Leaf Nutrient Composition Research Articles

Arbuscular mycorrhizal fungi inhibit necrotrophic, but not biotrophic, aboveground plant pathogens: a meta-analysis and experimental study.

Microbial mutualists can profoundly modify host species ecology and evolution, by extension altering interactions with other microbial species, including pathogens. Arbuscular mycorrhizal fungi (AMF) may moderate infections by pathogens, but the direction and strength of these effects can be idiosyncratic. To assess how the introduction of AMF impacts the incidence and severity of aboveground plant diseases (i.e. 'disease impact'), we conducted a meta-analysis of 130 comparisons derived from 69 published studies. To elucidate the potential mechanisms underlying the influence of AMF on pathogens, we conducted three glasshouse experiments involving six non-woody plant species, yielded crucial data on leaf nutrient composition, plant defense compounds, and transcriptomes. Our meta-analysis revealed that the inoculation of AMF lead to a reduction in disease impact. More precisely, AMF inoculation was associated with a decrease in necrotrophic diseases, while no significant impact on biotrophic diseases. Chemical and transcriptome analyses suggested that these effects may be driven by AMF regulation of jasmonic acid and salicylic acid signaling pathways in glasshouse experiments. However, changes in plant nutritional status and secondary chemicals may also regulate disease impact. These results emphasize the importance of incorporating pathogen life history when predicting how microbial mutualisms affect disease impact.

The Effect of Different Nutrient Management Practices on Yield and Leaf Nutrient Composition of Sweet Orange (Citrus sinensis L. Osbec)

The present study was carried out during three successive seasons. The experiment was laid out in Randomized block design (RBD) with thirteen treatments replicated four times to study the effect of different nutrient management practices on fruit yield and leaf nutrient composition. The result revealed that among the different treatments combination treatment (T13) with Application of NPK in 8 splits with drip irrigation + vermicompost @ 3 tonne ha-1 and biofertilizers i.e Azotobacter and PSB @ 2000 ml per ha and trichoderma @ 1 kg ha-1 + 8 spraying of Zn (0.5%), Fe (0.5%) and B (0.2%) found to be most effective in producing better yield and yield attributes. However, soil fertility as evident by changes in soil available N, P, K, S, Fe and Zn as well as leaf concentration of N, P, K, S, Fe, Zn and B significantly improved with combining application RDF, vermicompost and biofertilizer with or without fertigation along with foliar feeding of micronutrients viz. Zn, Fe and B.

Effect of Harvesting Stage and Drying Method on Cowpea Leaf Nutrient Composition

Cowpea leaves are lost annually due to infestation and spoilage when being transported to clients and the losses at the local markets are brought on by inadequate postharvest handling procedures and market glut, particularly during peak seasons. High moisture content from the cowpea leaves at harvest stage may contribute to increased spoilage hence lowering quantity and quality. The choice of appropriate harvesting stage and drying method can help to reduce this problem. The aim of this study was to determine the best harvesting stage and efficient drying method that would maintain high leaf nutrient composition. Cowpeas variety M66 was used for the research and the treatments included three harvesting stages (21, 35 and 49 days after sowing [DAS]), three drying methods (open sun, solar dryer and oven. Data was collected on iron, calcium, crude fibre, beta carotene, protein and moisture content. The data was subjected for variance using Statistical Analysis System 9.2 edition and significantly different means separated using least significant difference at 5%. The results indicated significant (p<0.05) differences in moisture, calcium, proteins, beta carotene and crude fibre content in both trials. Harvest stage and drying method did not significantly (p<0.05) influence the iron content. Oven and solar drying methods showed better nutrient and mineral retention in the three harvesting stages when compared to the open sun drying method.

Foliar Application of Growth Regulators and Nutrients for Better Quality Aspects of Guava Cv Lalit

The guava has tendency to bears flowers and fruits throughout the years but quality of fruits is highly influenced improper crop management practices and bahar season. The fruits of ambe bahar is poor in quality due to lack of nutrients availability and irregular orchard management practices. To carry out this new strategy to sustain the quality of guava through combination of nutrients and growth regulators, the present study was carried out during 2018-19 in 20-years-old orchard on mrig bahar season using foliar application of zinc sulphate (0.5%), borax (0.5%), GA3 (50 ppm), and NAA (40 ppm) either alone or in combinations, comprised of 9 treatments and 3 replications under Randomized Block Design. The results revealed that plants treated with 0.5% Borax along with 50 ppm GA3 significantly increased the leaf nutrient composition (1.09% leaf N, 0.014 % leaf P, 0.89% leaf K, 28.50 ppm Zn and 23.70 ppm B). The qualitative parameters of guava fruits also increased by borax and GA3, over untreated control.

Effect of Harvesting Stage on Cowpea Leaf Nutrient Composition

Effect of Harvesting Stage on Cowpea Leaf Nutrient Composition

Copper accumulation in five weed species commonly found in the understory vegetation of Mediterranean vineyards

Copper (Cu) concentration in agricultural soils often exceeds toxicological limits due to application of Cu-based fungicides. The potential of weeds for their use as functional cover plants in vineyard management and phytoremediation practices is little explored. We identified five weed species widely present in vineyards and assessed their Cu accumulation from eleven Mediterranean vineyards (soil Cu: 60–327 μg g−1) and two adjacent control sites (soil Cu: 15–30 μg g−1). Soils and plants were characterized by their physico-chemical properties and nutrient content. We applied multivariate techniques to analyze relationships between soil properties and leaf nutrient composition. Copper tolerance and accumulation traits were further tested in hydroponics using a series of CuSO4 concentrations (0.1–16 μM).Under field conditions, the highest Cu concentration in both roots and leaves were found in Lolium perenne (221 and 461 μg g−1, respectively), followed by Plantago lanceolata, Rumex obtusifolius and Taraxacum officinale (>100 μg g−1 Cu in leaves). Only one species, Trifolium repens, did not accumulate remarkable Cu concentrations. Overall, and as revealed by the multivariate analyses, leaf Cu concentration was driven by soil Cu content, soil texture, organic matter, nitrogen, and Cu uptake into roots. However, functional regression analysis and controlled experiments suggested that Cu might be additionally absorbed from the deposits on the leaf surface related to the Cu-fungicide treatments and soil dust. Our study highlights the importance of intra-specific variability in Cu accumulation among weed species in Cu-contaminated agricultural soils. Further validation of these findings under controlled conditions could provide essential insights for optimizing management and remediation strategies.

Foliar nutrition alleviate citrus plants from Asian citrus psyllid feeding by affecting leaf structure and secondary metabolism

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the primary vector of pathogenic bacteria disseminating Huanglongbing. Nutrients enhancement have been reported to be few optional methods to relieve Huanglongbing. However, limited studies have focused on the interactions between citrus plants and psyllid under nutritional enhancement. The present work was conducted to study psyllid feeding and psyllid feeding with nutrients enhancement. Our results suggested that psyllid feeding up-regulated the amino acid metabolism especial phenylalanine of leaf, which hence attracted more insect adults. Psyllid feeding significantly decreased palisade tissue pectin methylation but increased fibrous ring tissue, with increasing the concentration of different nutrients of leaves, resulted in an increased leaf thickness, leaf weight, and leaf dry mass per unit area. These changes facilitated psyllid feeding process, embodied in increased phloem ingestion and decrease in piercing process. While, foliar supply of nutrients affected the leaf nutrient composition, having cascading effect on down-regulation of amino acids mediated metabolism coupled with poor growth of palisade tissues, but accelerated the growth of fibrous ring tissues inhibited the ability of psyllid to recognize host, thereby, reduced the feeding efficiency of psyllid. Compared with the pesticide treatment, pesticide+nutrients treatment showed a higher reduction rate of psyllid population. Our study, hence, provided some evidences about behavior of psyllid under three distinct feeding environments, for insightful analysis of behavioral dynamics of psyllid feeding, an issue considered important for uncontrolled spread of Huanglongbing.

Differential elemental stoichiometry of two Mediterranean evergreen woody plants over a geochemically heterogeneous area

Leaf nutrient composition and stoichiometry reflect complex interactions of the plant with its environment and are useful traits to explore ecological processes and relationships. In the present study, the foliar elemental compositions of two common Mediterranean woody species, the evergreen broad-leaved Quercus ilex and the coniferous Pinus pinaster growing in an area of Central Italy known for geochemical and geothermal anomalies, were investigated. To assess the site-specific and age-dependent pattern of foliar composition and stoichiometry, macronutrients (C, N, P, K, Mg, S) and trace elements (Al, As, Ba, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Sb, V, Zn) were determined in leaves and needles of three different ages (6-, 12- and 24-month-old) collected from metalliferous (geothermal, mining) and rural areas. Leaves of Q. ilex showed comparatively high concentrations of micronutrients (i.e., Cu, Fe and Zn), while needles of P. pinaster accumulated significantly high concentrations of potentially toxic elements (i.e., As, Pb and S). No significant trend was found in elemental concentrations in relation to the age of leaves and needles. Multi-element stoichiometry of P. pinaster was driven by the geochemical heterogeneity of the sites, suggesting plastic adaptation at the sites with the most selective edaphoclimatic conditions (i.e., patches with nutrient poor and metalliferous soils). On the other hand, the content of both nutrients and potentially toxic elements in Q. ilex leaves varied little across the study area, reflecting stoichiometric stability; this is consistent with the ecophysiological features of Q. ilex as a late-successional species with a dominant role in the ecosystems of the Mediterranean area. Our findings demonstrate the value of foliar stoichiometric traits for understanding plant adaptation in a heterogeneous environment and also the consequences of biotic interactions during succession.

Bioagent consortia assisted suppression in grey blight disease with enhanced leaf nutrients and biochemical properties of tea (Camellia sinensis)

Microbial bioagents and botanicals contrastingly different in modes of action, and despite being used over the years, their comparative efficacy are not yet fully explored with regard to management of grey blight disease caused by Pseudopestalotiopsis curvatispora Petch in tea plantation of Assam, India. Four microbial antagonists-based formulations and seven botanicals at 2.5–10% concentration were tesed against mycelial growth of grey blight pathogen through dual culture assay and poisoned food technique, respectively, under in vitro conditions. Resultantly, two botanicals viz., Pongamia pinnata L. and Xanthium strumarium L. and two microbial bioformulations viz., Biometa as Metarhizium anisopliae and Biogreen as Trichoderma viride -based consortium of microbial antagonists were evaluated, singly and in combination through field studies in a grey blight affected 12-year -old tea plantation (grey blight susceptible clone TV-23) established on acidic Inceptisol with regard to suppression in grey blight disease incidence (PDI), green tea yield, culturable soil microbial population, leaf nutrients composition, and biochemical properties of tea. The consortium of microbial antagonists (Biogreen + Biometa) registered 11.34% higher suppression in grey blight disease at 4% concentration over combination of P. pinnata + X. strumarium at 10% concentration, both sprayed 5 times at 30 days interval in 150- days period, besides single microbial antagonist (Biometa) being inferior to consortium of microbial antagonists (Biogreen). Such a reduction in PDI resulted in 22.9% higher yield of green tea leaves with consortium of bioagents over botanicals due to significant elevation in soil culturable microbial population, and leaf nutrient composition. These responses were eventually associated with an improvement in biochemical properties (Polyphenols, caffeines, and antioxidants acivity) of tea. Our study, hence, provided both, in vitro and field evidence in favor of multipronged benfits of consortium of microbial antagonists for an extended control of grey blight disease of tea, a reliable alternative to conventionally used chemical fungicides towards tea health care with enhanced quality parameters.

Nitrogen and Phosphorus Fertilizers Improve Growth and Leaf Nutrient Composition of Moringa oleifera

Establishing the appropriate agronomic practices like fertilizer application is important for maximizing yield and improving nutritional quality of moringa (Moringa oleifera) leaves. The objective of the presented study was to determine the effects of nitrogen and phosphorus fertilizer rates on plant growth performance and leaf nutrient composition of moringa. The experiment was a 4 × 3 factorial, with four nitrogen levels (100, 200, 300, and 400 kg ha−1) and three levels of phosphorus (40, 80 and 120 kg ha−1). The experiment was laid out as randomized complete block design (RCBD), treatments were replicated four times. Twelve weeks after planting, the moringa trees treated with 100 kg N ha−1 and 80 kg P ha−1 were significantly taller by 46.8% than trees supplied with 400 kg N ha−1 and 120 kg P ha−1. Similarly, trees that received 100 kg N ha−1 and 80 kg P ha−1, and those treated with 200 kg N ha−1 and 80 kg P ha−1 had significantly greater stem diameter (>36%) compared to moringa trees that received 400 kg N ha−1 and 40 kg P ha−1. Crude protein was significantly higher by 26.3% in the 400 kg N ha−1 and 120 kg P ha−1 treatment combination than that of the 100 kg N ha−1 and 40 kg P ha−1 treatment combinations. Moringa trees that received 100 kg N ha−1 and 40 kg P ha−1 had the highest neutral detergent fiber content (30.71%), while the trees that received 400 kg N ha−1 and 120 kg P ha−1 had the lower neutral detergent fiber content of 22.77%. Based on the study, the combination of 100 kg N ha−1 and 80 kg P ha−1 can be recommended for maximum yield and nutritional content of moringa leaves.

The influence of organic, organo-mineral and mineral fertilizers on tree growth, yielding, fruit quality and leaf nutrient composition of apple cv. ‘Golden Delicious Reinders’

This work was carried out to obtain data about the vegetative growth, productivity, fruit external and internal quality and leaf nutrient composition of apple cv. ‘Golden Delicious Reinders’ from different fertilization regimes, with reference to their role in tree and fruit growth and development, especially for their specific recommendations. Organic, organo-mineral and mineral fertilizers were applied to soil during three consecutive years. Results showed that organo-mineral fertilizer called Italpolina (ITP) and N fertilizer called calcium ammonium nitrate (CAN) increased TPC, antioxidant activity, acidity, FW and D. Compound NPK induced the best values of SSC, TS and IS contents and TFC. Urea as a physiologically acidic N fertilizer mostly affected TS/TA and SSC/TA ratios. Interestingly, manure conditioned the best values of yield per tree and unit area and YE, while the greatest tree vigor was found in the control treatment (without fertilization). In paradox, the lowest tree growth was observed by CAN and compound NPK, i.e. fertilizers with high N contents. Compound NPK, organo-mineral ITP fertilizer and manure induced ideal balanced leaf nutritional values, followed by CAN and urea. Besides, it is highly important that experts and growers are encouraging the application and use of organic and organo-mineral fertilizers to increase soil fertility and its quality. Thus, the applied fertilizers behaved differently in terms of the impact on the tested properties. One improved agronomic properties, while the other improved pomological traits, nutritional value of fruits and the amount of elements in the leaf. However, cattle manure, organo-mineral Italpolina and compound NPK fertilizer could be recommended generally for fertilizing the ‘Golden Delicious Reinders’ apple on M.9 T337 in similar soil and climatic conditions. PCA can be a useful tool for segregation fertilizers that have the best influence on tree growth, productivity and apple fruit quality.

Increase in leaf organic acids to enhance adaptability of dominant plant species in karst habitats.

Estimation of leaf nutrient composition of dominant plant species from contrasting habitats (i.e., karst and nonkarst forests) provides an opportunity to understand how plants are adapted to karst habitats from the perspective of leaf traits. Here, we measured leaf traits—specific leaf area (SLA), concentrations of total carbon ([TC]), nitrogen ([TN]), phosphorus ([TP]), calcium ([Ca]), magnesium ([Mg]), manganese ([Mn]), minerals ([Min]), soluble sugars, soluble phenolics, lipids, and organic acids ([OA])—and calculated water‐use efficiency (WUE), construction costs (CC), and N/P ratios, and searched for correlations between these traits of 18 abundant plant species in karst and nonkarst forests in southwestern China. Variation in leaf traits within and across the abundant species was both divergent and convergent. Leaf [TC], [Ca], [Min], [OA], and CC were habitat‐dependent, while the others were not habitat‐ but species‐specific. The correlations among [TN], [TP], SLA, [TC], CC, [Min], WUE, [OA], and CC were habitat‐independent, and inherently associated with plant growth and carbon allocation; those between [CC] and [Lip], between [Ca] and [Mg], and between [Mg] and [WUE] were habitat‐dependent. Habitat significantly affected leaf [Ca] and thus indirectly affected leaf [OA], [Min], and CC. Our results indicate that plants may regulate leaf [Ca] to moderate levels via adjusting leaf [OA] under both high and low soil Ca availability, and offer new insights into the abundance of common plant species in contrasting habitats.

Efficiency of organic and bio-fertilization on reducing the rates of mineral fertilizers in Flame Seedless vineyards

This study was conducted during 2018, 2019 and 2020 seasons, on 10 years old Flame Seedless grapevines, grown on the experimental vineyard of Research Station Agriculture, EL-Matana, Esna, Luxor, Egypt to study the effect of organic and bio-fertilization on vegetative growth, nutrient status, and fruiting of Flame Seedless grapevines. The experiment was arranged in a complete randomized block design with seven treatments and three replications two vine per each. The obtained results could be summarized as follow: Using the recommended dose of nitrogen (RDN) via 50 or 25% mineral plus 50 or 75% or 50% organic and bio-form significantly increased, pruning wood weight, number of leaves/shoot and leaf area as well as leaf total chlorophyll and leaf nutrient composition compared to use RDN via mineral N fertilizer alone. No significant differences on these traits due to use RDN via 50% mineral plus 50 organic or bio, double form or 25% N plus 75 bio-form and triple born. All combined fertilization treatments significantly increased the yield and improved the cluster and berry traits compared to use RDN via mineral source only. It is evident from the foregoing results that double form 50% mineral plus 50% either organic or bio or triple form (25% N plus, 75 organic and bio.) improved the vegetative growth, yield and berry quality. In addition, it minimized the production costs and reduced environmental pollution.

Effect of some Antioxidants Spraying on Growth and Fruiting of Flame Seedless Grapevines

This study was conducted during 2018, 2019 and 2020 seasons, on 10 years old Flame Seedless grapevines, grown on the experimental vineyard of the Research Station, Matana, Esna, Luxor, Egypt to study the effect of antioxidants on vegetative growth, nutrient status, and fruiting of Flame Seedless grapevine. The experiment was arranged in a complete randomized block design with four treatments and three replications two vine per each. The obtained results could be summarized as follow: Spraying either citric acid, ascorbic acid or vitamin B12 significantly increased, pruning wood weight and leaf area as well as leaf total chlorophyll and leaf nutrient composition compared to spray water ones (check treatment). No significant differences on these traits due to spray with any ones compared to either. All antioxidants treatments significantly increased the yield and improved the cluster and berry traits compared to sprayed water. It is evident from the foregoing results that spraying with either ascorbic acid or citric acid or vitamin B12 at 250 ppm three times improved the vegetative growth, yield and berry quality.

Impact of Organic, Bio Fertilization and Humic Acid on Growth and Fruiting of Flame Seedless Grapevines under Sandy Soil Conditions

The present investigation was carried out during two successive seasons 2019 and 2020 on Flame seedless grapes cultivar grown in sandy soil at private farm, Naga Hamady, Qena Governorate, Egypt. Eight treatments of mineral N, humic acid, organic and biofertilization applied to study the effect of them on vegetative growth, soil nutrient status, and fruiting of Flame seedless grapevines. The experimental vines were arranged in a complete randomized design with eight treatments and three replications two vine per each. The obtained results could be summarized as follow: Using the recommended dose of nitrogen (RDN) via 25 to 50% mineral plus 25 to 50% Humic acid (HA) or compost and bio-mix significantly increased, leaf area, pruning wood weight, and leaf total chlorophyll as well as leaf nutrient composition compared to use RDN via mineral N fertilizer alone. All combined fertilization treatments significantly increased the yield and improved the cluster and berry traits compared to use RDN via mineral source only. The results of this investigation indicated that, most trace element and soil physical and chemical properties were increased with increasing the level of organic, bio fertilization and humic acid in studied soil. Also, it could be concluded that fertilized vines with 25 to 50% of nitrogen requirements plus HA or compost and bio-mix improved the vegetative growth and nutritional status, as well as, yield, cluster attributes and berry quality of Flame seedless grapevines under this experiment circumstances.

Missing association between nutrient concentrations in leaves and edible parts of food crops – A neglected food security issue

Crop nutrient deficiencies are determined based on leaf nutrient composition, and rarely on food composition. Consequently, it remains unclear whether leaf nutrients are useable to form conclusions on quality of produced foods. This study aimed to investigate the relationships between plant macro- (Mg, P, S, K, Ca) and micronutrient (Fe, Zn, Mn, Cu) concentrations of leaves and edible parts of three East African staple crops: Zea mays, Manihot esculenta, and Musa acuminata.Low phloem mobile nutrients Ca, Mn, Fe, Zn, and Cu showed the largest differences in correlations between leaves and edible parts. Perennial crops showed lower correlations between nutrient concentrations of leaves and edible parts than annuals. Leaves may provide information on plant health, however do not provide enough information to gauge both yields and food quality, particularly regarding micronutrients. Therefore, agricultural and nutritional scientists should harmonize methods to develop sustainable management options for increased food and nutrition security.

Determination of the Variability of Biophenols and Mineral Nutrients in Olive Leaves with Respect to Cultivar, Collection Period and Geographical Location for Their Targeted and Well-Timed Exploitation.

The interactive effects of cultivar, collecting period, and geographical location on the content and composition of biophenols and macro and micronutrients in olive (Olea europaea L.) leaf were investigated. Leaves of six cultivars were collected at three periods in two locations in Croatia. The leaves of Istarska bjelica cultivar had the greatest biophenol (oleuropein) potential, especially those sampled in January and in March at the location of Pag. All the cultivars yielded leaves with the highest concentration of biophenols in March, which coincided with the pruning period. Except for high oleuropein concentration in Istarska bjelica, flavonoids were found to be most useful for differentiating olive leaves according to cultivar. Verbascoside turned out to be the most potent differentiator of collecting periods, while phosphorus and zinc turned out to be most useful for differentiating locations. Despite different agroecological conditions at the two locations, cultivar exhibited a significant effect on olive leaf nutrient composition, which was certainly causally related to that of the biophenols. The results obtained showed that it is possible to plan more well-timed and efficient exploitation of biophenols from olive leaf based on the knowledge about the interactive effects of the three studied factors.

Biomass production and nutritional composition of Moringa oleifera under different planting spacings in a semi-arid condition of the northern South Africa

Moringa oleifera is an important plant with nutrients concentrated in the leaves. The leaves have high nutritional potential, which can contribute significantly towards human and animal nutrition. Therefore, the tree can feed communities when other foods are typically scarce. This study was conducted to evaluate the effect of planting density on biomass and nutritional composition of Moringa oleifera planted under the semi-arid conditions of the Limpopo Province. The study was conducted at Eiland (NBef Organic Farm) over two consecutive years, 2014–15 and 2015–16. The initial and post-planting physical and chemical properties of the soil at the site were carried out at depths of 0 to 30 and 30 to 60 cm. The experiment was established as a randomized complete block design and replicated eight times. The treatments included planting densities of 5 000, 2 500, 1 667 and 1 250 plants ha-1. Data collection included total dry matter yield, leaf yield (kg ha-1) and leaf nutritional composition. Results from the soil analysis revealed slight acidity and very low nitrogen content (0.08%) at all sampling depths before moringa establishment. In addition, excessive magnesium, manganese and copper contents in the soil were recorded. Soil properties such as phosphorus, potassium, zinc, copper, organic carbon and nitrogen were reduced after the first harvest. During the second harvest, similar soil nutrient reductions followed the same trend as compared to the first harvest except for phosphorus, which showed an increase as compared to initial soil sampling at the second harvest. During harvests 1 and 2, the increase in planting density resulted in increased biomass production. Planting densities also did not affect moringa leaf nutrient composition. The study showed that a population of 5000 plants ha-1 produced the highest biomass yield of more than 1.5 ton ha-1. This study also revealed that moringa contains a high level of leaf nutrients even under marginal production conditions, irrespective of the planting density. Key words: Biomass production, leaf nutritional composition, moringa, planting population

Evaluating the feasibility of human excreta-derived material for the production of hydroponically grown tomato plants - Part II: Growth and yield

Disposal of human excreta derived materials (HEDM), particularly domestic wastewater, presents a challenge in areas served with on-site sanitation systems, most particular in informal settlements. The use of HEDM for agricultural food production represents a couple of opportunities such as improved sanitation, household food security as well as the generation of informal income. In this study, tomato seedlings ‘Monica’ cv were grown in a hydroponic system and irrigated with HEDM (effluents from decentralized wastewater treatment system and nitrified urine concentrate). A commercial hydroponic fertilizer mixture was used concurrently as a control treatment. All the treatments were applied to the plants through fertigation using a drip irrigation system. Plant growth (plant height, stem diameter, leaf area index, root:shoot ratio and plant dry matter), physiological (photosynthesis and chlorophyll), yield components (fruit number, fruit mass, harvest index and crop yield), leaf nutrient composition (N, P, K, Mg, Ca, Cu, Mn, Fe, Zn and Na) and microbiological (Aerobic count, coliforms and faecal coliforms) parameters were measured to assess the potential of these HEDMs as nutrient sources for hydroponically produced tomatoes. The results showed that irrigating the tomatoes with HEDM increased harvest index relative to crops irrigated with a commercial hydroponic fertilizer mix. Tomato plants irrigated with a commercial hydroponic fertilizer mix achieved the highest growth and yield, however, irrigation with human excreta based sources improved plant physiological performance and leaf nutrient composition compared to crops irrigated with commercial fertilizer mix. In terms of microbiological analysis, tomatoes harvested from plants treated with HEDM recorded the highest population of bacterial count as compared to the commercial hydroponic fertilizer mix.These results showed that nutrients derived from human excreta can be a good source of nutrients for hydroponically grown tomatoes. Moreover this practice can effectively address the challenges of human waste disposal while at the same time providing the much-needed resources for increased food production through urban agriculture. However, further research on the effect of heavy metals, pathogens on tomato fruit quality is still needed for the adaptation of wastewater as nutrients sources for hydroponically grown tomatoes.

Standardization of Litchi Leaf Nutrient Composition for Tissue Analysis in Sub Tropics of India

ABSTRACTVariation in leaf nutrient composition with leaf age and position of leaflets was assessed for ‘Calcuttia’ and ‘Dehradun’ litchi cultivars under loam to sandy loam soils of north India. Leaf samples were collected from first to sixth pair of leaflets starting from the apex of terminal shoots to downward positions during December to May at monthly intervals at two locations for three successive years. The leaves were analyzed for N, P, K, Ca, Mg, Fe, Zn, Cu and Mn concentrations. In both litchi cultivars, leaf N, P, Zn and Cu contents remained more in young leaves; whereas, leaf Ca, Mg, Mn and Fe contents were observed higher in older leaves. Leaf K concentration exhibited inconsistent patterns; however, leaf K concentration in pair of leaflets on the shoot declined basipetal, being maximum in upper pair of leaflets and minimum in lower pair of leaflets. Levels of macro and micronutrients exhibited a degree of stability at second and third pair of leaflets when sampled during February–March. Leaf compositions differed significantly during active vegetative growth, flowering, and fruit development. The results revealed that 4–5 months old leaves from autumn flush at second and third pair of leaflets from the apex of terminal litchi shoots at the advent of panicle initiation (February–March) should be collected to assess the nutritional concentrations of litchi orchards under North India conditions.