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

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

Melatonin: Role in Increasing Plant Tolerance in Abiotic Stress Conditions

Nowadays, due to the environmental stress factors that limit the production of crops, it has become very difficult to find suitable areas to enable the plant to reach its optimum product potential. Abiotic stress is very effective in decreasing agricultural production. Factors such as drought, salinity, high and low temperature, flood, radiation, heavy metals, oxidative stress, and nutrient deficiency can be considered as abiotic stress factors, and these sources of stress negatively affect plant growth, quality and productivity. Melatonin (MEL) was first identified in plants in 1995 and is increasingly becoming important for its role and effects in the plant system. MEL has been shown to have a substantial role in plant response to growth, reproduction, development, and different stress factors. In addition to its regulatory role, MEL also plays a protective role against different abiotic stresses such as metal toxicity, temperature, drought, and salinity. In plants, an important role of MEL is to alleviate the effects of abiotic stresses. In this review, the effects of MEL on plant growth, photosynthetic activity, metabolism, physiology, and biochemistry under abiotic stress conditions as a plant growth regulator will be examined

Effect of Biochar and Process Water Derived from the Co-Processed Sewage Sludge and Food Waste on Garden Cress’ Growth and Quality

Very little is known about how products derived from the hydrothermal carbonization (HTC) of municipal waste affect the availability and uptake of nitrogen in plant nutrition. This study examined the effects of 60% sewage sludge and 40% food waste HTC products, i.e., biochar (BC) and process water (PW), as nitrogen sources on garden cress growth and quality. A fertilization program using four nitrogen doses [(control), 9, 12, and 15 kg da−1 N] and BC, PW, chemical nitrogen (CN), and their combinations were used in a pot experiment conducted under greenhouse conditions. The highest nitrogen dose often produced better results in terms of plant growth and quality. Additionally, fertilization with PW+CN and BC+CN at the highest nitrogen dose significantly improved plant height, plant fresh and dry weight, and root dry weight parameters of garden cress over the previous treatments. The highest stem diameter, number of leaves, and plant area values were obtained in the 15 kg da−1 N dose PW+BC application. The vitamin C content in cress decreased with the increasing levels of CN. The highest vitamin C content was obtained with 15 kg N da−1 PW fertilization. BC+PW and CN fertilization applications improved chlorophyll a, b, and the total contents of garden cress leaves. Moreover, the nitrate (NO3) concentration of cress increased with CN doses while it decreased in all BC and PW administrations. The 9, 12, and 15 kg N da−1 doses of PW+CN and the 15 kg N da−1 dose of BC+CN yielded the highest agricultural nitrogen utilization efficiency (ANUE) values. Plant nutrient content was positively affected in all fertilization applications, except for Na and Cl. However, it was determined that BC+CN fertilizer application improved plant nutrient uptake. Surprisingly, PW+CN treatment at the lowest nitrogen dosage resulted in the highest soil organic matter and total nitrogen content. In conclusion, it has been determined that biochar and process water have a synergistic effect with CN to increase plant growth by improving nitrogen efficiency, but their application alone without CN is insufficient to meet the nitrogen requirement

Evaluation of Some Agro-morphological Characteristics of Dwarf Snap Bean Genotypes Collected from Erzurum Province

The study was conducted in the trial area of the Department of Horticulture at Atatürk University during the 2022 cropping season to evaluate some agro-morphological characteristics of the dwarf-type snap bean genotypes collected from Erzurum along with the commercial cultivars SARIKIZ and GINA have been widely cultivated there. The genotypes tested in the study showed statistically significant variations in terms of all parameters examined. Genotypes ERZ PA 28 and ERZ UZ 36 reached the earliest fresh maturity time by 58 days.  The genotype with the longest pod was ERZ NR 104 (17.35 cm); the genotypes with the widest pod were ERZ UZ 36 (15.29 mm) and ERZ TO 49 (15.43 mm); and the genotype with the thickest pod was ERZ İS13 (8.75 mm). The ERZ TO 49 genotype had the most pods per plant (32.41), the highest yield per plant (217.73 g), and the highest yield per square meter (1360.79 g/m2), while the ERZ UZ 35 genotype produced the heaviest average pod weight (8.63 g). Additionally, in terms of the number of pods per plant, yield per plant, and yield per square meter, ERZ PA 28 has been determined to produce the results that are closest to ERZ TO 49. According to the study’s findings, ERZ IS 13, ERZ PA 28, ERZ UZ 32, ERZ UZ 35, ERZ UZ 36, ERZ TO 48, ERZ TO 49, ERZ NR 104, ERZ PS 111, ERZ PS 115, and ERZ PS 116 genotypes yields per square meter was founded that higher than commercial cultivars and other genotypes, can offer the producer a sufficient level of yield

Effect of Biochar and Process Water Derived from the Co-Processed Sewage Sludge and Food Waste on Garden Cress’ Growth and Quality

Very little is known about how products derived from the hydrothermal carbonization (HTC) of municipal waste affect the availability and uptake of nitrogen in plant nutrition. This study examined the effects of 60% sewage sludge and 40% food waste HTC products, i.e., biochar (BC) and process water (PW), as nitrogen sources on garden cress growth and quality. A fertilization program using four nitrogen doses [(control), 9, 12, and 15 kg da−1 N] and BC, PW, chemical nitrogen (CN), and their combinations were used in a pot experiment conducted under greenhouse conditions. The highest nitrogen dose often produced better results in terms of plant growth and quality. Additionally, fertilization with PW+CN and BC+CN at the highest nitrogen dose significantly improved plant height, plant fresh and dry weight, and root dry weight parameters of garden cress over the previous treatments. The highest stem diameter, number of leaves, and plant area values were obtained in the 15 kg da−1 N dose PW+BC application. The vitamin C content in cress decreased with the increasing levels of CN. The highest vitamin C content was obtained with 15 kg N da−1 PW fertilization. BC+PW and CN fertilization applications improved chlorophyll a, b, and the total contents of garden cress leaves. Moreover, the nitrate (NO3) concentration of cress increased with CN doses while it decreased in all BC and PW administrations. The 9, 12, and 15 kg N da−1 doses of PW+CN and the 15 kg N da−1 dose of BC+CN yielded the highest agricultural nitrogen utilization efficiency (ANUE) values. Plant nutrient content was positively affected in all fertilization applications, except for Na and Cl. However, it was determined that BC+CN fertilizer application improved plant nutrient uptake. Surprisingly, PW+CN treatment at the lowest nitrogen dosage resulted in the highest soil organic matter and total nitrogen content. In conclusion, it has been determined that biochar and process water have a synergistic effect with CN to increase plant growth by improving nitrogen efficiency, but their application alone without CN is insufficient to meet the nitrogen requirement

Determination of Effects of Bacteria, Mineral Fertilizer and their Combination on the Plant Growth of Tulip (Tulipa gesneriana L.)

© 2017 Inderscience Enterprises Ltd.Using biofertiliser in agricultural production has increased lately, in this context; we investigated the effects of four bacteria isolates (Paenibacilluspolymyxa-BI, Pseudomonas putida-BII, Bacillus subtilis-BIII and Kluyveracryocrescens-BIV) and 50% mineral fertilizer reduction with bacteria on plant growth of seven tulip cultivars. In the results, the effects of applications and cultivars were generally significant. With 1/2MF+BIII combination was ensured of shorter sprouting time. The bulb sprouting ratio was observed 97.33% (Jan Reus) and 99.78% (Parade) in varying proportions among the cultivars. The vegetation period had been longest with 1/2MF+BIII and American Dream cultivar. Treated applications showed the highest length and thickness of peduncle increased by 7.82% and 7.86% compared to control. The applications increased the plant height by 7.88% (BI) and the stem diameter by 6.06% (BIII) ratio. Dry matter in perianth increased by 6.30% with 1/2MF+BIV. As a result, the bacterial applications could be advised as fertiliser on plant growth of tulip

EFFECTS OF INTERCROPPING SYSTEM AND NITROGEN FERTILIZATION ON LAND EQUIVALENT RATIO, YIELD AND MINERAL CONTENT OF BROCCOLI

To determine effects of intercropping broccoli with onion and their correspondence to different nitrogen concentrations on growth, yield and nutrient contents, field studies were conducted for two years. In intercropping plots, onion sets were planted between broccoli rows. Broccoli and onion plants were also grown as monocrops. Nitrogen (N) was applied at three different rates (160, 200 and 240 kg ha(-1)) in both mono and intercrop plots of broccoli. The overall efficiency of intercropping was evaluated by employing Land Equivalent Ratios (LERs). Cropping systems significantly did not affect chlorophyll reading value, yield and other parameters observed. However, nitrogen application rate had significant effect on these parameters. The highest values of these parameters were generally observed in 240 kg N ha(-1) application. Macro and microelement content of broccoli leaves was affected neither by cropping systems nor by nitrogen fertilization except for N, Mn, Zn and NO3. Intercropping increased plant height but decreased the plant diameter of onion. There wasn't significant decrease in plant weight of intercropped onion at 240 kg N ha(-1) treatment when compared to monocropping. Broccoli intercropped with onion at 240 kg N he had the highest LER values, showing that intercropping practice could be more productive than monocropping especially in case of 240 kg N ha(-1) application

Foliar Applications of Humic Substances Together with Fe/Nano Fe to Increase the Iron Content and Growth Parameters of Spinach (<i>Spinacia oleracea</i> L.)

Iron deficiency, which severely decreases the plant yield and quality, is one of the major problems of calcareous soils. Foliar applications of humic substances and/or Fe fertilizers are environmentally friendly methods to cope with Fe deficiency. The aim of this study was to investigate the combined effect of Fe/nano Fe and humic/fulvic acid-based biostimulant foliar applications on the Fe content and plant growth parameters of spinach. Treatment solutions were prepared either by mixing a common Fe fertilizer, FeSO4·7H2O, with different commercial biostimulants (Fulvic-based: Fulvagra®, Fulvagra®WSG; Humic-based: HS300®, Humin Fe® and Liqhumus®, Grevenbroich, Germany) or by mixing nano ferrihydrite with different ratios of fulvic substance (FA-50, FA-75, and FA-100) and humic acid (Nano Iron). Growth parameters (plant fresh and dry weights, plant dry matter, root fresh and dry weights, root dry matter, leaf number per plant, and leaf area); chlorophyll reading value (SPAD); chlorophyll (a,b, and total) and carotenoid contents; and leaf and root mineral contents (N, P, K, Ca, Mg, S, Cu, Mn, Zn, B, active Fe, and total Fe) of samples were determined. Our results showed that foliar application of biostimulants together with Fe sources improved the nutrient uptake, chlorophyll contents, growth characteristics, and yield; however, not all humic substances had the same effect. When all parameters were considered, Fulvagra treatment—which contained 17% fulvic acid and microorganisms in its content together with 20 mM FeSO4·7H2O—was the most effective application, followed by FA100 treatment containing fulvic acid and 20 mM nano ferrihydrite. This finding indicates that fulvic acid containing biostimulants is more effective in foliar applications than humic-based biostimulants against Fe deficiency due to their low molecular weight which enables better penetration into the leaves. In conclusion, foliar applications of fulvic substances together with Fe fertilizers can be used to increase the Fe uptake of crops and the yields under Fe-deficient conditions