EFFECT OF SOME TREATMENTS ON GROWTH, YIELD AND FRUIT CHEMICAL COMPOSTION OF MELON AND CUCUMBER CROPS UNDER SANDY SOILS CONDITIONS

Transcription

1 EFFECT OF SOME TREATMENTS ON GROWTH, YIELD AND FRUIT CHEMICAL COMPOSTION OF MELON AND CUCUMBER CROPS UNDER SANDY SOILS CONDITIONS By MAHMOUD ABD EL-HAMED MOHAMED FAHMY B.Sc. Agric. Sci (Vegetable Crops), Fac. Agric., Cairo Univ., 2007 THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE In Agricultural Sciences (Vegetable Crops) Department of Vegetable Crops Faculty of Agriculture Cairo University EGYPT 2012

2 APPROVAL SHEET EFFECT OF SOME TREATMENTS ON GROWTH, YIELD AND FRUIT CHEMICAL COMPOSTION OF MELON AND CUCUMBER CROPS UNDER SANDY SOILS CONDITIONS M. Sc. Thesis In Agric. Sci. (Vegetable Crops) By MAHMOUD ABD EL-HAMED MOHAMED FAHMY B.Sc. Agric. Sci (Vegetable Crops), Fac. Agric., Cairo Univ., 2007 APPROVAL COMMITTEE Dr. ABDALLA BARDISI AHMED Professor of Vegetable Crops, Fac. Agric., Zagazig University Dr. MERGHANY MOHAMED MERGHANY Professor of Vegetable Crops, Fac. Agric., Cairo University Dr. SAID ABDALLA SHEHATA Professor of Vegetable Crops, Fac. Agric., Cairo University Date: 30 /12 / 2012

3 SUPERVISION SHEET EFFECT OF SOME TREATMENTS ON GROWTH, YIELD AND FRUIT CHEMICAL COMPOSTION OF MELON AND CUCUMBER CROPS UNDER SANDY SOILS CONDITIONS M. Sc. Thesis In Agric. Sci. (Vegetable Crops) By MAHMOUD ABD EL-HAMED MOHAMED FAHMY B.Sc. Agric. Sci (Vegetable Crops), Fac. Agric., Cairo Univ., 2007 SUPERVISION COMMITTEE Dr. SAID ABDALLA SHEHATA Professor of Vegetable Crops, Fac. Agric., Cairo University Dr. YASSER MOHAMED AHMED Lecturer of Vegetable Crops, Fac. Agric., Cairo University Dr. YOUSSOF TALAT EMAM EL-LITHY.. Head Research of Vegetable Crops, Hort. Res. Inst., Agric. Res. Center

4 Name of Candidate: Mahmoud Abd El-hamed Mohmed Degree: M.Sc. Title of Thesis: Effect of some treatments on growth, yield and fruit chemical compostion of melon and cucumber crops under sandy soils conditions Supervisors: Dr. Said Abdalla Shehata Dr. Yasser Mohamed Ahmed Dr. Youssof Talat Emam El-Lithy Department: Vegetable Crops Approval: 30/12/ 2012 ABSTRACT This investigation was carried out at the farm of Agricultural Researches Station, Wadi El-Natrown Area, fac. Agric, Cairo Univ., during the two successive summer seasons of 2009 and 2010 aiming to investigate the effect of magnetic iron, humic acid, compost and amino acids with different using treatments on the growth and yield attributes of cucumber and melon plant. Vegetative growth parameters such as,plant length, number of internodes on the main stem, number of branches per plant, fresh and dry weights as well as number of leaves per plant were significantly affected by all applied fertilizer types treatments. Since, the untreated plants (control) scored the lowest values as compared with the treated plants. The highest scored plant length values of cucumber and melon were recorded with humic acid at 1.5g/L and compost at20 t/fed, respectively in the 1st and 2nd seasons. In both seasons, compost treatments resulted in the highest mean number of internodes on the main stem. The highest recorded number of branches and leaves per plant was associated with magnetic iron treatments in both seasons and all the applied fertilizers affected the mean number of leaves significantly without notable significant differences among them. The lowest scored average plant fresh weight was observed with humic acid 0.5g/L while dry weight was observed with the untreated (control). The application of humic acid, amino acid and compost especially the high concentration produced heavier plants than magnetic iron, while plants received amino acids spray application scored relatively high plant fresh and dry weights with non significant differences as compared with magnetic iron treatment. In both seasons, significant effect of fertilizers types on cucumber and melon yield traits under investigation was observed. The highest significant value of number of fruits per plant was observed with compost treatments of 20 t/fed. However, control plants gave the lowest significant value. The highest fruit weight was obtained by humic acid, amino acid and compost m treatment with significant differences between the other treatments in both seasons compered with magnetic iron. Amino acid and humic acid treatments showed significant differences in the average fruit yield per plant compered with control. Key words: Organic and inorganic fertilizers, vegetative growth, cucumber and melon

5 ACKNOWLEDGEMENT I wish to express my deepest thanks to my supervisor Dr. Said Abdullah Shehata Professor of Vegetable Crops, Faculty of Agriculture, Cairo University for not only the supervision but also his great support and help in my practical life. Also, I feel deeply grateful to Dr. YASSER MOHAMED AHMED Lecturer of Vegetable Crops, Faculty of Agriculture, Cairo University for sharing in supervision. Sincere thanks to Dr. Youssof Talat Emam El-Lithy Head Research of vegetable crops, Hort. Res. Inst. for his valuable advices, help, kind support during this work.. Thanks are also extended to the staff members of the Vegetable Crops Dept., Fac. of Agric, Cairo Univ. and Hort. Res. Inst., Agric. Res. Center for their help, encouragement, and the facilities provided during the work of this thesis. Special deep appreciation and feelings to the best family I have ever seen. My Father Adb EL-Hamed Mohmed for his support and gaudiness. My Mother Magda Sayed for every minute and second she gives to her family. Finally to My life and My Sibilings "Ghada, Sara and Ahmed "

6 INTRODUCTION Cucumber (Cucumis sativus) and melon (Cucumis melo) are among the most important vegetable crops grown in Egypt for local consumption and exportation. In year 2010, cucumber area was feddans that produced ton per fed, with a total production of ton, whereas melon area was feddans that produced ton per fed, with a total production of ton. (Egypt, Minsitry of Agric. Agric. Statistics, 2011). However, new reclaimed lands, that have sandy soil (Table 1), have many problems such as poor fertility, low holding capacity and high ph. The application of humic acid, compost, magnetic iron and amino acid to this type of soil may overcome these problems. Excessive application of chemical fertilizers may affect soil health and sustainable productivity. Addition of organic manure, which can supplement nutrient requirement of crops to some extent, releases nutrient in gradual and is controlled way allowing greater production of vegetables with minor environmental impact. It is imperative to search for possible alternate organic source that can sustain soil health and crop production. Humic acid from lignite is the most concentrated form of organic material and it is a ready source for carbon and nitrogen. Humic acid improves the physical, chemical and biological properties of the soil and influences plant growth (Adani et al., 1998). Among the different functional actions of humic substances is their ability to improve plant growth, which has been well established in diverse plant species and growth conditions (Chen and Aviad, 1990

7 and Chen et al. 2004). Compost is one of the most major sources of fertilization. The application of compost positively affects the structure, porosity, water holding capacity, compression strength, nutrient content and organic matter content of the soil (Mays et al., 1973; Pinamonti and Zorzi, 1996; Smith, 1996) consequently improves plant growth, crop yield and crop quality (Pinamonti and Zorzi, 1996; Rodrigues et al., 1996; Smith, 1996). The utilization of compost and manure in agriculture is an age old practice. However, during the green revolution, the high yielding varieties of used seeds required heavy nutrient input and chemical synthetic fertilizers largely superseded the use of organic materials. The extensive use of synthetic fertilizers is not without problems. Compost had positive effects on plant growth and yield due to their high organic matter content, which improved not only soil physical and biological properties, but also chemical characteristics resulting in more available nutrient elements (Gupta et al., 1995). The effects of magnetic field on living systems, particularly the effect on growth of plants, have been the objective of numerous researchers. Amino acids in soil can be utilized directly, but the differences of uptake, transport, metabolism and physiological effects showed in plant because of different amino acids. Amino acid can easily be decomposed by sunlight and it does not keep a poison remnant in soil and plant. Its degradation product can also serve as crop product, crop nutrients and improve the quality and yield of crops. Amino acid fertilizers can promote crop growth, strengthen resistance, improve soil conditions and increase crop yields. The 2

8 present study aimed to investigate the effects of different fertilizer treatments including magnetic iron, humic acid, compost and amino acids, at different rates, on the growth and yield attributes of cucumber and melon plants under sandy soil conditions. 3

9 REVIEW OF LITERATURE 1. Vegetative growth a. Effect of compost Compost has been used extensively in reclamation of marginal and low quality soils. It has the unique ability to improve soil properties and the growing medi a physically (structurally), chemi cally (nutritionally) and biologically. Addition of compost to soil improves soil structure and lowers bulk density. Compost enhances the environmental sustainability of agriculture by decreasing chemical inputs and increasing soil organic matter (Mathur et al., 1993). The application of organic matter can affect plant growth by providing the soil with various forms of nitrogen (N), as well as hormone-like compounds (Piccolo et al., 1992). Previously, plants were not believed to be able to take up organic N. However, recent studies have shown that plants can take up soluble organic N from organic matter, such as amino acids (N asholm et al., 2000), proteins (Yamagata and Ae, 1999; Matsumoto et al., 2000) and mixtures of soluble organic N compounds (Okamoto et al., 2003). Adding different organic compost to the soil caused remarkable improvement of different growth characters and yield of peppermint (Tara et al., 1996). Compost and organic matter contain nutrients that are not readily available for plant uptake, unlike inorganic fertilizers. Thus, soil microorganisms must break down the organic nitrogen into inorganic nitrogen through the biological process of mineralization (Zublena et al., 1991). The amount of nitrogen as soil contains and needs can be 4

10 estimated by the amount likely to mineralize over a given period of time, but studies have shown that crop rotations, green manures, corer cropping, compost application and allowable fertilizers can keep soil fertility at optimum levels (Zublena et al., 1991; Mader et al., 2002; Sanchez et al., 2003; El-Tarabily et al., 2003 and Adediran et al., 2004). Soil under an organic management system can retain nitrogen in the soil langer and uptake of nitrogen is more efficient.in times of drought or flooding, organic soils retained optimum nutrient status allowing crops to survive through harsh conditions (Hepperly., 2005). Increased soil organic matter leads to increased soil quality, and a system that uses organic amendments is promoting the formation of soil biomass (Saleque et al., 2003). Bayoumi. (2005) found that organic fertilizers combined with benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH) increased significantly vegetative growth characters of cucumber (stem length, number of leaves/plant, leaf area /plant and chlorophyll content) especially at the earlier stage of growth as compared to the control plants (chemical fertilizer only). Organic fertilizers such as compost, compost tea and seaweed extracts (Algean) combined with BTH increased significantly vegetative growth characters of cucumber (stem length, number of leaves /plant, leaf area /plant and chlorophyll content) especially at the earlier stage of growth as compared to the control plants (chemical fertilizer only). (Bayoumi and Hafez, 2006). There is no doubt that mixing compost with mineral fertilization and adding them to sandy soil will improve soil structure and 5

11 consequently improves vegetative growth of the plants as compared to using mineral fertilizer alone. Such fact was proved by Abo sedera (2006) who found, under the conditions of sandy soil, that using compost at 20 ton/fed + 50% of NPK gave, significantly, higher dry weight/plant, as compared to the recommended dose of NPK. Najm et al. (2010) found no significant differences between 150 kg mineral N+5 ton cattle manure/ha and using 20 ton cattle manure/ha + 50 kg mineral N concerning leaf area index and plant height. Mahmoud et al. (2009) evaluated the effect of three compost types (plant residues, animal residues and mixed) when mixed with mineral nitrogen fertilizers, on cucumber (Cucumis sativa) plants and soil properties. The results showed that the mature compost of plant residues was higher in saturation percent and lower in C/N ratio, ph, electrical conductivity and bulk density than the animal and mixed composts. The experimental results confirmed that the combination of organic and inorganic fertilizers could increase plant growth, yield, quality and soil fertility. It also confirmed that composted organic wastes can be used to substitute for around 25% of chemical nitrogen fertilizers. Compost fertilization of soil at a rate of 8 ton/fed, foliar application of humic acid at a rate of 1 g l/1, foliar fertilization of amino acids at a rate of 2 ml l/1 and their combinations were used on strawberry. The results from this study showed that plants of strawberries grown from compost-fertilized plots exhibited generally higher plant length and fruit weight (Shehata et al., 2011). On roselle plants, (Hibiscus sabdariffa L.) a study was 6

12 conducted to improve the vegetative growth, yield characters and antioxidant activity of plants growing under different organic and inorganic media conditions in response to the spray of amino acids, humic acids and micro elements. The results showed great similarity which had been noticed with the majority of the studied characters in both seasons. The highest values of plant height, number of branches per plant, stem diameter, fresh and dry weights of leaves and branches per plant, number of days to flowering, number of fruits per plant, fresh and dry weights of sepals per plant and seed yield per plant were obtained when the plants were grown in a soil mixed with compost at 3 t/fed or magnetic iron at 100 kg/fed and sprayed with humic acid at 2.0 cm/l in comparison with the rest of the treatments. The lowest values of the characters were noticed always with the mixture of compost or magnetic iron with amino acids or with micro elements, although these values were still higher than that of the compost or a single magnetic iron, or that of the control treatment in both seasons (Yasser et al., 2011). b. Effect of magnetic iron The effects of magnetic field on living systems, particularly the effects on growth of plants have been the objective of numerous researchers. The first studies were conducted by Savostin (1930) who reported 100% increase in the rate of elongation of seedlings under the influence of magnetic condition, Similan results were reported by Audus (1960), Pittman (1977) and Kavi (1983). Magnetic field was used widely as pretreatment for seeds to increase seed vigor, seedling growth and yield as found by Pietruszweski (1993) and Ahmet (2003). 7

13 Previous studies by them indicated that suitable magnetic treatment increased the absorption and assimilation of nutrients and ameliorated photosynthetic activities. Experiments on summer cultivation of cucumbers in a magnetic field were conducted to determine the optimum growth conditions using the well-known effects of magnetic fields on germination and growth of vegetables. Seed processing at 5 Oe for 72 hours had remarkable effects. Most of the seeds germinated in 30 hours. However, no appreciable difference was observed between seeds processed at 150 Oe for one hour, and seeds not processed in a magnetic field. Overall, cultivation in a magnetic field after processing in a low magnetic field for a long time provides the most favorable growth conditions (Yamashiro, 1987) Li-hua et al. (1999) studied the seed germination and plant growth of cucumber from magnetic field treated seeds. The results showed that magnetic field was favorable to seedling growth and it increased the enzyme activity in seeds. The experiments are to provide theoretical basis for magnetic field application in vegetable production. De Souza et al. (2005) studied the effects of pre-sowing magnetic treatments on the growth and yield of tomatoes (cv. Vyta), under field conditions. Tomato seeds were exposed either to a 120 mt dynamic magnetic field (induced by an experimental electromagnet) for 10 min or to a 80 mt field for 5 min. Non-treated seeds were used as controls. In the nursery stage, the treatments led to a significant increase in root length, fresh and dry root weight, stem length, fresh and dry stem weight, leaf area and foliole dry weight. During the 8

14 vegetative stage, the leaf, stem and root relative growth rates of plants derived from magnetically treated seeds were greater than those shown by control plants. De Souza et al. (2008) studied the influence of pre-sowing magnetic treatments on plant growth and final yield of lettuce (cv. Black Seeded Simpson) under organoponic conditions. Lettuce seeds were exposed to full-wave rectified sinusoidal non uniform magnetic fields (MFs) induced by an electromagnet at 120 mt (rms) for 3 min, 160 mt (rms) for 1 min, and 160 mt (rms) for 5 min. Non treated seeds were considered as controls. In the nursery stage, the magnetic treatments induced a significant increase of root length and shoot height in plants derived from magnetically treated seeds. In the vegetative stage, the relative growth rates of plants derived from magnetically exposed seeds were greater than those shown by the control plants. The effects of a stationary magnetic field on the germination and initial stages of growth of tomato seeds (Lycopersicon esculentum L.) have been studied. The seeds were exposed to a magnetic field strength (125 or 250 mt) for different times as different treatments (doses D1 to D12). To evaluate germination number of germinated seeds (G), mean germination time (MGT), and the time required for 1 to 90% of the seeds to germinate (T1, T10, T25, T50, T75, and T90) were determined. Parameter T10, which is closely related to the early germination and latent period of seeds, was reduced when seeds were exposed to a magnetic field. The MGT was also reduced compared to control when seeds were exposed to magnetic field The germination 9

15 parameters recorded for each treatment were lower than corresponding control values, then germination rate of treated seeds is higher than the control (Martínez et al., 2009). Ghasemnezhad et al. (2012) investigated the growth and productivity of cucumber plants of seeds in which affected by different magnetic fields. The soaked seed samples of cucumber were exposed to a 20 μt AC magnet field for 30 minute. Similar seed samples also were treated with DC magnetic fields of 5 μt for 30 min. To compare the effect of different magnetic fields, control samples with three replications were placed in gape out of magnetic field for 30 min. Results of study showed that the germination of seeds was significantly influenced by different magnetic fields depending on the days after treatment application. The first germinated seeds were observed two days after beginning of test in DC magnetic field (0.7 seed) treatment. At the last days of experiments (day ninth) no difference was observed among treatments. The growth behavior of seedling of cucumber affected by different magnetic field on compared with control plants in greenhouse showed that seeds in which treated with AC magnetic field had better growth rate. c.effect of amino acids Saeed et al. (2005) on soybean found that treatments of amino acids significantly improved growth parameters of shoots and fresh weight. Many studies reported that the foliar application of amino acids caused an enhancement in plant growth, fruits yield and its components (El-Shabasi, et al., 2005) on cucumber and Awad et al., 2007 on 10

16 potato). Amino acids are a well known biostimulant which has positive effects on plant growth, yield and significantly mitigates the injuries caused by abiotic stresses (Kowalczyk and Zielony 2008). Al-Said and Kamal (2008) showed that every plant like any organism needs certain components for growth, whereas the basic components of living cells is proteins. The main source of protein in plant tissues is urea as source of nitrogen, and/or the amino acids. The requirement of nitrogen of amino acids in essential quantities is well known as a mean to increase growth and yield for all crops. Furthermore, nitrogen and/or amino acids are the fundamental ingredients for the process of protein synthesis. d. Effect of humic acid Humic substances are generated through organic matter decomposition and employed as soil fertilizers in order to improve soil structure and soil microorganisms. Foliar sprays of these substances also promote growth, and increases yield and quality in a number of plant species (Brownell et al., 1987; Yildirim, 2007; Karakurt et al., 2009) at least partially through increasing nutrient uptake, serving as a source of mineral plant nutrients and regulator of their release (Chen and Aviad, 1990; Atiyeh et al., 2002). Likewise, humic substances have been shown to stimulate shoot and root growth and nutrient uptake of vegetable crops (Tattini et al., 1990; Padem et al., 1997; Akinremi et al., 2000; Cimrin and Yilmaz, 2005). To elucidate the effects of humic substances, several hypotheses suggested the formation of a complex between these substances and mineral ions, 11

17 their involvement in the enhancement of enzyme. The incorporation of humic acids, that had been extracted from either pig manure vermicompost or food wastes vermicompost, into soilless plant growth media, when all needed plant nutrients were supplied, increased the growth of both tomato and cucumber plants significantly, results which are in good agreement with those reported by Chen and Aviad (1990) and Tattini et al. (1990). Plant growth was increased consistently in the first experiment by treatments of the plants with mg/kg humic acids, but decreased significantly when the concentrations of humic acids in the container medium exceeded mg/kg. Furthermore, the root to shoot ratios of tomato seedlings increased significantly with increasing concentrations of humic acids in the soilless container medium, indicating greater resource allocation towards the roots than the shoots. The application of humic acid has been reported to improve plant growth, increase fruit yield and quality in squash plants. Hartwigsen and Evans (1997) reported that Cucumis sativus (cucumber), Pelargonium hortorum (geranium), Tagetes patula (marigold), and Cucurbita pepo (squash) seeds were sown into plug cells (5 ml volume) filled with a germination substrate containing peat, vermiculite, and perlite. After the seeds were sown, the substrate was saturated with solution containing 0 (deionized water) 2500, or 5000 mg/l humic acid (HA). Additional treatments included seeds which were sown into the substrate and saturated with nutrient solutions corresponding to the nutrient concentration of each humic acid 12

18 solution. Seeds were placed in a growth chamber and maintained at 22 C and under a 12-h photoperiod with a PPF of 275 μmol m 2 s 1. After 10 d for cucumber and squash and 14 d for marigold and geranium, plants were harvested and root and shoot fresh mass recorded. Shoot fresh mass was not significantly affected by treatment for any of the species tested. Except for squash, root fresh mass was significantly increased by humic acid treatments. For cucumber, root fresh mass ranged from 0.24 g in deionized water to 0.34 g in 2500 and 5000 mg/l HA. Geranium root fresh mass ranged from 0.03 g in deionized water and 5000 mg/l HA to 0.05 g in 2500 mg/l HA. Marigold root fresh mass ranged from 0.02 g in deionized water to 0.03 g in 2500 and 5000 mg/l HA. Root fresh mass for nutrient controls were similar to those for deionized water. Different reports indicated that HA treatments improved growth and some fruit characteristics of various plants including cucumber, tomato, eggplant and pepper (Adani et al., 1998; Dogan and Demir, 2004; Karakurt et al., 2009; Arancon et al., 2006; Yildirim, 2007) were confirmed in our study. El-Shabrawy et al. (2010) evaluate humic acid and Azotobacter and Azospirillum as bacteria fixing nitrogen along with nitrogen levels at 30, 60 and 90 kg N/fed. plus uninoculated plants under recommended N dose 120 kg N/fed., in addition to their interaction on growth, yield and chemical composition of cucumber plants. The results revealed that, humic acid at 0.5 % as soil application increased the vegetative growth expressed as number of leaves, plant height (cm), plant fresh and dry weight (gm) and leaf area (cm 2 ) and increased 13

19 significantly fruits/plant, plant yield (kg/fed.) Early and total yield (ton/fed.). Also, soil application of humic acid at 0.5 % had significant effect on nitrogen, phosphours and potassium. However, NO 3 in cucumber fruits was not significantly affected by humic acid. The interaction between humic acid and biofertilizers plus nitrogen levels had significant effect on all traits under study in both seasons. The effect of three levels of humic acid (0.0, 1, and 2 g/l) and three levels of seaweed extract (0.0, 2, and 3 ml/l) on cucumber cv. Carol growing inside plastic house were investigated. The results showed that spraying humic acid or seaweed extract led to positive significant differences in leaf area, leaves chlorophyll content, plant length, fruits number, early and total yield as well as fruit weight, fruit length, yield per plant, fruit dry weight, fruit chlorophyll content and TSS as compared to untreated plants (Mohammad, 2010). The interaction between humic acid and seaweed extract had significant effect on all detected traits, since cucumber plants received 2 g/l humic acid and sprayed with 3 ml/l of seaweed extract were characterized by the highest values of all growth and yield characteristics. 2. Yield and its component a. Effect of compost The increment in early yield by combining compost with mineral fertilizer may be attributed to that applying both types of fertilizers increased the biological activity in the soil which increased phytohormones, organic acids and uptake of macro and microelements by plants (Frankenberger and Arshad, 1995) to be enough for both 14

20 plant growth and fruit requirements. In this concern Abd El-Moniem et al. (2002), on cucumber, found that higher early. yield of cucumber was obtained under the conditions of using 75% chicken manure and 25% miner fertilizer. Additionally, Abd El-Aziz (2003), proposed that the superiority of using organic manure mixed with inorganic nutrient solution treatments for early yield of cantaloup may be a result from the balance between macro and microelements availability. Roe and Comforth (1997) reported that both uncomposted dairy manure at 15 t.ha -1 and dairy manure compost at 22, 45 and 90 t ha 1 increased yields of cantaloupe plants. Abou-Hadid et al. (2001) found that application of organic matter increased the early and final yield. The increase in cucumber fruit final fresh weight were 15 % over control. Yousry et al. (2006) reported that, organic fertilizers such as compost, compost tea and seaweed extracts (Algean) combined with benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH)) showed significant increase in the fruit yields as compared to the control plants. Most of the organic materials produced the highest cucumber early yield and fruit quality, but total yield was equal or less than the chemical fertilizers. Bayoumi et al. (2006) found that organic fertilizers combined with BTH elevated the ascorbic acid content (chemical quality of cucumber fruits) and decreased the nitrate content, which is very harmful, as well as increased the fruit yields as compared to the control plants. 15