ABSTRACT. Intensive weed management is one of the most common practices in coffee cultivation areas. Consequently, some problems, such as soil degradation and the selection of herbicide resistant weed, have increased over time, but, if properly managed, weeds at coffee planting inter-rows can offer benefits of erosion control, nutrient recycling and crop sustainability. The aim of this study is to evaluate the effect of different weed management strategies on the productivity and coffee grain size, i.e., quality. The experiment is installed onto a resprouting Coffea arabica L. site, four years after it was established. Treatments are implanted at planting inter-row Urochloa ruziziensis, Pueraria phaseoloides, and spontaneous vegetation maintained by mowing, herbicides, and weeding. To measure dry matter accumulation, samples are taken with a 0.25 m2 square template at plots maintained by mowing and herbicide application. To evaluate the yield and granulometry, coffee fruits are harvested, processed and classified in a set of 14 sieves (grouped in flat or “moca” shapes). The methods of controlling herbicide and weeding show significance in relation to grain production, with the production of grains having a higher market value standing out, when compared with the other treatments. The accumulation of dry matter above soil, in treatments with herbicides and spontaneous vegetation positively influenced the early coffee productivity (2018), and with U. ruziziensis and spontaneous vegetation, positively influenced the productivity of late harvest (2019). The accumulation of dry matter on the soil tends to be positively linked to coffee productivity, especially in periods when there is a shortage of rain in the region under study; however, it cannot be stated that this influence relationship (causality) has a direct positive effect between dry matter mass production and productivity of future coffee plantations.

ABSTRACT. Crambe is an oilseed plant producing oil that can be used for various industrial purposes, including the production of biofuel. It is a short-cycle, non-food plant that can be grown as a second crop following soybean or corn crops and using the same agricultural machinery. This work aimed to estimate genetic parameters and correlations between traits of genotypes grown for two years in seven locations in two Brazilian states. The cultivar FMS Brilhante and the lines CR 1101, CR 1102, CR 1105, CR 1202, CR 1303, and CR 1304 were used. The traits evaluated were grain yield (YD), plant height (PH), stem diameter (SD), first fruiting branch height (BH), 1,000-seed weight (SW), and number of branches (NB). The correlations between traits were identified from the phenotypic covariance matrix through path analysis. Based on the joint analysis, the interaction of genotypes x years x locations was observed. Expressive genetic variability was verified for all evaluated traits, which allows gains to be made with the selection of genotypes. High broad-sense heritabilities based on plot means were verified for YD, BH, and SW (82, 84 and 77%, respectively), which indicates the possibility of directly selecting them. SW and SD showed the greatest direct effects and strongest correlations with YD.

RESUMO Objetivou-se modelar e determinar as propriedades termodinâmicas de sorção de água em pó de graviola. As isotermas foram determinadas pelo método estático nas temperaturas de 10; 20; 30; 40 e 50 °C e atividade de água entre 0,113 a 0,868 (decimal). O modelo de GAB descreveu bem o fenômeno de sorção de água do pó de graviola. O teor de água da monocamada variou de 12,589 a 9,109% b.s. Os valores de entalpia relacionados ao modelo de GAB foram negativos, com valor de -2581,035 kJ kg-1 para C0 e -107,758 kJ kg-1 para K0. O calor isostérico de sorção, a entropia e a energia livre de Gibbs apresentaram alta correlação com o teor de água de equilíbrio e a correlação entalpia e entropia se confirmou para a sorção de água em pó de graviola.

ABSTRACT The aim of this study was to model and determine the thermodynamic properties of moisture sorption in soursop fruit powder. The isotherms were determined by the static method at temperatures of 10, 20, 30, 40 and 50 °C, and a water activity of between 0.113 and 0.868 (decimal). The GAB model effectively described the moisture sorption phenomenon of soursop powder. The monolayer moisture content ranged from 12.589 to 9.109% db. The enthalpy values related to the GAB model were negative, with -2581.035 kJ kg-1 for C0 and -107,758 kJ kg-1 for K0. The isosteric heat of sorption, entropy and Gibbs free energy had a high correlation with the equilibrium moisture content, and the correlation between enthalpy and entropy was confirmed for moisture sorption in soursop powder.

RESUMO O estudo das propriedades termodinâmicas proporciona o conhecimento da afinidade do sorvente pela água e da espontaneidade do processo de sorção, sendo importante para projetar equipamentos de secagem e predizer o comportamento higroscópico durante o armazenamento. Este trabalho visou a determinar e avaliar isotermas de equilíbrio higroscópico e propriedades termodinâmicas, para diferentes condições de equilíbrio (teores de água e temperaturas) em sementes de girassol, utilizando-se o método estático indireto. Foram utilizadas sementes de girassol com teor inicial de água de 0,164 (decimal, base seca - b.s). Foram testados quinze modelos matemáticos para modelagem de equilíbrio higroscópico, sendo que o modelo de Smith foi o que apresentou melhor ajuste. Verificou-se que as propriedades termodinâmicas foram influenciadas pelo teor de água, o calor isostérico integral de dessorção aumentou com o decréscimo do teor de água de equilíbrio, variando de 1,787 a 2,670 kJ kg-1 para 0,198 a 0,0518 (decimal, b.s.), respectivamente, o processo de dessorção das sementes de girassol foi controlado pela entalpia e a energia livre de Gibbs, que variou de 3,6363 a 200,1730 kJ kg-1, foi positiva para as temperaturas estudadas, com aumento ao longo do processo de dessorção, demonstrando ser um processo não espontâneo.

ABSTRACT The study of the thermodynamic properties provides the knowledge of the sorbent affinity by the water and the spontaneity of the sorption process, important to design drying equipment and to predict hygroscopic behavior during storage. This work aimed to determine and evaluate isotherms of hygroscopic equilibrium and thermodynamic properties for different equilibrium conditions (water contents and temperatures) in sunflower seeds, using the indirect static method. Sunflower seeds with initial water content of 0.164 (decimal, dry basis - d.b.) were used. Fifteen mathematical models were tested for hygroscopic equilibrium modeling, and the Smith model presented the best fit. It was verified that the thermodynamic properties were influenced by the water content, the integral isosteric desorption heat increased with the decrease of the equilibrium water content, ranging from 1.787 to 2.670 kJ kg-1 to 0.198 to 0.0518 (decimal, d.b.), respectively, the desorption process of the sunflower seeds was controlled by the enthalpy and the Gibbs free energy, which varied from 3.6363 to 200.1730 kJ kg-1, was positive for the temperatures studied, with increase to during the desorption process, proving to be a non-spontaneous process.

Abstract J. curcas (physic nut) is one of the most promising oilseeds for biofuel production and the knowledge about genetic parameter estimates is important for its breeding. Here, we evaluated 121 families, from 48 to 60 months of age, aiming genetic evaluation and selection. The trial was set up in an 11 x 11 lattice design, with three replications and 4-plant plot. The traits evaluated were fruit yield (FY), grain (GY) and oil yield (OY), fruit husk percentage (FH) and seed oil content (OC). Individual heritabilities were low (0.19 to 0.23), requiring accurate selection and improvement methods. Moderate repeatabilities were observed for FY (0.54), GY (0.52), OC (0.30) and OY (0.51), indicating that the families evaluated maintained relative superiority over the years. With selection of the 20 best individuals, the predicted genotypic gains (66%) were greater than the additive gains (56%), indicating greater possibilities of success from cultivation of clones.