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Water deficit is one of the major limiting factors of seed crop germination and productivity. Consequently, superabsorbent polymers (SAPs) are among several technologies that enhance water use efficiency, leading to worthy seed germination. The objective of this study was to investigate the potential effect of three rates of SAPs (0.0%, 0.5%, and 1.0% w/w) on the seedling emergence of barley and fenugreek sown in a sandy soil using three replicates in a randomized complete block design. Outdoor pot experiments were conducted in Aswan Province, Egypt. The differences in the final germination percentages (FGPs) were not significant for both seeds, while the application of SAPs enhanced the seedling germination index (GI) with significant differences for both crop seeds. The application of SAP at 0.5% gave the highest GI for barley (2.47 day−1) and fenugreek (2.66 day−1) seeds. The sigmoidal function effectively described the cumulative germination percentage rates for both seeds as a function of time under the SAP levels with R2 greater than 0.992. The maximum rates were 69.4 and 64.6 day−1 for barley and fenugreek seeds at SAP 0.5%, respectively. The corresponding rates for 0.0% SAP were 11 and 12 day−1. The water germination efficiencies (WGE) were 27.76 and 30.04 cm−1 for 0.0% and 0.5% SAP for barley, while they were 23.07 and 29.9 cm−1 for fenugreek. Accordingly, SAPs could represent a promising solution for increasing moisture conservation for seed germination in a sand soil. For strategic management, barley is recommended for growth over fenugreek in a semidried soil. [ABSTRACT FROM AUTHOR]

Water deficit is one of the major limiting factors of seed crop germination and productivity. Consequently, superabsorbent polymers (SAPs) are among several technologies that enhance water use efficiency, leading to worthy seed germination. The objective of this study was to investigate the potential effect of three rates of SAPs (0.0%, 0.5%, and 1.0% w/w) on the seedling emergence of barley and fenugreek sown in a sandy soil using three replicates in a randomized complete block design. Outdoor pot experiments were conducted in Aswan Province, Egypt. The differences in the final germination percentages (FGPs) were not significant for both seeds, while the application of SAPs enhanced the seedling germination index (GI) with significant differences for both crop seeds. The application of SAP at 0.5% gave the highest GI for barley (2.47 day−1) and fenugreek (2.66 day−1) seeds. The sigmoidal function effectively described the cumulative germination percentage rates for both seeds as a function of time under the SAP levels with R2 greater than 0.992. The maximum rates were 69.4 and 64.6 day−1 for barley and fenugreek seeds at SAP 0.5%, respectively. The corresponding rates for 0.0% SAP were 11 and 12 day−1. The water germination efficiencies (WGE) were 27.76 and 30.04 cm−1 for 0.0% and 0.5% SAP for barley, while they were 23.07 and 29.9 cm−1 for fenugreek. Accordingly, SAPs could represent a promising solution for increasing moisture conservation for seed germination in a sand soil. For strategic management, barley is recommended for growth over fenugreek in a semidried soil.

This study was aimed to investigate the effects of two different concentrations of NaCl on germination traits of seeds of four sugar beet (Beta vulgaris L.) hybrids, including a commercial variety. The seeds were sown in Petri dishes with two levels of NaCl (60 and 180 mM) and the control (0 mM NaCl). Germination and water content and electrical conductivity, as a result of solute leakage from seeds, were analyzed through linear and nonlinear equations. Results showed that the commercial variety germination seemed to be more sensitive to a moderate salt concentration (60 mM NaCl) which, conversely, was not detrimental to water uptake and germination rate in the other hybrids. Adverse effects were more evident at higher salt level (180 mM NaCl), although to a different extent, in all hybrids and for most of the parameters evaluated. This study demonstrated that salinity could induce numerous disorders in sugar beet seeds during the germination process, the seriousness of which depended on both the salt level and genotype. [ABSTRACT FROM AUTHOR]

Three of the most frequently used sigmoidal growth curves from the Richards family are the logistic model, Gompertz model and Richards model. They are used in the analysis of organismal growth over time in many disciplines/studies and were proposed in many parameterisations. Choosing the right parameterisation is not easy. The correct parameterisation of the model should take into account such parameters that are useful to describe the analysed growth phenomenon and are biologically relevant without additional calculations. In addition, each parameter of the model only affects one shape characteristic of each growth curve, which makes it possible to determine standard errors and confidence intervals using statistical software. Growth curves in germination dynamics studies should provide information on topics such as the length of the lag in onset of germination, the maximum germination rate and, when it occurs, the time at which 50% of seeds will germinate and the final germination proportion. In this article, we present three parameterisations of the logistic, Gompertz and Richards models and indicate two parameterisations for each model, corresponding to the above-mentioned issues. Our proposition is parameterisation by taking into account the maximum absolute growth rate. Parameterisations indicated as useful for germination dynamics are characterised by the fact that each parameter has the same meaning in every model, so its estimates can be compared directly amongst the models. We also discussed the goodness-of-fit measures for nonlinear models and in particular measures of nonlinear behaviour of a model's individual parameters as well as overall measures of nonlinearity. All described models were used to study the dynamics of the epicotyl emergence of pedunculate oak. After checking the close-to-linear behaviour of the studied model parameters and by taking into account the criteria of model selection (AICc of each growth curve and the residual variance [RV]), the best model describing the dynamics of epicotyl appearance of pedunculate oak was the Richards curve. [ABSTRACT FROM AUTHOR]

This work tested the effect of after-ripening on seed germination of thirteen commercial seed lots from four open pollinated cultivars (Aydın Siyahı, Kemer, Pala and Topan) of aubergine (Solanum melongena L.). Seeds were stored (after-ripened) at 5 °C with at 9% seed moisture content over 14 days in the dark in hermetic conditions. After-ripened seeds were tested at 25 °C and 20/30 °C (16/8 h) together with a control at 20/30 °C for 14 days in petri dishes. Results indicated that after-ripening significantly (p < 0.05) increased total germination in six lots and normal germination in eight lots out of thirteen when germination was tested at 25 °C. Increases were also observed eleven lots in total and thirteen in normal germination percentages out of thirteen when seeds were tested at 20/30 °C. Cumulative germination showed that after-ripened seeds germinated faster than control either germinated at 25 or 20/30 °C. Results indicated that aubergine seed germination can be increased through after- ripening treatment which shows the presence of seed dormancy in this species. [ABSTRACT FROM AUTHOR]

Myroxylon balsamum is in great demand in Central America as its botanical and wood properties are useful in the pharmaceutical, timber and cosmetics industries. In Colombia, it is classified as near threatened (NT) due to over-exploitation for resin or wood, or habitat destruction in the department of Sucre. A guide was necessary to establish propagation practices for population restoration in natural areas. Here we quantify and analyze the germination behavior of M. balsamum. During the germination process, testa rupture occurred 15 days after sowing; obtaining a germination percentage of 77, 2% and germination rate of 23.3 days. The coefficient of variation for variable seedling height (AP), root length (LR), number of leaves (NH) and number of nodes per seedling (NN) generally showed a wide dispersion, but it was greater in the variables LR y NN. This high behavioural diversity maybe due to the provenance of the seed by different mother plants, their maturity or differences in genetic and physiological characteristics. [ABSTRACT FROM AUTHOR]