Germination and growth in control and primed seeds of pepper as affected by salt stress

Salinity is an important abiotic stress which can affect crop production in the world. One of the simplest methods for improving salinity tolerance of plants is seeds priming. This experiment was conducted to evaluate the effects of seeds priming with three solutions (KCl , NaCl and CaCl2) in germination and later growth of three pepper (Capsicum annuum L.) cultivars: Beldi, Baklouti and Anaheim Chili. Seeds germination was conducted in a completely randomized design under seven salinity levels (0, 2, 4, 6, 8, 10 and 12 g L-1) at room temperature for primed and control seeds. Plants derived from these germinated seeds (control and primed) were transplanted and cultivated in a greenhouse for 4 months and were irrigated permanently with seven salinity levels (0, 2, 4, 6, 8, 10 and 12 g L-1). The results showed that salinity affected all parameters under study like total germination percentage and chlorophyll level (a and b). As well, proline content increased as response to increasing salinity. The plants derived and grown from primed seeds showed a considerable tolerance to salt stress and gave better results. In fact, priming improved the salt resistance of pepper owing to more chlorophyll and proline accumulation. These results suggest that seed priming induced possible physiological adjustments in pepper seeds, especially in the early stages of development, and could be used as a suitable tool for improving germination and growth characteristics under salt stress conditions

Germination and Growth in Control and Primed Seeds of Pepper as Affected by Salt Stress

Salinity is an important abiotic stress which can affect crop production in the world. One of the simplest methods for improving salinity tolerance of plants is seeds priming. This experiment was conducted to evaluate the effects of seeds priming with three solutions (KCl , NaCl and CaCl2) in germination and later growth of three pepper (Capsicum annuum L.) cultivars: Beldi, Baklouti and Anaheim Chili. Seeds germination was conducted in a completely randomized design under seven salinity levels (0, 2, 4, 6, 8, 10 and 12 g L-1) at room temperature for primed and control seeds. Plants derived from these germinated seeds (control and primed) were transplanted and cultivated in a greenhouse for 4 months and were irrigated permanently with seven salinity levels (0, 2, 4, 6, 8, 10 and 12 g L-1). The results showed that salinity affected all parameters under study like total germination percentage and chlorophyll level (a and b). As well, proline content increased as response to increasing salinity. The plants derived and grown from primed seeds showed a considerable tolerance to salt stress and gave better results. In fact, priming improved the salt resistance of pepper owing to more chlorophyll and proline accumulation. These results suggest that seed priming induced possible physiological adjustments in pepper seeds, especially in the early stages of development, and could be used as a suitable tool for improving germination and growth characteristics under salt stress conditions

Use of Biostimulants to Improve Salinity Tolerance in Agronomic Crops

The world population is exceeding 7.63 billion, resulting in more than quadrupled compared to that of 1915 (1.8 billion), and according to the United Nations most recent predictions, we may reach 9.7 inhabitants by the year 2050. This exponential growth, along with the shift from rural to urban life, the increase in per capita food consumption, and the changes in diet in developing countries, due to the rise in income, are driving up the global food demand, which is expected to increase worldwide from 59% to 98% in the next 30 years. However, it will be hard to square the twin challenge of reconciling a maximization of agricultural production with environmental sustainability. Indeed, in the last 50 years, mechanization and new management techniques based on the massive use of fertilizers and irrigation have increased agricultural production also in arid and semi-arid areas, but they have also exacerbated the problems of soil salinity and pollution. In fact, one of the most serious effects of these unsustainable practices has been the salinization of at least 20% of all irrigated and productive lands. Therefore, the main objective of modern agriculture is to increase crop yield production and potential, also in marginal and salinized areas, through innovative farming systems and/or products with an eco-friendly approach. Among the new products which have favorable effects both on soil and cultivated crops, even under environmental constrains like salinity, are biostimulants. They include substances, metabolites, or mixtures of metabolites and/or microorganisms which, when applied to plants or soil, increase the nutrient availability, uptake, and assimilation while reducing the use of agrochemicals in agriculture and improving food resources, preventing leaching of nutrients, and increasing the response to stress in an eco-friendly perspective. Biostimulants do not replace fertilizers or pesticides but represent a complement to the action of both fertilizers and crop protection products, allowing enhancing crop performance even under stress. We will consider the biostimulants derived from plants or animals like seaweed extracts, humic substances, protein hydrolysates, microbial inoculations, etc. and will describe their beneficial effects on plants, especially nutrient use efficiency and plant fitness to abiotic stresses and in particular to salinity

Algae and Cyanobacteria as Biocontrol Agents of Fungal Plant Pathogens

none2noAbstract: Since long time, algae are used in agriculture as soil amendment for their beneficial effects on plant health and productivity. In fact, algae contain several molecules such as plant growth hormones (cytokinins, auxins, abscisic and gibberellic acid), polysaccharides, betaines and micronutrients. The research on algae, their compounds and their effects on plants have started in the middle 1950s and brought to the formulations of liquid products containing extracts with compounds readily available for plants. The algae extracts, besides having effects on plant growth, have demonstrated to improve plant resistance to both abiotic and biotic stresses. Among biotic stresses, algae showed antifungal activity against different pathogens especially of horticultural plants. From the middle of last century, plant management has always been dependent from the market demand that required growing quantity of ‘perfect’ fruits and vegetables over the year. In this scenario, the chemical industry of fertilizers and pesticides developed new products that have been used for years. In particular, pesticides have represented the base of the management of fungal plant pathogens. During the last decades, the use of both pesticides and chemical fertilizers has represented a serious risk for human health and brought disorder of ecosystem equilibrium. Consequently, algae for their biostimulant and antifungal effects may be considered useful tools to reduce the input of chemicals in integrated pest management strategies. In line with these strategies, the European Regulation EC 1107/2009, concerning the placing of plant protection products on the market and repealing Council Directives 79/117/ EEC and 91/414/EEC, recommends that priority should be given to non-chemical and natural alternatives wherever possible.mixedHillary Righini; Roberta RobertiHillary Righini; Roberta Robert