The Role of Nano-Silicon and Other Soil Conditioners in Improving Physiology and Yield of Drought Stressed Barley Crop

A field experiment was conducted in sandy soil to assess the effect of different sources of soil conditioners on barley (Hordeum vulgare L. cv. Giza 137) growth and its yield under drought stress. Plants were exposed to two levels of drought stress until grain maturity: (A) drought at 75% available water (AW) with NPK as control (treatment, T1); (B) mild drought stress at 50% AW with foliar spray of nano-silicon at 75 ppm (treatment, T2), foliar spray of nano-zeolite at 75 ppm (treatment, T3), perlite at 4 tons/h (treatment, T4), natural zeolite at 600 kg/ha (treatment, T5), bentonite at 4 tons/h (treatment, T6), and a combined treatment of T2+T3+T4+T5+T6 at the half amount of each material (T7). All the treatments received the recommended doses of organic matter. Vegetative growth and yield characters as well as anatomical characters were recorded. The physical and chemical soil properties were significantly improved by both foliar and soil conditioners application. The nutrients content of the barley crop were augmented under combined treatment (T7) as compared to other treatments. Under that treatment, barley crop chemical components, i.e. protein, ash, chlorophylls, amino acids, vitamins, and fibre were significantly higher compared to other treatments. In addition, gibberellic acid (GA3) and abscisic acid (ABA) content besides antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) activities were significantly affected by all treatments. The economical profits were achieved, as reflected by an investment factor value equal to or higher than 3, and this was achieved for all tested nanosilicon, zeolite, and soil conditioners indicated the effectiveness and profitability of studied treatments.

Effect of Soil Conditioning on Soil Penetration Resistance and Traction Power Demand of Ploughing

Soil compaction and degradation due to improper tillage are problems involving significant natural and economic damages. On compacted soils, suitable cultivation can be implemented only with higher energy and traction force input. In our study, the effect of a soil conditioner (Neosol) was examined on the penetration resistance of the soil and the traction power demand for ploughing in the experiment set up in the East-Slovak Plain in 2017 ‒ 2018 to justify several preliminary results showing that long-term soil conditioning results in enhanced root system, improved soil structure, cultivability, water- and salt regime. We found a positive effect of Neosol application with both investigated parameters and its long-term effect was also justified. The penetration resistance values of the soil of the untreated plot were 17 ‒ 23% higher, while the traction power demand values were 9 ‒ 32% lower in comparison with the Neosol treated plot in the first and the second year of the study, respectively. We assume the cumulative positive effect of soil conditioning on the physical soil properties in the study area, therefore the long-term application of Neosol is recommended for farms having similar soil properties.

Mineral Composition of Potted Cabbage (Brassica Oleracea Var. Capitata L.) Grown in Zeolite Amended Sandy Soil

Vegetables are essential components in human diets because they are rich in vitamins, minerals, and dietary fibre. There is a growing interest in human nutrition enhancement through vegetable consumption to reduce micro mineral deficiencies, especially in households with low buying power. A greenhouse pot experiment was conducted to evaluate the effect of zeolite amendment on the mineral composition of cabbage (Brassica oleracea var. capitata L.), in relation to the soil chemical status. The experiment was carried out over two growing seasons (winter/spring) of 2018 and 2019. The treatments were in the ratios of 0:10, 1:9, 2:8, 3:7 zeolite to sandy soil, on a weight-to-weight basis. Zeolite improved soil chemical status (p < 0.05), except for soil iron (Fe) and phosphorus (P) contents. There was also a general improvement of macro minerals in cabbage with increased zeolite application, especially in the second season. Zeolite did not improve the micronutrients of the vegetable. This indicates that cabbage planted under zeolite amended soils provides no additional contribution to the fight against micronutrient deficiencies. However, zeolite showed potential for soil conditioning in soil macronutrients and soil pH.

Thiol Compounds, Pre-Conditioning and Orientation of Explants – Important Factors Affecting Regeneration from Cotyledons of Legume Crop Sesbania Aculeata

Sesbania aculeata is a multipurpose legume crop grown primarily for green manuring in the rice-based cropping system. Besides this, it is an industrial crop and is also used as food in many parts of the world. The present work reports for optimization of various parameters (growth medium, plant growth regulators, pre-conditioning, orientation of explant, and presence of thiol compounds) affecting in vitro regeneration using mature cotyledon explants. The 5-day-old mature cotyledon explants excised from seedlings grown on Murashige and Skoog (MS) salts and Gamborg (B5) vitamins medium containing 15 μM 6-benzylaminopurine were cultured with its adaxial side facing on medium containing 2.5 μM 6-benzylaminopurine and 50 mg/L thiourea and produced multiple shoots (7 ‒ 8) in 100% cultures within 28 days. Healthy shoots were rooted on half-strength Murashige and Skoog (MS) salts and full-strength vitamins medium augmented with 2.5 μM indole-3-butyric acid.

Effect of Chicken Manure-Based Fertiliser on Bacterial Communities and Diversity of Tomato Endosphere Microbiota

The frequent use of chemical fertiliser produces harmful effects on the soil ecosystem. Therefore, biocompatible methods are used to improve plant health and production through natural fertiliser or plant beneficial microorganisms. This study aims to investigate the effect of amended chicken manure-based natural fertiliser on bacterial communities and plant beneficial bacteria of tomato endosphere microbiome using the high throughput 16S rRNA gene amplicon sequencing. The results showed Proteobacteria (89.4 ± 4.7% to 86.7 ± 3.9%), Actinobacteria (6.03 ± 2.9% to 3.56 ± 2.1%), and Firmicutes (3.34 ± 1.3% to 0.59 ± 0.3%) as the dominant bacterial phyla of tomato endophytic microbiome. Pseudomonas and Bacillus were the most abundant identifiable genera in the chicken manure root (CMR) (amended manure treatments) sample. There was no significant difference in alpha bacterial diversity (Shannon index: p = 0.48) and species richness (Chao 1: p = 0.43) between control original root (OR) and CMR. However, the distribution of the dominant phyla was mainly affected by manure fertilisation. The non-metric multidimensional scaling (NMDS) and PCoA of beta diversity analysis suggested a significant separation in bacterial communities of tomato endophytes between CMR and OR. The most differently abundant bacterial taxa belong to Bacteroidetes in the OR group, whereas the beneficial bacterial communities of Actinobacteria and Firmicutes were more abundant in the CMR group. Therefore, the chicken manure application can significantly affect bacterial communities of tomatoes´ root endophytic microbiome and effectively improve the abundance of the beneficial microbes as biofertilisers.

Drought Stress in Cereals – A Review

Drought is one of the most important factors that influences plant morphology, biochemistry, and physiology, and finally leads to the decline in crops productivity and seed quality. Climate change, severe changes in water availability together with thermal stresses environment coincide with increasing human population, and to reveal sustainable solutions it is necessary to understand: i) how cereals react to drought, ii) how the tolerance mechanisms are exhibited by the genotype, and iii) which approaches enable to increase the tolerance of crop species against limited water availability. Especially in cereals as in high-quality food sources, it is important to reveal the adaptation mechanisms to rainfall dynamics on arable land and to the prolonged period of drought. This review summarizes current knowledge on the impact of drought on cereals, the mechanisms these crops utilize to cope water scarcity and survive, and the most efficient approaches to improve their drought tolerance.

Rapid Identification of Rice Macronutrient Content in Saline Soils Using Smartphone Camera

Indonesia’s rice production has decreased by 6.83% (on average) in the last five years (2015 – 2019) because of some factors. Salinity (42%) is one of the leading factors that cause decreasing rice production besides climate change (21%), drought (9%), and other factors (28%). The smartphone camera serves as an alternative technology to prevent macronutrient deficiencies due to salinity. This study used aerial photos from android with visible light (R, G, and B), and the image was taken from a height of 5 m. The observation of macronutrient content in plant biomass was carried out using a free grid to adjust rice fields and saline soil. The formula was obtained from regression analysis and paired t-test between the biomass macronutrient and the extracted digital number of aerial photographs that have been stacked. The results showed that digital number (DN) from a smartphone was reliable to predict nitrogen (N), phosphorus (P), and potassium (K) content in rice with formula N = 0.0035 * DN + 0.8192 (R 2 0.84), P = 0.0049 * DN – 0.2042 (R 2 0.70), and K = 0.0478 * DN – 2.6717 (R 2 0.70). There was no difference between the macronutrient estimation results from the formula and the field’s original data.

Improvement of Weeds Management System and Fertilisers Application in Winter Wheat (Triticum aestivum L.) Cultivation Technologies

Wheat production plays a central role in the Russian agricultural system and significant land area is dedicated to this strategic crop. However, the wheat enterprise is highly constrained by weed interference which cause serious yield losses hence minimizing production income. The main objective of the study was to assess the efficacy of three various cultivation technologies as basic, intensive, and highly intensive systems on wheat biological efficiency. Three weed species Echinochloa crus-galli, Stellaria media, and Viola arvensis, and three winter wheat (Triticum aestivum L.) varieties Moscovskaya 40 (V1), Nemchinovskaya 17 (V2) and Nemchinovskaya 85 (V3) were studied. The data was analysed as a randomized complete block design with three replicates. Weed density, biological efficiency, yield performances, and selected qualitative parameters (measured through protein and gluten contents) were determined as affected by different cultivation technologies. The results showed that the high intensive cultivation technology (T3) was the most effective in reducing weed infestation levels as follows (0.3 plant/m2 Echinochloa crus-galli, 0.5 plant/m2 Stellaria media and 0.4 plant/m2 Viola arvensis) with biological efficiency of 96%, while 81% and 90% were recorded with basic and intensive cultivation system respectively. Moreover, the highest wheat yield 10.6 t/ha was obtained by T3, with the greatest grain quality 5% higher than basic cultivation technology designated in T1. The results were variety-dependent revealing the intrinsic genetic performances and the different patterns of high competitive ability. The current results open real opportunities concerning the implementation of potent wheat production systems.

Grain and Oil Yields of Safflower (Carthamus Tinctorius L.) Affected By Water Deficit and Growth Regulators

In order to evaluate the effects of growth regulators on yield parameters and oil content of safflower (Carthamus tinctorius L.), a field experiment was conducted under different irrigation intervals in 2019. All plots were irrigated regularly until the seedling establishment and thereafter irrigation intervals were applied after 70, 100, 130, and 160 mm evaporation from class A pan, as normal irrigation and mild, moderate, and severe water deficits, respectively. Foliar sprays of water (control), putrescine (60 µg/L), and 24-epibrassinolide (25 µg/L) at a rate of 1,000 L/ha were applied slightly before flowering. The results revealed that means of plant biomass, grains per capitol, grains per plant, grain yield, harvest index, oil percentage, and yield were decreased under limited irrigations, but 1,000-seeds weight was only reduced under severe water deficit. However, fo-liar sprays of growth regulators, particularly putrescine, increased grains per plant, grain yield, and harvest index, leading to an improvement in oil yield per unit area under different levels of water supply. These results suggest that foliar application of putrescine is a superior treatment for improving the productivity of safflower plants under normal and stressful conditions.

Effects of Ultraviolet-B Radiation in Plant Physiology

Over the past few decades, anthropogenic activities contributed to the depletion of the ozone layer, which increased the levels of solar ultraviolet-B (UV-B) radiation reaching the Earth`s surface. Generally, UV-B is harmful to all living organisms. It damages the cell`s Deoxyribonucleic acid (DNA), proteins, and lipids, and as a consequence, it affects the bio-membranes negatively. In this review, we summarize the major effects of UV-B in the plant`s main molecules and physiological reactions, in addition to the possible defence mechanisms against UV-B including accumulating UV-B absorbing pigments to alleviate the harmful impact of UV-B.