Increased Shoot Dry Weight Research Articles

Application of different phosphatic fertilizers influences the different phosphorus fractions and morphophysiological traits of wheat in saline sodic soil

Nutrient constraints in salt-affected soils are one of the limiting factors for crop production. We investigated phosphorus (P) availability to wheat crop and its correlations with different fractions of P in salt-affected soils in response to various phosphatic fertilizer’s application. Three different types of soils having electrical conductivity of soil extract (ECe) < 4 dS m−1 and sodium adsorption ratio (SAR) < 13.2 (mmol L−1)1/2, ECe 8 dS m−1 SAR 20 (mmol L−1)1/2 and ECe 12 dS m−1 and SAR 30 (mmol L−1)1/2 were used for this experiment. Different P fertilizers viz. control, diammonium phosphate (DAP), single super phosphate (SSP) and nitrophos (NP) were applied on these soils. The doses of nitrogen, phosphorus and potassium were remained same for all the treatments. The P fractions, agronomic parameters and P-availability to plants were determined. Results indicated increase in shoot dry weight (61%) and photosynthetic rate (9%) in SSP treated soil at EC 8 dS m−1 and SAR 20 (mmol L)1/2. The total P (7.6%) in soil and respiration rate (1.9%) in plant was recorded maximum in DAP treated soil at EC 8 dS m−1 and SAR 20 (mmol L)1/2, and membrane stability index (44%) in plant shoot, extractable P (23%) in soil and P concentration (22%) in shoot were recorded maximum in SSP treated soil at EC 12 dS m−1 and SAR 30 (mmol L)1/2. It was concluded that SSP fertilizer perform better in salt-affected soil for growth and yield of wheat compared to other phosphatic fertilizers.

Morphological and Physiological Changes of Hydroponic Lettuce Grown in Varying Potassium Concentrations and an Adaptive Lighting Control System

We investigated the growth dynamics of hydroponic lettuce (Lactuca sativa) driven by the influence that potassium (K+) has on crop growth. This study aimed to determine whether increased K+ concentrations under different daily light integrals (DLIs) in a hydroponic system will boost growth of greenhouse lettuce. This study was conducted within a controlled glass greenhouse environment with varying DLIs achieved by integrating an adaptive lighting control system over a 16-hour photoperiod. We used three K+ treatments of 200, 400, or 600 mg⋅L−1 K+ and six DLI lighting treatments of 11.1, 12.9, 14.6, 15.9, 16.9, and 17 mol⋅m−2⋅d−1. We found that increasing K+ did not increase shoot dry weight, leaf area, or specific leaf area with increasing DLIs. Although K+ and DLI had an interacting effect on the root dry weight fraction, leaf chlorophyll content, and quantum yield of photosystem II, the K+ treatments did not increase or decrease with increasing DLIs. The influencing factor was DLI, which led to increases in shoot dry weight and leaf area, whereas a decrease in specific leaf area was observed with increasing DLIs. Ultimately, adding supplemental concentrations of K+ did not enhance lettuce growth, nor did these effects show any increase with increasing DLIs.

Marigold Seed Pelleting with Plant Nutrients on Germination, Growth, Storage and Flower Yields

Background: Seed pelleting, a method involving seed coatings to enlarge seed size, is advantageous for marigold seeds because it improves water utilization efficiency during germination. Furthermore, the incorporation of vital plant nutrients into seeds fosters germination and growth, facilitating accelerated growth and increased yield in marigold plants. Methods: Marigold seeds were pelleted with NH4NO3 at rates of 0.048, 0.096 and 0.192 g, NaH2PO4.H2O at rates of 0.064, 0.128 and 0.256 g and KCl at rates of 0.013, 0.026 and 0.052 g. Growth was determined after incubation in 4 × 6 inch bags for 56 days. Storage longevity was determined after incubation in aluminum foil bags under controlled (15°C, 50% RH) and ambient conditions (27±2°C, 70% RH) for 6 months. Result: Seeds pelleted with NH4NO3, NaH2PO4.H2O and KCl demonstrated superior germination rates and germination speed. NaH2PO4.H2O pelleting led to increased shoot dry weight. The use of 0.256 g NaH2PO4.H2O resulted in the highest germination rate over 6 months. Pelleting with all three nutrients resulted in higher plants, particularly 0.256 g NaH2PO4.H2O, which led to more flowers per plant. Therefore, pelleting seeds with 0.256 g NaH2PO4.H2O is recommended to optimize the quality of marigold seeds.

Biocontrol potential of cell-free supernatant of Paenibacillus chitinolyticus against Plasmodiophora brassicae in two important Brassica species

Plasmodiophora brassicae is a serious threat to Brassica crops worldwide, resulting in substantial economic losses for growers. Biocontrol with chitinolytic bacteria producing chitinase is gaining attention as a natural alternative to chemicals. This approach is favored due to the essential role chitinases play in protecting against chitin-containing pathogens. Given that chitin is a major component in the resting spores of P. brassicae and plays a crucial role during pathogenesis, it is probable that Paenibacillus chitinolyticus, producing a high level of chitinase, could suppress P. brassicae by targeting chitin in a critical stage of this pathogen’s life cycle. Our research aimed to evaluate the effect of various applications of P. chitinolyticus on clubroot suppression in two economically important Brassica species: Chinese cabbage and rapeseed. The effectiveness of the cell-free supernatant (CFS) of an endemic strain of P. chitinolyticus from the Czech Republic at five different time points was studied in the greenhouse by measuring the disease severity index. Early application of P. chitinolyticus decreased the disease index significantly within both plant species resulting in increased shoot dry weight. In conclusion, the CFS of P.chitinolyticus has significant antagonistic activity against clubroot in Chinese cabbage and rapeseed in the early developmental stages of clubroot occurrence and holds the potential as a biofertilizer as well as bioprotectant agent in clubroot management of P. brassicae.

Exploring Leaf Anthocyanin Concentrations and Light Effects on Lettuce Growth

Anthocyanins are secondary metabolites classified as water-soluble, non-photosynthetic pigments with the potential ability to shield chloroplasts from excess light energy. This study investigated the morphological and physiological responses of six lettuce (Lactuca sativa) cultivars with different leaf anthocyanin contents grown in a greenhouse under different supplemental photosynthetic photon flux densities (PPFD). Cultivars ‘Cherokee’, ‘Teodore’, ‘Rex’, and ‘Rouxai’ decreased in specific leaf area with increasing PPFD, respectively. We observed that growth in cultivars with higher leaf anthocyanin content (‘Cherokee’ and ‘Rouxai’) increased with increasing PPFD. Light use efficiency (LUE) is an important physiological parameter affecting biomass accumulation, and cultivars ‘Cherokee’, ‘Rex’, ‘Teodore’, and ‘Rouxai’ had the highest LUE and shoot weight. We found that red lettuce varieties, especially ‘Cherokee’ and ‘Rouxai’, showed increased shoot dry weight as light intensity increased. Interestingly, these varieties also had the highest anthocyanin levels in their leaves. This suggests that higher anthocyanin content might contribute to the increased shoot dry weight under higher light intensity, although this was mainly evident in ‘Cherokee’.

Lupine Cultivation Affects Soil’s P Availability and Nutrient Uptake in Four Contrasting Soils

A substantial amount of phosphorus (P) in the soil is not readily available for plant uptake. Certain species may enhance P availability from poorly soluble P forms. This study focused on improving our comprehension of the effect of two lupine species (L. albus and L. angustifolius) on soil’s P mobilization and its link with soil acidity variations, comparing the response of the lupine species in terms of plant traits (i.e., aboveground biomass and nutrient uptake) with that of oats (Avena strigosa L.) in four contrasting soils (i.e., available P in soil, soil acidity, soil fertility, and texture). The phosphorus solubilization capacity was assessed on variations of P availability (PBray1) at four points in time, comparing soils with lupine to oat-containing soils and their baseline values. Compared to soils containing oats, at harvest, lupine soils had significantly increased PBray1 concentrations; the maximum average increment was around 5.3 mg kg−1, with L. albus in Sites 1 and 2, which presented higher organic matter (OM) contents than the other two sites. Lupine-induced soil acidification did not fully explain that P increase. Oats exhibited the highest increase in shoot dry weight in response to soil’s P availability, while lupine was the least affected. Nevertheless, L. albus showed similar or higher nutrient uptake than oats across all soils. The manganese (Mn) concentration was high in both lupine species’ shoot biomass; however, within each lupine species, across all soil types tested, these legumes had different Mn accumulation levels depending on the soil acidity. Lupinus albus had a higher ability to mobilize non-labile P in the light-textured soil with a high OM content, achieving comparable and higher plant P status than oats and providing N through biological N fixation (BNF), positioning it as a suitable crop for diversifying Uruguay’s agricultural crop rotation systems.

Selenium enrichment and quality improvement of Origanum vulgare plants grown under in vitro condition with salicylic acid

One of the important sources of human selenium intake is vegetables, so increasing of selenium in edible parts of plants, biofortification, provides an effective approach to reduce selenium deficiency. Origanum vulgare L. is an important medicinal plant which is also used as a valuable spice. The present study was done to evaluate the ability of selenium accumulation of micropropagated O. vulgare under sodium selenate and/or salicylic acid treatment. Micropropagation of O. vulgare was done from shoot-tips as explants on modified Murashige & Skoog (MS) medium. After 1 month, rooted plantlets were transferred to modified Murashige & Skoog solidified medium containing sodium selenate (0, 25 and 50 µM) and/or salicylic acid (0 and 100 mgL−1). After 4 wk, growth, selenium accumulation, biochemical parameters and oxidative stress indicators were determined. The results showed that the plantlets were able to accumulate 16.1 µg g−1 DW and 28.27 µg g−1 DW selenium in shoots at 25 and 50 µM selenate sodium concentrations respectively. Both concentrations of selenium increased shoot dry weight, length of shoot and root, soluble sugars and total protein content, peroxidase and superoxide dismutase activity. On the contrary, malondialdehyde content decreased under selenium treatment. It was found that by increasing selenium concentration the content of total protein, H2O2 and antioxidant enzymes activity increased significantly. Application of salicylic acid in combination with selenium improved growth but did not affect on selenium accumulation. The obtained results can be considered as the first report of biofortification of O. vulgare under tissue culture technique.

Effect of Different Types of Biochar Applications and Phosphate Fertilizer on the Quality and Yield of Edamame Soybeans on Andisols

Edamame soybean (&lt;em&gt;Glycine max &lt;/em&gt;(L.) Merr.) cultivation in phosphorus-limited Andisols presents a formidable challenge due to restricted phosphorus availability despite high phosphorus retention. Unlocking the full potential of this crop demands innovative solutions. This study delves into the transformative effects of biochar and phosphorus fertilizer, individually and synergistically, on edamame soybean growth in Andisols. Employing a randomized complete block design, researchers investigate three types of biochar (B0: control, B1: biochar pellets, B2: biochar powder) and four phosphorus fertilizer rates (P0: control, P1: 27 kg ha&lt;sup&gt;-1&lt;/sup&gt; P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;, P2: 54 kg ha&lt;sup&gt;-1&lt;/sup&gt; P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;, P3: 81 kg ha&lt;sup&gt;-1&lt;/sup&gt; P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;). The bamboo-derived biochar was produced using the Kon-tiki method at ±500 °C. The study reveals no significant interaction between biochar and phosphorus fertilizer. Individually, treatments with B1, B2, and phosphorus fertilizers significantly enhance ammonium, nitrate, and phosphorus availability compared to B0 and P0. Biochar-induced modifications improve phosphorus and nitrogen absorption by roots, resulting in increased shoot dry weight and the root/shoot ratio. However, the number of leaves is solely influenced by phosphorus fertilizer treatment. Additionally, both biochar and phosphorus fertilizers contribute to nitrate reductase activity, root volume, an increased number of pods per plant and higher protein content in edamame soybeans. B2 outperforms B1 and high P3 intensifies this effect, improving nutrient uptake and yield. In summary, biochar and phosphorus fertilizers demonstrate significant potential to revolutionize edamame soybean cultivation in phosphorus-limited Andisols, optimizing pod number per plant and enhancing quality with elevated protein content.

A short stature allele enhances tolerance to zinc deficiency and translocation of zinc in barley.

Zinc (Zn) content is of great importance in healthy human diet, crop productivity and stress tolerance in soils with zinc deficiency. The genes used to increase yield per unit area such as semi-dwarf 1 (sdw1) is commonly considered to reduce mineral content of grain. In the present study, influence of sdw1.d, a widely used allele for short plant height in barley breeding, on zinc accumulation and tolerance to zinc deficiency were investigated. A near isogenic line of sdw1.d allele, its recurrent parent Tokak 157/37 and donor parent Triumph were grown in zinc-deficient and-sufficient hydroponic cultures. Two experiments were conducted until heading stage and physiological maturity. In zinc-deficient conditions, sdw1.d allele increased shoot dry weight by 112.4 mg plant-1, shoot Zn concentration by 0.9 ppm, but decreased root Zn concentration by 6.6 ppm. It did not affect grain characteristics, but increased grain Zn content. In zinc-sufficient conditions, sdw1.d allele increased shoot Zn content, and decreased root Zn content. sdw1.d did not affect grain weight but increased grain Zn concentration by about 30% under zinc-sufficient conditions. The results showed that sdw1.d allele has no negative effect on tolerance to zinc deficiency, and even promotes tolerance to zinc deficiency by more Zn translocation. It was revealed that sdw1.d allele improves Zn accumulation under both zinc-deficient and zinc-sufficient condition. The sdw1.d allele could contribute to solving the problems in plant growth and development caused by zinc-deficiency via improving tolerance to zinc-deficiency. It could also provide a better Zn biofortification.

Unraveling the influence of TiO2 nanoparticles on growth, physiological and phytochemical characteristics of Mentha piperita L. in cadmium-contaminated soil

Among the metals contaminants, cadmium (Cd) is one of the most toxic elements in cultivated soils, causing loss of yield and productivity in plants. Recently, nanomaterials have been shown to mitigate the negative consequences of environmental stresses in different plants. However, little is known about foliar application of titanium dioxide nanoparticles (TiO2 NPs) to alleviate Cd stress in medicinal plants, and their dual interactions on essential oil production. The objective of this study was to investigate the effects of foliar-applied TiO2 NPs on growth, Cd uptake, chlorophyll fluorescence, photosynthetic pigments, malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents, total phenols, anthocyanins, flavonoids, antioxidant enzymes (SOD, CAT and POD) activity and essential oil content of Mentha piperita L. (peppermint) under Cd stress. For this purpose, plants were grown in Cd-contaminated (0, 20, 40, and 60 mg L−1) soil, and different concentrations of TiO2 NPs (0, 75, and 150 mg L−1) were foliar sprayed at three times after full establishment until the beginning of flowering. Exposure to TiO2 NPs significantly (P < 0.01) increased shoot dry weight (37.8%) and the number of lateral branches (59.4%) and decreased Cd uptake in plant tissues as compared to the control. Application of TiO2 NPs increased the content of plastid pigments, and the ratio Fv/Fm (13.4%) as compared to the control. Additionally, TiO2 NPs reduced the stress markers, MDA and H2O2 contents and enhanced the activity of the phenylalanine ammonia-lyase (PAL) enzyme (60.5%), total phenols (56.1%), anthocyanins (42.6%), flavonoids (25.5%), and essential oil content (52.3%) in Cd-stressed peppermint compared to the control. The results also demonstrated that foliar spray of TiO2 NPs effectively improved the growth and chlorophyll fluorescence parameters and reduced Cd accumulation in peppermint, which was mainly attributed to the reduction of oxidative burst and enhancement of the enzymatic (SOD, CAT, and POD) antioxidant defense system due to the uptake of NPs. The findings provide insights into the regulatory mechanism of TiO2 NPs on peppermint plants growth, physiology and secondary metabolites production in Cd-contaminated soil.

Elevated atmospheric CO2 concentration mitigates salt damages to safflower: Evidence from physiological and biochemical examinations

The physiological and biochemical responses of salt-stressed safflower to elevated CO2 remain inadequately known. This study investigated the interactive effects of high CO2 concentration (700 ± 50 vs. 400 ± 50 μmol mol−1) and salinity stress levels (0.4, 6, and 12 dS m−1, NaCl) on growth and physiological properties of four safflower (Carthamus tinctorius L.) genotypes, under open chamber conditions. Results showed that the effects of CO2 on biomass of shoot and grains depend on salt stress and plant genotype. Elevated CO2 conditions increased shoot dry weight under moderate salinity stress and decreased it under severe stress. The increased CO2 concentration also increased the safflower genotypes' relative water content and their K+/Na + concentrations. Also enriched CO2 increased total carotenoid levels in safflower genotypes and improved membrane stability index by reducing H2O2 levels. In addition, increased CO2 level led to an increase in seed oil content, under both saline and non-saline conditions. This effect was particularly pronounced under severe saline conditions. Under conditions of high CO2 and salinity, the Koseh genotype exhibited higher grain weight and seed oil content than other genotypes. This advantage is due to the higher relative water content, maximum quantum efficiency of photosystem II (Fv/Fm), and K+/Na+, as well as the lower Na+ and H2O2 concentrations. Results indicate that the high CO2 level mitigated the destructive effect of salinity on safflower growth by reducing Na + uptake and increasing the Fv/Fm, total soluble carbohydrates, and membrane stability index. This finding can be used in safflower breeding programs to develop cultivars that can thrive in arid regions with changing climatic conditions.

Biochar of Prosopis juliflora for Improving Crops Germination and Growth on Sandy–Loam Soil

Prosopis juliflora (Sw.) DC. is an invasive alien species (IAS) damaging agricultural and natural ecosystems that threat biodiversity in Ethiopia. This IAS can be managed by utilizing it as a resource in agricultural production. This study analyzed the role of P. juliflora biochar on germination and growth performance of maize and wheat under field conditions in Wollo, Ethiopia. A randomized complete block design (RCBD) was used to test the effect of biochar on sandy–loam soil with and without fertilizer. In this experiment, biochar from P. juliflora was applied on the above two crops at 5, 10, and 20 t/ha with and without N–P fertilizers. From the result, a 100% germination and high growth of test crops were observed from 10 t/ha biochar with fertilizer mixed treatments. The shoot dry weight of both maize and wheat showed significant differences among treatments. While a single dosage (10 t/ha) increased maize dry weight by 21% without fertilizer, but it reduced dry weight by 10% when used with fertilizer. In the case of wheat, single and double dose biochar with NPS treatments increased shoot dry weight by 22.2% and 30%, respectively. This showed that application of biochar up to 20 t/ha in combination with fertilizers can significantly improve crop growth. Thus, it can be concluded that the application of biochar of P. juliflora is a good soil amendment option and, thus, this IAS can be managed by utilization.

Pseudomonas putida and salicylic acid key players: Impact on arsenic phytotoxicity of quinoa under soil salinity stress

This study was performed in a completely randomized design with a factorial arrangement and three replicates to investigate the effects of salicylic acid (SA) and Pseudomonas putida addition on arsenic (As) remediation efficiency on the quinoa (Chenopodium quinoa Willd) plant under saline soil. The first factor was As (0, 40 mg/kg), the second factor was P. putida (no inoculation and inoculation), and the third factor was SA (0, 0.5 mM). P. putida inoculation in saline soil and foliar spray of SA increased shoot and root dry weights by 60.14% and 68.75%, 1000-grain weight by 71.75%, and proline and catalase activity by 6.20% and 79.48% compared to the control (no inoculation + 0 SA + 40 mg As/kg saline soil). Arsenic-spiked soil, + P. putida inoculation and SA treatments increased shoot dry weight by 63.15% and 1000 grain weight by 39.03%. The arsenic concentration of the root and shoot decreased by 16.20% and 29.37%, respectively, and the bioconcentration factor declined by 23.85% compared to saline-spiked soil. Indicating the superiority of P. putida and SA in reducing the As uptake by root by about 24% less. Bioremediation of As from soil, along with SA, proved very useful in this regard.

Controlling root zone temperature improves plant growth and pigments in hydroponic lettuce.

Air and root zone temperatures are important environmental factors affecting plant growth and yield. Numerous studies have demonstrated that air temperature strongly affects plant growth and development. Despite the extensive literature on air temperature, comprehensive studies on the effects of root zone temperature (RZT) on plant growth, elemental composition, and pigments are limited. In this study, we carefully observed the effects of RZT in red leaf lettuce to understand its effect on lettuce growth and pigment content. Lettuce (Lactuca sativa, red leaf cultivar 'Red Fire') was grown hydroponically in a plant factory with artificial light under three RZT treatments (15, 25, or 35 °C) for 13 days. We investigated the comprehensive effects of RZT on the production of red leaf lettuce by metabolome and ionome analyses. The 25 °C RZT treatment achieved maximum shoot and root dry weight. The 35 °C RZT decreased plant growth but significantly increased pigment contents (e.g. anthocyanins, carotenoids). In addition, a RZT heating treatment during plant cultivation that changed from 25 to 35 °C RZT for 8 days before harvest significantly increased shoot dry weight compared with the 35 °C RZT and significantly increased pigments compared with the 25 °C RZT. The 15 °C RZT resulted in significantly less pigment content relative to the 35 °C RZT. The 15 °C RZT also resulted in shoot and root dry weights greater than the 35 °C RZT but less than the 25 °C RZT. This study demonstrated that plant growth and pigments can be enhanced by adjusting RZT during different stages of plant growth to attain enhanced pigment contents while minimizing yield loss. This suggests that controlling RZT could be a viable method to improve lettuce quality via enhancement of pigment content quality while maintaining acceptable yields.

Effects of arbuscular mycorrhizal fungi inoculation on infection and growth of rice and pearl millet in upland fields with three water regimes

ABSTRACT Inoculation with arbuscular mycorrhizal fungi (AMF) may enhance crop growth in upland fields, depending on the water regime. To quantify changes in AMF infection rate and subsequent effects on nutrient uptake and growth, we grew rice (wetland crop) and pearl millet (dryland crop) genotypes with or without the commercial inoculant Dr. Kinkon (Glomus sp. R10) in Andosol upland fields in 2020 and 2021. Root infection rates were measured in shallow (0–10 cm) and deep (20–30 cm) layers under three water regimes: well-irrigated, half-irrigated, and non-irrigated. Inoculation enhanced shoot dry weight (SDW), plant height, tiller number, phosphorus (P) uptake, leaf water potential, photosynthetic rate (measured only in 2021) and root transversal area. The increase in SDW with inoculation was higher under well-irrigated than under water-limited conditions. The increment in pearl millet SDW was related to higher P uptake associated with higher infection rates, whereas that in rice SDW was related to maintenance of leaf water potential, greater root transversal area and root length density, and higher P uptake but not to infection rate parameters. Inoculation increased mycorrhizal and vesicular infection rates with the similar tendency for arbuscular infection rate and qPCR. Infection rates were similar across water regimes in both years despite significant differences in plant growth parameters with higher rates in deep than shallow layers. AMF inoculation enhanced infection rates, mostly independent of water regime, but plant growth enhancement was greater under the well-irrigated treatment and was more directly linked with infection rates in pearl millet.

Alternate micro-sprinkler irrigation and organic fertilization decreases root rot and promotes root growth of Panax notoginseng by improving soil environment and microbial structure in rhizosphere soil

It is a challenge to improve Panax notoginseng production and soil environment in arid area of Southwest China. Therefore, the objective of this study was to propose a new and promising alternate micro-sprinkler irrigation (D2) to cope with the challenge based on moderate deficit micro-sprinkler irrigation (D1) and slight deficit micro-sprinkler irrigation (D3). A two-year greenhouse experiment was conducted to evaluate the root rot incidence of Panax notoginseng among of the D1, D2 and D3 treatments by analyzing the soil water content (SWC), soil microbial biomass carbon (SMBC), nitrogen (SMBN), total phosphorus (TP) and total potassium (TK), soil available nutrients(AN, AP and AK), soil enzyme activity, soil microbial structure, plant growth parameters, plant dry matter, nutrients uptake (N, P and K), and root rot incidence. Experiment treatments consisted of three irrigation amounts (D1, D2 and D3) and four organic fertilizer levels [500 (F1), 1000 (F2), 1500 (F3), and 2000 (F4) kg hm−2] in 2017 and 2018, respectively. All treatments were designed using a randomized complete block with three replications. The results indicated that no significant differences in growth parameters [PH (plant height), SD (stem diameter), and LAI (leaf area index)] of Panax notoginseng were found among of the D1, D2 and D3 treatments in 2017 and 2018. Compared with the D1 and D3, the D2 treatment significantly increased shoot dry weight (SDW), root dry weight (RDW), total N, P, K uptake and decreased SMBC, SMBN, TP, TK, AN, AP, AK and root rot incidence in 2017 and 2018. The result suggested the D2 treatment had greater production advantages than the D1 and D3 treatments. In addition, compared with the F3 treatment, other F treatments (F1, F2, and F4) in the D2 treatment significantly enhance total plant dry matter, total N, P and K uptake. However, root rot incidence significantly increased with the increase of application F levels, and D2F3 can significantly decrease fungi/bacteria and fungi/actinomycetes in rhizosphere soil of healthy Panax notoginseng in 2018. According to analyzing the root rot incidence of different application F treatments, we found that 1500 kg hm−2 in the alternate micro-sprinkler irrigation might be recommended as an appropriate application F level to decrease root rot incidence of Panax notoginseng in the semi-arid area of Southwest China.

Biostimulant application of whey protein hydrolysates and potassium fertilization enhances the productivity and tuber quality of sweet potato

Utilizing biostimulants like protein hydrolysates is one of the most creative and promising approaches to improving nutritional efficiency, abiotic stress tolerance, or crop quality traits. In the present study, whey protein was hydrolysed with trypsin for 4 h at an enzyme/substrate ratio (1/300, w/w). The obtained whey protein hydrolysates (WPH) were chemically characterized, and their antioxidant activity was estimated. WPH, which was produced using trypsin for 4 hours and presented the highest antioxidant activity. Therefore, it was selected as a bio stimulant with potassium fertilization for enhancing the productivity and tuber quality of sweet potatoes. A field experiment was carried out during the two successive summer seasons, at a private vegetable farm in Faques City, Sharkia Governorate, Egypt, to study the effect of different potassium rates (50, 75, and 100 kg K2O/fad) and WPH at 0.10 and 0.20% as a foliar application compared to unsprayed plants (control). The interaction between K2O at 100 kg /fad and spraying with WPH at 0.15% increased shoot dry weight/ plant, N, P, and K uptake by shoots, yield/plant, marketable yield, and total yield/fad, as well as average tuber root weight. It was concluded that the most efficient bio-stimulating foliar spray treatment for increasing sweet potato productivity was WPH (0.20%).

The beneficial effects of bare and CMC-supported α-FeOOH, Fe3O4, and α-Fe2O3 nanoparticles on growth, nutrient content, and essential oil of summer savory (Satureja hortensis L.) under Cd, Pb and Zn stresses.

This research studies the impacts of iron oxide nanoparticles (FeONPs) on alleviating the toxic effects of cadmium (Cd), lead (Pb), and zinc (Zn) on summer savory (Satureja hortensis L.). Different types of soil additives, including bare and carboxymethylcellulose (CMC)-supported hematite (α-Fe2O3), goethite (α-FeOOH), and magnetite (Fe3O4), were applied at three rates (0, 0.25, and 0.5% w/w) to a Cd, Pb, and Zn-contaminated soil sample. The experimental results showed that the application of FeONPs increased plant height, dry weights of shoot and root, and yield and content of essential oil. Bare and CMC-supported FeONPs increased the content of K, P, and Fe in the aerial parts of summer savory. However, these soil additives reduced the contents of Cd, Pb, and Zn in plant tissues. CMC-supported FeONPs proved to be more efficient additives in diminishing the toxic effects of Cd, Pb, and Zn in summer savory compared to their bare forms. Bare and CMC-supported goethite NPs were able to restrict the uptake of Cd, Pb, and Zn by summer savory roots in the metal-contaminated soil. The application of CMC-supported goethite at an application dose of 0.5% (w/w) increased shoot dry weight, shoot concentrations of K, P, and Fe, and yield of essential oil by about 62.6, 76.6, 77.1, 210, and 230%, respectively. Conversely, they reduced shoot concentrations of Cd, Pb, and Zn by about 64.6, 68.7, and 40.6%, respectively, compared to the control. These are significant results and indicate that CMC-supported goethite is likely to be the most effective soil additive in diminishing the toxicity of Cd, Pb, and Zn to metal-stressed summer savory.

Large root cortical cells and reduced cortical cell files improve growth under suboptimal nitrogen in silico.

Suboptimal nitrogen availability is a primary constraint to plant growth. We used OpenSimRoot, a functional-structural plant/soil model, to test the hypothesis that larger root cortical cell size (CCS), reduced cortical cell file number (CCFN), and their interactions with root cortical aerenchyma (RCA) and lateral root branching density (LRBD) are useful adaptations to suboptimal soil nitrogen availability in maize (Zea mays). Reduced CCFN increased shoot dry weight over 80%. Reduced respiration, reduced nitrogen content, and reduced root diameter accounted for 23%, 20%, and 33% of increased shoot biomass, respectively. Large CCS increased shoot biomass by 24% compared with small CCS. When simulated independently, reduced respiration and reduced nutrient content increased the shoot biomass by 14% and 3%, respectively. However, increased root diameter resulting from large CCS decreased shoot biomass by 4% due to an increase in root metabolic cost. Under moderate N stress, integrated phenotypes with reduced CCFN, large CCS, and high RCA improved shoot biomass in silt loam and loamy sand soils. In contrast, integrated phenotypes composed of reduced CCFN, large CCS, and reduced LRBD had the greatest growth in silt loam, while phenotypes with reduced CCFN, large CCS, and high LRBD were the best performers in loamy sands. Our results support the hypothesis that larger CCS, reduced CCFN, and their interactions with RCA and LRBD could increase nitrogen acquisition by reducing root respiration and root nutrient demand. Phene synergisms may exist between CCS, CCFN, and LRBD. CCS and CCFN merit consideration for breeding cereal crops with improved nitrogen acquisition, which is critical for global food security.

Effect of Rhizobium Inoculation and Organic Manures on Growth and Yield of Groundnut (Arachis hypogaea L.) in Malakal, Sudan*

Field experiments were conducted for two rainfed seasons(2006 and 2007) and one irrigated season (2008) at the Agricultural Farmof the Upper Nile University in Malakal (Sudan). The objective of theexperiments was to study the effect of each of farmyard manure, waterhyacinth compost, Rhizobium seed inoculation and in dual combinationson groundnut symbiotic performance and growth and yield under bothrainfed and irrigation systems. The organic fertilizers were applied at therate of 15 t ha-1 each. The results showed that each organic manure alonesignificantly increased shoot dry weight, number of nodules plant -1 andpod and hay yields than the control in both rainfed and irrigation systems.Rhizobium seed inoculation with either manure significantly increasedplant shoot and plant root dry weights, plant nodulation, early podformation, absorption of plant N and plant P compared to the control.Moreover, these treatments significantly increased groundnut pod andhay yields over that of the control.