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O uso intensivo da terra tem efeitos negativos sobre a microbiota do solo e também sobre a produtividade agrícola. Os fungos micorrízicos arbusculares são micro-organismos do filo Glomeromycota, que atuam na absorção de água e nutrientes para as plantas. Através desta pesquisa, avaliamos a ecologia das espécies de FMAs na formação de gramíneas forrageiras utilizadas em terras cultiváveis do Piauí. Foram avaliadas dez áreas cultivadas diferentes tipos de gramíneas. Procedeu-se a extração dos glomerosporos presentes em amostras de solo, identificação das espécies de FMAs e colonização radicular. As espécies de FMA pertencentes ao Filo Glomeromycota, Classe Glomeromycetes recuperadas nos dez tratamentos foram organizados em 4 Ordens (Diversisporales, Gigasporales, Glomerales, Archaeosporales), 5 Famílias (Acaulosporaceae, Dentiscutataceae, Glomeraceae, Archeosporaceae, Ambisporaceae) e 5 gêneros: Acaulospora, Ambispora, Archaeospora, Dentiscutata, Glomus. Com os resultados sobre a identificação de micro-organismos edáficos específicos do Piaui, foi possível compreender a ecologia espécies indígenas de fungo micorrízicos arbusculares (FMAs) característicos do Estado piauiense.

The use of an alternative technique to increase the germination of an legume species used in animal feed was investigated based on the effects of low-pressure plasma on the wettability, imbibition, and germination of seeds of Desmanthus virgatus. A conventional nitriding reactor with an argon atmosphere (Ar) and controlled temperature at 30º C was used to apply three different exposure times: 1, 3, and 5 minutes, with a set of intact seeds considered as the control. The experimental design was completely randomized, and the means were compared by the Tukey test at 5% probability to analyze the different experimental conditions tested. The statistical analyses were performed with the software Origin 8.0. The apparent contact angle indicated an increase in the wettable surface with the treatment time, verifying the hydrophilic character of the plasma on the seed. Seeds treated for 3 and 5 minutes showed higher germination than the 1-minute treatment and untreated seeds. In the imbibition test, the leached solution showed lower conductivity in the treated samples than in the untreated sample, indicating less nutrient loss to the solution. The pH remained within the neutral range among the treated samples. The superficial changes in the seeds caused significant gains in the germination parameters, promoting improvement in the indices and rate of germination and contributing to the uniformity of the seed lot with the use of low-pressure plasma as a tool for breaking dormancy.

The effects of cold atmospheric plasma (CAP) of dielectric barrier discharges on the wettability, imbibition and germination ofLeucaena leucocephalawere investigated. It was established that CAP treatment markedly hydrophilized the seed coat, especially at longer treatment times. From the profile of the imbibition curve and visual observation, it was possible to verify that there are two resistance barriers to water penetration: integument surface and region of the macrosclereid cell wall (light line). Although the plasma interacts only in the integument, increasing the density of hydrophilic sites increases the capacity of water absorption, producing enough driving force to overcome the second resistance barrier. The existence of these two barriers changes the three-phase pattern generally observed during seed germination. Despite an increase in imbibition, the plasma treatment conditions used in this work, were not enough to overcome completely the dormancy barrier.

Usually, in the Brazilian semiarid region where dry and humid periods are well determined, phenological events are mainly affected by seasonal rainfall and availability of water in the soil. The studies in these regions have importance especially to understand the dynamics of dry forests. Thus, the objective of this work was to characterize the phenophases of trees P. pyramidalis, C. blachetianus, A. pyrifolium and J. mollissima, and their relationship with the temporal distribution of rainfall, which occurs in the form of pulses. Furthermore, the effect of goat grazing was evaluated. The experimental areas presented different caprine stockings, where first had ten and the second five. The third stocking remained without goats during the experimental period. For the phenological follow-up, 50 tree individuals of each species were selected, tagged and monitored weekly, at Experimental Station, in the municipality of São João do Cariri-PB. In order to quantify the phenological events, the percentage of Fournier intensity was used, registering the presence and absence of the phenophases: sprouting, flowering, fruiting and senescence, whose data were related to the water pulses and inter-pulses. The phenological events presented annual patterns, with interannual variations in intensity. We observed that the phenophases occur in synchrony with the temporal distribution of the rainfall pulses in the area of its occurrence. As the dry season progresses, reduction in sprouting, flowering and fruiting occurs when the inter-pulses of rainfall was intensified. The presence of goats did not influence the phenological development of the species.

Plasma technology is a fast, cost-effective, and pollution-free method that can be used in place of conventional methods to overcome seed dormancy. The goal of the present study was to determine the effect of different application times of atmospheric plasma on soaking and germination of Hybanthus calceolaria seeds in order to accelerate these processes. Helium plasma jet produced by dielectric barrier discharge was used to treat H. calceolaria seeds with applications of 1, 5, and 10 minutes. The treated seeds were characterized considering their weight variation during soaking, changes in electrical conductivity, and pH. It was found that germination depended on the plasma application time. The treatment of H. calceolaria seeds with atmospheric plasma for 1 minute provided 3.5 times greater germination in comparison to untreated seeds. Atmospheric plasma technology obtained by dielectric barrier discharge had potential of being used as a germination accelerant in H. calceolaria seeds. The treatment of H. calceolaria seeds using atmospheric plasma for 1 minute favored germination. A tecnologia de plasma constitui-se em um método rápido, econômico e livre de poluição que pode ser utilizada na superação de dormência de sementes em substituição aos métodos convencionais. O objetivo com esse estudo foi verificar o efeito do tempo de aplicação de plasma atmosférico sobre a embebição e germinação de sementes de Hybanthus calceolaria visando à aceleração destes processos. Jato de plasma de gás hélio, produzido por descarga em barreira dielétrica (DBD), foi utilizado para tratar as sementes de H. calceolaria por 1, 5 e 10 minutos de aplicação. As sementes tratadas foram caracterizadas quanto à variação de peso durante a embebição, variações da condutividade elétrica e pH. Verificou-se que a germinação depende do tempo de aplicação do plasma. O tratamento de sementes de H. calceolaria com plasma atmosférico por 1 min. proporcionou incremento na germinação de 3,5 vezes em comparação com as não tratadas. A tecnologia de plasma atmosférico, obtido por barreira dielétrica, apresenta potencial de utilização como acelerador da germinação de sementes de H. calceolaria. O tratamento de sementes de H. calceolaria à plasma atmosférico durante 1 minuto favorece a germinação.

The effect of plasma applied to mulungu (Erythrina velutina) seeds was studied to verify its influence on the germination, water absorption, wettability and structure of the seeds. The plasma jet used in this study was produced by dielectric barrier discharge (DBD) in a helium gas flow of 0.03 L/s at a distance of 13 mm for 60 s. The plasma treatment significantly affected the seed germination rate, which was approximately 5% higher than that of the untreated group. Micropyle and hilum contributed a greater proportion to uptake. When sealed in the hilar or micropyle regions the amount of water absorbed into the seed decreased approximately 75% compared to the unsealed seed. This difference suggests that these two regions together act cooperatively in the water absorption. However, when plasma treated seed was blocked in the micropyle region, water absorption was higher higher than in seeds blocked hilum. This difference suggests that the plasma treatment changed the wettability of the hilum more effectively than it changed the micropyle. These results indicate that plasma can significantly change the hydrophilicity, water absorption and percentage of seed germination in E. velutina.

Objetivou-se avaliar o efeito da inclusao de niveis crescentes de torta de girassol (0, 15, 30, 45% da materia seca) sobre as medidas corporais, medidas de carcaca e viabilidade economica das dietas experimentais de ovinos confinados. Foram utilizados 20 cordeiros deslanados, nao castrados, com peso medio inicial de 17±1,4 kg alimentados a vontade. As medias in vivo foram efetuadas imediatamente antes do abate e as medidas de carcaca na carcaca fria. As medidas corporais nao foram (P>0,05) influenciadas pela inclusao da torta de girassol e os animais apresentaram media de 64,8 cm para altura de cernelha e 91,65 cm de perimetro toracico. O comprimento externo da carcaca apresentou comportamento linear negativo (P

This study aimed to evaluate the inclusion sunflower cake (Hellianthus annuus L.) in diets of feedlot sheep. It was used 20 crossbred Santa Ines lambs, intact males, initial body weight of 17 ± 1.4 kg and 120 days of age were confined for 70 days. The diets were constituted by grass hay, grain ground corn, soybean meal, mineral salt and increasing inclusions of sunflower cake (0, 15, 30 and 45%). At the end of the feedlot period, the animals were slaughtered. The average daily gain and body weight were not affected (P> 0.05) by the inclusion of sunflower cake. However, the dry matter intake was a linear increase (P 0.05) by the inclusion of sunflower cake. The subcutaneous fat thickness increased (P 0.05) by the inclusion of sunflower cake. The inclusion of sunflower cake increased feed conversion, but no influence on the weight of body parts of the sheep. It is recommended to include up to 15% of sunflower cake in diets of feedlot sheep.