Cucumber Growth Parameters Research Articles

Evaluation of Biochars against Fusarium oxysporum f. sp. radicis-cucumerinum and their Impact on Growth Parameters of Cucumber in Pot Condition

The present study was conducted under greenhouse conditions to evaluate the efficacy of biochars prepared from different plant parts against the pathogen Fusarium oxysporum f. sp. radicis-cucumerinum causing root and stem rot of cucumber. Three types of raw materials were used to prepare the biochars (Eucalyptus wood, citrus wood, and greenhouse waste). The prepared biochar was collected and filled into pots at four concentrations (1%, 2%, 3%, and 4% W/W). All biochars were effective in reducing the incidence of the disease up to 3% concentration with minimum mortality (4.17%) obtained with Eucalyptus wood (EW) + Citrus wood (CW) + Greenhouse waste (GHW). The biochars also positively influenced the plant growth parameters like seed germination, root length, and shoot length. Maximum shoot length 7.73 cm and root length 12.10 cm was observed with 3% Eucalyptus wood (EW) + Citrus wood (CW) + Greenhouse waste (GHW) biochar treated seeds.

Synthesis and surface morphology of banana biochar-based nano-fertilizer and its effect on first stages of growth parameters of cucumber, broccoli, and red okra

Smart agro-practices over the years have revolutionized the agriculture sector and promoted the concept of sustainable agriculture. One such practice is use of agro-waste biochar in agricultural, environmental, and climatic operations. The viability of using a biochar-based nanocomposite as a support fertilizer for the gradual release of nitrogen, potassium, and phosphorus in various media is examined in this study. The banana peel biochar (BPBC) and its nanocomposite (BNF) were prepared using a simple yet comprehensive chemical process. Synthesized materials were evaluated using FT-IR and SEM/EDX. Physical attributes as well as fertilizer basic characteristics were determined and prepared nanocomposite demonstrated noticeably better water absorbance ratio (68%), equilibrium water content (78.97%), and swelling ratio (3.64 g g−1) than biochar, which is advantageous for preserving soil water levels. The salt index values (0.087mmhos/cc) of the created nanocomposite performed better when compared to the conventional fertilizers due to their safer application. Long-term availability of all doped minerals to the plants, during experimental cycle, was revealed by slow-release nutrient studies in water and soil, which is ideal for promoting germination and growth. The findings of this research revealed that prepared BNF showed improved germination parameters i.e., time for 50% germination (3.4, 3.3, 4.4 days), germination index (3.1, 3.5, 2.4), final germination percentage (91.7, 100, 83.3%), mean germination time (4.0, 3.9, 4.9 days), for cucumber, broccoli and okra, respectively. In addition to that the prepared BNF facilitated enhanced shoot and root length in all the three vegetables as compared to conventional fertilizers. The dose optimization studies depicted that best results of germination as well as plant growth parameters are facilitated by BNF (37.5 kg/ha) owing to enhancement in soil quality by supplying additional organic matter in addition to provision of nutrients on slow-release.

Management of Root-Knot Nematode with Non-Chemical Methods for Sustainable Production of Cucumber under Protected Cultivation

The multi-faceted benefits of growing crops under protected cultivation are gradually establishing it as a promising technology for vegetable cultivation in India. However, the adoption of successive cropping patterns in soil-based closed structures is leading to the buildup of soil-borne pathogens and pests, which are becoming a major hindrance to the sustainable production of these crops, particularly in the northern plains. Root-knot nematodes (RKNs) are a critical threat to protected cultivation and farmers are required to contribute a significant amount of time and money for their management. To reduce the overdependence of chemicals, the present study explored the potential of plant-based by-products as amendments for the management of RKN in cucumbers grown under a plastic greenhouse. A pot trial was conducted to assess the efficacy of different plant-based amendments against nematodes in cucumber plants. The pot trial results revealed that the application of mustard cake (MC) and neem cake (NC) at 1 t ha−1 either alone or as a combined application with farmyard manure (FYM) of 2.5 t ha−1 was effective against RKN infestation, reflecting the improved plant growth parameters of cucumber. Based on the results of the pot trials, treatments with plant-based amendments and FYM i.e., T1: MC 1 t ha−1; T2: NC 1 t ha−1; T3: FYM 2.5 t ha−1; T4: MC 1 t ha−1 + NC 1 t ha−1 + FYM 2.5 t ha−1, along with the treated check carbofuran 3 G 2 kg (a.i.) ha−1 (T5) and untreated check (T6), were evaluated in multi-locational field trials. The results revealed that the combined application of MC 1 t ha−1 + NC 1 tha−1 + FYM 2.5 t ha−1 exhibited promising results in decreasing RKN infestation (56–58%) in all of the three RKN-infested polyhouses, with significantly enhanced yields at all of the three locations. Soil organic carbon also increased significantly in the amended plots, indicating improved soil health. The results of the present work hold good promise for the management of RKN in the protected cultivation of cucumber with an environment friendly approach, along with the additional incentives of improved soil health.

Isolation of Bacillus aryabhattai GW320 from the Cucumber Rhizospheric Soil and Evaluation of Plant Growth Promoting Activity

Currently, as part of eco-friendly agriculture in Korea, useful agricultural microorganisms are provided to farmers through 141 agricultural technology centers nationwide. In particular, there are very few cities and counties agricultural technology centers are using indigenous and patented microorganisms. Thus, this study was aimed to isolate Bacillus aryabhattai GW320 from soil rhizosphere of cucumber cultivation and to estimate the effect on the growth promoting effect of cucumbers. As a result, the GW320 strain showed robust plant growth-promoting rhizobacteria (PGPR) activities such as plant growth promoting hormone, nitrogen utilizing activity, and urea solubilizing activities. Furthermore, in comparison with control group, the strain increased plant height 22 to 33% and leaf width by 7 to 9% in cucumber, and elevated plant inorganic components. In addition, when the results of cucumber growth promotion, plant inorganic components, and soil properties were analyzed, the optimum microbial treatment concentration the isolate GW320 was found to be the best when the stock solution was diluted 100 times, and 1.0 × 107CFU mL-1. Concluding remark of this study is that this indigenous strain isolated from rhizosphere of cucumber in Gunwi-gun promoted growth of cucumber, suggesting the importance of indigenous bacterial strain scientifically confirmed in terms of eco-friendly treatment in agricultural field. Various growth parameters of cucumber after 4 weeks according to treatment of B. aryabhattai GW320.

UTILIZATION OF SOLAR ENERGY IN GREENHOUSE HEATING DURING WINTER SEASON IN EGYPT

The main aim of this study is to investigate the utilization of solar energy as a renewable energy source and compared to the traditional energy in greenhouses heating during winter season. To achieve that study, the effect of two different heating systems (Traditional heating (G1) and solar heating (G2)) on the cucumber growth parameters during growth period and cucumber fruit characteristics and total yield were investigated. Temperature and relative humidity during the growth season were recorded. The obtained results indicated that the indoor air temperatures ranged from 18.78 to 25.29 and 18.00 to 25.15 ᵒC for G1 and G2, respectively, whereas the outdoor air temperature ranged from 11.00 to 21.66 ᵒC. The temperatures were added by using electrical (G1) and solar energy (G2) for greenhouse heating ranged from 1.5 to 9.3 and 0.85 to 7.78 ᵒC, respectively, during experimental period. The indoor relative humidity ranged from 63.33 to 88.67 and 70.93 to 93.94 % for G1 and G2, respectively, whereas the outdoor air relative humidity ranged from 45.93 to 92.73 %. The plant length, stem diameter and total leaf area values for cucumber grown in G1 were higher than those of the plant growth in G2. The fruit length was 24.79 and 19.44 cm for G1 and G2, respectively. The fruit diameters were 3.36 and 3.19 cm for G1 and G2, respectively. The results also indicate that the fruit weight and number of fruits per plant were 115.07 and 108.73 g and 19 and 17 for G1 and G2, respectively. The total yield values of cucumber were 182.09 and 152.92 kg for G1 and G2, respectively, during growth period.

Nano-selenium, silicon and H2O2 boost growth and productivity of cucumber under combined salinity and heat stress

The production of cucumber under combined salinity and heat stress is a crucial challenge facing many countries particularly in arid environments. This challenge could be controlled through exogenous foliar application of some bio-stimulants or anti-stressors. This study was carried out to investigate the management and improving cucumber production under combined salinity and heat stress. Nano-selenium (nano-Se, 25 mg L-1), silicon (Si, 200 mg L−1) and hydrogen peroxide (H2O2, 20 mmol L−1) were foliar applied on cucumber plants as anti-stress compounds. The results revealed that studied anti-stressors improved growth and productivity of cucumber grown in saline soil regardless the kind of anti-stressor under heat stress. The foliar application of nano-Se (25 mg L−1) clearly improved cucumber growth parameters (plant height and leaf area) compared to other anti-stressor and control. Foliar Si application showed the greatest impact on enzymatic antioxidant capacities among the other anti-stressor treatments. This applied rate of Si also showed the greatest increase in marketable fruit yield and yield quality (fruit firmness and total soluble solids) compared to untreated plants. These increases could be due to increasing nutrient uptake particularly N, P, K, and Mg, as well as Se (by 40.2% and 43%) in leaves and Si (by 11.2% and 22.1% in fruits) in both seasons, respectively. The potential role of Si in mitigating soil salinity under heat stress could be referred to high Si content found in leaf which regulates water losses via transpiration as well as high nutrient uptake of other nutrients (N, P, K, Mg and Se). The distinguished high K+ content found in cucumber leaves might help stressed plants to tolerate studied stresses by regulating the osmotic balance and controlling stomatal opening, which support cultivated plants to adapt to soil salinity under heat stress. Further studies are needed to be carried out concerning the different response of cultivated plants to combined stresses.

Fusarium oxysporum Isolates Collected from the same Geographical Zone Exhibited Variations in Disease Severity and Diversity in Morphological and Molecular Characters

Thirty Fusarium oxysporum f. sp. cucumerinum (FOC) isolates were collected from Kafr El-Sheikh governorate, Egypt to study their pathogenic variability and genetic diversity. All isolates caused the typical symptoms of wilting with different severity degrees and reduced cucumber growth parameters and crop productivity under greenhouse conditions. We have classified the isolates to different groups based on pathogenicity, morphological characters, disease quantum degrees and genetic variation. The polymorphisms obtained from RAPD and protein profiles revealed a high degree of genetic diversity and their cluster analysis was matched with the results obtained from the pathogenicity. Previously it was believed that the different collection regions of the same pathogen isolates were the cause for their pathological and morphological differences, and there was no genetic variation can be occurring between isolates as long as they were collected from the same place. In our results, the genetic diversity of FOC isolates proves that the genetic variation of fungus isolates can occur in the same geographical location.

Biological control of root knot nematode, Meloidogyne incognita, in vitro, greenhouse and field in cucumber

Aspergillus flavus, Penicillium chrysogenum and Pochonia chlamydosporia as culture filtrates applied alone and in combinations in vitro and in planta green house and field studies against M. incognita using cucumber cultivar “Beith alpha”. In vitro study conducted on M. incognita, cumulative percent hatch inhibition and J2s mortality of M. incognita reached to 100% over 72 h of incubation in spring, 2014 and 2015 by fungal bio-agent combination viz., P. chrysogenum + P. chlamydosporia. All the fungal bio-control agents significantly suppressed M. incognita on cucumber in green house and field trials. The fungal bio-control agent combination viz., P. chrysogenum + P. chlamydosporia had the greatest effects on nematode galling indices, egg masses and adult females per 10 g of cucumber roots and substantially reduced the reproductive factors in both year greenhouse experiments. Field trials conducted under natural field infestation at Dargai, filtrates of the fungal bio-agent combination P. chrysogenum + P. chlamydosporia reduced the nematode parameters and enhanced the plant growth parameters of cucumber in the spring, 2014 and 2015 years trials with attendant yield increase. These data suggest that filtrates of fungal bio-agents viz., A. flavus, P. chrysogenum and P. chlamydsporia could be used alone or in different combinations in an integrated pest management as an effective strategy for M. incognita.

Exogenous priming of chitosan induces upregulation of phytohormones and resistance against cucumber powdery mildew disease is correlated with localized biosynthesis of defense enzymes

In recent years, exploration of biopolymer-based materials to avoid hazardous chemicals in agriculture has gained enormous importance for sustainable crop improvement. In the present study, chitosan a biopolymer derived from crab-shell was used in different concentrations as priming agent to cucumber seeds and were evaluated for its effect to enhance plant growth parameters as well as its ability to induce resistance against powdery mildew disease. Among the treatments, seeds-primed with 2.5 mg/mL exhibited early seedling germination of 90% and vigour of 2665 and also remarkably enhanced the cucumber growth parameters which might be fairly attributed to the stimulation of phytohormones content in primed plants over the controls. More importantly, under greenhouse conditions a significant induced disease protection of 66.6% against powdery mildew disease was noticed in chitosan-pretreated plants at 2.5 mg/mL. The induced resistant plants also showed a significant deposition of lignin, callose and H2O2. Notably, polyphenol oxidase, phenylalanine ammonia-lyase, peroxidase and glucanase defense-responsive enzymes were upregulated in chitosan-primed plants. Considered together, these results determine that the susceptible cucumber cultivar elicits immunity after perception of priming with chitosan to upregulate phytohormones and synthesize defense-responsive enzymes, thereby induce resistance against powdery mildew disease and strengthen the growth-promotion of cucumber plants.

The Influence of Colour and Thickness of Nylon Mulch on Soil Temperature, Moisture, Percent Germination and Some Growth Parameters of Cucumber (cucumis sativus L.) Seedlings

Heat, moisture and oxygen are important factors that has controlled seed germination, thus A 2 ×4 factorial greenhouse experiment was conducted to determine the influence of colour and thickness of nylon mulch on soil temperature, moisture, percent germination and selected growth indicators of cucumber (Cucumis sativus L.) seedlings in a completely randomized design (CRD), where the treatments; nylon colour (white and black) and thicknesses (0, 1.5, 3.0, and 4.5 mm) were replicated three times. The analysis of variance showed that the white nylon thickness had positive significant (P ≤ 0.05) influence on soil temperature, soil moisture, plant height and number of leaves, while black nylon thickness had positive significant (P ≤ 0.05) influence on soil moisture and plant height and a negative significant (P ≤ 0.01) influence on percent germination, it was also discovered that 1.5 mm thickness of the white nylon contributed significantly (p ≤ 0.05) to the parameters measured, therefore, white nylon of 1.5 mm thickness could be recommended as mulch material for cucumber production in a sandy clay soil.

Bacillus subtilis as a bio-agent combined with nano molecules can control powdery mildew disease through histochemical and physiobiochemical changes in cucumber plants

The effect of bio-agent Bacillus subtilus, nano titanium dioxide (TiO2) and Zinc oxide (ZnO) as well as the combination compared with fungicide (Topas100) was investigated under laboratory (in vitro) and greenhouse conditions against powdery mildew disease caused by Podosphaera xanthii. Most of treatments were strong to inhibit the spore germination of P. xanthii. B. subtilus and B. subtilus + nano-Tio2 were the most effective followed by Topas100, B. subtilus + nano-ZnO, nano-ZnO and Nano-TiO2 compared with control. Most of treatments significantly reduced the disease symptoms and diseases severity (%) particularly bio-agent, nano-ZnO and combination of B. subtilus + nano-ZnO, however, the fungicide treatment showed the best inhibition. As a consequence of treatments histo-biochemical and growth parameters of cucumber were changed. Reactive oxygen species (hydrogen peroxide and superoxide) were accumulated early. Chlorophyll content, catalase, peroxidase, and polyphenol oxidase activities were increased under various treatments, however, electrolyte leakage (EL) was decreased. The growth characters e.g. plant height, leaves number, fresh and dry weight/plant was significantly improved because of treatments. Combined of B. subtilus and nano-Zinc oxide treatment was the best treatment and promising to be an alternative to fungicide, consequently, decreasing the environmental pollution, cost and harmful effect of fungicide on human health.

Response of Fish Pond Effluent on Soil Chemical Properties and Growth of Cucumber (Cucumis sativus) in Igbariam South Eastern, Nigeria

The response of fish pond effluent on soil chemical properties and growth of cucumber (Cucumis sativus) in Igbariam South Eastern, Nigeria was studied during 2018 farming season at the Teaching and Research Farm of the Department of Soil Science, Faculty of Agriculture, Chukwuemeka Odumegwu Ojukwu University, Igbariam Campus, Anambra State, Nigeria. The field experiment which was laid out in a Randomized Complete Block Design (RCBD), comprised three treatments and three replications as follows: T1 – Control (No treatment): T2 – Fish Pond Effluent (40,000 litres/hectare) and T3 – Fish Pond Effluent (20,000 litres/hectare) + 200kg/ha fertilizer (NPK 20: 10:10). Results obtained revealed that, the treatments were significantly (P=0.05) different on some chemical properties of soil and Growth Parameters of Cucumber. The highest values of the Soil Chemical Properties (Available Phosphorus -6.6 mg/kg; Total Nitrogen -0.8g/kg; Organic Carbon – 5.8g/kg; Organic Matter – 10.1g/kg were recorded at the plot where Fish Pond Effluent was applied at the rate of 20,000 litres/hectare with 200kg/ha of fertilizer (NPK 20: 10:10). Fish Pond Effluent had no significant effect on the pH of the soil as the pH of the treated plots was almost at par with the Control. While the highest values of Number of leaves (37.9), Vine length (39.47cm) and Number of Branches (2.80) were also recorded at the plot where fish pond effluent was applied at the rate of 20,000L/ha with 200kg/ha of NPK fertilizer (20:10:10) at 7 WAP.

Impact of some industrial solid wastes on the growth and heavy metal uptake of cucumber (Cucumis sativus L.) under salinity stress

This study was conducted to investigate the effect of industrial solid wastes (ISWs) and salinity on growth and heavy metals uptake by cucumber (Cucumis sativus L.). The soil was treated with 5% and 10% of the ceramic factory (CFW), stone cutting (SCW) and sugar factory (SFW) wastes. Plant of cucumber was grown under greenhouse conditions in control and ISWs treated soils and stressed with electrical conductivities of 0, 4 and 8 dS m−1. Plants were harvested after 2 months and separated into root, shoot, and fruit. Then, dry weights and heavy metals contents in each fraction of plants were determined. The addition of all ISWs in soil increased total heavy metals content in the soil. In all treatments, growth parameters of cucumber decreased when irrigated with saline waters. As compared to control soil, the addition of CFW and SCW to soil decreased plant dry weight, while, it was improved with the addition of the SFW. The result of plant analysis showed that there was an increase in the contents of heavy metals (except Cr) in all parts of cucumber with the addition of ISWs. Salinity decreased the content of Zn uptake and increased another heavy metal uptake by all parts of the plants. The application of ISWs and salinity did not show a significant effect on bioconcentration (BCF) and transfer factor (TF) of heavy metals in plants. The health risk index (HRI) values of all heavy metals for both adults and children were found to be less than 1, so, the health risk of heavy metal for people who consume cucumber grown in these industrial areas was generally assumed to be safe.

Soil Chemistry and Cucumber (Cucumis sativus L.) Yield as Influenced by 16 Years of Composted Poultry Litter Addition

Poultry litter is increasingly used as organic amendment in market gardening in Côte d’Ivoire. To know about the sustainability of this practice, its impacts on soil quality should be known. This study aimed at assessing the effect on soil fertility of composted poultry litter addition for 16 years following two distinct ways, and identifying soil parameters driving cucumber yield. Trials were laid out in a Fisher randomized block design with 3 treatments replicated 5 times each: Control (C), Surface-applied compost (SAC) and Buried compost (BC). Soil (0-20 cm) chemical characteristics and cucumber growth and yield parameters were measured. Values of all parameters were higher with compost addition compared to the control, except for the C:N ratio. SAC and BC showed similar values of organic C, total N, CEC, pH and available phosphorus. However, Ca2+, Mg2+, K+ and base saturation were higher in SAC than in BC. Relative to values in the control, the greatest changes in soil parameters were observed with exchangeable cations, followed by soil organic matter. Soil organic C and total N concentrations have doubled in SAC while Ca2+, Mg2+, and K+ increased at greater rate (702.4, 400.9 and 186.67% respectively). Also, cucumber growth parameters were the highest with compost addition compared to the control. Significant effect of the compost application way on cucumber was also observed: collar diameter, leaf area and fresh fruit yield in SAC (0.72±0.02 cm, 258.9±12.3 cm2, 11.1±1.3 t ha-1, respectively) were higher than in BC (0.56±0.01 cm, 230.2±2.5 cm2, 5.4±0.5 t ha-1 respectively). Fruit yields in SAC and BC were four times and twice higher than in the control (2.6±0.3 t ha-1), respectively. Cucumber growth parameters were determined by soil concentration in Mg2+ while yield was determined by Ca2+. Composted poultry litter should be promoted for a sustainable soil fertility management in vegetable farming systems.

Effects of some micronutrients and macronutrients on the root-knot nematode, Meloidogyne incognita, in greenhouse cucumber (Cucumis sativus cv. Negin)

The effects of some micronutrients (iron, zinc and silicon) and macronutrients (nitrogen, phosphorus and potassium) were evaluated on the root-knot nematode, Meloidogyne incognita and plant growth parameters of cucumber (Cucumis sativus cv. Negin) in two independent trials. Each of iron, zinc and silicon micronutrients was used at 5 mg/kg of soil, as iron sequestrene (Fe-EDDHA), zinc sulfate (ZnSO4) and sodium siliconate (Na2O3Si), respectively. Furthermore, nitrogen at 60, 120 and 180 mg/kg, phosphorus at 25, 50 and 75 mg/kg and potassium at 12.5, 25 and 37.5 mg/kg of soil were used as urea, triple superphosphate and potassium sulfate, respectively. At four-leaf stage seedlings, 8000 nematode eggs and juveniles (2 egg and juveniles/gr soil) were added around the roots. After 60-days, data analysis indicated silicon + iron, significantly reduced the number of galls/g of root by 55 and 42% compared to control, in the two experiments, respectively, but none of these treatments resulted in significant positive effects on the growth or yield of the studied cucumber cultivar. When macronutrients were evaluated, results showed that N120P25K25 (120 mg/kg of Nitrogen, 25 mg/kg of phosphorus and 25 mg/kg of potassium) and N120P50K25 (120 mg/kg of nitrogen, 50 mg/kg of phosphorus and 25 mg/kg of potassium) significantly reduced the number of galls by 96 and 81% (experiment 3) and 79 and 70% (experiment 4) when compared with control, respectively. These both treatments also improved cucumber growth parameters such as shoot dry and fresh weights, root fresh weight and fruit yield.

Vinegar residue compost as a growth substrate enhances cucumber resistance against the Fusarium wilt pathogen Fusarium oxysporum by regulating physiological and biochemical responses.

Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cucumerinum (FOC) is the most severe soil-borne disease attacking cucumber. To assess the positive effects of vinegar residue substrate (VRS) on the growth and incidence of Fusarium wilt on cucumber, we determined the cucumber growth parameters, disease severity, defense-related enzyme and pathogenesis-related (PR) protein activities, and stress-related gene expression levels. In in vitro and pot experiments, we demonstrated the following results: (i) the VRS extract exhibited a higher biocontrol activity than that of peat against FOC, and significantly improved the growth inhibition of FOC, with values of 48.3%; (ii) in response to a FOC challenge, antioxidant enzymes and the key enzymes of phenylpropanoid metabolic activities, as well as the PR protein activities in the roots of cucumber, were significantly increased. Moreover, the activities of these proteins were higher in VRS than in peat; (iii) the expression levels of stress-related genes (including glu, pal, and ethylene receptor) elicited responses to the pathogens inoculated in cucumber leaves; and (iv) the FOC treatment significantly inhibited the growth of cucumber seedlings. Moreover, all of the growth indices of plants grown in VRS were significantly higher than those grown in peat. These results offer a new strategy to control cucumber Fusarium wilt, by upregulating the activity levels of defense-related enzymes and PR proteins and adjusting gene expression levels. They also provide a theoretical basis for VRS applications.

Nondestructive measurement method for greenhouse cucumber parameters based on machine vision

The use of machine vision technology for nondestructive online measurements of cucumber parameters was investigated. This technology was first used to capture images of a cucumber canopy. Next, a segmentation algorithm (excess green minus excess red (ExG-ExR)) was used to extract the cucumber canopy area and image parameters (i.e., coverage ratio, canopy length and canopy width). These parameters were combined with those obtained by manual measurements (i.e., stem height, stem diameter, leaf number, and fruit number) to generate five inversion models for four cucumber growth parameters. The results showed that the ExG-ExR segmentation method yielded a 99.5% contact ratio and a 98.2% recognition rate in the extraction of the cucumber canopy region. The inversion models were validated with new images using the following three different cultivation modes: 4 × 2, 4 × 3 and 4 × 4. The inversion results showed that the coefficients of determination (R2) between the measured values and inversion values of stem height, stem diameter, leaf number, and fruit number exceeded 0.921, 0.899, 0.95 and 0.908, respectively. Thus, the inversion method can provide nondestructive online measurements of cucumber parameters.

English

Scarcity of freshwater is becoming an increasing problem primarily in the arid and semi-arid regions of the world. The study was designed to investigate the effects of wastewater irrigation on soil properties and growth parameters of cucumber (Cucumis sativus) in southwestern Nigeria. The irrigation treatments consisted of kitchen wastewater, rainwater and groundwater in a randomized complete block design (RCBD) in three replications. Soil samples were collected in the 0 to 20 cm range, analyzed before irrigation application and after harvest according to USDA standard procedures while crop growth parameters were recorded 3, 5 and 7 weeks after planting. Soil pH decreased in all the soil samples after the different water applications, the lowest pH from kitchen wastewater. Electrical conductivity (EC) increased slightly in all soil samples, the highest EC value of 8.59 × 10-4 dS/m from groundwater irrigation. The sodium adsorption ratio (SAR) increased in all the irrigation treatments but was below the critical value of 13. The stem girth and leaf area were not significantly affected by water type (WT) during the three periods of evaluation but leaf numbers and plant length differ significantly at seven week of growth. Soil condition was not significantly impacted by the use of kitchen wastewater, however, appropriate wastewater treatment and water management practices have to be followed to remove the toxic elements which could be hazards to vegetable production and the environment. Key words: Wastewater, groundwater, electrical conductivity, sodium adsorption ratio.

Compensation effect of bacterium containing biofertilizer on the growth ofCucumis sativusL. under Al-stress conditions

Biofertilizers are used to improve soil fertility and plant production in sustainable agriculture. However, their applicability depends on several environmental parameters. The aim of our study was to evaluate the effect of free-living bacteria containing fertilizer on the growth of cucumber (Cucumis sativus L. cvs. Delicates) under aluminium (Al) stress. Different responses to Al stress of cucumber growth parameters were examined in terms of root elongation and physiological traits, such as Spad index (relative chlorophyll value), biomass accumulation of root and shoot, Al uptake and selected element contents (Fe, Mn, Zn, Mg) of leaves and root. The applied bacteria containing biofertilizer contains Azotobacter chroococcum and Bacillus megaterium. The dry weights of cucumber shoots and roots decreased in line with the increasing Al concentration. Due to different Al treatments (10-3 M, 10-4 M) higher Al concentration was observed in the leaves, while the amounts of other elements (Fe, Mn, Zn, Mg) decreased. This high Al content of the leaves decreased below the control value when biofertilizer was applied. In the case of the roots the additional biofertilizer treatments compensated the effect of Al. The relative chlorophyll content was reduced during Al-stress in older plants and the biofertilizer moderated this effect. The root/shoot ratio was decreased in all the Al-treatments in comparison to the control. The living bacteria containing fertilizer also had a modifying effect. The root/shoot ratio increased at the 10-4 M Al2(SO4)2 + biofertilizer and 10-4 M Al(NO3)3 + biofertilizer treatments compared to the control and Al-treatments. According to our results the biofertilizer is an alternative nutrient supply for replacing chemical fertilizers because it enhances dry matter production. Biofertilizer usage is also offered under Al polluted environmental conditions. Although, the nutrient solution is a clean system where we can examine the main processes without other effects of natural soils. The soil can modify the results, e.g. the soil-born microorganisms affect nutrient availability, and also can modify the harmful effects of different heavy metals. The understanding of basic processes will help us to know more about the soil behaviour.