Foliar Potassium Research Articles

Effect of Potassium Foliar Application and Fertigation on Biological Aspects and Plant Growth Biomass of PepperP (capsicum annuum). تأثير الرسمدة والرش الورقي للبوتاسيوم علي المکونات الحيوية والکتلة الحيوية للنبات الفلفل.

Two field experiments were carried out at a private farm, Damietta, Egypt to study the effect of foliar application and fertigation on the biological aspects as (plant height, number of leaves and root length and plant growth biomass (i.e., fresh and dry and shoot/root ratio and relative growth rate) as well as chlorophyll contents of pepper. Four foliar potassium treatments ((K0 (control), K1; 2kg fed-1 , K2; 4kg fed-1, and K3; 6kg fed-1) ) combined with three fertigation treatments (K0 (control), K1; 66kg fed-1 K2; 132kg fed-1) were arranged in a split-plot design with three replicates. The results showed that plant height and root length increased significantly by potassium fertigation and foliar application compared to the control. In contrast, potassium fertigation and foliar application had no significant effect on leaf area and leaf area index in both seasons. Pepper fresh and dry weights decreased by increasing K fertigation compared to the control, while potassium foliar application (K-leaf) significantly increased pepper fresh and dry weights with increasing potassium compared to the control except with the treatment of 6 kg fed-1 in both seasons. Potassium fertigation and foliar application had no significant effect on chlorophyll A, B, total carbohydrates and total phenols. While vitamin C increased by increasing potassium fertigation. The treatment of 50% in the recommended dose recorded the highest vitamin C values in both seasons and the potassium foliar application with K- leaf at the rate of 4 kg k fed-1 gave the highest vitamin C values in both seasons.

Influences of girdling and potassium treatments on fruit quality and some physiological characters of ‘Fremont’ mandarin variety

Abstract Growing citrus involves cultural treatments such as girdling and foliar potassium treatment to increase fruit size, yield and quality. The aim of the study was to evaluate the effects of single and double stem girdling, potassium nitrate (KNO3) treatment on leaves and combinations of these treatments on the fruit yield, size and quality characteristics, leaf chlorophyll concentration and leaf nitrogen content, leaf fluorescence (PSII) and leaf sugar content of the ‘Fremont’ mandarin variety. Girdling treatments were applied on the stem by removing 4 mm wide ring of bark at the end of anthesis and after the June fruit drop. Foliar KNO3 applications were applied at a concentration of 4% twice (90 days and 120 days after full anthesis) in the experiment. The single girdling (SG) and double girdling (DG) treatments on stems increased fruit yield (kg · tree−1) by approximately 40% relative to the control (C). Treatments did not significantly affect the internal fruit quality of the ‘Fremont’ mandarin variety except in fruit colour and appearance. The highest impact on fruit size was found in the DG + KNO3 treatment. According to treatments and periods, the SPAD values varied between 62.08 and 70.67, whereas the PSII values varied between 0.698 and 0.756. The treatments significantly increased the leaf nitrogen (N) concentration and the fructose, glucose and sucrose concentrations relative to the control. The highest N concentration content was detected in the foliar potassium treatment, and the highest total sugar content was detected in the SG treatment.

Foliar Potassium Sulfate Application Improved Photosynthetic Characteristics, Water Relations and Seedling Growth of Drought-Stressed Maize

Changing climates and frequent spells of drought have increased the risk of crop failure, especially in arid and semi-arid regions, thus multiplying the vulnerability of food-insecure populations. The exogenous application of potassium (K) can potentially ameliorate the adverse effects of drought in maize by maintaining cell osmotic potential and turgidity, provided its optimum doses are applied. The present experiment comprised two maize cultivars, viz. Islamabad Gold (drought tolerant) and Azam (drought susceptible), grown under well-watered (80% water-holding capacity (WHC)), mild drought (60% WHC) and severe drought (40% WHC) conditions. Different doses of K, viz. 0%, 1% and 2%, were also tested to screen out the most superior concentration. Drought stress markedly reduced root and shoot lengths (25% and 16%, respectively) along with their dry weights (20% and 10%, respectively). Moreover, a substantial reduction in leaf relative water content (RWC) (24%), stomatal conductance, transpiration and photosynthesis rates, chlorophyll pigments a, b and total chlorophyll contents (31%) were recorded, compared with well-watered conditions. However, foliar application of K2SO4 at 2% concentration outperformed other doses by improving growth attributes, RWC (10%), total chlorophyll (9%) and proline (12%) under severe drought conditions. Our findings confirmed the effectiveness of foliage-applied K2SO4 in ameliorating drought effects in rainfed maize; however, more doses and sources of K could be tested for developing it as a potent source to cope with water stress.

Leaf antioxidant machinery stimulation by Meloidogyne javanica infestation: A case study on Cucumis melo seedlings

Following nematode infestation, leaf-localized responses are vital not only as early infection signs but also as an indication of actions required to preserve crop productivity. In this context, the leaf-level physiological responses of cantaloupe seedlings were evaluated after 40 consecutive days of cultivation under different Meloidogyne javanica juveniles (J2s) inoculation regimes (0, 100, and 850 J2s plant−1). Leaf growth parameters and photosynthetic pigments (chlorophyll, carotenoids) content were not affected by J2s infestation, while foliar Potassium concentration significantly declined. The RuBIsCo activase gene expression was negatively associated with the J2s inoculation level. Total flavonoids, total phenolics, lipid peroxidation indexes, phenylalanine ammonia-lyase activity, as well as, ascorbate peroxidase gene transcription, were higher in the inoculated plants (regardless of the J2s inoculant level). Taken together, present data indicate that J2s infestation impacts primarily the Potassium levels in leaves. Additionally, a substantial stimulation of the plant antioxidant machinery (independent of the nematode infestation intensity) is triggered. Finally, it was established that the transcriptional regulation of the RuBIsCo activase 1 gene under biotic stress has the capacity to be employed as a potential stress indicator marker.

ALLEVIATION OF WATER DEFICIENCY EFFECT BY APPLICATION OF POTASSIUM SILICATE TO FABA BEAN INTERCROPPED WITH SUGAR BEET IN SANDY SOIL

Two field experiments were carried out at Ismailia Agricultural Research Station, Agricultural Research Center, Ismailia governorate (Lat. 30° 35' 30 N, Long. 32° 14' 50 E, 10 m a.s.l.),Egypt, during 2018/2019 and 2019/2020 growing seasons. The objective of this study was to determine the rate of potassium silicate that could mitigate the effect of water shortage on productivity of faba bean intercropped with sugar beet and its effects on water and land equivalent ratios, as well as farmer’s net revenue. In split plot design with three replications, three irrigation treatmentsi.e., 120, 100and 85% Evapotranspiration (mm/d) (ETo) were assigned to the main plots, while three rates of sprayed potassium silicate (unsprayed (control), 200 ppm and 300 ppm) were arranged in sub-plots. The results showed that irrigation with 120% ETo and spraying with 200 ppm potassium silicate attained the highest yield and its components for both faba bean and sugar beet under their intercropping system in both growing seasons. For faba been and sugar beet, N, K and Si content were positively affected by irrigation levels at 100% ETo with foliar potassium silicate 200 ppm, but P content was positively affected by irrigation levels at 120% ETo with foliar 200 ppm potassium silicate. The available P and K in the soil were positively affected by irrigation with 120% ETo with foliar 300 ppm potassium silicate. N content was positive affected by irrigation with 100% ETo with foliar 200 ppm potassium silicate. The highest values of water and land equivalent ratios (WER and LER), as well as total and net return were obtained under irrigation with 120% ETo and spraying with 200 ppm potassium silicate. However, both WER and LER under application of 100% ETo and 200 potassium silicate were higher than irrigation with120% ETo and unsprayed plants in both growing seasons. The highest value of farmer net revenue was obtained when 120% ETo and spraying with 200 ppm potassium silicate were applied. Thus, to attain the highest faba bean with sugar beet in an intercropping system and highest water and land equivalent ratios, as well as farmer’s net revenue, 120% ETo and spraying with 200 ppm potassium silicate should be applied. However, in case of water shortage, 100% ETo and spraying with 200 ppm potassium silicate could be applied to mitigate the effect of water deficiency.

Response of Rice Crop to Nitrogen Fertilizer Rates with Foliar Application with a Mixture of Potassium and Zinc on Growth and Yield

Two field experiments were conducted at Sakha Agricultural Research Station,Kafr El-Sheikh Governorate , Egypt, during 2018 and 2019 seasons.to to investigate the effect of different proportions of nitrogen rates with foliar potassium and Zinc their combined effect on growth and yield components .The treatments i.e.,45kgN/fad ,60kgN/fad,45Kg N/fad+spray with 2% K2O,45Kg N/fad+spray with 2 % Zn, 45Kg N/fad+spray with 1% K2O+1%Zn, 60 kg N/fad+spray with 2 % K2Oand 60 kg N/fad + spray with 2 % Zn, 60kg N/fad+spray with 1% K2O+1%Zn .The used variety was Sakha 107.The experiments were performed in Randomized Complete Block Design with four replications.The collected data include physiological traits, yield attributes yields and grain quality characteristics. The main obtained results are summarized as following all mistuned traits were significantly and pristinely responded to tested nitrogen treatment combined with foliar spray of K2O, Zn mixture in both study seasons .The highest means of dry matter, leaf area index ,crop growth rate, net assimilation rate , panicle number/m2, panicle length, panicle weight,filled grains numbers/panicle ,1000 grain weight. Grain, and biological yields and grain content of carbohydrates,crude protein and amylase were produced when rice plants received 60kgN/fad.+ mixture spray of K2O,Zn at 1% for each.The grain quality showed the same pattern of above mentioned traits. It could be concluded that high growth, yield attributes, grain yield and grain quality traits, as well as physiological parameters could be approached by apply 60kg N/fad along with foliar spray of K2O, Zn mixture twice at 15 and 30 days after transplanting

Improving Grain Productivity and Quality Criteria of Broadcasted Giza 179 Rice Variety Via different Potassium Treatments

Field experiments were conducted in the 2018 and 2019 seasons at the Experimental Farm of Sakha Agriculture Research Station, Kafr-ELSheikh, and laboratory experiments conducted at Seed Technology Department, Field Crops Research Institute A.R.C. Giza, Egypt. The study aimed to evaluate the influence of different potassium application methods as follow, control treatment (no potassium application), 50 Kg K2O/ha as one basal batch and two splits, ½ as basal and ½ at 25 days after sowing and foliar potassium concentrations (0, 0.5, 1 and 1.5 % K2O) on Giza 179 rice variety. Twelve combinations were performed in a randomized complete block design with four replications. Yield attributes and grain yield, as well as grain quality charcteristics which involved grain dimension, milling recovery charcteristics, amylose content (AC), gel consistency (GC), gelatinization temperature (GT), and kernel elongation, were estimated. The findings revealed that splitting potassium fertilizer plus applying foliar application at the rate of 1.0 % lead to preferable yield attributes outcome, outstripped grain yield by 12.63 and 11.93 %, and ameliorated both of head rice percentage by 9.87 and 8.29 %, AC content by 4.19 and 4.02 % and decreased GC by 0.59 and 0.88 %, respectively in both seasons compared with one batch basal application. Using splitting potassium application plus foliar spray at 1.0 % K2O can apply to Giza 179 rice variety to optimize both of grain quantity and quality outcomes. Influence of different potassium treatments exhibited a significant effect on Seed Technology characteristics results.

Using regional forest nutrition data to inform urban tree management in the northeastern United States

Managing tree health in urban environments is complicated due to the disconnect that exists between novel environmental conditions created by urbanization and those under which tree species evolved. Soils influence tree health and growth, but optimal nutrient and pH recommendations are often informed by agricultural and horticultural norms which do not typically include norms for forest tree species. At the Arnold Arboretum in Boston, Massachusetts, USA, we investigated the relationships between tree health, foliar chemistry, and soil chemistry for three native forest tree species (Acer saccharum, Quercus alba, and Tsuga canadensis) located throughout the arboretum. We compared these ranges and relationships to data collected from trees of the same species growing in forested areas throughout the northeastern United States. For all species, the distributions of most foliar nutrient concentrations were similar in the arboretum and across the region. However, foliar potassium (K) concentrations were lower at the arboretum than in reference datasets. Soil pH was higher at the arboretum than most forest soils in the region, potentially a result of liming and irrigation with city water. Concentrations of soil and foliar magnesium were also high at the arboretum. Potassium deficiency could result from the blocking of K uptake by magnesium or limited K availability due to forest floor loss. In addition, there is some evidence that manganese is at low to deficient levels. These results show the value of comparing chemical conditions between urban tree populations with trees in natural forests in nearby rural settings to identify potential areas of concern and inform soil management strategies.

Exogenous Potassium Treatments Elevate Salt Tolerance and Performances of Glycine max L. by Boosting Antioxidant Defense System under Actual Saline Field Conditions

Salinity is one of the major issues that limits field crop productivity in an arid and semiarid environment. Therefore, two field trials were carried out over two seasons of 2018 and 2019 to investigate the enhancement of different methods of potassium application (i.e., recommended soil amendment (control; K2O), seed soaking (SS) and foliar spray (FS) in the form of potassium sulfate (K2SO4, 6 mM)) on antioxidant protection, physio-biochemical, yield and quality traits of soybean (cv. Giza 22) grown in normal (electrical conductivity; EC = 2.68 dS m−1) and saline soil (EC = 7.46 dS m−1). Physio-biochemical attributes (total chlorophyll, carotenoids, K+ and K+/Na+ ratios, performance index and catalase (CAT) activity), growth traits (i.e., shoot length, number and area of leaves plant−1 and shoot dry weight), yield and its components and seed quality (number of pods plant−1, 100-seed weight, seed yield ha−1 and seed protein and oil contents) were significantly decreased when soybean plants were grown in saline soil compared with those grown in normal soil. In contrast, activity of enzymatic antioxidants (i.e., superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione peroxidase (GPX)), contents of non-enzymatic antioxidants and osmoprotectants (i.e., total soluble sugars, free proline, ascorbic acid and α-tocopherol), Na+, Cl−, H2O2 and malondialdehyde (MDA) were increased in soybean plants grown in saline soil compared with normal soil. However, under salt-stressed conditions, potassium applied through SS or FS significantly enhanced all soybean growth, photosynthetic efficiency, K+ content, ratio of K+/Na+ and activity of CAT, SOD, APX and GPX as well as improved yield and quality traits, while potassium application did not affect the contents of non-enzymatic antioxidants and osmoprotectants. For instance, foliar potassium application (FS) increased seed yield ha−1 by 92.31% and protein content by 63.19% compared with the control under the salt stress condition. In addition, both applications of potassium significantly reduced Na+, Cl−, H2O2 and MDA contents in soybean plants compared with those obtained from control treatments. Exogenous application of K2SO4 was more effective than SS at improving soybean physio-biochemical attributes, yield and seed quality traits under soil-salinity stress.

Wheat Production Functions Under Irrigated Saline Environment and Foliar Potassium Fertigation

Wheat Production Functions Under Irrigated Saline Environment and Foliar Potassium Fertigation

Quick Method to Quantify the Potassium and Sodium Content Variation in Leaves of Banana Varieties.

The current study describes novel and quick methods for the quantification of K+ and Na+ in banana leaves using Horiba Laqua twin ion meters. Foliar K+ and Na+ content measured by ion meter significantly correlated with standard test values by coefficients of 0.83 and 0.46, respectively. About 48 absorbance values associated with potassium concentrations at wave numbers (1581 to 1583 and 3194 to 3410 cm-1) and 15 sodium associated wave numbers (3773 to 3996 cm-1) predicted potassium and sodium content with regression coefficients of 0.999 and 0.588, respectively. K+ and Na+ cations of fresh leaves in seven banana varieties were quantified using ion meters and new information of differences in the foliar potassium and sodium contents was found between banana varieties within the AAB group. The Rasbali (Silk subgroup) variety possessed greater potassium (5413 mg/L) and sodium (188 mg/L) ions than Amti (Mysore subgroup).

Foliar applied potassium stimulate drought tolerance in canola under water deficit conditions

Drought is a burning issue all over the world that has led to remarkable reductions in the growth and yield of crops. Based upon the current problem, a series of two rain out shelter pot research experiments were performed to evaluate the drought tolerance in canola by foliar application of potassium (K) under water deficiency conditions in the Department of Agronomy, University of Agriculture Faisalabad, Pakistan. Four varieties of canola (Faisal Canola, Cyclone, Shiarlae, and Dunkled) were tested under two water deficit levels (100% FC and 50% FC) and two treatments of foliar potassium application i.e., 0% K and 2% K. The data was recorded with standard procedures when the plants were grown up to maturity. Results concluded that drought posed a significant decrease in all parameters under study. However, supplemental foliar application of potassium at the rate of 2% at both (vegetative and reproductive) stages of canola enhanced the water potential (0.24% and 0.23%), osmotic potential (0.12% and 0.11%), turgor pressure (0.66% and 0.58%), respectively. Similarly, the chlorophyll contents as chlorophyll a (0.25% and 0.28%), chlorophyll b (1.26% and 1.80%) and leaf carotenoid contents (0.20% and 0.62%) were also increased where K was applied at the rate of 2% during vegetative and reproductive stages of canola. The foliar applied K at the rate 2% enhanced leaf photosynthetic rate (13.11 µmol CO2 m−2 s−1 and 15.96 µmol CO2 m−2 s−1), transpiration rate (5.36 µmol CO2 m−2 s−1 and 5.54 µmol CO2 m−2 s−1) and stomatal conductance (0.22 µmol CO2 m−2 s−1 and 0.26 µmol CO2 m−2 s−1) of the plants at both stages. Yield attributes such as thousand seed weight (1.03% and 1.03%), seed yield (0.58% and 0.58%) and biological yield (0.35% and 0.38%) were increased by foliar K application under water deficit conditions at both stages. The genotype Shiralae showed significant improvement among all others genotypes under normal as well as water deficit conditions

Foliar Potassium-Induced Regulations in Glycine Betaine and Malondialdehyde Were Associated with Grain Yield of Heat-Stressed Bread Wheat (Triticum aestivum L.)

Heat stress at reproductive stages of wheat causes grain shriveling. The present study aimed at comparing thermo-sensitivity of terminal stages of wheat and optimization of foliar potassium to alleviate heat and to determine correlation of biochemical attributes with agronomic attributes. The experiment was laid out in a randomized complete block design under split treatment structure and replicated thrice. Main plot was comprised of heat stress (H), viz. H0 = no heat imposition; H1 = heat stress imposition from complete emergence of spike to grain filling initiation, and H2 = heat stress imposition from flowering initiation to grain filling initiation. Foliar potassium (K) sprays consisted of K0 = control (water spray); K15 = 15; K30 = 30; K45 = 45; and K60 = 60 g L−1. Under “H0” similar and more glycine betaine, water relations and lesser malondialdehyde were recorded with 45 and 60 g L−1 K, While 60 g L−1 K proved more beneficial under “H1” and “H2” for these attributes, “H1” proved more damaging compared with “H0” and “H2” for grain yield and yield components, while similar and more improvements in grain yield and yield components were recorded with 45 and 60 g L−1 K compared with other doses. Conclusively, more deleterious responses were observed under “H1” compared with other heat treatments. Application of 40 g L−1 K under “H0” and 60 g L−1 K under heat stress exhibited more remarkable responses. Moreover, a strong association of biochemical attributes with agronomic parameters was recorded.

Leaf Morphological Traits and Leaf Nutrient Concentrations of European Beech Across a Water Availability Gradient in Switzerland

Climate change and the expected increase in frequency of dry summers are likely to affect the growth of important tree species. We investigated relationships between morphological and chemical leaf traits of European beech (Fagus sylvatica L.) and environmental factors along a water availability gradient consisting of 12 sites located throughout Switzerland. We found that leaf dry mass and leaf area tended to decrease with increasing long-term mean annual precipitation (MAP) and actual to potential transpiration (AT/PT), two correlated variables that form the water availability gradient. These results contrast with those of several other studies, and might be explained by favourable temperature and humidity conditions during leaf formation in spring at the dry sites. Although the relationship was not linear over the whole gradient, the drier sites were characterized by beech with a lower specific leaf area, along with higher foliar potassium (K) and lower foliar nitrogen (N) concentrations. These patterns likely reflect strategies developed as an adaptation to reduced water availability, but they also result from variation in the availability of nutrients in soil across our sites. In the case of N, there are indications that atmospheric deposition plays a role in foliar concentrations.

Water productivity of wheat cultivars under saline irrigation and foliar potassium fertigation

Availability of fresh water is one of the limiting factors affecting the growth and yield of a variety of crops. Besides this, declining water table depths and deterioration of its quality is rampant in many parts of the world today. Salt-affected irrigated land in the world is increasing over the years. Sustaining crop growth and yield with proper management of irrigation water under saline environment necessitates modification in the conventional crop cultivation practices. A field experiment was conducted on two winter wheat (Triticum aestivum L.) cultivars (viz. salt tolerant cultivar KRL-1-4 and salt non-tolerant cultivar HD-2894) under saline irrigation regimes (1.7 to 12 dSm-1) with and without foliar potassium fertigation in the research farm of the Water Technology Center (WTC), ICAR-IARI, New Delhi, India. In this experiment potassium was applied in the ratio of K+: Na+ (1: 10) as foliar application during the heading stage of the crop. The KRL-1-4 cultivar under foliar treatment resulted in increase in water productivity by 6.3 to 21.1% as compared to the non-foliar treatments with irrigation water salinity ranging from 1.7 to 12 dSm-1. The increase in water productivity of wheat with foliar potassium fertigation over the non-foliar application for the HD 2894 cultivar was found to vary from 3.8 to 14.9% with irrigation water salinity upto 12 dSm-1. Overall, it was observed that the water productivity of both cultivars under foliar potassium fertigation resulted in higher water productivity for all salinity regimes as compared to the non-foliar treatment.

Effect of foliar potassium fertilization on yield and fruit quality of strawberry, raspberry and blueberry

Effect of foliar potassium fertilization on yield and fruit quality of strawberry, raspberry and blueberry

Improving Quality Attributes of Tomato during Cold Storage by Preharvest Foliar Application of Calcium Chloride and Potassium Thiosulfate

The aim of this trial was to investigate the pre-harvest foliar application of calcium chloride and potassium thiosulfate each at 0.0, 0.2 and 0.4 % on some quality of tomato fruit (hybrid 65010) during cold storage. The experimental layout of cold storage experiments was a split-split-plot based on Randomized Complete Blocks design with three replications. Time of cold storage, calcium chloride and potassium thiosulfate levels were randomly distributed in the main, sub-and sub-sub plots, orderly. At the termination of cold storage, effect on tomato fruit titratable acidity, vitamin C and lycopene contents while, negative impact on firmness and total soluble sugars contents was obtained. At termination of cold storage, pre-harvest foliar calcium chloride at 0.2 and/or 0.4 % caused increments in fruit titratable acidity, vitamin C, total soluble sugars, lycopene and firmness contents. In addition, pre-harvest foliar potassium thiosulfate at 0.4 % enhanced fruit vitamin C, total soluble sugars, lycopene and firmness contents and also increased titratable acidity content. Generally, the interaction between cold storage × pre-harvest foliar calcium chloride or potassium thiosulfate at 0.2 and/or 0.4% increased fruit total titratable acidity, vitamin C, total soluble sugars, lycopene and firmness contents. Also, the interaction between pre-harvest calcium chloride × potassium thiosulfate at 0.4 % was distinguished and increased all studied fruit quality at the end of cold storage. The interaction treatment of cold storage × calcium chloride at 0.4 % × potassium thiosulfate at 0.4 % was the best that improved fruit quality more than others.

Improving Quality Attributes of Tomato during Cold Storage by Preharvest Foliar Application of Calcium Chloride and Potassium Thiosulfate

The aim of this trial was to investigate the pre-harvest foliar application of calcium chloride and potassium thiosulfate each at 0.0, 0.2 and 0.4 % on some quality of tomato fruit (hybrid 65010) during cold storage. The experimental layout of cold storage experiments was a split-split-plot based on Randomized Complete Blocks design with three replications. Time of cold storage, calcium chloride and potassium thiosulfate levels were randomly distributed in the main, sub-and sub-sub plots, orderly. At the termination of cold storage, effect on tomato fruit titratable acidity, vitamin C and lycopene contents while, negative impact on firmness and total soluble sugars contents was obtained. At termination of cold storage, pre-harvest foliar calcium chloride at 0.2 and/or 0.4 % caused increments in fruit titratable acidity, vitamin C, total soluble sugars, lycopene and firmness contents. In addition, pre-harvest foliar potassium thiosulfate at 0.4 % enhanced fruit vitamin C, total soluble sugars, lycopene and firmness contents and also increased titratable acidity content. Generally, the interaction between cold storage × pre-harvest foliar calcium chloride or potassium thiosulfate at 0.2 and/or 0.4% increased fruit total titratable acidity, vitamin C, total soluble sugars, lycopene and firmness contents. Also, the interaction between pre-harvest calcium chloride × potassium thiosulfate at 0.4 % was distinguished and increased all studied fruit quality at the end of cold storage. The interaction treatment of cold storage × calcium chloride at 0.4 % × potassium thiosulfate at 0.4 % was the best that improved fruit quality more than others.

Responding of Long Green Pepper Plants to Different Sources of Foliar Potassium Fertiliser

Abstract The aim of this study was to explore the efficiency of foliar potassium fertiliser relative to morphological, physiological and biochemical properties of hybrid long pepper (Capsicum annuum). Pepper plants were grown in a greenhouse and supplied with three sources of foliar potassium fertilisers, i.e., potassium-humate (1 g/L = 1,250 g/ha), potassium sulfate (1 g/L = 1,250 g/ha), and potassium chloride (1 g/L = 1,250 g/ha). Water served as control. The impacts of these treatments on the phytosynthetic parameters (photosynthetic rate, stomatal conductance, intercellular CO2, leaf carotenoids) and chlorophyll a and b, metabolic compounds and nitrogen, phosphorus and potassium were measured. The phytosynthetic parameters significantly improved by different foliar potassium application and the highest level of photosynthetic activity was noted in plants supplied with potassium sulfate, followed by potassium-humate and potassium chloride. Plant biomass accumulation, cholorophyll (a and b), and total yield showed larger increases in plants fertilised with potassium sulfate than those fertilised with potassium-humate; smallest increases occurred with potassium chloride. Concentrations of total sugars, carotenoids, chlorophyll (a and b), and endogenous level of nitrogen, phosphorus, and potassium contents in plants and fruits were possitively influenced by varying sources of potassium. The fruit color parameters and total soluble solid were also significantly increased with all foliar potassium treatments compared with control. Foliar application of potassium sulfate recorded the highest values and significantly increase all anatomical characters for leaf, stem and fruit of pepper plant.

Response of Sweet Pepper Capsicum Annulus L. (Qurtuba Cultivar) To Spraying With Two Types of Potassium Fertilizer Cultivated In Plastic House

Field experiment was conducted in the non-heated plastic house at Al-Mussaib Technical College in the autumn season 2016 to study the Response of sweet pepper Capsicum annuum L. (Qurtuba cultivar) to foliar spraying with two types of foliar commercial Potassium fertilizers in loamy sand soil. To study the effect of four levels of potassium fertilizer and micronutrients (0, 4, 6, 8 ml.L-1), four levels of potassium fertilizer and Sulfur KTS (0, 2, 4, 6 ml.L-1) and their interaction on some vegetative and flowering growth indicators, yield and its components. The experiment was designed according to the Randomized Complete Block Design (RCBD) and the averages were compared with the least significant difference (LSD), with a significant level of 5%. The result indicated to the excelling of the spraying treatment with potassium and micronutrient (8 ml.L-1) by giving it a significant level in increasing the averages of plant height, number of branches, leaf area, dry weight for total vegetative, number of flowers in plant, percentage of fruit set, the leaves content of (chlorophyll, nitrogen, Phosphorus and potassium), early and total yield, the content of vitamin C, and percentage of Total Soluble Solids, with an increasing percentage of (19.47, 29.54, 16.68, 30.01, 11.26, 24.09, 38.16, 24.36, 16.67, 34.00, 21.87, 20.27, 50.46, 45.96, 39.33, 70.85%), respectively, compared to control treatment. Which is the same behavior as spraying treatment with potassium fertilizer and sulfur, where treatment (4 ml.L-1) was excelled in all the above traits, where the percentages of increasing were (31.72, 53.53, 49.88, 15.82, 14.84, 24.54, 19.79, 36.73, 21.05, 47.55, 24.53, 19.07, 49.43, 48.01, 30.29, 36.56%), respectively, compared to the control treatment. As for interaction treatments, it has showed excelling the spraying treatment with a mixture of (8 ml. L-1 + 4 ml. L-1) by giving it the highest values for all the above traits amounted of (109.5 cm, 6.4 branches, 25.3 dm2, 132.7 g, 62.7 flower, 43.9% 2.22%, 0.75%, 2.55%, 34.6 fruits, 108.3 g, 0.790 kg. plant-1, 3.747 kg. plant-1, 69.2 mg.100 ml-1, 10.4%), respectively.