-Storage is an important step in the production of soybean seeds, mainly in tropical regions, where high temperatures can drastically reduce seed quality. The storage at cooler temperatures may be a feasible alternative to preserve seed quality during storage. The objective of this study was to evaluate the physiological quality of soybean seeds artificially cooled by a dynamic process and stored in an environment, with non controlled temperature and relativity humidity. Two seed lots of cultivars Monsoy 8757, TMG 115 RR and BRS Valiosa RR were used. After processing and during packaging the seeds were cooled to 18 o C by a dynamic process. Seed samples were collected after 0, 60 and 120 days of storage, using the following parameters germination, accelerated aging, seedling emergence in sand, speed of emergence index, electrical conductivity, tetrazolium and seed health. Although soybean seeds artificially cooled by the dynamic method may have slightly superior performance in maintaining physiological quality during storage in non-refrigerated warehouse, for lots of high physiological quality, these advantages are not observed.

A B S T R A C TThe objective of this study was to determine the desorption isotherms of 'cajuzinho-docerrado' achenes (Anacardium humile St. Hil.) in various conditions of temperature and water activity, as well as to select the one that best represents the phenomenon and to determine the isosteric heat of desorption. The fruits were collected at the Emas National Park, in the municipality of Mineiros-GO, Brazil, pulped and then subjected to drying in silica gel at temperature of 25 ± 2 °C until the moisture contents of 17.6, 13.6, 11.1, 8.7 and 5.3 (d.b.%). After drying, the desorption isotherms were determined by the indirect static method. The water activity (Aw) was determined at different temperatures, and the achenes were placed in a B.O.D. chamber, regulated at 10, 20, 30 and 40 °C. Data of hygroscopic equilibrium moisture content were fitted to different mathematical models through nonlinear regression analysis, using the Gauss-Newton method. The Copace model was the one that best represented the hygroscopicity of 'cajuzinho-do-cerrado' achenes, while the integral isosteric heat of desorption of 'cajuzinho-do-cerrado' achenes for the moisture content range of 4.51 to 13.40 (% d.b.) varied from 2,734.82 to 2,548.49 kJ kg -1 . Isotermas de dessorção e calor isostérico de aquênios de cajuzinho-do-cerrado R E S U M OObjetivou-se, com este trabalho, determinar as isotermas de dessorção de aquênios de cajuzinho-do-cerrado (Anacardium humile St. Hil.) em diversas condições de temperatura e atividades de água e selecionar aquela que melhor representa o fenômeno e determinar o calor isostérico de dessorção. Os frutos foram coletados no Parque Nacional das Emas, no município de Mineiros -GO, despolpados e em seguida submetidos à secagem em sílica gel a temperatura de 25 ± 2 °C, até atingirem os teores de água de 17,6; 13,6; 11,1; 8,7; 5,3 (% b.s). Após a secagem foram determinadas as isotermas de dessorção pelo método estático indireto. A atividade de água (Aw) foi determinada sob diferentes temperaturas sendo os aquênios acondicionados em câmara B.O.D., regulada a 10, 20, 30 e 40 °C; aos dados de teor de água de equilíbrio foram ajustados a diferentes modelos matemáticos por meio da análise de regressão não linear, pelo método Gauss-Newton. O modelo Copace foi o que melhor representou a higroscopicidade dos aquênios de cajuzinho-do-cerrado enquanto os valores de calor isostérico integral de dessorção dos aquênios de cajuzinho-do-cerrado para a faixa de teor de água de 4,51 a 13,40 (% b.s.) variaram de 2734,82 a 2548,49 kJ kg -1 .

Native Cerrado plants are exposed to soils with low pH and high availability of Al. In this study, we measured the Al content in adult plants, and investigated the effects of various Al doses on germination and early development of Eugenia dysenterica plants. For germination tests, the seeds were soaked in Al solution and evaluated for twenty days in growth chambers. In a second experiment, young plants were cultivated in hydroponic systems with various Al concentrations to evaluate the morphological, anatomical and physiological characteristics of E. dysenterica. Anatomical changes and low germinative vigor were observed in seeds germinated in 600 and 800 μmol Al3+ L−1. In the hydroponic system, 200 μmol Al3+ L−1 stimulated root growth in young plants. The activity of antioxidant enzymes and the accumulation of phenolic compounds were greatest at the highest Al doses, preventing changes in gas exchange and chlorophyll a fluorescence. Starch grain accumulation was noted in plant cells exposed to 200 and 400 μmol Al3+ L−1. Adult E. dysenterica trees also accumulated Al in leaves, bark and seeds. These data suggest that E. dysenterica is tolerant to Al.

Abstract: The aim of this study was to evaluate the effects of pre-harvest desiccant herbicides on the yield and the physiological and technological quality of cowpea seeds after harvest and after storage. The experiment was conducted in a randomized block design with four replications. A split-plot design (6 × 2) was composed of the desiccant herbicides flumioxazin (30 g ai.ha-1), glufosinate ammonium (500 g ai.ha-1), paraquat (400 g ai.ha-1), saflufenacil (70 g ai.ha-1), and carfentrazone (24 g ai.ha-1) and an untreated control, as well as two seed evaluation periods, at harvest and six months after h arvest. Desiccants were applied at the R5 stage. The desiccants affected the yield, classification, color, and physiological quality of seeds of ‘BRS Guariba’. The glufosinate ammonium and paraquat herbicides compromised seed physiological quality. Flumioxazin did not affect seed yield components, color, and physiological quality. Storage at 20 °C for six months affected seed physiological quality.

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The use of soybean varieties resistant to the herbicides dicamba and 2,4-D may lead to drifts towards areas grown with non-resistant varieties. The aim of this study was to evaluate the effects of dicamba and 2,4-D underdoses applied at the phenological stages V4 and R2 of soybeans. Two experiments were conducted with dicamba or 2,4-D in a randomized block design with four replications. The 4 × 2 + 1 factorial scheme was composed of four doses (0.028, 0.28, 2.8, and 28 g ae ha−1) of dicamba or 2,4-D applied at two phenological stages (V4 and R2) + a control treatment (without herbicide application). Dicamba underdoses caused damage to soybean crop affecting its vegetative growth and yield; the injuries caused by 2,4-D were neither enough to damage crop nor affect yield components. Dicamba underdoses applied at V4 caused injuries of up to 41%, while in R2 they reached 70%. Plant height decreased by up to 61% when treated with dicamba. Soybean yield was reduced by 29 and 76% when the simulated drift occurred at V4 and R2, respectively, and at a dose of 28 g ae ha−1 of dicamba. For the tested underdoses, only 2,4-D had no effect in soybean crop yield.

The objective of this study was to evaluate the internal morphology of seeds of Campomanesia pubescens (Mart. ex DC.) O. Berg with varying water content through X-ray image analysis, and correlate the images with the germination of these seeds. Fruits were collected in Jataí, Goiás, Brazil, and taken to the Seed Laboratory of the Federal Institute Goiano, Rio Verde Campus, where they were processed and the seeds were extracted. To establish the predetermined water content (43%, 37%, 34%, 31%, and 28% wet basis), seeds with an initial water content of 43% were kept in an oven with forced air circulation at a temperature of 40 °C until they reached the predetermined water content levels. Next, the seeds were placed in acrylic holders with double-sided tape and transported to the Federal University of Lavras (UFLA), where they were exposed to different intensities of radiation. The X-ray test was conducted with 200 seeds per treatment, and images of the internal structures of the seeds were evaluated. The seeds were returned to the Seed Laboratory of the Federal Institute Goiano, Rio Verde Campus, where the germination test was initiated. The experimental design was completely randomized, in a factorial design (5 × 4), in which there were five water content levels and four seed classes, with four replications. The X-ray test was efficient in the identification of filled, malformed, damaged and empty seeds, which germination rate above 50% in the filled seeds. This visualization of the internal morphology of the seed can be useful to select seeds of better quality, improving the percentage of germination of C. pubescens seeds.

The objective of this study was to evaluate different pre-germination treatments, histochemical characteristics and physiological performance of Sapindus saponaria L. seeds as a function of temperature and the germination substrate. The S. saponaria seeds were collected in the municipality of Rio Verde, GO, and analysed through the execution of 2 tests (dormancy breakage and germination tests). Test 1 consisted of 10 treatments for overcoming dormancy, whereas test 2 consisted of a 35-day evaluation of germination on several substrates (paper and sand) under the following 4 temperature conditions: 20, 25, 30°C and alternating 20-30°C (± 0.5°C). The results of the dormancy breakage and germination tests were submitted to analysis of variance (ANOVA), and the means were compared by the Tukey test. Scarifying S. saponaria seeds with concentrated sulfuric acid for 90 min provided a relatively high speed and percentage of emergence, without causing anatomical damage. Pre-germination treatments using high- (42 °C) or low-(10 °C) temperature stress caused cellular damage in the endosperm region of S. saponaria seeds. The greatest percentage of S. saponaria seeds germinated on a paper substrate at 30°C.