Abstract Multiple-trait best linear unbiased prediction (BLUP) is generally the most appropriate method to predict genetic values because it considers the genetic and residual correlations among traits and leads to higher selective accuracy. Thus, the aim of the present study was to analyze the interrelationships among traits related to cotton fiber length through path analysis under multiple-trait BLUP. To that end, 36 elite lines were evaluated in three envi ronments and phenotyped for fiber quality and agronomic traits. Variance components were estimated via residual maximum likelihood (REML). The genetic correlation coefficients among traits were obtained through the mixed model output, and a correlation network was constructed to graphically express these results. Subsequently, path analysis was performed considering fiber length as the main dependent variable. Genetic parameters indicate that the phenotypic variance for most traits is mainly composed of residual effects, which reinforces the need for more accurate statistical methods, such as multiple-trait BLUP. The results for genetic correlations and path analysis reveal the difficulty of selection based on important fiber quality traits, especially fiber length, since most traits show a low cause-and-effect relationship, while other important traits have an undesirable cause-and-effect relationship. Path analysis under multiple-trait BLUP proved to be suitable and useful for studying interrelationships among traits related to cotton fiber length.

Resumen La mejor predicción lineal insesgada de rasgos múltiples (BLUP) es, en general, el método más apropiado para predecir valores genéticos porque considera las correlaciones genéticas y residuales entre rasgos y conducta con mayor precisión selectiva. Por lo tanto, el presente estudio tuvo como objetivo estudiar las interrelaciones entre los rasgos relacio nados con la longitud de la fibra de algodón a través del análisis de ruta en BLUP de rasgos múltiples. Con este fin, se evaluaron treinta y seis líneas élite en tres ambientes y se fenotipificaron para muchos rasgos relacionados con la calidad de la fibra y los rasgos agronómicos. Los componentes de la varianza se estimaron mediante la máxima verosimilitud residual (REML). Los coeficientes de correlación genética entre rasgos se obtuvieron a través de la salida del modelo mixto, y para expresar gráficamente estos resultados se construyó una red de correlación. Posteriormente, realizamos el análisis de ruta considerando la longitud de la fibra como variable dependiente principal. Los parámetros genéticos indican que la variación fenotípica para la mayoría de los rasgos se compone principalmente de efectos residuales, lo que refuerza la necesidad de utilizar métodos estadísticos más precisos, como BLUP de rasgos múltiples. Los resultados encontrados para las correlaciones genéticas y el análisis de ruta revelan la dificultad de la selección basada en rasgos importantes de la calidad de la fibra, especialmente la longitud de la fibra, ya que la mayoría de los rasgos muestran una relación de causa y efecto muy baja, y otros rasgos importantes presentan una relación de causa y efecto no deseada. El análisis de ruta en BLUP de rasgos múltiples resultó ser adecuado y útil para el estudio de las interrelaciones entre los rasgos relacio nados con la longitud de la fibra de algodón.

O potássio é o segundo nutriente mais exportado pela cultura da soja. Dessa forma, sua disponibilidade no solo pode influenciar tanto o rendimento da cultura, como a qualidade e composição química das sementes de soja. Este trabalho teve como objetivo avaliar o efeito da adubação potássica sobre caracteres agronómicos, teor de óleo e qualidade sanitária de sementes de soja. Os ensaios decorreram no ano agrícola 2012/13 em dois locais distintos no Estado de Minas Gerais, Brasil. O delineamento experimental constou de um esquema em blocos casualizado, com três repetições, e tratamentos dispostos em esquema fatorial 4 x 6, com quatro cultivares (TMG 127 RR, TMG 1179 RR, BRSMG 850G RR, NA7255 RR) e seis doses de potássio (0, 40, 80, 120, 160 e 200 kg.ha-1). Foram avaliados o rendimento, altura de plantas, inserção de primeira vagem, acama de plantas, teor de óleo e a sanidade de sementes. O aumento nas doses de potássio alterou a composição química das sementes e incrementou significativamente o teor de óleo; no entanto, não houve efeito para os caracteres agronómicos e o rendimento de grãos. Os níveis de patógenos nas sementes aumentaram à medida que se diminui o fornecimento de potássio para as plantas.

Potassium is the second most exported nutrient for soybean. Thus, their availability in the soil can influence both crop yield, the quality and chemical composition of soybean seeds. The objective of this work was to evaluate the effect of potassium fertilization on agronomic traits, oil content and sanitary quality of soybean seeds. The trials took place in the agricultural year 2012/13 in two separate locations in the state of Minas Gerais, Brazil. The experimental design consisted of a randomized block design, with three replications, and treatments arranged in a factorial scheme 4 x 6, with four cultivars (TMG 127 RR, TMG 1179 RR, BRSMG 850G RR, NA7255 RR) and six doses potassium (0, 40, 80, 120, 160 and 200 kg ha-1). They evaluated the yield, plant height, first pod insertion, plants lodging, oil content and seed health. The increase in potassium levels altered the chemical composition of seeds and increased significantly oil content; however, there was no effect on the agronomic characteristics and grain yield. The contents of the seed pathogens increase as it decreases the potassium supply to the plants.

Knowledge about the growth and nutritional aspects of Anacardium othonianum Rizz. (’caju-de-arvore-do-cerrado’), which is a native fruit of the Brazilian Cerrado (savannah), is still incipient. The objectives of the present study were to characterize growth and nutrient accumulation of A. othonianum seedlings grown in a nutrient solution. The experiment was designed in randomized complete blocks with four replicates and six treatments, and the experimental period was 180 d after transplanting (DAT). Each treatment corresponded to an evaluation period that was performed every 30 d. During each sampling period, characteristics related to growth and nutrient accumulation in the plant were evaluated. Plant growth was continuous throughout the cycle with the following maximum values at 180 DAT: 16.76 cm for stem length, 8.09 mm for stem, 11.27 leaves per plant for the number of leaves, and 329.60 cm² for leaf area. The monthly rates of plant fresh matter and DM accumulation were 3.15 and 1.05 g, respectively. The accumulation of nutrients in A. othonianum seedlings had the following order: Ca > N > K > P > Mg > S for macronutrients and Fe > Mn > B > Zn > Cu for micronutrients.

A mangabeira (Hancornia speciosa Gomes) é uma frutífera pertencente à família Apocynaceae, originária do Brasil. A produção de mudas desta espécie em grande escala ainda é limitada pela escassez de conhecimentos técnicos e nutricionais. Para obter maiores esclarecimentos sobre o assunto, este trabalho objetivou caracterizar os sintomas visuais de deficiência de micronutrientes, avaliar o crescimento e o acúmulo de nutrientes foliar de mudas de mangabeira, submetidas a diferentes soluções nutritivas com suspensão de micronutrientes. Plantas de mangabeira foram cultivadas em solução nutritiva, dentro de casa de vegetação, no delineamento de blocos casualizados, com quatro repetições. Os tratamentos foram constituídos de solução nutritiva completa e omissão individual de boro, cobre, ferro, manganês, zinco e molibdênio. Os sintomas visuais de deficiências de nutrientes mostraram-se, de maneira geral, facilmente caracterizáveis. A produção de matéria seca foi afetada pela omissão de micronutrientes, e o tratamento que mais limitou o comprimento do caule, diâmetro do caule, comprimento da raiz, número de folhas de mudas de mangaba e massa seca das folhas, massa seca total e o crescimento relativo da mangabeira, foi a omissão de ferro. Os conteúdos de micronutrientes das plantas do tratamento completo obedeceram à seguinte ordem decrescente de micronutrientes Fe>Mn>Cu>Zn>B em folhas de mangabeira.

Hancornia speciosa Gomes (Mangaba tree) is a fruit tree belonging to the Apocynaceae family and is native to Brazil. The production of seedlings of this species is limited by a lack of technical and nutritional expertise. To address this deficiency, this study aimed to characterize the visual symptoms of micronutrient deficiency and to assess growth and leaf nutrient accumulation in H. speciosa seedlings supplied with nutrient solutions that lack individual micronutrients. H. speciosa plants were grown in nutrient solution in a greenhouse according to a randomized block design, with four replicates. The treatments consisted of a group receiving complete nutrient solution and groups treated with a nutrient solution lacking one of the following micronutrients: boron (B), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), and molybdenum (Mo). The visual symptoms of nutrient deficiency were generally easy to characterize. Dry matter production was affected by the omission of micronutrients, and the treatment lacking Fe most limited the stem length, stem diameter, root length, and number of leaves in H. speciosa seedlings as well as the dry weight of leaves, the total dry weight, and the relative growth in H. speciosa plants. The micronutrient contents of H. speciosa leaves from plants receiving the complete nutrient solution treatment were, in decreasing order, Fe>Mn>Cu>Zn>B.

Os conhecimentos de nutrição mineral da mangabeira (Hancornia speciosa Gomes) são relativamente escassos e incipientes, faltando dados consistentes sobre sua demanda nutricional desde a fase de viveiro até a fase de produção. Com o objetivo de caracterizar os sintomas visuais de carências de macronutrientes, avaliar os efeitos da deficiência no crescimento, produção de massa da matéria seca e conteúdo foliar de mangabeira, foi conduzido um experimento em casa de vegetação no IF Goiano em Rio Verde - GO, nos períodos de janeiro a junho de 2011, onde plantas de mangaba foram cultivadas em solução nutritiva, no delineamento de blocos casualizados, com quatro repetições. Os tratamentos foram constituídos de solução nutritiva completa e omissão individual de nitrogênio (N), fósforo (P), potássio (K), magnésio (Mg), cálcio (Ca) e enxofre (S). A omissão dos nutrientes na solução nutritiva resultou em alterações morfológicas, traduzidas como sintomas característicos de deficiência nutricional, diminuição no crescimento e produção de massa da matéria seca, e o acúmulo de nutrientes apresentou a seguinte ordem decrescente para os macronutrientes: N>K>Ca>P>S>Mg em folhas de mangabeira.

Knowledge of the mineral nutrition requirements of mangabeira (Hancornia speciosa Gomes) is relatively scarce and rudimentary because there is a lack of consistent data concerning its nutritional demands at different developmental stages. The aim of this research was to characterize the visual symptoms of macronutrient deficiencies and to evaluate the effects of these deficiencies on the growth, the production of dry matter, and the leaf content of mangabeira. To achieve this goal, a greenhouse experiment was conducted at the Goiano Federal Institute (Instituto Federal Goiano) in Rio Verde - GO, from January to June 2011 in which mangabeira plants were arranged in a random block design and grown in nutrient solutions. This experiment was replicated four times. The plants were treated with either a complete nutrient solution or a nutrient solution from which the individual macronutrient of interest (nitrogen (N), phosphorous (P), potassium (K), magnesium (Mg), calcium (Ca), or sulfur (S) had been omitted. The omission of a macronutrient from the nutrient solution resulted in morphological alterations that were characteristic symptoms of the particular nutritional deficiency and caused decreases in growth and dry matter mass production. The accumulation of macronutrients displayed the following order in mangabeira leaves: N>K>Ca>P>S>Mg.