), número médio de sementes por vagem (NSVG), massa de cem grãos (MCG) e peso total de sementes (PTS). Foram calculadas medidas de tendência central, de dispersão e de distribuição, foi verificada a normalidade dos dados e determinado o tamanho de amostra necessário para a estimação da média de cada caractere, assumindo-se erros de estimação iguais a 1, 2, …, 20% da média. Depois, foram calculados os coeficientes de correlação linear de Pearson e estimados os efeitos diretos e indiretos das variáveis explicativas sobre PTS por meio de análise de trilha. Em C. spectabilis, são necessárias 121 plantas para estimação da média dos caracteres NRP, MSPA, MSVG, NVG, NS e PTS com erro máximo de 10% da média. Já para a estimação da média de AP, PMVG, NSVG e MCG nesse mesmo nível de precisão, são necessárias 6 plantas. A variável NS apresentou elevada correlação e efeito direto sobre PTS, indicando relação de causa e efeito e possibilidade de seleção indireta. As demais variáveis explicativas apresentaram efeitos indiretos sobre PTS via NS.

Resumo em Inglês:

ABSTRACT The aims of this research were to determine the sample size needed to estimate the mean of traits and evaluate the linear relationships between traits of Crotalaria spectabilis plants. An experiment with C. spectabilis was conducted in the 2014/2015 season, and the following characters were evaluated in 100 plants: plant height (AP), number of productive branches (NRP), dry matter of the aerial part (MSPA), dry matter of the pods (MSVG), number of pods (NVG), weight of each pod (PMVG), number of seeds (NS), average number of seeds per pod (NSVG), mass of hundred grains (MCG), and total weight of seeds (PTS). Measures of central tendency, dispersion and distribution were calculated, the normality of the data was checked, and the sample size needed to estimate the mean of each trait was determined, assuming estimation errors equal to 1, 2, …, 20% of the mean. Then, the Pearson’s linear correlation coefficients were calculated, and the direct and indirect effects of the explanatory variables on PTS were estimated by path analysis. In C. spectabilis, 121 plants are required to the mean estimation of NRP, MSPA, MSVG, NVG, NS, and PTS traits, with a maximum estimation error of 10% of the mean. In this same level of accuracy, 6 plants are needed for the estimation of the mean of AP, PMVG, NSVG, and MCG. The variable NS showed high correlation and direct effect on PTS, indicating a relation of cause and effect and the possibility of indirect selection. The other explanatory variables had indirect effects on PTS via NS.

Resumo em Português:

RESUMO O teste de condutividade elétrica é um teste de vigor de sementes utilizado para avaliar a qualidade das sementes e complementar o teste de germinação. O tamanho da amostra necessária para a estimação da média de condutividade elétrica de sementes é diretamente proporcional à variabilidade dos dados e confiabilidade desejada na estimativa. Uma técnica adequada para dimensionamento amostral é a utilização de intervalos de confiança, obtidos por reamostragem, com a vantagem de não dependerem da distribuição de probabilidade dos dados. O objetivo deste trabalho foi estimar o tamanho de amostra necessário para o teste de condutividade elétrica individual em sementes de girassol. Foram utilizados 7 lotes de sementes de girassol, sendo 3 da cultivar Hélio 250, 2 da cultivar BRS 323 e 2 da cultivar BRS 324. O teste de condutividade elétrica individual foi realizado com 400 sementes de cada lote, e o tamanho de amostra foi determinado pelo número de sementes a partir do qual a amplitude do intervalo de confiança de 95% (AIC95%) foi menor ou igual a 15, 20, 25, 30 e 35% da estimativa da média. O tamanho de amostra de 483, 257, 172, 115 e 85 sementes é suficiente para a estimativa da média de condutividade elétrica individual de sementes de girassol com AIC95% igual a 15, 20, 25, 30 e 35% da estimativa da média, respectivamente, para todos os lotes e períodos de embebição.

Resumo em Inglês:

ABSTRACT The electrical conductivity is a seed vigor test used to assess seed quality and complement the germination test. The sample size required to estimate the average electrical conductivity of seeds is directly proportional to the variability of the data and desired reliability in the estimate. A suitable technique for sample dimension is the use of confidence intervals obtained by resampling. This technique has the advantage of not depending on the probability distribution of the data. The objective of this study was to estimate the sample size required for the individual electrical conductivity test in sunflower seeds. Seven lots of sunflower seeds were used: 3 lots of the cultivar Hélio 250, 2 of the BRS 323, and 2 of the BRS 324. The individual electrical conductivity test was conducted with each lot of 400 seeds, and the sample size was determined by the seed number from which the amplitude of the 95% confidence interval (AIC95%) was less than or equal to 15, 20, 25, 30, and 35% of the mean estimate. The sample size of 483, 257, 172, 115, and 85 seeds is sufficient to estimate the average of the individual electrical conductivity of sunflower seeds with an AIC95% equal to 15, 20, 25, 30, and 35% of the mean estimate, respectively, for all lots and soaking periods.

Resumo em Inglês:

ABSTRACT Spectral remote sensing offers the potential to provide more information for making better-informed management decisions at the crop canopy level in real time. In contrast, the traditional methods for irrigation management are generally time-consuming, and numerous observations are required to characterize them. The aim of this study was to investigate the suitability of hyperspectral reflectance measurements of remote sensing technique for salinity and water stress condition. For this, the spectral indices of 5 maize cultivars were tested to assess canopy water content (CWC), canopy water mass (CWM), biomass fresh weight (BFW), biomass dry weight (BDW), cob yield (CY), and grain yield (GY) under full irrigation, full irrigation with salinity levels, and the interaction between full irrigation with salinity levels and water stress treatments. The results showed that the 3 water spectral indices (R970 − R900)/(R970 + R900), (R970 − R880)/(R970 + R880), and (R970 − R920)/(R970 + R920) showed close and highly significant associations with the mentioned measured parameters, and coefficients of determination reached up to R2 = 0.73*** in 2013. The model of spectral reflectance index (R970 − R900)/(R970 + R900) of the hyperspectral passive reflectance sensor presented good performance to predict the CY, GY, and CWC compared to CWM, BFW, and BDW under full irrigation with salinity levels and the interaction between full irrigation with salinity levels and water stress treatments. In conclusion, the use of spectral remote sensing may open an avenue in irrigation management for fast, high-throughput assessments of water status, biomass, and yield of maize cultivars under salinity and water stress conditions.

Resumo em Inglês:

Abstract Phyllochron and leaf appearance rate are both important parameters in the production efficiency of agricultural crops. The objectives of this study were to determine the phyllochron and leaf appearance rate in 4 oat cultivars (Avena sativa L.) in 3 sowing dates and verify the variability of phyllochron and leaf appearance rate among cultivars and sowing dates. The experimental design was the completely randomized with 12 treatments and 20 repetitions. Treatments were formed by the combination of 4 cultivars (URS Charrua, URS Taura, URS Estampa, and URS Corona) and 3 sowing dates in 2014 (April 28, May 28, and July 14). In each plant (repetition) of each treatment, the number of expanded leaves (NEL) was counted 3 times per week from the first leaf emission until flowering. For each plant, cultivar, and sowing date, linear regression was adjusted between NEL and accumulated thermal time (ATT) and between NEL and number of days after emergence (DAE). Phyllochron was determined by the inverse of the angular coefficient of the linear regression between the NEL and ATT. The leaf appearance rate was determined by the inverse of the angular coefficient of the linear regression between NEL and DAE. In oat, there is variability of phyllochron and leaf appearance rate among cultivars and sowing dates. Phyllochron oscillates between 95.88 and 117.70 °C day∙leaf−1 and leaf appearance rate, between 6.41 and 9.65 days∙leaf−1. The oat cropping management in function of phyllochron and leaf appearance rate is dependent on cultivars and sowing dates.

Resumo em Inglês:

ABSTRACT The aim of this study was to examine the early performance of ‘Kampai’ and ‘Rubimel’ peach on 3 training systems. The study was conducted between 2010 and 2013. Treatments were the training systems ‘Ypsilon’, Central Leader, and Open Center, arranged in a randomized complete block design. Assessed parameters were production per tree, fruit weight, yield, fruit firmness, and soluble solids. The early yield and economic return are greater in Central Leader training system for both cultivars. Besides, training system does not influence fruit quality attributes.

Resumo em Inglês:

ABSTRACT Cucumber mosaic virus (CMV) is one of the most economically damaging viral pathogens affecting vegetable crops around the world. In the present research, 50 cabbage (Brassica oleracea L.) lines chosen from the Black Sea Agricultural Research Institute (BSARI, Turkey) were evaluated for their reaction to CMV. The level of resistance to CMV was determined based on biological assays, symptom expression, disease severity rating, and viral titer, as determined by ELISA. Eight cabbage lines were identified as moderately susceptible and 3 were susceptible to the CMV-BA isolate. These plants exhibited various symptoms and accumulated high levels of virus titer. However, the results showed that 17 lines had high resistance, 12 were found to be resistant and 10 were found to be moderately resistant to the CMV. The lines that showed high levels of resistance to the virus in this study could be used as sources of CMV resistance in cabbage breeding programs.

Resumo em Inglês:

ABSTRACT Glyphosate is the herbicide most used worldwide. In cropping systems that rely on repeated applications of glyphosate or cultivate genetically modified soyabean crop, there are numerous cases of glyphosate resistant weeds, including Conyza bonariensis. Differences among competitive ability of Conyza spp. have been found. However, little information is available on the fitness costs related to glyphosate resistance in Conyza bonariensis. We evaluated growth, phenology, and seed viability of glyphosate-resistant (GR) and glyphosate-susceptible (GS) Conyza bonariensis from Brazil, in 2012 (fall/winter) and 2013 (spring/summer). When grown alone, in pots, C. bonariensis GR biotype developed more rapidly than the GS biotype, as evidenced by their earlier bolting, flowering, and seed set. In 2012, GR biotype showed 221.9 cm of plant height compared to 181.1 cm from GS, at the flowering time. In both years, the seed production per plant was superior for GR biotype, showing germination higher than 80% against 66.5% from the GS biotype. Thus, C. bonariensis GR biotype confirmed no fitness penalty also showing characteristics that allow us to infer in superior competitive with the absence of the herbicide. It is important to point out that the biotypes evaluated here have different genetic background and the differences between them may not be fully attributed to the resistance to glyphosate. However, the GR biotype can persist in the environment and outcompete with GS biotypes regardless of further glyphosate selection of pressure.

Resumo em Português:

Resumo Calacarus heveae Feres (Eriophyidae) e Tenuipalpus heveae Baker (Tenuipalpidae) podem causar intenso desfolhamento em plantas de seringueira. Na perspectiva do Manejo Integrado de Pragas, o uso de clones com resistência é uma importante estratégia de controle. O objetivo deste trabalho foi avaliar a resistência de clones de seringueira ao ataque desses ácaros em experimento conduzido em Votuporanga (SP). Foram avaliados os clones IAC 301, IAC 330, IAN 4493, OS 22, PB 233, PB 254, PC 96, PC 119, PC 140, PC 141, PM 10 e RRIM 600, totalizando 12 tratamentos e 3 repetições, em delineamento experimental em blocos casualizados. As avaliações populacionais de C. heveae e T. heveae foram realizadas pela contagem em laboratório dos ácaros e exúvias presentes em 6 folíolos por parcela. Os níveis de desfolhamento foram avaliados com uma escala de notas variando de 0 (ausência de desfolhamento) a 5 (desfolhamento total). Os clones IAC 301, PB 254 e PC 119 apresentam resistência por não preferência e/ou antibiose ao ácaro C. heveae.

Resumo em Inglês:

Abstract Calacarus heveae Feres (Eriophyidae) and Tenuipalpus heveae Baker (Tenuipalpidae) can cause heavy defoliation on rubber trees. From the view of Integrated Pest Management, the use of clones with resistance is an important control strategy. The objective of this study was to evaluate the resistance of rubber tree clones to infestation of these mites. The experiment was carried out in Votuporanga, São Paulo State, with IAC 301, IAC 330, IAN 4493, OS 22, PB 233, PB 254, PC 96, PC 119, PC 140, PC 141, PM 10, and RRIM 600 clones, totaling 12 treatments and 3 replicates, in randomized blocks experimental design. The population assessment of C. heveae and T. heveae was performed in laboratory by counting mites and exuviae presence in 6 leaflets per plot. The defoliation levels were evaluated with a score scale varying from 0 (no defoliation) to 5 (total defoliation). IAC 301, PB 254, and PC 119 clones have resistance by no preference and/or antibiosis to C. heveae mite.

Resumo em Inglês:

ABSTRACT Meloidogyne incognita is one of the most widespread and damaging plant-parasitic nematodes throughout the world and substantially affects growth and yield of okra (Abelmoschus esculentus L). In the present study, effects of M. incognita on yield parameters of 12 okra cultivars with varying levels of resistance or susceptibility were assessed. M. incognita caused significant reductions in yield parameters of okra plants of all the cultivars. Maximum reduction of 34.1% in yield was observed in highly susceptible (HS) cultivar Sharmeeli. The nematode caused 20 and 17.6% reductions in yields in susceptible (S) cultivars Okra Sindha and Anmol, respectively. Moderately susceptible (MS) cultivars suffered 5.9 to 12.9% reductions in yields. In case of moderately resistant (MR) cultivars (Sanam, Dikshah, Arka Anamika, Ikra-1 and Ikra-2), the reductions in yields were the minimum and ranged from 2.9 to 6.5%. The reductions in other yield parameters of okra cultivars were observed in the order HS > S > MS > MR. As the MR cultivars suffered less damage by the nematode, they are recommended for cultivation in fields heavily infested with M. incognita.

Resumo em Português:

RESUMO É crescente a adoção de preparos reduzidos do solo e de plantio direto; no entanto, estudos em solos cultivados com raízes e tubérculos são escassos e apresentam resultados controversos. Este trabalho teve por objetivo avaliar o impacto de sistemas de preparo em propriedades físicas de um Argissolo Vermelho-Amarelo, bem como a produtividade e o formato de raízes tuberosas de batata-doce cultivada nesse solo. Foi instalado experimento em blocos ao acaso, em esquema de parcelas subdivididas. As parcelas corresponderam aos tratamentos: preparo com aração e gradagem (PAG), preparo com aração, gradagem e confecção de leira (PAG + L), confecção de leiras sem revolvimento prévio do solo (Leira), preparo reduzido (PR) e preparo reduzido com palha superficial (PRCP); e as subparcelas, a 4 épocas de coleta: 90; 120; 150 e 180 dias após plantio da batata-doce. A confecção de leira (Leira e PAG + L), em oposição ao preparo reduzido, promoveu menores valores de densidade do solo, resistência do solo à penetração e microporosidade, maiores valores de porosidade total e macroporosidade, além de maiores produtividades comerciais de raízes tuberosas, bem como maior porcentagem de massa seca. Logo, o preparo do solo altera as características físicas de maneira expressiva e, para a confecção de leiras, são desnecessárias as etapas de aração e gradagem, visto que Leira e PAG + L apresentam valores semelhantes nas propriedades físicas estudadas e na produtividade comercial.

Resumo em Inglês:

ABSTRATC The adoption of reduced tillage and no-tillage is growing fast in many crops, but studies in soil cultivated with roots and tubers are rare and show controversial results. Thus, this study aimed to assess the impact of tillage systems on physical properties of an Alfissol type as well as the sweet potato tuberous roots yield and root shape cultivated in that soil. The experiment was conducted in randomized blocks design, in split-plot scheme. The plots consisted of the treatments: tillage with moldboard plow and disking (PAG), tillage with moldboard plow, disking and making mounds (PAG + L), making mounds without previous soil mobilization (Leira), reduced tillage (PR) and reduced tillage with straw on the soil surface (PRCP). The subplots consisted of 4 collect periods: 90; 120; 150 and 180 days after planting of the sweet potato crop. Making mounds activity (Leira and PAG + L), opposite to reduced tillage, promoted lower values of soil bulk density, soil resistance to penetration and soil microporosity, higher scores of total soil porosity and soil macroporosity, besides the highest commercial tuberous roots yields and higher dry mass percentage. It was concluded that soil managements influence expressively the soil physical properties and, for making mounds, the activities of moldboard plow and disking are unnecessary, since Leira and PAG + L present similar values in the physical properties studied and in commercial tuberous roots yield.

Resumo em Português:

RESUMO A fertirrigação é uma das principais formas de adubação parcelada; entretanto, se aplicados em excesso, os fertilizantes podem prejudicar o desenvolvimento da cultura. O objetivo deste trabalho foi avaliar o acúmulo e exportação de macronutrientes em um cultivo de beterraba sob 2 manejos de fertirrigação em diferentes níveis de salinidade do solo. O experimento foi realizado em casa de vegetação no município de Botucatu (SP). Os tratamentos constituíram-se da combinação dos fatores salinidade do solo (1,0; 3,0; 6,0; 9,0; 12,0 dS∙m−1), manejo da fertirrigação (M1= tradicional e M2= com controle da concentração iônica) e cultivares de beterraba (C1 = Early Wonder e C2 = Itapuã), em um esquema fatorial 5 × 2 × 2, com 4 repetições em blocos casualizados. Após a colheita, foram determinados os acúmulos dos macronutrientes (N, P, K, Ca, Mg, P e S mg∙planta−1). Houve um aumento do acúmulo dos nutrientes estudados para ambas as cultivares e manejos de fertirrigação até níveis de condutividade elétrica entre 3 (M1) e 6 (M2) dS∙m−1. A ordem de exportação dos macronutrientes foi diferenciada para as cultivares estudadas. Para a cultivar Early Wonder, seguiu-se a seguinte ordem: K > N > Ca > Mg > P > S, enquanto que, para a cultivar Itapuã, a ordem foi K > N > Mg > Ca > S > P.

Resumo em Inglês:

ABSTRACT Fertigation is a major form of fertilizer installments; however, if applied in excess, the fertilizers can damage the crop development. The objective of this study was to evaluate the accumulation and exportation of macronutrients in a beet cultivation under 2 fertigation managements at different levels of soil salinity. The experiment was conducted in a greenhouse in the city of Botucatu, Brazil. The treatments consisted of the combination of soil salinity (1.0, 3.0, 6.0, 9.0 and 12.0 dS∙m−1), fertigation management (M1 = traditional and M2 = control of the ionic concentration), and varieties of beets (C1 = Early Wonder and C2 = Itapuã) in a 5 × 2 × 2 factorial design with 4 replications in randomized blocks. After harvest, it was determined the accumulation of macronutrients (N, P, K, Ca, Mg, P, and S mg∙plant−1). There was an increased accumulation of nutrients studied for both cultivars and fertigation managements until electrical conductivity levels between 3 (M1) and 6 (M2) dS∙m−1. The order of macronutrients exportation was different for the studied cultivars. The cultivar Early Wonder followed the following order: K > N > Ca > Mg > P > S, while, for the Itapuã cultivar, the order was K > N > Mg > Ca > S > P.

Resumo em Português:

RESUMO O objetivo deste trabalho foi avaliar a decomposição da palha de cana-de-açúcar e o potencial para incremento de carbono no solo em função da biomassa inicialmente aportada e do uso de vinhaça. O experimento consistiu de incubação (240 dias, no escuro, umidade de 70% da capacidade de retenção de água do solo e temperatura média de 28 °C) de quantidades de palha equivalentes a 2; 4; 8; 16 e 24 t∙ha−1, com ou sem aplicação de vinhaça (200m3∙ha-1), na superfície de amostras (camada 0-20 cm) de um Latossolo Vermelho-Amarelo.. Determinaram-se C-CO2 liberado, massa seca de palha remanescente, carbono remanescente na palha e teor de carbono no solo. A taxa de decomposição da palha não foi influenciada pela biomassa aportada inicialmente, mas, na presença de vinhaça, os valores ficaram entre 70 e 94%, enquanto que, nos tratamentos sem vinhaça, esses valores foram de 68 a 75%. O incremento variou entre 14 e 35% na taxa de decomposição da palha (16 e 24 t∙ha−1) devido à aplicação de vinhaça, porém não foi acompanhado pelo C-CO2 liberado, o que foi explicado pela duplicação do teor de carbono no solo, estimado por meio de balanço de massa e confirmado analiticamente pelos teores de carbono nas amostras de solo. Conclui-se que a decomposição da palha de cana-de-açúcar, sob condições não limitantes de umidade e temperatura, independeu da biomassa aportada inicialmente sobre o solo e que a aplicação de vinhaça acelerou a decomposição da palha e potencializou a entrada de carbono no solo.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate sugarcane straw decomposition and the potential of increasing soil carbon as a function of the initial biomass and vinasse addition to soil surface. The experimente consisted of incubation (240 days, in the dark, humidity equivalent to 70% of soil water retention capacity and average temperature of 28 °C) of Oxisol soil samples (0-20 cm soil layer) with straw added to soil surface at rates of 2; 4; 8; 16 and 24 t∙ha−1 and with or without vinasse addition (200 m3∙ha-1). The following variables were determined: released C-CO2, remaining straw dry matter, carbon straw and soil carbon concentration. The added biomass did not influence straw decomposition rate, but vinasse treatments provided rates between 70 and 94% compared to 68 to 75% for the ones without vinasse. The straw (16 and 24 t∙ha−1) decomposition rate increased between 14 and 35% due to vinasse addition, but the same behavior was not observed for released C-CO2. This result was explained by the twofold increase of soil carbon concentration, estimated by mass balance and confirmed analytically by the carbon concentration of soil samples. It was concluded that sugarcane straw decomposition, under no limiting conditions of humidity and temperature, did not depend on biomass initially added and that vinasse addition accelerated straw decomposition and potentialized carbon input into the soil.

Resumo em Português:

RESUMO A cultura do arroz de terras altas no Mato Grosso ainda não está consolidada nos sistemas de produção, tampouco estão definidos os efeitos dos atributos físicos do solo e a correlação destes com a produtividade do arroz em sistemas de integração lavoura-pecuária. Diante disso, o objetivo do trabalho foi determinar a variabilidade espacial dos atributos físicos do solo e da cultura do arroz em semeadura direta sob diferentes plantas de cobertura, utilizando-se técnicas de análise de componentes principais e geoestatística. O experimento foi realizado no município de Santa Carmem, norte do Estado de Mato Grosso. Uma malha regular com 100 pontos foi instalada em uma área de 26.400 m2. Amostras de solo e de planta foram coletadas nos pontos da malha para a caracterização dos atributos físicos do solo e agronômicos do arroz. A produtividade média do arroz após os consórcios de braquiária com feijão-caupi, crotalária e campim-sudão foi de 1,70 Mg∙ha−1, com elevada variabilidade, com valor mínimo de 0,70 Mg∙ha−1 e máximo de 3,12 Mg∙ha−1. No consórcio de feijão-caupi e braquiária, o solo apresentou as maiores densidades e resistências à penetração, que não foram restritivos à produtividade do arroz, sendo verificados nesse consórcio as maiores produtividades, que se correlacionaram com a menor incidência de mancha de grãos. Nos demais consórcios, observaram-se menores produtividades, que foram correlacionadas negativamente com a maior incidência de mancha de grãos; entretanto, o solo apresentou maiores valores de macroporosidade e porosidade total.

Resumo em Inglês:

ABSTRACT The production systems of upland rice culture in Mato Grosso are not consolidated yet while the effects of soil physical properties and their correlation with rice yield in crop-livestock integrated systems are not defined as well. Therefore, this study determined the spatial variability of physical properties of soil and rice cultivated in no-tillage system under different cover crops, using principal components analysis and geostatistics. The experiment was conducted in Santa Carmen, northern Mato Grosso. A regular grid with 100 sample points distributed in an area of 26,400 m2 was installed. Soil and rice samples were collected to determine rice variables and soil physical properties. The average rice yield was 1.70 Mg∙ha−1, ranging from 0.70 to 3.12 Mg∙ha−1. The highest yields were observed in consortium with cowpea and brachiaria and were associated with lower incidence of grain spots, despite higher soil density and penetration resistance. The consortium with brachiaria, crotalaria, and sudangrass had lower yields, which was associated with higher incidence of grain spots, despite higher soil macroporosity and total porosity.

Resumo em Inglês:

ABSTRACT Applications for long periods of organic animal waste as a source of nutrients to crops can contaminate the soil and the surface and subsurface waters. This study aimed to evaluate how the utilization of organic waste, after successive applications, affects P fractions in the soil and consequently environmental contamination. In an experiment conducted for 8 years, totaling 12 applications with pig slurry manure (PSM), liquid cattle manure (LCM), swine deep bedding (SDB), and mineral fertilizer (NPK), 460; 505; 1.111; and 535 kg P∙ha−1 were added to the soil through PSM, LCM, SDB, and NPK, respectively. In September 2012, soil samples were collected in the layers 0.0 – 0.04; 0.04 – 0.08; 0.08 – 0.12; 0.12 – 0.16; 0.16 – 0.20 m, prepared and subjected to a sequential chemical fractionation of P. The 12 applications of pig slurry, liquid cattle manure, swine deep bedding and NPK fertilizer for eight years (urea + triple superphosphate + potassium chloride) provided accumulations of P fractions in the soil that were above the necessary for a proper nutrition to plants considering the available P fractions (AER + organic NaHCO3 + inorganic NaHCO3) in the soil. In addition, they showed that the use of swine deep bedding, followed by pig slurry, means higher levels of available P fractions in the soil. In this sense, the establishment of a dosage of organic waste to meet the nitrogen need of crops is not an environmentally appropriate parameter. It may cause P accumulation in the soil, increased absorption ability of plants and soil support, contributing to environmental contamination.

Resumo em Português:

RESUMO O metil jasmonato (MJ) é um regulador endógeno que pode influenciar o processo de amadurecimento de frutos e o sistema de defesa contra patógenos. O objetivo do trabalho foi verificar a influência desse regulador na fisiologia pós-colheita, no controle da antracnose e nas características físico-químicas de goiabas (Psidium guajava L.) ‘Kumagai’. As goiabas foram colhidas nos estádios verde e amarelo e tratadas com 0, 1 e 10 µmol∙L−1 de MJ por volatilização em tambores herméticos (200 L) com circulação de ar por 24 h. Os frutos foram inoculados com Colletotrichum gloeosporioides (105 conídios∙mL−1) 24 e 48 h após o tratamento. Durante o amadurecimento, a 25 °C e 80 – 90% de UR, foram realizadas análises de respiração, produção de etileno, incidência e severidade da antracnose e análises físicoquímicas. Os dados foram submetidos à análise de variância e as médias, comparadas pelo teste de Tukey (p ≤ 0,05 e 0,10). A aplicação de 1 e 10 µmol∙L−1 de MJ provocou discreto aumento na respiração, produção de etileno e amarelecimento da casca em frutos colhidos no estádio amarelo. O tratamento com 1 e 10 µmol∙L−1 de MJ não teve efeito na redução da severidade e na incidência de C. gloeosporioides quando aplicado em frutos nos 2 estádios de amadurecimento e inoculados após 24 ou 48 h do tratamento. Conclui-se que a aplicação de 1 e 10 µmol∙L−1 de MJ teve pouca influência no amadurecimento e não controlou a antracnose em goiabas ‘Kumagai’.

Resumo em Inglês:

ABSTRACT Methyl jasmonate (MJ) is an endogenous regulator that can influence fruit ripening and the defense system against pathogens. This work verified the influence of this regulator on postharvest physiology, control of anthracnose and physicalchemical attributes of ‘Kumagai’ guava (Psidium guajava L.). Guavas harvested at mature-green and ripe stages were treated with 0, 1 and 10 μmol∙L−1 MJ as gas in hermetic containers (200 L) with air circulation for 24 h. Fruit were inoculated with Colletotrichum gloeosporioides spore suspension (105 spores∙mL−1) 24 and 48 h after treatment. During ripening, at 25 °C and 80 – 90% of relative humidity, respiration, ethylene production, anthracnose incidence, severity and quality of guavas were assayed. Data were subjected to analysis of variance and means, compared by Tukey’s test (p ≤ 0.05 and 0.10). The application of 1 and 10 μmol∙L−1 MJ had little influence on ripening of ‘Kumagai’ guava with a slight increase in respiration, ethylene production and yellowing of fruit harvested at ripe stage. Treatments with 1 and 10 μmol∙L−1 MJ did not reduce the severity and incidence of C. gloeosporioides when applied in fruit harvested at ripe and mature-green stages and inoculated 24 or 48 h after MJ treatment. In conclusion, the MJ treatment, at 1 and 10 μmol∙L−1 concentrations, had little influence on ripening and did not control anthracnose in ‘Kumagai’ guavas.

Resumo em Inglês:

ABSTRACT Weather conditions influence the quality parameters of pineapple guava fruit during growth and development. The aim of this study was to propose a model of pre-harvest fruit quality as a function of weather conditions in the cultivation area. Twenty trees were flagged per farm in 2 localities of the Department of Cundinamarca, Colombia: Tenjo (2,580 m.a.s.l.; 12.5 °C; relative humidity between 74 and 86%; mean annual precipitation 765 mm) and San Francisco de Sales (1,800 m.a.s.l.; 20.6 °C; relative humidity between 63 and 97%; mean annual precipitation 1,493 mm). Measurements were performed every 7 days during 2 harvest periods starting on days 96 (Tenjo) and 99 (San Francisco de Sales) after anthesis and until harvest. The models were obtained using Excel® Solver, and a set of data was obtained for the 2 different cultivar periods and each study site. The results showed that altitude, growing degree days, and accumulated precipitation are the weather variables with the highest influence on the physicochemical characteristics of the fruit during growth. The models of fresh weight, total titratable acidity, and skin firmness better predict the development of fruit quality during growth and development. Equations were obtained for increases of length and diameter as a function of fruit weight and for days from anthesis as a function of growing degree days and altitude. The regression analysis parameters showed that the models adequately predicted the fruit characteristics during growth for both localities, and a cross-validation analysis showed a good statistical fit between the estimated and observed values.