April-June 2020


Effect of Organic Acids and Plant Growth Promoting Rhizobacteria (PGPR) on Biochemical Content and Productivity of Wheat under Saline Soil Conditions

Soad Y. S. El-Sayed, Rehab H. Hagab

ABSTRACT: An experiment was done to examine the survival ability of the plant growth promoting rhizobacteria PGPR under investigation (Rhizobium leguminosarum and Paenibacillus polymyxa) under salt stress to ensure their efficiency in saline soil when they used as PGPR inoculants. Data revealed the initial screening by spotting on media supplemented with different concentrations of salt (0.3, 0.6, 0.9, 1.2 and 1.5M NaCl) in which indicated that R. leguminosarum and P. polymyxa were able to grow at all concentrations of NaCl with different log numbers. However, the growth was reduced as the concentration of NaCl increased. Also, data revealed that both R. leguminosarum and P. polymyxa succeed to solubilize the phosphorus and produce IAA at the NaCl concentrations 0.3 and 1.5M NaCl. However, P. polymyxa show highest P-solubilization ability at different salt concentrations. The data also revealed the potentiality of testing PGPR in production of HCN and siderophores at different concentrations of NaCl, in which both PGPR have the ability to produce HCN and siderophores at 0.3 and 1.5M NaCl however P. polymyxa was superior in production of HCN and siderophore. A field experiment was conducted at the Sahl El-Hussinia, El-Sharkia governorate, Egypt during winter-growing season of 2018/2019 to study the effect of PGPR (R. leguminosarum and P. polymyxa) inoculants and foliar application of organic acids (humic and ascorbic acids) on wheat growth and productivity under salt stress. The experiment was laid out in randomized complete block design (RCBD).The results showed that, the best treatment was (AsA +HA+ mixture of PGPR) treatment has a high biological yield, which increased by 43.00%, grain yield by 43.11% and led to increases in 1000-grain weight by 35.19%. In addition, chemical constituents as (antioxidant activity, phenolic components and NPK uptake) of wheat crop gave the
highest significant value by (AsA +HA+ mixture of PGPR) treatment. It is obvious from obtaining data in this study that all treatments play an important role in the alleviation of salt stress on wheat plants through their positive effect on biochemical contents of the plant.

[ FULL TEXT PDF 227-242 ] DOI: 10.36632/mejar/2020.9.2.20


Effects of Serratia marcescens and Prodigiosin Pigment on the Root-Knot Nematode Meloidogyne incognita

Omnia M. Mohamd, Rania A. A. Hussein, Dina S. S. Ibrahim, Mona H. Badawi and Hussien E. Makboul

ABSTRACT: The effect of Serratia marcescens culture and culture filtrate on juvenile mortality of the rootknot nematode Meloidogyne incognita was studied in vitro and in vivo on tomato seedlings. The percent of mortality was proportional to the concentration of culture filtrate and exposure period. Prodigiosin from S. marcescens was extracted with actone and ethyl acetate then purified using
puriflash column and characterized by TLC, mass spectrometry, FTIR. Prodigiosin was screened for controlling root-knot nematode at juvenile stage. The obtained results revealed that the molecular weight of the pigment was 324.7 m/z, this confirms that the pigment extracted from S. marcescens is prodigiosin. In FTIR analysis red pigment from S. marcescens revealed absorption at 3315.3 per cm (N-H) and 2941.6 per cm (aromatic C-H), 1450 (C-H) alkenes, 1020, 1141 (C-O, C-N) carboxylic groups. Bacterial cultures showed better results than the control of nematode alone with a value of 58.5 % for juveniles mortality. The culture filtrate of S. marcescens at the four tested concentrations showed nematicidal activities against newly hatched juveniles of M. incognita after 72 h of exposure. The pigment was found effective against juvenile stage of M. incognita at low concentrations (EC50 value after 72 h was 31.9 mg ml-1). It is proved that the use of microbial secondary metabolites can be effective for nematode control rather than using whole organism.

[ FULL TEXT PDF 243-252 ] DOI: 10.36632/mejar/2020.9.2.21


Metabolites of Aquatic Cyanobacteria Represent a Unique Source of Biopharmaceutical Agents

El Hanafi K.M., Badawi H. Mona and Waleed D. Saleh

ABSTRACT: Cyanobacteria constitute a vast potential resource in various applications such as pharmaceutical, agriculture, food, feed, fuel, fertilizer, industry and in combating pollution. In this study, the biodiversity of aquatic cyanobacteria was monitored in various water resources representing those of the River Nile at Giza and Ain Sokhna, Red sea in Egypt as well as some United Arab
Emirates water supplies. Total number of six isolates were secured and subjected for morphological and microscopic examinations. Three isolates representing the most common members were identified using the molecular biology techniques. Those were closely related to the genera Anabaena sp., Oscillatoria sp. and Synechocystis sp. of the Gene Bank. They were evaluated for their potential capacities as anti-fungal and anti-bacterial agents as well as measuring their anti-oxidant activities. The examinations of chloroform, diethyl, hexane and methanol extracts of the tested cyanobacterial cultures indicated the presence of several metabolites including 9-hexadecenoic acid, leukotriene C4, neophytadiene, phthalic acid, hexadecanoic acid, octadecenoic acid, octasiloxane hexadecamethyl, phytol acetate, octadecadienoyl chloride and cyclohexasiloxane dodecamethyl. Adopting the disk
diffusion method, the cyanobacterial extracts as anti-bacterial substances arranged the examined cultures in the descending order of Anabaena > Synechocystis > Oscillatoria with inhibition zone averages of 11.3, 10.7 and 10.3 mm respectively. Similarly, the experimented microbiota considerably varied in their anti-fungal capabilities where the cyanobacterium Anabaena seemed the most active one. In respect to the anti-oxidant activity, Oscillatoria was the pioneer among the other tested ones. All in all, this study supports the applicability of such very unique aquatic creatures in the biotechnological approaches and pharmaceutical ones in particular.

[ FULL TEXT PDF 253-269 ] DOI: 10.36632/mejar/2020.9.2.22


Influence of Plant Densities Interacted with Boron Foliar spraying on sunflower productivity

Abido, W.A.E. and El-Shimaa A.M. Abo-El-Kheer

ABSTRACT: Plant densities and born fertilizer had a great importance among the agronomic factors that have a strong effect on plant productivity. For this reason, two experiments were performed at Kafralgraidh Village, Kafrelshiekh Governorate, Egypt, during 2018 and 2019 summer seasons using a strip-plot design with four replicates to investigate the effects of four plant densities (23333, 28000, 35000 and 46666 plant/fed) resulted from four hill spacing (30, 25, 20 and 15 cm), respectively and five boron foliar application i.e. without foliar spraying as control treatment, foliar spraying with water and three levels of boron foliar fertilizer (100, 150 and 200 ppm), on growth parameters, yield, its attributes, seeds oil content and its qualities of sunflower. The obtained results declared that plant densities significantly affected plant growth characters, yield, and its attributes and oil content as well as oil qualities. Results indicated that the maximum averages of total chlorophyll content, stem height, stem diameter, head diameter, 1000-achenes weight and achenes weight/head were resulted from the lowest plant density 23333 plants/fed. While, the highest averages of leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), achenes yield/fed and oil, oleic and linoleic contents were recorded with a plant density of 35000 plants/fed. Otherwise, increasing plant density from 23333 to 46666 plant/fed caused a gradual increased in palmitic and stearic contents. Data also declared that the foliar spraying with boron significantly influenced all studied characters. The maximum averages of all studied characters were recorded from foliar spraying with 200 ppm of boron. Therefore, for maximizing the achenes yield oil content of sunflower plants it could be recommended to sowing at a plant density of 35000 plants/fed resulted from hill spacing 20 cm, also spraying plants with 200 ppm of boron under the ecological conditions of the experiment area.

[ FULL TEXT PDF 270-281 ] DOI: 10.36632/mejar/2020.9.2.23


Technical Efficiency and Technological Gaps in Agricultural Production in Selected African Countries: A Stochastic Metafrontier Approach

Aminu F.O., Ayinde I.A. and Sanusi R.A.

ABSTRACT: The study applied stochastic metafrontier model to estimate technical efficiency (TE) and technology gap ratios (TGR) in agricultural production of selected African countries. Secondary data on Agricultural production indices of four Africa countries (Nigeria, Benin, Ghana and Cameroon) over a period of 54 years (1961-2014) sourced from Food and Agricultural Organization (FAOSTAT) database was used for the study. The results of the analysis showed that, the technical efficiency scores from the region ranged from 0.822 to 0.986 with a weighted average of about 85%, indicating that the agricultural production in Africa produces 85 percent of the potential output given the technology available in each country. Also, the technological gap faced by the agriculture sector in the selected countries when their performances were compared with the regional level was estimated to be 0.774, which implies that, on the average, the selected Africa countries will have to close a gap of about 22.6% in order for them to be technically efficient. Benin recorded the lowest productivity potential ratio, while Ghana had the highest. In terms of technical efficiency relative to the meta frontier, Nigeria is the most technical efficient country while Benin appears as the least performing region. Considering the importance of agricultural production to these countries and the region as a whole, there is a need for appropriate policies directed towards the provision of technology related services that would enhance efficiency.

[ FULL TEXT PDF 282-293 ] DOI: 10.36632/mejar/2020.9.2.24


Foliar supplementation with micronutrients during early growth of bitter gourd fruit (Momordica charantia) augments resistance to melon fly (Bactrocera cucurbitae) infestation by activation of antioxidant system

Seshadri Shivashankar and Manoharan Sumathi

ABSTRACT: Melon fly is the most destructive pest of cucurbits all over the world. Although, the pest is controlled by the use of insecticides, the risks of development of resistance in the pest due to continued application of pesticide and accumulation of toxic residues in fruits have led to the search for alternative non-chemical control strategies which are eco-safe and environment friendly. In this study, an attempt was made to examine the effect of foliar mineral nutrition on pest incidence and fruit quality. The field study was laid out in a Randomized complete block design in which bitter gourd fruits during the early fruit development phase were sprayed with micronutrient solution containing Ca, Cu, Mg and Mn. Results showed that melon fly infestation was significantly reduced coupled with increased fruit yield and quality. Treated fruits showed significantly higher levels of antioxidants, phenolic acids and flavonoids compared to Control indicating that mineral nutrients protect bitter gourd through activation of antioxidant system in the host combined with their inhibitory effects on oviposition, adult emergence and increased mortality of melon fly larvae. The study established that resistance to melon fly could be induced by supplementing the levels of Ca, Cu, Mg and Mn in bitter gourd fruit by exogenous application at a time when the fruit is most vulnerable to infestation. It appears, therefore, possible to explore foliar micronutrient supplementation as a component of Integrated Pest Management (IPM) strategy for the successful control of melon fly infestation in bitter gourd coupled with higher yield and improved fruit quality.

[ FULL TEXT PDF 294-307 ] DOI: 10.36632/mejar/2020.9.2.25


Production of stunted pot plants from Ruellia simplex

T.M. Noor El-Deen

ABSTRACT: A pot experiment was carried out at Botanical Garden of National Gene Bank, Agricultural Research Center, Giza, Egypt during 2018 and 2019 seasons to investigate the effect of pinching treatments and foliar spraying with paclobutrazol (PBZ) on Mexican petunia (Ruellia simplex C.Wright), aiming to produce more compact plants. Three pinching treatments (non, single after 1 month from transplanting and double after 1 and 3 months from transplanting) and 4 PBZ concentrations of 0, 50, 100 and 150 ppm at one-month interval and their combined treatments laid out as a factorial RCBD was employed in this study. Best single-treatment results of dense foliage were found with single pinching or PBZ at either 50 or 100 ppm. As for combined effects, single pinching + spraying with PBZ at 100 ppm was the superior combined treatment; with a reduced plant height by 50.17 and 50.06%, increased number of branches/plant by 95.85 and 96.18%, reduced number of leaves/plant by only 10.27 and 9.26% and increased number of flowers/plant by 51.97 and 48.43% in both seasons, respectively. However, this treatment delayed flowering by 5.3 days in the first season only. The highest values regarding chlorophylls (a and b), carotenoids and total indoles were recorded by this superior combined treatment. Finally, it is recommended to treat Mexican petunia plants cultivated in 16-cm-pots filled with peat moss + perlite (1:1 by volume) with single pinch after 1 month from transplanting + 4 applications at one-month interval with PBZ at 100 ppm
for optimum stunting with satisfied quality as pot plant.

[ FULL TEXT PDF 308-320 ] DOI: 10.36632/mejar/2020.9.2.26