Sole Treatments Research Articles

Intercropping Spinach and Red Amaranth With Brinjal Under Different Planting System

The experiment was conducted at Agronomy Research Field of Bangladesh Agricultural Research Institute, Gazipur, during the rabi season of 2018 to 2019 and 2019 to 2020 to find out the suitable crop combination of spinach (Spinacia oleracea) and red amaranth (Amaranthus cruentus) with brinjal (Solanum melongena) for higher brinjal equivalent yield, monetary advantage and maximize land utilization through intercropping system. Treatments were: T1 = 2 rows spinach (50%) in between two rows of brinjal (100%), T2 = 3 rows Spinach (75%) in between two rows of brinjal (100%), T3 = 2 rows red amaranth (50%) in between two rows of brinjal (100%), T4 = 3 rows red amaranth (75%) in between two rows of brinjal (100%), T5 = Sole brinjal ( 80 cm × 60 cm), T6 = Sole spinach (Line to line 20 cm) and T7 = Sole red amaranth (Line to line 20 cm) were used in the study. All the intercropping combinations showed better performance in terms of brinjal equivalent yield, gross return and benefit cost ratio (BCR) over sole crops. Among the intercropping combinations, 3 row spinach (75%) in between two rows of brinjal (100%) was the most feasible and profitable intercropping system in respect of brinjal equivalent yield (34.72 t ha-1), land equivalent ratio (1.57), gross return (Tk. 6,94,346 ha- 1), gross margin (Tk. 4,59,088 ha-1) and benefit cost ratio (2.95). From the two years, results revealed that all intercropping treatments were productive as compared to sole treatments but 3 rows spinach (line to line 20 cm) 75% in between two rows of brinjal (80 cm × 60 cm) 100% intercropped combination might be agronomically feasible and economically profitable.
 Bangladesh Agron. J. 2022, 25(1): 91-96

Development and Application of Dual-Sensors Label in Combination with Active Chitosan-Based Coating Incorporating Yarrow Essential Oil for Freshness Monitoring and Shelf-Life Extension of Chicken Fillet.

This study aimed for the application of active chitosan coating incorporating yarrow essential oil (YEO) together with the development of an on-package sensor label based on bromocresol purple (BCP) and methyl red (MR) for shelf-life extension and freshness monitoring of chicken breast fillet. Physiochemical and microbiological attributes of chicken meat coated with sole chitosan, YEO, and chitosan + YEO were compared with those of uncoated (control) samples. Chitosan + YEO coated chicken meat stayed fresh with no significant changes (p > 0.05) in pH (5.42-5.56), TVB-N (12.55-15.36 mg N/100 g), TBARs (0.35-0.40 mg MDA/kg) and total aerobic psycrotrophic bacteria (3.97-4.65 log CFU/g) in days 1-15. There was no response of the dual-sensors label toward the variation in chemical and microbiological indicators of chicken meat coated with chitosan + YEO. However, either uncoated, sole chitosan, or sole YEO treatments indicated a three-stage freshness status with the fresh stage belonged to a period earlier than day 7 (with no distinct color change in both sensor labels); the semi-fresh stage corresponded to storage days between 7-9, wherein a gradual color change appeared (MR from pink to orange, BCP from yellow to light purple); and the spoiled stage occurred in day 9 onward with a drastic color change (MR from orange to light yellow, BCP from light purple to deep purple). In general, the dual-sensors successfully responded to the variation of chemical and microbiological indicators and visual color of uncoated samples during storage time. Based on the obtained results, the application of chitosan + YEO coating efficiently prolonged the freshness of chicken breast meat, where on-package dual-sensors systems were able to detect the freshness stages of meat samples during storage time.

Effect of Maize–Legume Intercropping on Maize Physio-Agronomic Parameters and Beneficial Insect Abundance

In developing countries, intercropping is commonly used to boost land productivity and agricultural benefits. However, in the Yucatan region of Mexico, maize (Zea mays L.) yields remain low, despite consistent fertilizer and pesticide inputs in traditional intercropping systems. Furthermore, little is known about the photosynthetic mechanisms that occur when maize plants interact with legumes, and there is a lack of understanding of how intercropping systems affect other organisms in the system, such as beneficial and insect pest population dynamics. A field experiment was carried out on the Yucatan Peninsula in 2021 to assess the impact of maize–legume intercropping systems on maize yield, physiological characteristics as evaluated by gas exchange measurements, and the abundance of beneficial insects in traditional and novel maize intercropping systems. The experiment was carried out with a randomized complete block design with three replicates. Treatments included maize intercropped with a novel legume, crotalaria (Crotalaria juncea L.), maize intercropped with a traditional legume, cowpea (Vigna unguiculata (L.) Walp.), and sole maize as a control. Significant differences in plant height were shown at growth stages V12 (45 days after sowing) and VT (60 days after sowing). No differences were observed in stem diameter, leaf area index, or chlorophyll content. The maize/cowpea intercrop increased the photosynthesis rate by 12.9% and 9.84% in the maize/crotalaria and sole maize, respectively (p < 0.001), and transpiration rate by 6.5% and 8.5% in the maize intercropped with crotalaria and sole maize treatments, respectively (p < 0.001), of maize plants. No significant effects on stomatal conductance or water use efficiency were observed, but the carbon intercellular rate was reduced by 9.74% and 9.15 when compared to the maize/crotalaria and the sole maize treatments, respectively. Overall, intercropping treatments attracted more beneficial insects than sole maize. For predators, the families that stood out were Coccinelidae, Formicidae, Araneidae, Thomisidae, Syrphidae, Chrysomelidae, Oxypidae, Vespidae, Reduviidae, Carabidae, Asilidae, Salthicidae, Dolichopodidae, while among parasitoids, the most frequent families were Eurytomydae, Braconidae, Tachinidae, Pteromalidae, Scelionidae, and Figitidae. In comparison to the maize/cowpea and maize/crotalaria treatments, the sole maize treatment resulted in a grain yield increase of 24.5% and 32%, respectively. However, sole maize was not statistically different to that of maize/cowpea intercropping. In conclusion, our findings suggest that maize/cowpea intercropping could be a viable alternative to sole maize cropping systems for enhancing maize yield and the abundance of beneficial insects, without increasing interspecific competition with the maize crop. Therefore, the maize/cowpea intercropping system represents a sustainable planting alternative for promoting maize grain yield and also promoting edible legume production within the system. Furthermore, the outcomes of this study can serve as a theoretical framework for increasing maize–legume intercropping profitability under growing conditions on the Yucatan Peninsula.

Effect of Some Soil Conditioners on Water-Use Efficacy, Growth, and Yield of Date Palm Siwi Grown in Sandy Soil under Different Irrigation Regimes to Mitigate Climate Change

A field experiment was carried out at Al-Bahariya Oasis, Giza, Egypt, during three successive seasons to find out the effect of application of bentonite (BN) as a natural clay deposit at either 6 or 12 kg/palm tree and humic substances (HS) as organic amendment at either 0.75 or 1.0 L/palm tree incorporated with Bacillus polymyxa (BP) as a biofertilizers at 14 and 28 mL/L rates on growth, yield, and fruit weight of 10-year-old Siwi date palm cv. (Phoenix dectylifera L.). Siwi trees were cultivated in sandy texture soil at a distance of 8 × 8 m and were irrigated with 100%, 85%, and 70% of ET crop. Effects of the previous treatments on growth, date palm crop, soil properties, water relations, water-use efficiency (WUE), and economic return were also studied. The obtained results showed that the mean values of leaf length, leaflet length and width, fruit set%, bunch weight, yield/palm, yield/fed, fruit weight, flesh weight, and fruit pulp weight were increased in response to the different individual and combined treatments used in this study with various significance levels compared to the control treatment means in the studied three seasons. However, the superiority was for combining between amending the sandy soil with either low concentrations of BN (6 kg/tree) + HS (0.75 Liter/tree) + BP (14 mL/L) or high concentrations of BN (12 kg/tree) + HS (1.0 L/tree) + BP (28 mL/L) and irrigation with 85% of ETc water level, as such combinations attained the highest values in most of the mentioned values over both the sole and combined treatments in the studied three seasons. Furthermore, the results indicated that the highest monthly ETc values occurred during June and July months, while the lowest values occurred during December and January months. Additionally, water productivity (WP) increased considerably by reduction of water quantity (70% ETc) associated with soil conditioner treatment (BN.12 kg +HS 1 L + BP. 28 mL/L), and values were 2.17, 2.25, and 2.27 kg fruit/m3 of water irrigation during the growing seasons, respectively. The highest net return was attributed to irrigation with 85% of ETc water level along with the application of soil conditioners at high rates. Accordingly, it is advisable to apply the soil conditioners of bentonite (at 6 or 12 kg/tree) and humic substances (at either 0.75 or 1.0 L/tree) with B. polymyxa (at either 14 or 28 mL/L) plus irrigation with either 85% or 70% of ETc water level to obtain the best growth, highest yield, (WP), and gross return from var. Siwi date palm grown under an oasis agro-system.

Intercropping legumes and cereals increases resource use efficiency and crop productivity in low phosphorus soils under semi-arid Mediterranean conditions

ABSTRACT Intercropping ensures multiple benefits like enhancement of yield, environmental security, production sustainability, and greater ecosystem services. In order to better understand how mixed crop cultures mitigate stressful conditions, this study aims to highlight the beneficial effect of the intercropping legume–cereal in enhancing nutrient uptake for plant growth and productivity in low phosphorus (P) soils. To address this question, faba bean (Vicia faba L. cv. Sidi Aich) and barley (Hordeum vulgare L. cv. Rihane 3) were grown as sole- and inter-crops over two growing seasons in 2017 and 2018 in a northern Algerian agro-ecosystem with a semiarid Mediterranean climate. The results showed that the plant growth and nodulation were significantly increased by 18% and 32%, respectively, for intercropping than for sole cropping and so more in 2018 compared to 2017. Moreover, grain yield and resource use efficiency (N and P) were significantly improved, as indicated by higher land equivalent ratio (LER > 1) in intercropping over sole cropping treatments. Also, the P and N concentrations measured in the rhizosphere were increased compared to bulk soil and even more so in the rhizosphere of intercropped species over two seasons. Our findings suggest that intercropping cereals with legumes may achieve high crop productivity and land use efficiency at reduced input levels.

Evaluation of pesticide combinations against brown planthopper and sheath blight in rice

Field experiment was conducted at Regional Agricultural Research Station, Maruteru, West Godavari (A.P.) during two kharif seasons of 2019 and 2020 to evaluate the compatibility of combinations of insecticides and fungicides against brown planthopper and sheath blight in rice. The results revealed that pymetrozine and triflumezopyrim as sole treatments are highly effective against brown planthopper (BPH), Nilaparvata lugens (Stal) by registering over 90% reduction in BPH population. While, pymetrozine and triflumezopyrim in combination with azoxystrobin and azoxystrobin + tebuconazole are highly effective against BPH and sheath blight, Rhizoctonia soloni Kuhn in by registering over 90% and >50% reduction in BPH population and sheath blight severity, respectively and registered 64.23% to 73.03% higher grain yields than untreated control. It was also found that there was no adverse effect of fungicides on the efficacy of insecticides or vice versa. The insecticides tested were physically compatible with fungicides and no phytotoxic symptoms observed on rice crop when pesticides were applied in combination. Thus, pymetrozine and triflumezopyrim are compatible with test fungicides and can be safely used as tank mix for the simultaneous management of BPH and sheath blightin rice.

Effects of Combined Application of Solid Pyrolysis Products and Digestate on Selected Soil Properties of Arenosol and Plant Growth and Composition in Laboratory Experiments

Biochars as soil amendments have been reported to improve soil properties and may have an important role in the mitigation of the consequences of climate change. As a novel approach, this study examines whether biochar and digestate co-application can be utilized as cost-effective, renewable plant nutrients. The effects of two types of biochar—wood chip biochar (WBC) and animal bone biochar (ABC), applied alone or in combination with an anaerobic digestate—on soil physicochemical properties, on the levels of selected elements, and on growth yields of ryegrass were studied in laboratory experiments. Most parameters were significantly affected by the treatments, and the investigated factors (biochar type, application rate, and the presence of digestate), as well as their interactions, were found to have significant effects on the characteristics investigated. The easily soluble phosphorus content (AL-P2O5) of the soil increased in all WBC and ABC biochar treatments, and the presence of digestate caused a further increase in AL-P2O5 in the case of anaerobic digestate-supplemented ABC treatment (ABCxAD). The pH increased in both ABC and WBC treatments, and also in the case of ABCxAD treatments. Similar increases in the salt content were detected in ABC-treated samples and in ABCxAD treatments at higher application rates. WBC increased the water holding capacity and carbon content of the soil. Phytotoxic effects of biochars were not detected, although higher doses resulted in slower germination. Combined biochar–digestate applications resulted in increased plant yields compared to sole biochar treatments. Thus, biochar–digestate combinations appear to be applicable as organo-mineral fertilizers.

Integration of annual forage legume with maize for better feed availability of livestock in maize dominated mixed farming system of Southern Region, Ethiopia

This study was conducted at Dore Befano and Meskan district of Sidma regional state and Gurage zone of south nation, nationalities, and peoples of southern Ethiopia’s (SNNPR), where maize dominated. The trial was conducted to evaluate the outcome of under sowing lablab on the grain yield, Stover, and appropriate time and seeding rate of forage crop under sowing. The trial was implemented using a 3 by 3 factorial combination with two sole treatments in an RCBD with three replications. The treatments were sole Maize (T1). Sole forage (T2) and Maize & Forage Simultaneous with maize sowing date full Simultaneous with maize sowing date 75%, Simultaneous with maize sowing date at 50%, Maize & Forage After 15 days of maize sowing full, after 15 days of maize sowing 75%, After 15 days of maize sowing 50%, Maize & Forage After 30 days of maize sowing full, Maize & Forage After 30 days of maize sowing 75% and Maize & Forage After 30 days of maize sowing 50% T3 to T11 respectively. Under sowing of lablab with maize did not affect the grain yield of maize. Among experiments, T5 was a more appropriate seeding rate and sowing time for under sowing of lablab with maize.

The efficacy of combining paraffin oil with conventional fungicide treatments against grape powdery mildew in Eger

We aimed to test the combination of paraffin oil (PFO) with regular fungicide treatment to assess its efficacy against grape powdery mildew (GPM) in a small spraying experiment on two Vitis vinifera L. cultivars (Chardonnay and Kékfrankos) with different susceptibility to Erysiphe necator. The visual symptoms of GPM on leaves and clusters were examined at three phenological states. The harvest yield was characterized by two methods, data were analyzed with one-way ANOVA and Tukey post-hoc test. Regular fungicide treatment (CT) and its combinations with PFO showed better results in both varieties to repress GPM in 2015 relative to sole PFO treatments. Mean values of combined treatments were often lower than CT but did not differ significantly from each other. The same was observed in 2016, despite the higher pressure of GPM, and missed the third survey. No significant differences were detected between treatments in yield. In contrast, the mean cluster weight of CT and combined treatments resulted in (insignificantly) higher values in each variety and year. In summary, the sole PFO showed some disease control capability as reported earlier, but this effect was greatly affected by the given vintage. Combining PFO with CT resulted in increased protection against GPM relative to the solely applied fungicides. However, this effect was not significant in all cases. It also depended on the vintage and cultivar characteristics. The beneficial impact of paraffin oil as an additive to CT may be due to the induction of plant stress responses and/or its ability to support the adherence and absorption of the combined agents.

Nutrient Inputs for Rehabilitation of Non-responsive Soils in the Guinea and Sudan Savannah Agroecological Zones of Ghana: Impact on Grain Yield and Soil Quality

Studies have shown that the continuous application of N, P, and K fertilizers has led to the depletion of secondary and micronutrients, which have become limiting nutrients hindering crop growth and yield. An on-farm trial was conducted to determine the effect of site-specific nutrient fertilizers and compost on soybean yield, phosphorus use efficiency, and soil properties, at Nyong Guma, Serekpere, Daffiama Saapare, and Naaga in northern Ghana. Nine (9) treatments (3 rates of mineral fertilizer × 3 rates of FertiSoil) were applied in a factorial combination arranged in randomized complete block design with three replications. On average, the soybean grain yield increased significantly with the combined application of FertiSoil and mineral fertilizer at full rates at Nyong Guma, Serekpere, and Naaga from <1,000 kg ha−1to > 1,500 kg ha−1. The co-application of 50% recommended rate (RR) of mineral fertilizer and 5 t ha−1FertiSoil increased soybean grain yield by over 250% at Daffiama Saapare. The application of 50% RR mineral fertilizer significantly increased phosphorus use efficiency by 5–55% compared to its combination with FertiSoil or FertiSoil alone at different rates across locations. Incorporation of 5 t ha−1FertiSoil and 100% RR mineral fertilizer significantly increased exchangeable K, Ca, and Mg, and microbial C and P by 0.33, 2.84, 0.56 cmol(+)kg−1and 102.7, 33.37 mg kg−1, respectively, at Serekpere. The combined application of 5 t ha−1FertiSoil and 50% RR mineral fertilizer relatively increased soil organic C (42%) and available P (12%) at Naaga. The soil quality index revealed that the addition of 5 t ha−1FertiSoil to 100% RR mineral fertilizer was the most sustainable nutrient management option across the study sites. Sole mineral fertilizer treatments at 50% RR were the most profitable in all the study locations ranging from value cost ratio (VCR) of 2.7–7.6. The application of limiting nutrients and organic amendments serves as an efficient nutrient management option to improve soil health, crop production and economic profitability on smallholder non-responsive soils.

Photonic Crystal-Enhanced Photodynamic Antibacterial Therapy

Photonic Crystal-Enhanced Photodynamic Antibacterial Therapy

Effect of Arbuscular Mycorrhizal Fungi (AMF) and Rhizobium Inoculation on Growth and Yield of Glycine max L. Varieties

Biofertilizers are preparations containing living cells that help crop plants in the uptake of nutrients. This study aimed to investigate the effect of coinoculation of arbuscular mycorrhizal fungi and Rhizobium species on the growth and nutrient uptake of three varieties of Glycine max: Belsa 95, Afgat M5, and Nova E3, in the greenhouse and the field. These varieties were obtained from the Gambela research center of Ethiopia. Commercial Rhizobium inoculants were obtained from the Menagesha Biotechnology Institute (MBI), and the previously isolated indigenous AMF inoculants were mass-produced using Sorghum bicolor as a trap plant. Two kilograms of sterilized soil and sand in a 2:1 ratio were used for greenhouse treatments, and 2 m × 3 m plots were used for field treatments. In the greenhouse trials, for all the three varieties was recorded better yield plant−1 in coinoculated treatments with fertilizer application and without fertilizer application, respectively. The highest root number plant−1 (10.0 ± 1.2 and 10.0 ± 1.7) was recorded for variety 1 with the application of only fertilizer and fertilizer + Rhizobium, respectively, and the highest values (8.7 ± 1.9 and 4.7 ± 0.8) were recorded for coinoculated treatments with fertilizer application for varieties 2 and 3, respectively. For sole mycorrhiza-inoculated treatments in the greenhouse was recorded higher dry biomass (16.67% for V1, 42.20% for V2, and 22.18% for V3) as compared with the control. Moreover, for combined inoculation of AMF + Rhizobium and AMF + Rhizobium + fertilizer were recorded 27.01% and 66.99% for V1, 42.20% and 70.33% for V2, and 36.84 and 80.20% for V3, respectively. That means tripartite interactions favor the growth response in association with higher P and N uptake. Finally, it is recommended to apply biofertilizers as the plant-fungi-Rhizobium interactions may have a bigger potential role in maintaining sustainable agriculture with effective environmental resilience.

Comparative Effects of Mineral Fertilizer and Two Poultry Manures on the Growth and Yield of Maize/Soybean Intercrop

Maize/soybean intercrop was established in the experimental farm of NCRI Badeggi. The design of the experiment was RCBD, with eight treatments and three replicates. The experiment was designed to investigate the comparative effects of mineral fertilizer, and two poultry manures on the growth parameters and yield of maize /soybean intercrop. The study evaluated the effects of broiler and local chicken manure applied each at the rates of 2 t/h, 4t/h and 6t/h with or without mineral fertilizer. NPK fertilizer at the rates of 40 kg/ha and 20kg/ha combined with poultry manures at the rates of 2 t/h and 4t/h respectively, while poultry manure at 6 t/h and NPK at 60 kg/ha were applied as sole treatments. There was a control treatment with neither poultry manure nor mineral fertilizer. Data were separately collected on the vegetative and yield parameters of both maize and soybeans. Agronomic activities such as weeding, thinning and applications of insecticides were appropriately carried out. Local chicken manure integrated with an ample quantity of NPK fertilizer enhanced the growth and yield parameters of both maize and soybean in maize soybean intercrop. Results obtained from this experiment indicated that local chicken manure at the rate of 2 t/ha and 4 t/ha integrated with NPK fertilizer, at the rate of 40kg/ha and 20kg/ha respectively, significantly influenced the number of cob per plot, cob weight per plot, grain weight per plot, days to 50% silking, as well as days to maturity in maize. Sole local chicken manure applied at the rate of 6 t/ha significantly enhanced plant vigour in soybean, three weeks after planting. The yield performance of maize crops treated with Local chicken manure surpassed those of sole broiler manure and sole NPK fertilizer. Results from this work also demonstrated the efficiency of poultry manure when integrated with commercial fertilizer.

Innovating the Synergistic Assets of β-Amino Butyric Acid (BABA) and Selenium Nanoparticles (SeNPs) in Improving the Growth, Nitrogen Metabolism, Biological Activities, and Nutritive Value of Medicago interexta Sprouts.

In view of the wide traditional uses of legume sprouts, several strategies have been approved to improve their growth, bioactivity, and nutritive values. In this regard, the present study aimed at investigating how priming with selenium nanoparticles (SeNPs, 25 mg L−1) enhanced the effects of β-amino butyric acid (BABA, 30 mM) on the growth, physiology, nitrogen metabolism, and bioactive metabolites of Medicago interexta sprouts. The results have shown that the growth and photosynthesis of M. interexta sprouts were enhanced by the treatment with BABA or SeNPs, being higher under combined treatment. Increased photosynthesis provided the precursors for the biosynthesis of primary and secondary metabolites. In this regard, the combined treatment had a more pronounced effect on the bioactive primary metabolites (essential amino acids), secondary metabolites (phenolics, GSH, and ASC), and mineral profiles of the investigated sprouts than that of sole treatments. Increased amino acids were accompanied by increased nitrogen metabolism, i.e., nitrate reductase, glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), glutamine synthase (GS), cysteine synthesis serine acetyltransferase, arginase, threonine synthase, and methionine synthase. Further, the antioxidant capacity (FRAP), the anti-diabetic activities (i.e., α-amylase and α-glucosidase inhibition activities), and the glycemic index of the tested sprouts were more significantly improved by the combined treatment with BABA and SeNPs than by individual treatment. Overall, the combined effect of BABA and SeNPs could be preferable to their individual effects on plant growth and bioactive metabolites.

Cover Crop Species Composition Alters the Soil Bacterial Community in a Continuous Pepper Cropping System.

Cover crops can improve soil biological health and alter the composition of soil microbial communities in agricultural systems. However, the effects of diversified cover crops on soil microbial communities in continuous cropping systems are unclear. Here, using different soil biochemical analysis, quantitative PCR and 16S rRNA amplicon sequencing, we investigated the effects of cover crops, alone or in mixture, on soil physicochemical properties in 2019 and 2020, and soil bacterial communities in 2020 in a continuous pepper cropping system. A field trial was established before pepper planting and eight treatments were included: fallow (no cover crop; CK); three sole cover crop treatments: wheat (Triticum aestivum L.; W), faba bean (Vicia faba L.; B), and wild rocket (Diplotaxis tenuifolia; R); and four mixed treatments: wheat + wild rocket (WR), wheat + faba bean (WB), wild rocket + faba bean (RB), and wheat + wild rocket + faba bean (WRB). The pepper yield was increased in the WR and WB in 2019 and 2020, and in the WRB in 2020. Cover crops increased the soil pH, but decreased the concentrations of NH4+ and available phosphorus. Bacterial abundance was increased by cover crop treatments, and community structure was altered in the W, WB, and WRB treatments. Moreover, we found that pH was the key factor associated with the changes in the abundance and structure of the bacterial community. Cover crop treatments altered the bacterial community structure with shifts in the dominant genera, which have plant-growth-promoting and/or pathogen-antagonistic potentials, e.g., increased the abundances of Streptomyces, Arthrobacter, and Bacillus spp. in the W and WRB, and Gaiella spp. in the WB. Overall, we found that cover crops altered the soil physicochemical properties and bacterial community, and these changes varied with species composition of the cover crops, with wheat and its combination with legumes as most effective treatments. These results suggest that the diversification within cover crops could provide better crop yield stimulatory affects by altering soil biochemical environment.

Antibiotic Resistance Genes and Potentially Pathogenic Bacteria in the Central Adriatic Sea: Are They Connected to Urban Wastewater Inputs?

Despite last decades’ interventions within local and communitarian programs, the Mediterranean Sea still receives poorly treated urban wastewater (sewage). Wastewater treatment plants (WWTPs) performing primary sewage treatments have poor efficiency in removing microbial pollutants, including fecal indicator bacteria, pathogens, and mobile genetic elements conferring resistance to antimicrobials. Using a combination of molecular tools, we investigated four urban WWTPs (i.e., two performing only mechanical treatments and two performing a subsequent conventional secondary treatment by activated sludge) as continuous sources of microbial pollution for marine coastal waters. Sewage that underwent only primary treatments was characterized by a higher content of traditional and alternative fecal indicator bacteria, as well as potentially pathogenic bacteria (especially Acinetobacter, Coxiella, Prevotella, Streptococcus, Pseudomonas, Vibrio, Empedobacter, Paracoccus, and Leptotrichia), than those subjected to secondary treatment. However, seawater samples collected next to the discharging points of all the WWTPs investigated here revealed a marked fecal signature, despite significantly lower values in the presence of secondary treatment of the sewage. WWTPs in this study represented continuous sources of antibiotic resistance genes (ARGs) ermB, qnrS, sul2, tetA, and blaTEM (the latter only for three WWTPs out of four). Still, no clear effects of the two depuration strategies investigated here were detected. Some marine samples were identified as positive to the colistin-resistance gene mcr-1, an ARG that threatens colistin antibiotics’ clinical utility in treating infections with multidrug-resistant bacteria. This study provides evidence that the use of sole primary treatments in urban wastewater management results in pronounced inputs of microbial pollution into marine coastal waters. At the same time, the use of conventional treatments does not fully eliminate ARGs in treated wastewater. The complementary use of molecular techniques could successfully improve the evaluation of the depuration efficiency and help develop novel solutions for the treatment of urban wastewater.

Effect of pearl millet based intercropping systems on yield and economics of pearl millet [Pennisetum glaucum (L.) R.Br.

The field experiment was carried out during kharif season of 2019 at Chaudhary Charan Singh Haryana Agricultural University, Hisar to study the effect of different intercropping systems of pearl millet with legumes and oilseed on yield and economics of pearl millet. The eleven treatments were evaluated in randomized block design with three replications. The performance of sole pearl millet hybrid HHB 299 at 45 cm row spacing proved the best in terms of grain (48.83 q ha-1) and stover (100.11 q ha-1) yield and yield attributing traits. It was comparable to sole pearl millet in paired row and pearl millet + green gram (2:1). Among intercropping systems, maximum values of yield attributes of pearl millet were obtained in pearl millet + green gram (2:2) and maximum pearl millet yield (44.68 q ha-1) was in pearl millet + green gram (2:1). Pearl millet equivalent yield (PEY) and net returns of pearl millet-green gram in 2:1 row ratio was found superior than all the sole and intercropping treatments. The highest benefit-cost ratio was recorded under sole pearl millet crop (2.84) followed by intercropping of pearl millet with green gram in 2:1 row ratio (2.77).

Alfalfa (Medicago sativa L.) growth and yield in desert soil fertilized with raw and anaerobically digested cattle manure

Anaerobic digestion is a biological method used to treat organic wastes for bioenergy production and it creates nutrients rich digestate that is used as a soil fertilizer. However, the ability of digestate to improve the productivity of desert soil is not well documented. A pot experiment was conducted to test the efficiency of raw (RM) and anaerobically digested cattle manure (DM) in supporting alfalfa (Medicago sativa L.) seeds germination, growth and yield in virgin desert soil. Treatments of combination with urea and biofertilizer (local rhizobium strain) (BF) were also used beside the untreated soil as a control, and the application rate of fertilizers was corresponded to 150 kg Tot N ha−1. During the experiment, final germination percentage (FGP %), germination index (GI), a total number of plant stems (TS), plant height, deficiency symptoms, number of nodules (NN), dry biomass of shoot, root, and total biomass were all assessed. The results showed that the application of DM and RM increased all parameters as compared with the control treatment. In comparison with other treatments, DM gave the highest germination, lower deficiency symptoms, taller plants, increased TS, increased NN and biomass yield (i.e., root, shoot and total biomass). Furthermore, combination with urea reduced all measured parameters in comparison with RM and DM sole treatments. It was concluded that the best management for improving alfalfa growth and yield at the cultivation in virgin desert soil is to apply anaerobically digested cattle manure as a soil fertilizer.

Ethylene participates in zinc oxide nanoparticles induced biochemical, molecular and ultrastructural changes in rice seedlings

Nowadays, the applications of engineered nanoparticles (ENPs) have been significantly increased, thereby negatively affecting crop production and ultimately contaminating the food chain worldwide. Zinc oxide nanoparticles (ZnO NPs) induced oxidative stress has been clarified in previous studies. But until now, it has not been investigated that how ethylene mediates or participates in ZnO NPs-induced toxicity and related cellular ultrastructural changes in rice seedlings. Here, we reported that 500 mg/L of ZnO NPs reduced the fresh weight (54.75% and 55.64%) and dry weight (40.33% and 47.83%) in shoot and root respectively as compared to control. Furthermore, ZnO NPs (500 mg/L) reduced chlorophyll content (72% Chla, 70% Chlb), induced the stomatal closure and ultrastructural damages by causing oxidative stress in rice seedlings. These cellular damages were significantly increased by exogenous applications of ethylene biosynthesis precursor (ACC) in the presence of ZnO NPs. In contrary, ZnO NPs induced damages on the above-mentioned attributes were reversed through the exogenous supply of ethylene signaling and biosynthesis antagonists such as silver (Ag) and cobalt (Co) respectively. Interestingly, ZnO NPs accelerate ethylene biosynthesis by up-regulating the transcriptome of ethylene biosynthesis responsive genes. The antioxidant enzymes activities and related gene expressions were further increased in ethylene signaling and biosynthesis associated antagonists (Ag and Co) treated seedlings as compared to sole ZnO NPs treatments. In contrary, the above-reported attributes were further decreased by ACC together with ZnO NPs. In a nutshell, ethylene effectively contributes in ZnO NPs induced toxicity and causing ultrastructural and stomatal damage in rice seedlings. Such findings could have potential implications in producing genetic engineered crops, which will be able to tolerate nanoparticles toxicity in the environment.

Intercropping pea (pisum sativum) with lettuce (lactuca sativa) and its Impact on the Growth, Yield and Nutritional Quality

A field experiment was carried out during the two successive seasons of 2017/18 and 2018/19. The aims of the experiment were to investigate the effect of different planting arrangement patterns: T1 (3 pea: 1 lettuce), T2 (2 pea: 1 lettuce), T3 (1 pea:1 lettuce), T4 (side pea: side lettuce) in addition to sole lettuce and sole pea (control) treatments regarding the growth, yield, and nutritional quality, along with the financial aspects of applying intercropping systems for lettuce and pea productivity. The obtained results revealed that all intercropping treatments except for T4 (side pea: side lettuce) treatment reduced the pea yield by 17%-62.9% and 17.2%-61.6% but increased the lettuce yield by 12.2%-37.7% and 27.7%- 60 % in the first and second seasons respectively according to the intercropping system applied. The highest pea yields were produced by both sole pea andT4 treatments, while the lowest pea yield was form T3, in both seasons. T3 treatment depressed pea pod yield to 60% of its mono-cropped yield. On the other hand, T1 and T2 treatments produced the highest yield for lettuce in both seasons. Intercropping lettuce with pea, led to an improvement in the protein percentage in pea. LER of pea/lettuce intercropping treatments were more than unit. Moreover, the highest values for both LER and MAI obtained fromT1 treatment. Calculated “aggressiveness” suggested that all secondary crop treatments were more dominant than pea in all intercropping treatments.