scholarly journals Effect of Potassium Level on Severity of Drechslera Leaf Spot of Calathea picturata ‘Vandenheckei’

1991 ◽  
Vol 9 (2) ◽  
pp. 101-102
Author(s):  
A.R. Chase ◽  
T.K. Broschat

Abstract Severity of Drechslera leaf spot (Drechslera setariae) of Calathea picturata ‘Vandenheckei’ was affected by potassium fertilization rate with ½, 1 or 2 times the recommended rate (1400 g/m3) causing a reduction in number of lesions caused by Drechslera setariae compared to plants receiving no potassium. In addition, plant quality, height and number of leaves were unaffected by potassium rate during the test period. Leachate electrical conductivity was unaffected by these potassium rates and was approximately 1000 μhos/cm two months after fertilization.

2017 ◽  
Vol 30 (2) ◽  
pp. 412-419 ◽  
Author(s):  
ARTHUR BERNARDES CECÍLIO FILHO ◽  
ALEXSON FILGUEIRAS DUTRA ◽  
GILSON SILVERIO DA SILVA

ABSTRACT The intensive cultivation of vegetables with frequent chemical fertilization may cause accumulation of nutrients in the soil. This, in turn, may reduce crop yields and damage the environment due to contamination of ground water and rivers. Thus, to increase the effects of P (0, 100, 200, 300 and 400 kg ha -1 of P2O5) and K (0, 60, 120, 180 and 240 kg ha-1 of K2O) doses on the growth and productivity of radish cultivars (Sakata 19 and Sakata 25) in a soil with high levels of these nutrients, two experiments were conducted in randomized blocks with the factors cultivars and doses arranged in a 2 x 5 factorial design with three replications. Number of leaves per plant, leaf area, shoot and root dry mass, total and commercial productivity, percentage of cracked roots and P and K contents in the plant and in the soil were evaluated. The Sakata 19 cultivar performed better than the Sakata 25 in both experiments. The fertilization with P or K did not influence the growth and the productivity of both radish cultivars. Therefore, both cultivars of radish evaluated do not need to be fertilized with P and K when planted in a Latosol with high levels of these nutrients.


2008 ◽  
Vol 26 (4) ◽  
pp. 197-203
Author(s):  
A.K. Hagan ◽  
J.R. Akridge ◽  
K.L. Bowen

Abstract Impact of nitrogen (N) rate on spot anthracnose, powdery mildew, and Cercospora leaf spot as well as their impact on the growth of field-grown ‘Cloud 9’ and ‘Cherokee Chief’ flowering dogwood was assessed in 2003, 2004, and 2005. From 2001 to 2005, ammonium nitrate was applied at 4.1, 8.3, 16.5, 33.0 and 66.0 g N·m−2 (37.5, 75, 150, 300, 600 lb N·A−1). Heritage 50W fungicide was applied to one ‘Cherokee Chief’ and ‘Cloud 9’ flowering dogwood in each plot, while the second was untreated. Powdery mildew and Cercospora leaf spot were impacted by N rate more than spot anthracnose. In two of three years, powdery mildew intensified, particularly on the non-treated trees, as N rates increased. Cercospora leaf spot intensity (AUDPCI) and defoliation (AUDPCD) on the fungicide-treated and non-treated trees was influenced by N-rate in two of three and one of three years, respectively. Regardless of fungicide treatment, Cercospora leaf spot incited leaf spotting and defoliation was often lower at the two highest than the two lowest N rates. A reduction in the bract and leaf spot phases of spot anthracnose at the highest N rate was noted in 2004. While spot anthracnose was negatively correlated with trunk diameter in all three years and tree height in 2003 and 2004, Cercospora leaf spot intensity and defoliation were negatively correlated with tree height and trunk diameter in all three and two of three years, respectively. Powdery mildew had no impact on tree height or trunk diameter. Heritage 50W not only controlled spot anthracnose and powdery mildew but also slowed Cercospora leaf spot development sufficiently to enhance leaf retention and fall color.


Author(s):  
Aline Mako Yoshikawa ◽  
Filipe Pereira Giardini Bonfim ◽  
Vicente Wagner Dias Casali

The development and yield of plants is directly related to the effects of salinity. There are several reports in scientific studies of significant reduction in the growth and production of tomato in soils with high electrical conductivity. The correction or recovery of salinized soils, although technically possible, is a slow and very expensive process, making it necessary to develop new technologies. The objective of this study is to evaluate the production of tomato (Solanum lycopersicon L.) seedlings using seeds pelleted with a homeopathic preparation of Natrum muriaticum (Nat-m) submitted to saline stress. The treatments consisted of the pelletization of tomato seeds with six dynamizations of Nat-m (3cH, 5cH, 7cH, 9cH, 11cH and 13cH). Coated or uncoated seeds (controls) were placed in phenolic foam blocks, kept in plastic trays previously moistened with 50 mM NaCl saline solution (2.922 g.L-1 of NaCl, electrical conductivity = 4.5 dSm-1) and nutrient solution (0.15 dS.m-1) at half the ionic strength, containing 4, 1, 2, 1, 0.5 and 0.5 mmol.L-1 of N, P, K, Ca, Mg and S, and 17.5, 9.5, 10.5, 2, 0.45 and 0.35 mmol.L-1 of Fe, Mn, Zn, Cu and Mo, respectively. The variables evaluated were germination percentage, germination speed index, shoot length, leaf area, number of leaves, root volume, root dry matter, and shoot dry matter. The treatments pelleted seeds/talc Nat-m 5cH and pelleted seeds/talc Nat-m 7cH increased all variables evaluated. They differed statistically from the controls, with a positive response for the development of tomato seedlings under disequilibrium conditions.


1978 ◽  
Vol 50 (2) ◽  
pp. 67-77
Author(s):  
Hilkka Tähtinen

Fourteen one-year N- and K-fertilization experiments for potato were carried out on coarse mineral soils on different sites in Finland. The nitrogen fertilization (from 50 to 156 kg/ha N) was given in the form of ammonium nitrate limestone, and the potassium (42—179 kg/ha K) in potassium sulphate. The nitrogen fertilization affected significantly both the yield and the quality of the tubers. The maximum tuber yield was achieved at the nitrogen application rate of 110 kg/ha. The economically most advantageous fertilization rate was 80 kg of nitrogen per hectare, if only the amount of the yield was taken into account. The nitrogen fertilization weakened the quality of the tubers. The weight and the size of the tubers increased, but the starch content of the tubers decreased as a result of the nitrogen fertilization. The starch yield also turned out to be the smallest at the heaviest nitrogen fertilization. Further, the biggest rate of nitrogen weakened the flavor of the tubers, depressed their mealiness, and increased slightly their discoloration when raw. The fertilization had no effect on the darkening of cooked potatoes. In these one-year experiments, the increase of the potassium fertilization from 42 kg/ha K did not have a significant effect on the yield and the quality of the tubers.


Author(s):  
Nahed S. A. El-Shayeb ◽  
Naglaa F. S. I. Elbohy ◽  
Mohammed A. I. Abdelkader

To enhance growth and productivity of roselle plant, two field experiments were done during the two consecutive summer season of 2019 and 2020 at Experimental Farm (Ghazala Farm), Faculty of Agriculture, Zagazig University, Egypt. This study included different pinching time treatments (after 4, 6, 8 and 12 weeks from sowing date) as the main factor and potassium fertilization rate (0.0, 25, 50 and 75 kg K2O/ feddan) as sub-factor as well as their combinations to improve growth, yield, anthocyanin content and some chemical contents of Hibiscus sabbdariffa plant. Results could be summarized as follow: The longest roselle plants were recorded with the control treatment (pinched after 4 weeks from sowing date), whereas pinching after 12 weeks from sowing date increased number of branches/plant. Also, apical bud pinching after 12 weeks from sowing date recorded the highest number of fruits per plant, dry sepals yield/plant and per feddan. Delaying pinching date from 4 to 8 weeks gradually increased anthocyanin content. In addition, total chlorophyll content as well as total carbohydrates, total nitrogen, total phosphorus and potassium percentages were increased with delaying pinching date especially after 12 weeks, in most cases. Potassium fertilization rate at 75 kg per feddan recorded the highest values of growth, yield components and the chemical constituents with significant differences between this rate and the other rates under study. Generally, the combination treatment between pinching after 12 weeks from sowing date and 75 kg potassium fertilization rate had significant effect in most parameters compared to the other combination treatments during both seasons.


Author(s):  
Daiane G. dos Santos ◽  
Belísia L. M. T. Diniz ◽  
Manoel A. Diniz Neto ◽  
João H. C. S. Silva ◽  
William N. de Oliveira Filho ◽  
...  

ABSTRACT Irrigation is a limiting factor for the development of crops, and all water sources contain salts, which can accumulate in the soil and in the plant, compromising its development. The use of vermicompost is one of the alternatives to mitigate the negative effects of salts on plants. This organic compost is a soil conditioner and a nutrient source for plants. Thus, this study aimed to evaluate the growth and chorophyll of noni (Morinda citrifolia L.) in response to the salinity of irrigation water in substrates with and without vermicompost. A completely randomized design in a 4 × 3 factorial scheme was used, corresponding to four levels of electrical conductivity of the irrigation water (0.5, 1.5, 3.0 and 4.5 dS m-1), in three soil substrates (without humus, with 33.33 and 66.66% of humus). Three months after germination, the following variables were evaluated: plant height; stem diameter; number of leaves; chlorophyll index (a, b and total) in the leaves; and fresh and dry matter of shoots and roots. The increase of salinity in irrigation water negatively influences growth in height, stem diameter, biomass production and chlorophyll a and total indexes, but with lower intensity in substrates with humus, that improves the fertility of the substrate and favors the growth of noni plants, regardless of the salinity of the irrigation water; however, its beneficial effect decreases with the intensification of electrical conductivity of irrigation water.


2017 ◽  
Vol 1 (1) ◽  
pp. 23
Author(s):  
Freddy Manyari ◽  
Jhonny Valverde Flores

Vinasse and biocarbon are used as recuperators of saline-sodium soils. The objective was to analyze remediation process of saline-sodium soils in the district of Tambo Grande, Piura. A sample of 10 kg of saline soil was used and it was taken to the laboratory for testing. Two columns of ground were built; at the lower end of each column was placed a leachate collecting vessel. The columns were divided into two treatments: the first was treated with water and the second was treated with vinasse; the conditions of the field washing were simulated for each column, periodically the leachates were analyzed and at the end of one month of treatment was performed analysis each of the soils in the columns. The final results indicated a decrease PSI (0.49), sodium (3.52 meq/L), Electrical Conductivity (1.46 dS/m), as well as an increase of nutrients mainly potassium (20 meq/L) and percentage of organic matter (2.17%). To evaluate the effectiveness of the soil, tests were carried out in pots with a culture called wild radish (raphanus sativus) in four pots of which one was a blank sample (without any treatment) and the remaining three had the soil treated with vinasse with different proportions of (25%, 50%, 75% by weight), for which the growth (cm) and vigor (number of leaves, number of shoots) of the crop were taken as parameters. The results indicated a better growth in the treatment with 25% of biochar, also evidenced the lack of growth in the control treatment.


Irriga ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 347-360
Author(s):  
Amitair Ferreira Lima ◽  
Geocleber Gomes De Sousa ◽  
Maria Vanessa Pires De Souza ◽  
Francisco Barroso Da Silva Junior ◽  
Silas Primola Gomes ◽  
...  

CULTIVO DO MILHETO IRRIGADO COM ÁGUA SALINA EM DIFERENTES COBERTURAS MORTAS     AMITAIR FERREIRA LIMA1; GEOCLEBER GOMES DE SOUSA2; MARIA VANESSA PIRES DE SOUZA3; FRANCISCO BARROSO DA SILVA JUNIOR4; SILAS PRIMOLA GOMES2 E CLARISSA LIMA MAGALHÃES5   1 Engenheira agrônoma formada pela Universidade da Integração Internacional da Lusofonia Afro-Brasileira (Avenida da abolição, 3, Centro, 62.790-000, Redenção/Ce, Brasil). E-mail: [email protected] 2 Prof. Doutor, Instituto de Desenvolvimento Rural, Universidade da Integração Internacional da Lusofonia Afro-Brasileira (Avenida da abolição, 3, Centro, 62.790-000, Redenção/Ce, Brasil). E-mail: [email protected], [email protected] 3 Mestranda pelo programa de pós graduação em fitotecnia da Universidade Federal Rural do Semiárido, Campus Mossoró (Av. Francisco Mota, 572, Bairro Costa e Silva, CEP: 59.625-900, Mossoró/RN, Brasil). E-mail: [email protected] 4 Mestrando pelo programa de pós graduação em ciência do solo da Universidade Federal do Ceará, Campus do Pici (Av. Mister Hull, 2977, Pici, 60.021-970, Fortaleza/Ce, Brasil). E-mail: [email protected] 5 Discente no curso de agronomia da Universidade da Integração Internacional da Lusofonia Afro-Brasileira (Avenida da abolição, 3, Centro, 62.790-000, Redenção/Ce, Brasil). E-mail: [email protected]     1 RESUMO   Objetivou-se com o presente trabalho, avaliar o crescimento e acúmulo de biomassa de plantas de milheto irrigadas com água salina em solo com diferentes coberturas. O experimento foi realizado em agosto de 2018, a pleno sol na horta didática da Universidade da integração internacional da Lusofonia Afro-Brasileira (UNILAB), Redenção, Ceará. O delineamento experimental foi inteiramente casualizado (DIC), em esquema fatorial 5x4, com 4 repetições. O primeiro fator referente aos valores de condutividade elétrica da água de irrigação - CEa: A1 (1,0 dS m-1), A2 (2,0 dS m-1), A3 (3,0 dS 11 m-1), A4 (4,0 dS m-1) e A5 (5,0 dS m-1), versus as coberturas adotadas, C1 (sem cobertura-controle), C2 (palha de arroz), C3 (bagana de cana-de-açúcar) e C4 (resíduos vegetais de espontâneas). Aos 35 dias após a semeadura, foram avaliadas: altura das plantas (AP), número de folhas (NF), diâmetro do colmo (DC), comprimento de raiz (CR), área foliar (AF), matéria seca da parte aérea (MSPA), da raiz (MSR) e total (MST), pH do solo e a condutividade elétrica do extrato de saturação do solo (CEes). O aumento da condutividade elétrica na água de irrigação, promoveu aumento da salinidade no extrato de saturação do solo, assim como reduções na emissão do número de folhas no milheto e o uso da cobertura morta amenizou os efeitos da salinidade contida na água, nas variáveis: MSPA, MSR, MST, DC e AP, sendo a cobertura de casca de arroz a alternativa mais eficiente na atenuação desses efeitos.   Palavras-chave: Penissetum glaucum L., estresse salino, proteção do solo     LIMA, A. F.; SOUSA, G. G.; SOUZA, M. V. P.; SILVA JUNIOR, F. B.; GOMES, S. P.; MAGALHÃES, C. L. CULTIVATION OF MILLET IRRIGATED WITH SALINE WATER IN DIFFERENT MULCHES     2 ABSTRACT   The objective of this work was to evaluate the growth and accumulation of dry matter of millet plants irrigated with saline water in soil with different mulches. The experiment was carried out in August 2018, under full sun in the didactic garden of the University of the International Integration of Afro-Brazilian Lusophony (UNILAB), Redenção, Ceará. The experimental design was completely randomized (DIC), in a 5x4 factorial scheme, with four replicates. The first factor referring to the values of electrical conductivity of the irrigation water: A1 (1.0 dS m-1), A2 (2.0 dS m-1), A3 (3.0 dS m-1), A4 (4.0 dS m-1) and A5 (5.0 dS m-1), versus the coverages adopted, C1 (without cover), C2 (rice straw), C3 (sugarcane bagana) and C4 (vegetable spontaneous waste). At 35 days after sowing, plant height (AP), number of leaves emitted (NF), stalk diameter (DC), root length (CR), leaf area (AF), shoot dry matter (MSA), root dry matter (MSR), total dry matter (MST), soil pH and soil saturation extract electrical conductivity (CEs) were assessed. The increase in the electrical conductivity in the irrigation water promoted an increase in salinity in the soil saturation extract, as well as reductions in the number of leaves in the millet, and the use of the mulch reduced the effects of the salinity contained in the water in the following variables: MSPA, MSR, MST, DC and AP, with rice husk coverage being the most efficient alternative to mitigate these effects.   Keywords: Penissetum glaucum L., saline stress, soil protection.


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