Doses Of P2O5 Research Articles

An Analysis of the Effects of Phosphorus Solubilizing Bacteria (PSB) on Phosphorus Intake to Increase Groundnut Productivity

Background: Groundnut (Arachis hypogaea L.) is a self-pollinated, auto-tetraploid legume crop with 2n=40 chromosomes and belongs to the family Fabaceae. Microbial inoculant Azotobacter (Azotobacter chroococcum), Bacillus (Bacillus subtilus) and Pseudomonas (Pseudomonas sps.) were applied @ 250 g/acre. Consortium comprised of 3 microbial inoculants/strain @ 166.0 each for 500 g per acre Methods: For in depth studies field experiment on PSBs along with two doses of P2O5 were carried out during two consecutive Kharif season in 2020 and 2021 on SG99.The use of phosphate solubilizing bacteria as inoculants simultaneously increases P uptake by the plant and crop yield. Strains from the genera Pseudomonas, Bacillus and Azotobacter are among the most powerful phosphate solubilizes. Result: Results revealed that the different treatments of recommended dose and double dose of PSBs exerted their significant effect on initiation of flowering, 50% flowering, completion of flowering and days to maturity.

Adjusting Irrigation and Phosphate Fertilizer to Optimize Tomato Growth and Production

The efficient use of phosphate fertilizers and optimization of the amounts of irrigation water can maximize tomato growth and fruit production. This study aimed to evaluate the effects of different phosphorus (P) doses and sources on the growth and production components of tomato plants of the cultivar Gaúcho Melhorado Nova Seleção subjected to different irrigation water percentages. To achieve this, we set up an experiment using a factorial design to test the effects of four doses of P2O5 (corresponding to 25%, 50%, 100%, and 200% of the recommended dose), two P sources (monoammonium phosphate—MAP and organomineral—OM), and four irrigation water percentages (50%, 75%, 100%, and 125% of field capacity). Tomato plant growth improved when water was supplied at a percentage close to 100% of field capacity, with increased plant height, leaf length, and number of flowers observed (increases of 11.95%, 7.33%, and 13.87%, respectively, compared to 50% of field capacity). However, both excess and deficit irrigation resulted in morphological changes in tomato plants. Additionally, we observed that OM was more effective than MAP in increasing plant diameter and number of flowers, with increases of up to 36.4% and 227.6%, respectively, when using OM. Conversely, tomato growth was negatively affected by higher doses of MAP doses, suggesting that 25% of the recommended dose may yield the best growth rates. We verified that tomato plants can compensate for low phosphorus doses by increasing productivity with higher water amounts (125%–42.40 t ha−1), but high phosphorus doses result in greater fruit production with lower water percentages (50%–41.52 t ha−1).

Brackish Water, Phosphate Fertilization and Trichoderma in the Agronomic Performance of Beet Crops

The study hypothesis proposes that the use of Trichoderma, associated with fertilization with 100% of the recommended phosphorus, may mitigate saline stress and maximize the productivity and quality of the tuberous root. This study aims to evaluate the mitigating effects of phosphate fertilization and Trichoderma harzianum in beet plants under salt stress, by measuring the initial growth, leaf gas exchange, productivity and quality of the beet. The experimental design used was entirely randomized, in a 3 × 2 × 2 factorial scheme, referring to three doses of phosphate fertilization (25%, 50% and 100%), with and without the use of Trichoderma-based inoculation, and two levels of electrical conductivity of the irrigation water (0.5 and 6.2 dS m−1). Salt stress negatively affected the leaf area of the beet. The shoots’ dry mass was reduced as the electrical conductivity of the irrigation water increased, especially in the treatment with the 25% P2O5 dose. Salt stress reduced photosynthesis to a greater extent at the 25% P2O5 dose and in the absence of Trichoderma harzianum. Increasing the electrical conductivity of the irrigation water reduced transpiration and increased leaf temperature at the 25% P2O5 dose and in the presence of Trichoderma harzianum. The 25% P2O5 dose increased the stomatal conductance of the beet. The higher electrical conductivity of the irrigation water negatively affected water use efficiency, most significantly at the 25% P2O5 dose. Our data showed that the doses of 50% and 100% P2O5 were more efficient at increasing the productivity and quality of the beet, with the tuberous root diameter being higher under the lower electrical conductivity of the water and the absence of Trichoderma harzianum. The pH was high under the lowest electrical conductivity of the water, with a dose of 25% P2O5 and the absence of Trichoderma harzianum.

Impacto de la fertilización con biocarbón y SiO2 en el desarrollo del banano

El banano necesita muchos nutrientes, lo que lleva a los agricultores a depender de fertilizantes químicos que dañan el suelo. Una solución es combinar abonos orgánicos con fertilizantes químicos en menor cantidad. En este marco, el objetivo fue medir el desarrollo de un cultivar de banano en varios tratamientos de biocarbón más dosis fija de SiO2, KNO3 y P2O5. El biocarbón (BC) se obtuvo del raquis del banano a una temperatura de 350 °C por 2 horas. En el ensayo se evaluaron 10 plantas por tratamiento que se conformaron por dosis por planta de: 100 g de BC + 100 g SiO2, 20 g de BC + 100 g SiO2 y 100 g SiO2 (parcela testigo). Estas dosis se aplicaron en la semana uno, ocho y 14 del ensayo. La dosis de fertilizantes para todos los tratamientos se conformó de 75 kg ha-1 KNO3 + 50 kg ha-1 P2O5, y que se aplicaron 15 días antes que la dosis de biocarbon y en la semana seis del ensayo. El estudio demostró que el tratamiento con 20 g de biocarbón fue el más efectivo en términos de altura de la planta y circunferencia del pseudotallo, superando al tratamiento con 100 g y al control. Asimismo, el tratamiento con 100 g de biocarbón mostró el mayor peso de racimo en comparación con los otros tratamientos. Los tratamientos con biocarbón, silicio y fertilizantes tuvieron un efecto en las plantas de banano superior a la fertilización química, lo que sugiere su potencial aplicación en la agricultura.

Arbuscular mycorrhizal fungi and phosphorus affect Araucaria angustifolia seedling growth

Symbioses between plants and arbuscular mycorrhizal fungi (AMF) provide many advantages, including a reduced need for fertilization. In this study, the effects of AMF inoculation and phosphorus application on the growth and nutritional status of Araucaria angustifolia seedlings were evaluated. The treatments included inoculation with AMF (Gigaspora margarita, Rhizophagus intraradices, Acaulospora colombiana, Acaulospora scrobiculata, or Dentiscutata heterogama), inoculation with a mixture of AMF in 100 g of 50-year-old araucaria forest soil, application of two doses of P2O5 (25 or 100 mg kg-1), and the control. A completely randomized design was used, with seven replicates per treatment. The growth parameters, macronutrient and micro-nutrient contents, root colonization, and mycorrhizal effects on the extracted nutrients were evaluated at 75 and 150 d post germination. Analysis of variance, correlations, and principal component analysis (PCA) were used to evaluate that data. Inoculation with AMF had favorable effects on growth parameters, root colonization, and the extraction of macronutrients and micro-nutrients. In particular, the mixture of AMF from the 50-year-old araucaria forest soil, R. intraradices, and A. colombiana were beneficial. Similarly, the application of 25 mg of P2O5 significantly affected the growth of A. angustifolia seedlings compared to other treatments and increased the efficiency of root colonization.

Fontes alternativas de fósforo na produção de beterraba visando ao sistema orgânico

ABSTRACT The demand for beet produced in the organic system has increased. This study aimed to evaluate the beet production with the use of different proportions of phosphorus sources. A randomized block design was used. The treatments were established in a 6 x 2 + 1 factorial arrangement, corresponding to 6 proportions of the phosphorus fertilizers Yoorin® thermophosphate (YT) and bone meal (BM) (100 % of P2O5 with YT; 80 % of P2O5 with YT + 20 % of P2O5 with BM; 60 % of P2O5 with YT + 40 % with BM; 40 % of P2O5 with YT + 60 % with BM; 20 % of P2O5 with YT + 80 % with BM; and 100 % of P2O5 with BM), 2 doses of P2O5 (180 - recommended - and 360 kg ha-1) and 1 control without these phosphorus fertilizers. The plant height, number of leaves, root and shoot fresh and dry weight, transverse and longitudinal root diameter and total root yield were evaluated. The recommended fertilizer dose resulted in higher values, when compared to twice the recommendation. The proportion of 0 % of thermophosphate and 100 % of bone meal provided the highest mean values for the evaluated parameters. High phosphorus doses showed to be harmful to beet production.

Application of Bacillus spp. Phosphate-Solubilizing Bacteria Improves Common Bean Production Compared to Conventional Fertilization.

The use of phosphate-solubilizing bacteria (PSB) can be a sustainable strategy to increase phosphorus availability and promote satisfactory crop yields. The objective of this study was to evaluate whether inoculation with PSB in common bean increases (i) growth, (ii) nutrition, (iii) yield, and (iv) grain quality, and (v) reduces the chemical phosphorus application dose to obtain maximum yields. The experiment was conducted in an Oxisol using a randomized block design in a 4 × 4 factorial scheme, with four replicates, using the cultivar IAC 2051. The first factor was four doses of P2O5 (0, 20, 40 and 60 kg ha-1), and the second factor was four doses of PSB (0, 100, 200 and 300 mL ha-1). For leaf area and leaf chlorophyll content, the association of PSB inoculation with a P2O5 dose of 40 kg ha-1 promoted the best conditions for the common bean. P2O5 application increased yield by 79 kg ha-1 for each 10 kg ha-1 added. PSB inoculation at a dose of 192 mL ha-1 promoted P export of 15.3 kg ha-1, and the PSB dose of 159 mL ha-1 increased yield by 389 kg ha-1 (12%) compared to the control. Grain quality remained within the standards required by the consumer market, being little affected by the treatments. Improvements in common bean growth and nutritional and physiological status promoted by P2O5 application and PSB were essential in increasing yield, so these are sustainable production strategies.

Requirement of phosphorus and its use efficiency by sunflower (Helianthus annuus L.) in high phosphorus soils

Field experiments were conducted during kharif 2008, 2009 and 2010 to find out the phosphorus requirementto sunflower crop grown in a soil with high initial available phosphorus (110-119 kg P2O5/ha). Three years pooled data revealed that application of 100% recommended dose of P2O5(RDP) resulted highest seed yield of 12.18 q/ha. The seed yield increased significantly by about 9.51, 11.75, 12.50 and 13.62 per cent due to application of 25 (11.74 q/ha), 50 (11.98 q/ha), 75 (12.06 q/ha) and 100 (12.18 q/ha) per cent RDP, respectively over control (10.72 q/ha). However, the differences in seed yields observed at 50, 75 and 100% RDP are narrow and imperceptible. The per cent phosphorus derived from fertilizer (% Pdff) and phosphorus-use efficiency decreased significantly from 21.10 to 19.93 per cent and 24.19 to 6.67 per cent, respectively due to increase in P level from 25 to 100% RDP, whereas the fertilizer P uptake and soil P uptake increased from 1.58 to 1.75 kg/ha and 5.93 to 7.03 kg/ha, respectively with increase in P level from 25 to 100% RDP. The extent ofsaving in P fertilizer in these soils is ranged from 75 to 100 per cent depending upon the P build up in the soil.

Development of Soil Test based Fertilizer Prescription Equation Using Integrated Nutrient Management Approach for Targeted Yield of Maize Crop in a Vertisol of Chhattisgarh Plain, India

Field experiments were conducted at the research farm of Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.) during kharif 2021, and kharif 2022. To study the fertilizer requirement and. Yield performance a regression model was performed to evaluate the variation between yield and fertilizer and found that fertilizer N contribute 87% and 88% (R2 value 0.87,0.88). When applied through NPK variation found about 91 % and 90% (R2 value 0.91, 0.90), for recommendation of fertilizer prescription a ready reckoner was prepared based on these equations for a range of soil test values and for yield targets of 50,60 and 70 q ha-1 for maize, it was found that for a soil test value of 200 kg ha-1 of KMnO4 -N the fertilizer N doses required 91 kg ha-1, 133 kg ha-1 and 175 kg ha-1. For a soil test value of 12 kg ha-1 of Olsen-P, the dose of fertilizer P2O5 required for the yield target was 33 kg ha-1,48 kg ha-1 , 63 kg ha-1 respectively. Similarly for a soil test value of 250 kg ha-1 of NH4OAc-K the fertilizer K doses required 54 kg ha-1, 72 kg ha-1, 91 kg ha-1.

Combined Phosphorus and Water stress Conditions Induce Negative Mycorrhizal Response in Maize (Zea mays L.)

Arbuscular mycorrhizal fungi (AMF) confer both positive and negative effects on the plant symbionts, depending on the prevailing growth condition. We investigated the effect of concurrent variations in phosphorus and soil moisture on percentage root colonization (%RC), mycorrhizal growth response (MGR) and drought response index (DRI) of SAMMAZ-16 maize variety in timescale. The experimental factors were AMF inoculation (addition or no addition), P2O5 applications (30, 60 or 90 kg ha-1) and water regimes (100% and 50% of the soil’s field capacity introduced after 4WAS). The result shows that the overall %RC was 62.22% at 8 weeks after sowing (WAS) and 71.33% at 12 WAS. With 30 and 60 kg P2O5 ha-1 application a rate, %RC was significantly higher at 12 WAS than that of similar application rates at 8 WAS. However, %RC was not different between 8 WAS and 12 WAS in 90 kg P2O5 ha-1 application. AMF inoculation tended to equilibrate the shoot growth of the inoculated plants to that of non- inoculated plants that received 50% higher doses of P2O5 under amply watered conditions. Increasing phosphorus application progressively alleviated the negative mycorrhizal response of the plants at the early stage of growth (week 4) and in 50% FC category at the other sampling times. Higher doses of P2O5 application improved the DRI of the maize in both samplings but the trend was more consistent in AMF-inoculated plants. We conclude that AMF inoculation would be detrimental to the growth of SAMMAZ-16 when there is combined phosphorus and water stress factors

Phosphate Management for High Soybean and Maize Yields in Expansion Areas of Brazilian Cerrado

The low phosphorus (P) availability is considered one of the most limiting factors for suitable crop production in Brazilian Cerrado areas. We aimed to define the best P fertilizer management for maximum soybean and maize grain yield and minimum soil P adsorption in new agricultural areas. Two experiments were carried out in a Hapludox (pH 5.0) over six years. The first experiment evaluated five P fertilizer management (correction and maintenance): correction and maintenance at furrow; correction incorporated and maintenance at furrow; correction at furrow and maintenance broadcasted; correction and maintenance broadcasted; gradual correction (five years) and maintenance at furrow. The second experiment evaluated doses of P2O5: 0, 60, 120, 180, 240, 300 kg ha−1 year−1 applied at furrow or broadcasted. The P correction incorporated (0–20 cm) and maintenance at furrow resulted in higher yield and soil labile P. The yield increased up to 250 kg ha−1 of P2O5, and soil P fractions linearly increased, independent of application mode. Thus, the best P management would be full correction incorporated in bulk soil and maintenance at furrow; initial P correction (up to 250 kg ha−1 of P2O5) is essential in new Cerrado areas. These results are useful for orientating P management decisions in new sustainable agricultural systems.

Effect of Rock Phosphate, Single Super Phosphate and Phosphorus Solubilizing Bacteria on Phosphorus Concentration and Dry Matter Yield of Paddy

The majority of tropical and subtropical soils are acidic which are mostly deficient in phosphorus and have strong phosphorus sorption capacity. Exploring different phosphorus inputs is essential not only to increase crop production but also to improve soil phosphorus status to avoid further soil degradation. Acidic nature of the soils of these regions help to solubilize the rock phosphate and increases the amount of phosphorus that is made available to the plants. A pot experiment was conducted in Department of Soil Science and Agricultural Chemistry of College of Agriculture, Central Agricultural University, Imphal (Manipur) during kharif season of 2021 to study the effect of rock phosphate, single super phosphate and phosphorus solubilizing bacteria on phosphorus concentration and dry matter yield of paddy. To each experimental pot, recommended dose of 60 kg of N ha-1 in the form of urea and 30 kg K2O ha-1 in the form of muriate of potash were applied as basal and thoroughly mixed with the soil. Rock phosphate and single super phosphate were administered to the pots as phosphorus sources according to different sets of treatment based on the recommended amount of 40 kg P2O5 ha-1 for paddy. Seeds were treated with Bacillus megatherium. Result revealed that the changes in soil phosphorus concentration and dry matter yield of paddy were significantly affected by rock phosphate applied either singly or in combination with single super phosphate and phosphorus solubilizing bacteria. All the parameters showed different trend of changes during the whole crop growth stages till harvest. Among the treatments higher values were recorded in soil treated with T10 (50% recommended dose of P2O5 from single super phosphate + 50% recommended dose of P2O5 from rock phosphate + phosphorus solubilizing bacteria). Addition of phosphorus solubilizing bacteria enhances release of less soluble and fixed forms into easily available form as well as reduces phosphorus fixation. Efficiency of rock phosphate as phosphorus source for crop production is improved by the solubility effect of phosphorus solubilizing bacteria.

Phosphorus fractions and their relationships with soil chemical attributes in an integrated crop-livestock system under annual phosphates fertilization

The main factors affecting phosphorus (P) availability in soils are mineralogy, acidity, and concentration of elements in the soil solution. Moreover, P fertilizer sources and amounts can affect P cycling and adsorption of this element on colloids. In this research, we hypothesized that the use of phosphate sources of different solubilities can alter soil P adsorption process, due to chemical compositions of these sources and, in ICLS, the soil-plant-animal system can change the P forms distribution on soil profile and its interactions with the soil chemical attributes. To examine these hypotheses, a field experiment was conducted over 5 years, under a Haplic Cambisol, in an incomplete factorial scheme, with the treatments being composed of three P sources (triple superphosphate, rock phosphate—Arad and magnesium thermophosphate), three doses of total P2O5 (60, 120, and 180 kg ha−1) plus a treatment without application of phosphate fertilizer. Phosphate applications occurred annually, broadcast without incorporation, at the time of sowing the annual winter forage, in a crop rotation system that included pasture in autumn-winter and grain crops in spring-summer. Soil samples were collected at depths of 0 to 5, 5 to 10, 10 to 15, 15 to 20, and 20 to 30 cm and evaluated by Hedley P fractionation and the soil chemical attributes were quantified. The use of different phosphates applied broadcast without incorporation did not influence the concentrations of soil P fractions over a 5 year study. Phosphate fertilizer doses above 120 kg ha−1 of total P2O5 increased moderately labile and non-labile P fractions. The highest concentration of labile P was found up to 15 cm soil depth. It was found that P lability is strongly associated with calcium and total organic carbon concentrations in the soil profile. High concentrations of basic cations and sulfate in the soil solution increased moderately labile and non-labile P fractions. The complexity of ICLS interactions to maintain phosphorus dynamics in the soil was shown to be an intricate P release/adsorption process associated with soil chemical attributes.

Effects of nano guano, nano phosphate rock, and SP-36 fertilizers on maize growth and phosphorus uptake in inceptisol

Nanotechnology fertilizers are fertilizers associated with objects measuring 1 nm to 100 nm capable of controlling or manipulating at an atomic scale. Phosphorus is one of the essential nutrients needed by plants in large amounts. Maize is a strategic commodity requiring optimal nutrients. Inceptisol is soil that has relatively low fertility and chemical properties. The addition of P nutrients to the soil plays an important role in improving soil quality. This study aimed to compare the types of P fertilizers of nano guano, nano phosphate rock, and SP-36 with various doses of P2O5 and determine the most effective type. This research was arranged in a completely randomized design (CRD) with two factors. The first factor is the type of fertilizer, consisting of nano guano, nano phosphate rock, and SP-36. The second factor is the dose of P2O5 with four treatment levels, namely 0 kg.ha-1, 50 kg.ha-1, 100 kg.ha-1, and 150 kg.ha-1. The results showed that nano phosphate rock was the most effective fertilizer for maize in Inceptisol. The optimum dose of P fertilizer was 100 kg.ha-1, which was able to produce the highest plant height (215.67 cm) and phosphorus uptake (0.4765 g/plant).

Phosphorus availability in an Oxisol in pastures grown in Southern Brazilian Amazonia

The objective of this study was to verify and compare the P availability in an Oxisol cultivated with Megathyrsus maximus cv BRS-Zuri and Urochloa decumbens cv Basilisk and to predict the best soil P extractor in pastures in Southern Amazonia. Two experiments were carried out, one with BRS-Zuri grass and the other with Signal grass. The experimental design was randomized blocks with five doses of P2O5 based on the maximum capacity of adsorption of P (MCAP), corresponding to 0, 3, 6, 12 and 24% MCAP, with doses 0, 54, 108, 216 and 432 kg ha-1 of P2O5, with four replicates. In each cut of the grasses were determined the dry mass, the accumulation of leaf P and by the Mehlich-1 and resin extractors verified the available P. There were effects of P2O5 doses on the variables analyzed in both grasses. The appropriate class of P by Mehlich-1 was 14.6 mg dm-3 (BRS-Zuri) and 7.2 (U. decumbens) mg dm-3, by the resin extractor was 20.5 mg dm-3 (BRS-Zuri) and 14.40 mg dm-3 (U. decumbens). The resin extractor yielded the highest correlation indexes between PR and soil P content.

Phosphate Fertilization and Mycorrhizal Inoculation Increase Corn Leaf and Grain Nutrient Contents

The agricultural use of arbuscular mycorrhizal fungi, such as Rhizoglomus intraradices, can increase the efficiency of phosphate fertilization for the benefit of the corn plant and grain nutrition. In this study, a field experiment was conducted in an area of Selvíria/MS, Brazil, in the years 2019 and 2020, to verify the effects of reduced doses of phosphorus combined with the inoculation of corn seed with R. intraradices on corn plant growth and grain nutrient contents. The experiment was laid in a randomized block design in subdivided plots with four repetitions and twenty treatments resulting from combining five doses of P2O5 (0%, 25%, 50%, 75%, and 100% of the recommended dose) with four doses (0, 60, 120, and 180 g ha−1) of an inoculant containing R. intraradices. Leaf and kernel macro- and micronutrient contents were evaluated. The foliar P content in 2020 was a function of the interaction between phosphate fertilization and AMF inoculation, with the highest leaf P content observed at the 100% of P2O5 combined with AMF inoculation between 120 and 140 g ha−1. In the grains Mg content, an interaction was observed between the two factors in 2020 and the response surface, showing that the highest Mg content was obtained when maximum doses of P2O5 and maximum doses of inoculant were combined. A response surface showed that, in 2020, the highest leaf Zn content occurred when 35–55% P2O5 is applied with no inoculation and when P2O5 is limited to 20–30%, and there is inoculation with doses between 90 and 150 g ha−1. Phosphate fertilization increased foliar K (2019) and Mg (2020) contents, with maximum points at doses of 76.57% and 88.80%, respectively.

Bean nutrition and development in the function of reduced phosphorus doses and inoculation with arbuscular mycorrhizal fungus

It is widely accepted that mycorrhizal fungi increase phosphate fertilization efficiency. The objective of this study was to evaluate the effects of reduced phosphorus applications and inoculation with arbuscular mycorrhizal fungi (AMF) on the nutrition and initial growth of the carioca-type common bean (Phaseolus vulgaris L). The study was conducted at the Faculty of Engineering of Ilha Solteira, in the city of Ilha Solteira/SP, Brazil, where there was temperature and humidity monitoring as well as irrigation control. The experimental design was randomized blocks with a 5 × 2 factorial scheme and four replications. The treatments consisted of a combination of five doses of P2O5 (0%, 25%, 50%, 75%, and 100% of the recommended dose for beans) applied during sowing, with or without inoculation with AMF - Rhizophagus intraradices - at 200 g ha−1. The root volume, root dry matter, dry mass of the aerial part, and the concentration and accumulation of macro- and micronutrients in the aerial part were evaluated. Inoculation with AMF enhanced the root system, growth of the aerial part, and absorption of most nutrients, resulting in greater nutrient accumulation and increased phosphorus absorption. The combined inoculation and phosphate treatments increased the concentration and accumulation of nutrients in common beans.

Effect of NPK fertilization on the chemical properties and bioactive compounds of the cabezona pineapple fruit

Objective: To evaluate the effect of NPK fertilization on the chemical properties and bioactive compounds of the cabezona pineapple fruit. Design/methodology/approach: 15 NPK fertilization treatments were evaluated and carried out in the field in a random complete block design with four repetitions per treatment. At the end of the crop cycle, we determined the pH, °Brix and citric acid % of the fruits that were harvested, following the methodology established in NMX-FF-028 and 011. The pH of the juice was measured directly using a potentiometer. Ascorbic acid was measured with a SIGMA-ALDRICH® kit, the total polyphenol contents were determined following the methodology of De la Cruz-Ricardez et al. (2020), while total flavonoid contents were measured following a modified version of the methodology proposed by Hossain et al. (2011). Results: The mean values for °Brix, citric acid %, and pH were 7.3, 7.1 and 3.4 respectively, without significant differences between treatments. A highly significant difference in the concentration of ascorbic acid was observed between treatments; treatment three had the highest concentration (19.4 mg 100 g-1 FF). There were no significant differences between the fertilization treatments and the control, regarding total polyphenol content (41.34 mg 100 g-1 FF) and flavonoids (1.6 mg 100 g-1 FF) concentrations. Study limitations/implications: The ripening degree of the pineapple fruit directly influences the chemical properties and the concentration of bioactive compounds. Findings/conclusions: NPK fertilization had no effect on °Brix and pH. The citric acid percentage and the total polyphenol content increased as the doses of P2O5 increased. The ascorbic acid concentration and total flavonoid content are not affected by the NPK fertilization dose.

Residual Influence of Nitrogen, Phosphorus and Potassium Doses on Soil and Eucalyptus Nutrition in Coppice

The management of fertilizer is an important strategy for better nutrition and productivity of eucalyptus. Therefore, the objective of this research was to evaluate the isolated residual effect (carryover) of N, P and K fertilization on macro- and micronutrients in soil, leaf litter, leaf nutritional diagnosis and initial growth attributes of eucalyptus in a coppice system. Three experiments were carried out in a randomized block design with five replications. Experiment 1: four residual doses of N (0, 70, 105 and 140 kg ha−1) were applied as ammonium nitrate. Experiment 2: four residual doses of P2O5 (0, 40, 70 and 100 kg ha−1) were applied to plantations in furrows using triple superphosphate. Experiment 3: four residual K2O doses (0, 90, 135 and 180 kg ha−1) were applied as potassium chloride. The residual N doses did not influence leaf nutrient contents and initial growth of eucalyptus; however, increasing P residual doses increased soil P and Zn content, litter K content, decreased leaf Mg content, and increased initial growth (height and wood volume of eucalyptus). The residual K doses increased leaf litter K content and leaf Mn and Zn content but decreased leaf litter Ca, B and Fe and leaf Mg content. Residual potassium fertilization did not significantly influence the initial growth of eucalyptus in the Brazilian Cerrado.

Dry Matter Production and Nutrient Uptake of Coloured Capsicum Hybrids (Capsicum annuum var. grossum L.) as Influenced by Different Irrigation Levels under Shade Net

Aim: The experiment was aimed at evaluating the influence of different irrigation levels on dry matter production and nutrient uptake of coloured capsicum hybrids.
 Study Design: Split plot design with three replications
 Place and Duration of Study: Horticultural farm, College of Agriculture, Rajendranagar, Hyderabad during rabi 2018-19.
 Methodology: The experiment was laid out in split plot design and the treatments comprises of four irrigation levels viz., drip irrigation at 0.4, 0.6, 0.8 and 1.0 Epan as main treatments and three hybrids viz., Indra (green), Orobelle (yellow), Bomby (red) as sub treatments and replicated thrice. The recommended dose of nutrients were 100:80:60 N, P2O5 and K2O kg ha-1 and entire dose of P2O5 was applied as basal, N and K2O was applied through venturi meter as fertigation on three days interval from 9 to 153 DAT. The crop was transplanted at 45 cm × 40 cm spacing in September under a green shade net. Irrigation scheduling was done based on daily evaporation data recorded from USWB class ‘A’ pan evaporimeter. The cumulative daily evaporation during crop growth period was 737.5 mm. Quantity of water applied including special operations of 26 mm and effective rainfall during crop growth period were 245.3, 392.0, 546.5 and 698.5 mm and 58.6, 64.2, 74.6, 82.6 mm out of 127.4 mm of rainfall for 100, 80, 60 and 40 per cent irrigation treatments, respectively as per water balance method. Bed size was 7.6 m × 0.9 m.
 Results: Significantly higher yield (47.50 t ha-1) was recorded with drip irrigation at 1.0 Epan than rest of the treatments. Indra recorded significantly higher yield (40.27 t ha-1) than other two hybrids. The interaction effect between drip irrigation levels and hybrids was not significant on Dry Matter Production and N, P & K uptakes and economics of capsicum. DMP and nutrient uptake were significantly higher with drip irrigation at 1.0 Epan than 0.8, 0.6 and 0.4 Epan throughout the crop growth over other drip irrigation levels. Among hybrids, Indra recorded significantly higher DMP and nutrient uptake than other two hybrids.