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Sesame (Sesamum indicum L.) is an oilseed crop flourishing in marginal lands. It has a high nutritional value because it is rich in protein and fat and has many health benefits. However, the varieties of this crop available in Egypt are very few. Seventeen new sesame lines incurred evaluation in two crop seasons, 2021-2022, for seed yield under eight environments comprising normal and drought conditions in sandy and clay soils. Applying 16 parameters and non-parameters of stability helped select stable and adaptive sesame lines under ideal and drought conditions, with the genotypes arranged in a randomized complete block design with three replicates. Line C5.8 achieved the highest relative productivity in sandy and clay soils and exhibited a good source for breeding programs under drought conditions. Four lines, C1.3, C9.15, C9.6, and C9.20, under eight different environments had higher seed yield than the control. A genetic-environment interaction (GEI) effect on seed productivity occurred in all sources of the combined analysis. The association between seed yield and stability parameters showed the possibility of using a selection index that included some of them to identify sesame genotypes with higher yield and genetic stability. [ABSTRACT FROM AUTHOR]

The absence of calcium decreases the production of peanuts compared to any other element. To investigate the influence of calcium (Ca) applications on the production and seed quality of four diverse peanut cultivars from different regions—USA (NC-7), Egypt (Giza-6) and Nigeria (Samnut-23 and Samnut-24)—under clay soil conditions, two experiments were carried out at the Agricultural Experimental and Research Station, Cairo University, Egypt, during the two seasons of 2016 and 2017. The experimental design was a randomized complete block in a spilt-plot arrangement with three replications. The main plots were allocated to four peanut cultivars (Giza-6, Samnut-23, Samnut-24 and NC-7), and the sub-plots were devoted to calcium applications (soil application in the form of calcium sulfate dihydrate, foliar application in the form of calcium oxide and the control treatment of distilled water). Results indicated that all four peanut cultivars responded differently to the application of calcium fertilizers. The calcium application significantly enhanced peanut growth, yield components, biological, pod, seed, oil yields, seed oil, free fatty acids and seed calcium percentages in different cultivars. Soil calcium application significantly improved peanut production compared to foliar calcium application. NC-7 cultivar treated with the soil Ca application resulted in the maximum values of biological yield (92.9-ton ha−1), pod yield (6.8-ton ha−1), seed yield (4.4-ton ha−1), oil yield (2247.0 kg ha−1), pod index (203.2 g) and seed index (84.1 g). The interaction between the NC-7 cultivar and soil calcium applications is recommended to attain the best combination, leading to the highest yield and seed quality of peanuts. [ABSTRACT FROM AUTHOR]

This research aims to improve the engineering properties of expansive soil by using locally low-cost materials such as crushed glass wastes and lime. The studied expansive soil is considered unsuitable soil for civil engineering projects such as roads and buildings, as it was classified according to the AASHTO classification A-7-6. This soil was treated only with different ratios of crushed glass wastes (0%, 5%, 10%, 15%, and 20% by weight of dry soil), as well as the soil was treated only with different ratios of lime (0%, 2%, 4%, 6%, and 8% by weight of dry soil). Experiments of Atterberg limits, standard Procter, direct shear, free swell, swelling pressure, and both un-soaked and soaked California Bearing Ratio tests were carried out on the untreated and treated soil. The results showed that by increasing added percentage of crushed glass wastes and lime separately, the consistency properties (Atterberg limits), the shear strength parameters (direct shear test), free swell, swelling pressure, and both un-soaked and soaked California Bearing Ratio of the studied expansive soil were improved; except for compaction characteristics, by adding crushed glass wastes the M.D.D was increased and O.M.C was decreased while by adding lime, the M.D.D was decreased and O.M.C was increased. This helps to make use of low-cost local materials, clean the environment of glass wastes, and recycle these wastes so that they can be used on an environmental, economic, and engineering level. This aligns with Egypt's Vision 2030 sustainable development approach in both the environmental and economic dimensions. [ABSTRACT FROM AUTHOR]

The current article aimed to examine the effect of organic and biofertilizers on the growth and yield of lavender essential oil (Lavandula Officinalis L.). This experiment was conducted over two consecutive seasons in 2018/2019 and 2019/2020 at the net house of the Central Laboratory of the Agricultural Climate Research Center in Dokki, Giza Governorate, Egypt. To assess the effects of biofertilizers (Azospirillum spp., Azotobacter spp.) and active dry yeast on the vegetative development, chemical composition, yield, and essential oil concentration of lavender. The obtained results showed that, treated plants with compost + Azospirillum spp. + Azotobacter spp. was the superior treatment, which improved plant growth characters i.e., plant height, number of branches, fresh and dry weights/herb. Chlorophyll a, b and carotenoids concentrations, the phenolic compounds, flavonoid content, total carbohydrates content in dry matter of herb, Nitrogen, Phosphorus and Potassium, total free amino acids, the total antioxidants and the endogenous hormones in all cuts. Essential oil content carried out to evaluate the quality of oil. Also, significant increase was showed with active dry yeast. [ABSTRACT FROM AUTHOR]

Water scarcity and weed infestation are major challenges to soybean production. Therefore, two field experiments were conducted in a strip plot design including three replicates in the 2019 and 2020 summer seasons at Sakha Agricultural Research Station, Agricultural Research Centre, Egypt, to investigate the effect of three irrigation levels (I0 (100%), I1 (90%), and I2 (80%)), and six weed control treatments of pendimethalin (T1), oxyfluorfen (T2), bentazon + clethodim (T3), imazethapyr (T4), hand-hoeing twice (T5), and untreated check (T6) on annual weeds, physiological traits, water relations, and yield and its components of soybean cv Giza 111. Results indicated that intermediate irrigation levels lead to the highest yield and economic return, while the herbicide program that resulted in the greatest weed control gave the highest yield. The rate of weed infestation in field experiments was 19.7 and 21.8 t ha−1 dry weights, which decreased soybean yield by 56.9 and 57.1%, compared to treatment (T4). The interactions between 100 irrigation level (I0) and imazethapyr (T4), bentazon + clethodim (T3), and hand-hoeing twice (T5) gave the highest significant values of the most studied characters. Furthermore, under 90% irrigation, all weed control treatments give the best control of weeds and the highest values of the economic criteria. [ABSTRACT FROM AUTHOR]

A two-year experiment (2018 and 2019) was conducted to investigate the conjoint effect of applying rice straw as a soil mulch and treating snake cucumber (Cucumis melo var. flexuosus) plants by potassium silicate solution (4 mM) either by soaking seeds or by foliar applications for different periods, on soil fertility, vegetative growth and yield traits, antioxidant activities in plant, nutrient uptake, and total yield under heat stress conditions. The experiment was conducted during summer season (the maximum weekly temperature ranged from 35.8 to 40.6°C) on a clay soil at Dokki field under greenhouse conditions, Giza governorate, Egypt. The treatment of T5 (soaking seeds for 24 h in potassium silicate solution) combined with covering soil with rice straw gave superior effects on enhancing soil fertility and nutrient uptake, increasing chlorophyll content, increasing antioxidant enzymes activity, decreasing proline and other free amino acids (FAA), total soluble salts (TSS), and vitamin C content, and these were probably the reasons that increased the plant tolerance to face the stress. Total yield increased by 13.4 and 8.19% under rice straw soil cover. Also, its highest values were achieved by the treatment of T5 (173 and 200%), during the two tested seasons, respectively. Results of this study suggest that the conjoint effect of using rice straw as a soil cover and treating plants with potassium silicate solution (4 mM) by soaking their seeds for 24 h is beneficial for improving soil fertility, nutrient uptake as well as for crop production under heat stress conditions. [ABSTRACT FROM AUTHOR]

Three extractions were used to assess the availability of micronutrients in different soil collections. The suitability of some extractions under the conditions of Egyptian soils will be discussed. Three extraction methods (Mehlic 3, Soltanpour and Kelowna) were used for the determination of available Fe, Zn, Mn, Cu and B content of the soil samples (sand, calcareous and clay) during 2020 season. Surface soil samples (0-30 cm) were collected from three sites of Al Boston area in the new Nobaria, Governorate, Egypt, during 2020 season. From each selected plot, ten points were selected in a zig-zag path. The results revealed that the highest values of available Fe, Zn and Cu were given with the extraction solution of Soltanpour, while the highest values of available Mn and B were given with the extraction solution of Mehlic 3. On the other hand, the results showed that clay soil recorded the maximum available Fe, Zn, Mn and Cu, while calcareous soil recorded the maximum available boron content. The interaction between different extraction methods and soil samples was highly significant during 2020 season. [ABSTRACT FROM AUTHOR]

Peach fruit fly, Bactrocera zonata (Saunders, 1841) is a destructive polyphagous pest threatening the horticultural production in Egypt. Licorice, Glycyrrhiza glabra (Linnaeus, 1753) is a plant growing in Egypt and many other countries and famous for saponins groups that have insecticidal effect against broad spectrum of insect pests. In the present study, the insecticidal effect of licorice roots aqueous extract (LRAE), petroleum oil, KZ light mineral oil 96% (EC), water and an emulsion (1/4 L LRAE + ? L petroleum oil + ½ L KZ light oil 96% (EC)) treatments in a ratio 1 L: 29 L water were used in Matabi® sprayer of 20 L capacity against B. zonata pupae in sandy and clay soils. In sandy and clay soils LRAE reduced B. zonata population by 74.44% and 87.55% while petroleum oil, KZ light mineral oil 96% (EC) prevented flies emergence (100% reduction). Water treatment suppressed B. zonata population by 78.61% in sandy soil but caused 100% population reduction in clay soil. The emulsion reduced B. zonata population by 96.94% in sandy soil and 100% in clay soil. The best method for application of the emulsion was to spray as one target spray technique for eight seconds that was sufficient to obtain suitable coverage on soil with spray speed 1.2 km / hour. The persistence of the emulsion that highly reduced B. zonata larval populations was 3.5 and 4.5 days in sandy and clay soils, respectively. The flies emerged from B. zonata pupae treated with the emulsion neither feed nor move naturally. The histological studies showed that these flies suffered changes in the eyes, labellum, muscles and midgut tissues that were different from the emerged control treatment flies. [ABSTRACT FROM AUTHOR]

Field experiments were conducted during two successive growing seasons ( 2017/2018 and 2018/2019) in Guava orchard at Kafr Al Dawar district, Beheira Governorate, Egypt, to investigate the effect of water regime levels: 100% (E1), 80% (E2) and 60% (E3) of crop evapotranspiration (ETc) under two irrigation systems: furrow irrigation (I1) and surface drip irrigation (I2) on water use efficiency, growth parameters, yield components, and economic analysis of four years old guava trees grown in clay soil. The field experiments were implemented in arandomized complete block design with three replicates.  The obtained results indicated that the highest shoot length, number of leaves/m and leaf area were obtained due to T2E1 treatment (drip irrigation with 100% ETc), followed by I2E2 treatment (drip irrigation with 80 % ETc). The average highest guava yield of the two growing seasons was 26.64 tons/ha which was obtained as a result of I2E1 treatment (drip irrigation with 100% of ETc). The lowest guava yield (20.24 and 17.90 tons/ha) were obtained due to I1E3 treatment (furrow irrigation with 60% of ETc) for the two growing seasons, respectively. Yield components such as number of fruits/m, length of fruit (cm), diameter of fruit (cm), fruit size (cm³), fruit weight (gm.) and yield (kg/tree) were significantly effected (P˂ 0.05)  by water regime levels and irrigation systems. Water use efficiency (WUE) of drip-irrigated treatments was higher than that obtained from furrow irrigated treatments in the two growing seasons. WUE increased from 2.37 to 3.34 kg.m-3 for drip - irrigated treatment, and from 1.63 to 2.18 kg.m-3 for furrow -irrigated treatments.  Fruit quality such as TSS (%), acidity (%) and TSS / Acidity ratio were not significantly affected by irrigation systems and water regime. For the economical results, the maximum value of net return was due to I2E1(24411 LE/fed)treatment for the two growing seasons and the minimum value of total return was the result of T1E3 (6344 LE/fed)treatment for the two growing seasons. The maximum values of water productivity were obtained under T2E1 (5.56 LE/m³) and I2E2 (5.25 LE/m³)  treatments in the two growing seasons. [ABSTRACT FROM AUTHOR]

Biochar has not been adequately used by farmers to improve the clay textured soil productivities in the world. Therefore, the objective of this study is to investigate the effect of the co-application of biochar with different rates of phosphorus (P) fertilizer on selected soil physical properties and wheat yield on clay textured soil over two growth seasons. Biochar treatments occupied the main plots at a rate of 0.0 and 10 t ha−1, while the sub-plots were devoted to phosphorus rates at rates of 0%, 50%, 100%, and 150% of recommended P fertilizers. Biochar (10 t ha−1) and P at different rates decreased soil bulk density significantly. Meanwhile, it increased aggregate stability, saturated hydraulic conductivity and soil water retention significantly at (p <.05), and it improved the grain yield of wheat. More grain yields in the soil treated with biochar than untreated soil under all P application rates for both years were probably caused partially by more nutrients (N, P, and K) were applied from biochar itself. Grain yield of wheat in the soil-amended biochar and P did not increase significantly between the application at 50%, 100% and 150% P. The results of this study indicate that phosphorus blends with biochar can be used to decrease the bulk density of clay textured soils and to improve crop production in these soils. [ABSTRACT FROM AUTHOR]

Two field experiments were conducted during two consecutive summer seasons of 2014 and 2015 in an administrative field at Diarb Negm District, Sharkia Governorate, under Agronomy Department supervision, Faculty of Agriculture, Zagazig University, Egypt. The aim of this study was to investigate the response of two yellow maize hybrids (Single Cross 176 and Three-way Cross 352) to three plant densities (20000, 24000 and 30000 plants/fad.), and nitrogen-farmyard combination fertilizer levels (60, 80 and100 kg N/fad., without addition of farmyard manure (FYM) and 60 kg N/fad.+20 m3 FYM/fad., 80 kg N/fad.+ 20 m3 FYM/fad., and 100 kg N/fad.+20 m3 FYM/ fad.) under clay soils conditions. The obtained results could be summarized as follows: The tried three maize plant densities had different effects on plant height (cm), ear diameter and length (cm), number of rows/ear, number of kernels/row, 100-kernel weight, kernel weight/ear, and biological yield (ton/fad.) during both seasons and their combined analysis, but the differences among the tried three maize plant densities on aforementioned traits did not reach the level of significance. Results of the first season and the combined analysis detected significant differences among the tried plant densities on ear yield/fad. Where, ear yield/fad., and grain yield/fad., in the first season and combined analysis, harvest index and grain: stover ratio in the two seasons and their combined analysis were significantly increased due to increasing maize density from 20000 or 24000 and up to 30000 plants/fad. Maize SC 173 cultivar appeared to produced taller plants, longer ears and larger number of kernels/row than TWC 352 cultivar. The later produced larger ear diameter, number of rows/ear, 100-kernel weight, kernel weight/ear, ear yield/fad., grain and biological yields/fad., than SC 173 one. No significant differences between two maize cultivars regarding harvest index and grain: stover ratio was observed. The first and the second increments in nitrogen levels up to 100 kg N/fad., with or without addition of farmyard manure was accompanied by a significant increase in ear diameter (cm), ear length (cm), number of rows/ear, number of kernels/row, 100-kernel weight (g), kernel weight/ear (g), ear yield/fad., grain and biological yields (ton/fad.) but harvest index and grain: stover ratio were reduced during both seasons and their combined analysis. These results finally recommend sowing maize cultivar TWC 352 with dense planting of 30000 plants/fad., and raising nitrogen level up to 80 kg N/fad., with addition of farmyard manure to maximize grain yield/fad., under the experimental site and other likely environmental condition. [ABSTRACT FROM AUTHOR]

A pot experiment was conducted under greenhouse condition at the Experimental Farm, Faculty of Agriculture, Zagazig University, Egypt. The experiment aimed to study the effect of different potassium sources (potassium sulphate and potassium feldspar) at the recommended rate (40 mg K kg-1) either single or in combination with soil amendments i.e., farmyard manure (FYM) and sulfur (S) with or without silicate dissolving bacteria (SDB) on yield and nutrients uptake by wheat through the investigated clayey soil. Soil were taken from the surface layers (0-30 cm) from Hehia District, Sharkia Governorate, Egypt. Application of K-sulphate or K-feldspar as individual application or combined with different soil amendments under SDB gave increase in straw and grain yield, potassium uptake, biological yield, 1000 grain weight and protein content of wheat plants compared to untreated soil. The highest value for each of yield, K-uptake and available K was found in clayey soil treated with K-sulphate combined with FYM plus S in the presences of SDB, while the lowest ones were obtained with untreated soils in absence of soil amendments and SDB. Application of Ksulphate showed greater value in each of yield, protein content, K-uptake by wheat plants and soil available potassium than K-feldspar. Application of SDB to K-sulphate or K-feldspar increased yield, protein content, K-uptake of wheat and available potassium compared to the untreated ones. [ABSTRACT FROM AUTHOR]

Two field experiments were carried out on Jerusalem artichoke crop during two successive seasons of 2016 and 2017 at Soil Salinity Laboratory Research, Agricultural Research Center, Alexandria Governorate, Egypt. Each experiment included sixteen treatments representing the combination of two types of soils; i.e., clay and calcareous, two trimming treatments; i.e., without trimming (T0) and trimming (T1) [removing of flowering buds before opening with 10-20 cm from ends of vegetative branches], and four fertilization treatments; i.e., 75 kg nitrogen/feddan + Halex-2 (F1), 75 kg nitrogen/feddan + yeast extract (F2), 75 kg nitrogen/feddan + Halex-2 + yeast extract (F3) and 100 kg nitrogen/feddan (F4). The experimental layout was presented as a split-split-plot in a randomized complete blocks design with three replicates. Two types of soil were assigned in the main plots; two trimming treatments were allocated to the sub-plots and four fertilization treatments which were, randomly, distributed in the sub-sub-plots. Planting Jerusalem artichoke tubers in clay soil encouraged each of the vegetative growth, yield and its component characters compared to planting in calcareous soil. Un-trimming Jerusalem artichoke growing plants resulted in positive effects on the vegetative characters, tubers' yield and its components traits compared to trimming treatment. Adding moderate amount of nitrogen fertilizer (75 kg N/ fed.) combined with Halex-2 plus yeast extract yielded statistically equal results if 100 kg N/fed. was added to the growing plants for most studied characters especially the economic ones. Maturity date trait did not affect with any of the applied treatments on Jerusalem artichoke growing plants. It turned out from the obtained results that a quarter of nitrogen fertilizer quantity could be saved by adding a mixture of biostimulants (Halex-2 + yeast extract) to the growing plants, in addition to un-trimming the ends of branching whether the cultivation was in clay or calcareous soils. [ABSTRACT FROM AUTHOR]

The current experiment was carried out in a clay soil at Sids Agricultural Research Station, Beni-Swief Govemorate Egypt during the two seasons of 2013/2014 and 2014/2015 to study the effect of planting methods on productivity and storability as well as crop-water relations for some onion cultivars. Three planting methods: planting on flat land (P1), on ridges (P2) and on raised bed (P3). Three cultivars namely, Giza 6 Mohassan (C1); Giza 20 (C2) and Giza red (C3). The split-plot experimental design in four replicates were performed, where planting methods were occupied the main plots while the split ones were allocated to the onion cultivars. The important findings could be summarized as follows:- * Amount of irrigation water applied and seasonal consumptive use under P3 treatment were reduced in comparison with those under P1 and P2 for all cultivars in the two seasons. * The highest averages of plant height, no. of leaves/plant, bulb length, no. of days to maturity and TSS % in the two successive seasons, were detected from planting onion on ridges of 60 cm width (P2). While, bulb diameter, plant weight and dry matter % were detected for planting onion on raised bed (P3) for all onion cultivars. * The marketable onion, total yields and bulb weight were increased with P3 comparable with P1 and P2. The lowest value of culls onion yield was obtained with P1 compared with P2 and P3 for all cultivars in the two seasons. * Water productivity and water use efficiency values were improved under P3 as compared with the values with P1 and P2 for all cultivars in the two seasons. * Planting onion on raised bed (P3) for all onion cultivars resulted in significant decrease in weight loss % at different storage periods, in both seasons. [ABSTRACT FROM AUTHOR]

• Groundwater head increased up to 26.70 cm for the year 2060. • Land subsidence under the over-pumping scenario is specified. • The shoreline moves inland with a drawdown to 2, 9.50, and 14.80 m. • Future infrastructure planning should consider the land subsidence threat. Land subsidence (LS) due to the Sea Level Rise (SLR) and over-pumping was observed in many groundwater aquifers worldwide. The geotechnical properties and numerical simulation are considered a new integrative approach to investigate the LS hazard. This study investigates the environmental hazards related to LS in the quaternary sediments using laboratory and numerical modeling in the coastal aquifer of Nile delta, Egypt, due to SLR and over-pumping. Therefore, the geotechnical tests are conducted for the aquifer cap and classify the surficial soil as silty clay with moderately complex dispersive characteristics. In addition, hydraulic conductivity and one-dimensional consolidation of silty clay samples were analyzed to estimate the long-term settlement. Consequently, the groundwater head and drawdown were simulated for the current situation. Three proposed future scenarios are SLR and increased abstraction using the SEAWAT code. The results show that groundwater heads increased to 5.65, 14.50, and 26.70 cm for 2020, 2040, and 2060, respectively. Moreover, the estimated LS under the over-pumping scenario reached 7.60, 32.40, and 52.70 cm, with a maximum drawdown of 2.10, 9.70, and 15.10 m. SLR and over-pumping induce more inundation in the northern part due to SLR. The shoreline moves inland with a drawdown to 2, 9.50, and 14.80 m. Integration of measured and groundwater simulation settlements would provide appropriate information about the potential environmental hazards. Moreover, the future LS scenarios help stakeholders to make the right decision in developing effective measures in coastal aquifers to minimize the adverse impacts of LS on infrastructure waterways and human life. [ABSTRACT FROM AUTHOR]

The experimental work was carried out at El-Gemmeiza Agricultural Research Station, Gharbia Governorate, Egypt during 2009/2010 winter growing season to study the effect of using sprinkler irrigation in clay soil condition and barley production. The sprinklers layouts were square and triangular. Also, two irrigation levels and two fertilizers levels were used. The results showed that the amounts of applied water were 5077, 4201 and 3068 m3 ha-1 for flood and sprinkler 100% ETc and 50% ETc, respectively. The highest values of coefficient of uniformity, distribution uniformity and application efficiency of low quarter were achieved by the square layout. Grain yield increased from 4.55 Mg ha-1 with flood to 5.70 Mg ha-1 under sprinkler irrigation with square layout at 100% ETc and 100% fertilizer. Straw yield increased from 5.36 Mg ha-1 with flood to 9.65 Mg ha-1 under sprinkler irrigation with square layout at 100% ETc and 100% fertilizer. Water use efficiency increased from 0.90 kg m-3 with flood to 1.64 kg m-3 under sprinkling method with triangular layout at 50% ETc and 100% fertilizer. Energy use efficiency increased from 13.66 kg kW-1 h-1 with flood to 18.20 kg kW-1 h-1 under sprinkler irrigation with triangular layout at 50% ETc and 100% fertilizer.In conclusion, square layout at 100% ETc with 100% fertilizer gave the best results. [ABSTRACT FROM AUTHOR]

Abstract: Laboratory batch experiments were designed to study the adsorption of cadusafos on two types of soils: clay loamy and sandy, collected from two regions around the Nile Delta in Egypt. The adsorption process is fast reaching equilibrium in 60min, decreases with increasing soil mass and independent on pH in the range 3–11. The experimental results were well fitted to linear partition model, and to a lesser extent to Freundlich non-linear model, Temkin and Dubinin–Radushkevich models. However, the 1/n parameter of Freundlich relation being of value around one supported the linear partition model. The K d values obtained from the linear model were 4.20 and 2.74L/g for sandy and clay soils, respectively. The energy of adsorption calculated from D–R equation was 4.36 and 5.04kJ/mol for clay and sandy soils, respectively, in the range assigned to physical forces. This kind of weak interaction, together with pH-independence implies that for the studied soils the organic content (that is higher in the clay soil) is not a major parameter in the adsorption of cadusafos. Water movement taking place more readily in sandy soil caused increased uptake relative to the case of clay soil. The higher uptake in sandy soil denotes that cadusafos may be mobile with a potential to leach and eventually pollutes ground water and surface water. The kinetics of adsorption was well fitted by the pseudo-second order equation. The intraparticles diffusion is of lower significance in case of sandy soil than in clay soil. Thermodynamic parameters indicated that the adsorption is spontaneous, endothermic accompanied by increase in entropy. [Copyright &y& Elsevier]

The symbiotic and competitive performances of two highly effective rhizobia nodulating French bean P. vulgaris were studied in silty loam and clayey soils. The experiments were carried out to address the performance of two rhizobia strains [CE3 and Ph. 163] and the mixture thereof with the two major cultivated bean cultivars in two soil types from major growing French bean areas in Egypt. Clay and silty loam soils from Menoufia and Ismailia respectively were planted with Bronco and Giza 6 phaseolus bean cultivars. The data obtained from this study indicated that rhizobial inoculation of Giza 6 cultivar in clayey soil showed a positive response to inoculation in terms of nodule numbers and dry weight. This response was also positive in dry matter and biomass accumulation by the plants. The inoculant of strain CE3 enhanced plant growth and N-uptake relative to Ph. 163. However, the mixed inoculant strains were not always as good as single strain inoculants. The competition for nodulation was assessed using two techniques namely fluorescent antibody testing (FA) and REP-PCR fingerprinting. The nodule occupancy by inoculant strain Ph. 163 in both soils occupied 30–40% and 38–50 of nodules of cultivar Bronco. The mixed inocula resulted in higher proportions of nodules containing CE3 in silty loam soil and Ph. 163 in clayey soil. The native rhizobia occupied at least 50% of the nodules on the Bronco cultivar. For cultivar Giza 6, the native rhizobia were more competitive with the inoculant strains. Therefore, we suggest using the studied strains as commercial inocula for phaseolus bean. To cite this article: H. Moawad et al., C. R. Biologies 327 (2004). [Copyright &y& Elsevier]

The conventional sub-surface drainage (FD) in the Nile delta clay soil, northern Egypt, results in excessive drainage and low irrigation efficiency (IE). However, a shallower placement of drain might reduce drain outflow and increase IE. The ultimate objective of the present study was to determine the optimum drain depth that minimizes drain outflow and maximizes IE and irrigation water use efficiency (IWUE), while maintaining crop yield and soil salinity. Compared to FD at 120 cm below the soil surface (BSS), the effect of four controlled drain depths (CD) at 40, 60, 80 and 100 cm BSS on drain outflow, IE, salinity buildup, yield and IWUE were investigated for two seasons (2017–18 and 2018–19; wheat-sunflower cropping system). Measurements were conducted for sunflower (as a summer crop). Irrigation was applied based on the soil water content of FD-treatment, thus irrigation depth varied for each treatment. The results showed that decreasing drain depth significantly reduced drain outflow and water input, while IE, seed yield and IWUE were increased. The maximum seed yield and IWUE were obtained at the shallowest drains. Compared with FD at 120 cm, drain depth at 40 cm decreased drain outflow (by 77.20%) and water input (by 29.3%), while increased seed yield and IWUE by 27% and 86%, respectively. Based on water balance, water-uptake from shallow groundwater was maximum for CD-40 cm treatment (31.05% of water-uptake) and was significantly higher than the other treatments. However, by the end of the second season, treatment with drain depth at 40 cm BSS recorded the highest soil salinity (3.6 dS m−1) due to the upward capillary rise of shallow groundwater. Increased soil salinity had no effect on seed yield because it was below the salinity threshold of sunflower. In terms of IE and IWUE, decreasing drain depth to 40 cm BSS is recommended, but with potential salinity buildup. Therefore, drain at 60 cm BSS (had similar seed yield to drain at 40 cm BSS) might lead to significant water-saving (21.8%), while maintaining seed yield and soil quality. In conclusion, modifying the drainage system by reducing drain depth and considering crop water-uptake from shallow groundwater might contribute to water saving. After all, careful water and soil management (e.g., periodic leaching), and suitable cropping systems should be considered for salinity management when decreasing drain depth. • Decreasing drain depth reduced drain outflow and water input and increased irrigation efficiency. • Shallow placement of drain increased seed yield and water use efficiency (WUE) of sunflower. • Shallow placement of drains makes the shallow groundwater available for crop use. • The maximum productivity and WUE were obtained at the shallowest drain depth (40 cm). [ABSTRACT FROM AUTHOR]

Potato brown rot, caused by Ralstonia solanacearum, ranked globally as the second most important bacterial plant pathogen. In the present study, the influence of different cropping programs in potato brown rot management was investigated in four infected fields in Egypt. Two districts were selected as sandy soils in Giza (Wardan) and Behera (Ganuob El-Tahrir) governorates. The other two were selected as silty clay in Minufyia (Talia) and Beni-Suef (Sids) governorates. The followed crop succession included corn, potato intercropped with cabbage, onion, cowpea, wheat, corn again, and ended by potato. The pathogen was undetectable after corn, onion, and wheat. It decreased in cowpea and cabbage rhizospheres in the clay soils. The pathogen was undetectable at all districts, except at Sids, where the pathogen was significantly decreased but was not eradicated. This was possibly attributed to the high ratio of NO3− and Na+ at this district. Decreased R. solanacearum density after corn coincided with the high ratio of fluorescent pseudomonads, endospores, and actinomycetes, being most clear in the poor soils (Wardan) and less clear under iron excess at Ganoub El-Tahrir as well as the clay soils. Corn rhizosphere supported an array of antagonistic actinomycetes such as strains similar to Streptomyces intermedius, Streptomyces albidoflavus group, Streptomyces argenteolus group, and Streptomyces erythrogriseus. Intercropping potato with cabbage decreased the density of the pathogen in rhizosphere, which is associated with greater antagonistic fluorescent pseudomonads, Bacillus spp. and Serratia spp. Onion soil and rhizosphere associated with abundance of antagonists and fluorescent pseudomonads, followed by S. maltophilia and Bacillus spp. Wheat soil and rhizosphere supported fluorescent pseudomonads and antagonistic Streptomyces spp., especially in sandy soils. The pathogen was undetectable after planting the ending potato in the three districts, Wardan, Ganoub El-Tahrir, and Talia. This was accompanied by a general oligotrophism and increased ratio of fluorescent pseudomonads, endospores bacteria, and actinomycetes along with a diversity of R. solanacearum antagonists such as S. maltophilia, Citrobacter freundii, Acinetobacter sp., Delftia sp., and Serratia marcescens. [ABSTRACT FROM AUTHOR]

The new site is located in desert region of rugged topography. Quaternary boulders, gravels, sands and clays intercalation are the main rock types in the area. Geophysical evaluation of the subsurface lithology and structures using 2D and 3D electrical resistivity tomography (ERT) of the proposed site for construction was the main target of the present study, in addition finding empirical relationships between rock's electrical resistivity and some geotechnical parameters are also another target. Four geoelectrical resistivity layers were discriminated after the 2D inversion. Inspection of all 2D inverted profiles and 3D electrical resistivity depth slices showed rapid lateral and vertical variations in electrical resistivity values indicating heterogeneity in soil section. Clayey gravels or clayey sands and clays facies are predominant and hence swelling actions of the foundation beds is highly expected. The results of electrical resistivity tomography (ERT) were correlated with that inferred from the boreholes within the investigated area. The geotechnical parameters: liquid limit L.L%, plastic limit P.L%, free swelling F·S% and density Qu were calculated for representative samples collected from drilled boreholes. All samples showed considerably high L.L%, low to moderate P.L% with high F·S% which characterizes clayey soil. A trial for finding empirical relationships between the geotechnical properties and the rock electrical resistivity (L.L%, P.L%, F·S% and Qu) were carried out. These relations revealed that there is a considerable correlation between them when the rock has a resistivity more than 400 Ω m and poor correlation when the electrical resistivity is less than 400 Ω m. Accordingly, inferring applicable empirical equations between rock electrical resistivity and geotechnical parameters can be strong in the dry successions with a limited clays content, but in the wet or clayey soil materials the correlation will be weak and risky in application. From all obtained results and relationships, highly engineering awareness should be taken into account during establishing any construction in this site. • Establishing a new building needs high awareness by subsurface geologic features. • The results show rapid resistivity variation indicating heterogeneity in soil/rock. • Empirical equations between resistivity and geotechnical parameters were calculated. • The equations show a good correlation when the soil/rock has resistivities >400 Ωm. • The correlation is strong in dry sequences with limited clay and moisture contents. [ABSTRACT FROM AUTHOR]