EFFECT OF PUMICE AMENDMENT ON PHYSICAL SOIL PROPERTIES AND STRAWBERRY PLANT GROWTH

We report the results of a research carried out in Turkey in 2004 to determine the effectiveness of different levels of pumice amendments to soil using strawberry plants. Two grades (2-4 mm and 4-8 mm) of pumice were added to soil and three amendment levels (15%, 30% and 45% by volume) were applied. Finally 6 different growing media types were formulated. The amount of moisture retained at different tensions and distribution of pore size of these growing media were determined. Some plant properties such as the number of leaves, leaf area, fresh and dry root weight, most developed root length and increasing fresh weight of day-notr strawberry plants cv. Fern grown on these media were determined. The best plant growth was observed on media including 4-8 mm pumice grade and 45% pumice amendment ratio with soil

How Abiotic Stress Conditions Affects Plant Roots

Roots are generally subject to more abiotic stress than shoots. Therefore, they can be affected by such stresses as much as, or even more, than above ground parts of a plant. However, the effect of abiotic stresses on root structure and development has been significantly less studied than above ground parts of plants due to limited availability for root observations. Roots have functions such as connecting the plant to the environment in which it grows, uptaking water and nutrients and carrying them to the above-ground organs of the plant, secreting certain hormones and organic compounds, and thus ensuring the usefulness of nutrients in the nutrient solution. Roots also send some hormonal signals to the body in stress conditions such as drought, nutrient deficiencies, salinity, to prevent the plant from being damaged, and ensure that the above-ground part takes the necessary precautions to adapt to these adverse conditions. Salinity, drought, radiation, high and low temperatures, heavy metals, flood, and nutrient deficiency are abiotic stress factors and they negatively affect plant growth, productivity and quality. Given the fact that impending climate change increases the frequency, duration, and severity of stress conditions, these negative effects are estimated to increase. This book chapter reviews to show how abiotic stress conditions affect growth, physiological, biochemical and molecular characteristics of plant roots

Principles of Irrigation Management for Vegetables

Vegetables have a very high percentage of water content. Some of the vegetables, such as cucumber, tomato, lettuce, zucchini, and celery contain over ninety-five percent of water. As a result of the high-water content in the cells, they are extremely vulnerable plants to water stress and drought conditions. Their yield and quality are affected rapidly when subjected to drought. Therefore, irrigation is essential to the production of most vegetables in order to have an adequate yield with high quality. However, over-irrigating can inhibit germination and root development, decrease the vegetable quality and post-harvest life of the crop. Determination of suitable irrigation systems and scheduling to apply proper amount of water at the correct time is crucial for achieving the optimum benefits from irrigation. This determination requires understanding of the water demand of the vegetable, soil characteristics, and climate factors. All these factors have major impact for the success and sustainability of any vegetable irrigation. This section contains fundamentals of water requirements on different vegetables and summarizes important issues related to soil, water, and vegetable growth relations together with irrigation management concept by evaluating the challenging issues on the selection of proper irrigation system, suitable irrigation timing, and other parameters to increase vegetable yield in an irrigated agriculture

EFFECT OF PUMICE AMENDMENT ON PHYSICAL SOIL PROPERTIES AND STRAWBERRY PLANT GROWTH

We report the results of a research carried out in Turkey in 2004 to determine the effectiveness of different levels of pumice amendments to soil using strawberry plants. Two grades (2-4 mm and 4-8 mm) of pumice were added to soil and three amendment levels (15%, 30% and 45% by volume) were applied. Finally 6 different growing media types were formulated. The amount of moisture retained at different tensions and distribution of pore size of these growing media were determined. Some plant properties such as the number of leaves, leaf area, fresh and dry root weight, most developed root length and increasing fresh weight of day-notr strawberry plants cv. Fern grown on these media were determined. The best plant growth was observed on media including 4-8 mm pumice grade and 45% pumice amendment ratio with soil

Peat Use in Horticulture

Peat is a spongy substance which is an effect of incomplete decomposition of plant residues in different stages of decomposition. Between the several organic matters which are used as substrate for horticultural plants cultivation in soilless conditions, peat is the unabandonable ingredient for mixtures for commercial production of plants. Peat is used in horticulture as a component of garden plant substrates, in agriculture for the production of garden soil and as an organic fertilizer, and in balneology as a material for baths and wraps. The use of peat for agriculture and horticulture is determined by the following quality parameters: the degree of decomposition, ash content, pH, the presence of carbonates, the density of the solid phase, bulk density, and porosity. As an organic material, the peat forms in the acidic, waterlogged, and sterile conditions of fens and bogs. The conditions seem like the development of mosses. The plants do not compose as they die. Instead of this, the organic matter is laid down and accumulates in a slow time as peat due to the oxygen deficiency in the bog. This makes peat a highly productive growing medium. In the present novel review, we discuss the peat use in horticulture

Physiological, Morphological and Biochemical Responses of Exogenous Hydrogen Sulfide in Salt-Stressed Tomato Seedlings

Salinity causes yield and quality losses in agricultural production and therefore great economic losses around the world. Hydrogen sulfide (H2S) is known to play a crucial role to ease physiological and metabolic processes in plants, and also increases the tolerance of the plant against many abiotic stress conditions. In this study, we investigated the effects of H2S treatments (0, 25, 50, 75 and 100 µM NaHS were applied as H2S donor) to the tomato seedlings to alleviate the harmful effects of salt stress (0, 75 and 150 mM NaCl). There was a significant decrease in plant growth and development in parallel with the increased salt level. Visible changes in plant development were observed after the dose of 75 mM NaCl in the tomato seedling. The effects of different doses of exogenous H2S treatment were found to be significant. H2S treatment increased the stress tolerance in tomato seedlings by arranging the mineral element and hormone content. Furthermore, H2S relieved the effect of stress in plants by increasing photosynthetic activity (photosynthesis rate (Pn), transpiration rate (Tr), stomatal conductivity (gs) and intercellular CO2 concentration (Ci)) of the plant. In addition, the effect of H2S on salt stress tolerance in tomato seedlings may be due to its positive effect on mineral element contents. As a result, based on the beneficial effects of H2S in tomato seedlings under salt stress, this treatment can be considered as an alternative resilience method for cultivation in saline soils or irrigation with low quality waters

The Yield Responses to Crop Bioremediation Practices on Haplustept and Fluvaquent Saline-Sodic Soils

Crop production in salty-sodic soils causes poor crop growth due to ion imbalance, water stress, low hormonal and enzymatic balances. The use of rhizobacteria promoting plant growth in saline and sanitary areas (PGPR) is an economical and environmentally friendly approach that increases and eliminates the tolerance of plants to salt. Field experiments were conducted to determine the response of barley, maize and sorghum crop yields to the application of the bacteria (Halobacillus sp), which was preliminarily experimented by a greenhouse study, on two big soil groups (Haplustept and Fluvaquent). The experiment was established with four different treatments; T0 (control-no application), T1 (the gypsum application), T2 (the PGPR application), and T3 (the gypsum + PGPR application) on the high saline and sodic soils in a semi-arid region. The observations of the present study indicate positive impacts of PGPR applications on crop yield and soil productivity. The gypsum + PGPR treatment was the most effective treatment obtaining higher yields owing to significant improvement in the plant photosynthetic activity, chlorophyll content, stomatal conductance, enzymes, hormones, amino and organic acids, and crop-soil productivity. The seed inoculation with the Halobacillus sp bacteria cultures help in alleviation of stress and enhance crop productivity under the short-term gypsum application on Haplustept and Fluvaquent saline-sodic soils