scholarly journals Chlorophyll a fluorescence and development of zucchini plants under nitrogen and silicon fertilization

2020 ◽  
Vol 38 (1) ◽  
pp. 45-52
Author(s):  
Jackson De Mesquita Alves ◽  
Alex Serafim De Lima ◽  
Francisco Romário Andrade Figueiredo ◽  
Toshik Iarley Da Silva ◽  
Lourival Ferreira Cavalcante ◽  
...  

Zucchini (Cucurbita pepo L.) has a great economic and productive potential in the semi-arid region of Brazil, due to the wide acceptance by consumers and quick financial return. The nitrate (NO3-) assimilation process in C3 plants such as zucchini is related to photorespiration, and Si accumulated near the stomata reduces the transpiration rate, making the photosynthesis cycle more efficient. The objective of this study was to evaluate the interaction between nitrogen and silicon fertilization ongrowth, chlorophyll index, and chlorophyll a fluorescence of zucchini plants. The treatments were distributed in a split-plot scheme in a randomized block design with three replicates. The plot was arranged by silicon levels (0 and 6 g/plant) and the subplots constituted by five nitrogen levels (30, 60, 90, 120 and 150 kg ha-1). Leaf, stem and total dry masses, chlorophylla, chlorophyll b, total chlorophyll, chlorophyll a/b ratio and chlorophyll a fluorescence were evaluated. The highest dry matter productions in zucchini were obtained in treatments without Si. Si and N application together positively influences the chlorophyll a/b ratio of zucchini plants. The interaction between Si and N positively influences the maximum fluorescence, variable fluorescence and quantum yield of photosystemII of zucchini plants.

2021 ◽  
Vol 29 ◽  
pp. 204-210
Author(s):  
Gustavo Soares Wenneck ◽  
Reni Saath ◽  
Roberto Rezende ◽  
Lucas Henrique Maldonado da Silva

The measurement of leaf pigments using non-destructive methods can be influenced by water management conditions and the use of nutrients in cauliflower, not showing adequate correlations with chlorophyll contents. The objective of this study was to evaluate the correlation between the SPAD index and the pigment content in cauliflower leaves managed with different water conditions and the application of silicon (Si). The cultivation was carried out in a protected environment in the city of Maringá, Paraná State from October 2019 to March 2020. It was adopted a randomized block design, with treatments in a 3 x 4 factorial scheme, with three levels of water recharge (40; 70 and 100% of crop evapotranspiration (ETc)) and four doses of Si (0; 50; 100 and 150 kg ha-1), with four replications. Once plants showed developed inflorescence, the SPAD index was determined in the field and the levels of chlorophyll a, chlorophyll b, and carotenoids in the laboratory using leaves from the upper third. The correlation between water recharge and Si fertilization on the SPAD index was determined. The proportion of carotenoids in relation to total pigments was compared under different conditions. Correlation analysis was performed considering silicon fertilization, water recharge, leaf pigments, and the SPAD index. Silicon fertilization reduced the levels of carotenoids in addition to being related to chlorophyll a (100% of ETc) and chlorophyll b (70% of ETc). The correlation of the SPAD index with pigments is variable with the water condition of the crop, in a condition without water deficit, it is related to chlorophyll a and in a condition of 70% replacement of ETc, it is correlated with chlorophyll b.


2019 ◽  
Author(s):  
João Macedo Moreira ◽  
Aldrin Martin Pérez-Marin ◽  
Jucilene Silva Araújo ◽  
George Rodrigues Lambais ◽  
Aldo Sales

The study aimed to evaluate the efficiency of nutrient use in three cactus forage (CF) cultivars (Opuntia stricta and Nopalea cochenillifera), 365 days after planting under different types of fertilizer in two research sites (Condado and Riachão) of the semi-arid region of Paraiba state, Brazil. The experimental design was a randomized block design with treatments in a factorial scheme (3×4), three cultivars of CF (Orelha de elefante Mexicana; Miúda; Bahiana), and four fertilizer treatment (Control; Manure; Manure with Nitrogen; Mineral fertilization) with four replications. The CF cultivars did not differ significantly in nutrient use. That means of physiological efficiency by CF cultivars were 1.62, and 2.36 kg of biomass per kg of nutrient applied in Condado and Riachão, respectively. The efficiency of nutrient recovery was 16% for the Condado, according the following order: K> P> Ca> N> C = Mg and 12% for Riachão: K> P> N> C = Ca = Mg. In the two research sites, the treatment with mineral fertilization significantly increased the efficiency use of N, P and K in comparison to the other treatments. The average for efficiency of nutrient utilization was 25% and 19% for Condado and Riachão, respectively, in the following order for Condado: K> P> N> Ca = Mg> C, and Riachão: K> P> N> C> Mg = Ca. In a CF production system aiming to obtain a yearly harvest cycle, it is necessary to replenish of K and P to maintain the nutritional balance between the soil and CF plant.


2018 ◽  
Vol 10 (4) ◽  
pp. 361 ◽  
Author(s):  
Vinicius S. G. da Silva ◽  
Mauro W. de Oliveira ◽  
Vilma M. Ferreira ◽  
Terezinha B. A. Oliveira ◽  
Elaine R. Galvão ◽  
...  

Sugarcane produces a large amount of biomass, extracts and accumulates high amounts of nutrients. In the literature the nutritional requirements for most cultivated varieties in the past are found, however there is little information on the new varieties currently planted. The objective of this study was to evaluate the nutritional requirement of four sugarcane varieties, currently very planted, in the cycles of plant-cane, first and second ratoon. The study was installed in a Yellow Oxisol. The experimental design was a randomized block design, with five replications, and four treatments: RB867515, RB92579, SP813250 and VAT90212. During maturation of the cane, in the three evaluation cycles, the productivity of natural biomass and the nutritional requirement of macronutrients of the varieties were determined. It was evidenced that the cultivars of sugarcane are of high productive potential and resemble the accumulation of biomass, observing a yield of 158, 128 and 107 t ha-1 in the cycles of plant-cane, first and second ratoon. Regarding the nutritional requirement, the varieties did not differ among them and expressed the following order of need in the plant-cane K > N > Ca > Mg > S > P, in the first and second ratoon, the sequence observed was K > N > Ca > S > Mg > P.


2017 ◽  
Vol 9 (10) ◽  
pp. 168 ◽  
Author(s):  
Francisco V. da S. Sá ◽  
Hans R. Gheyi ◽  
Geovani S. de Lima ◽  
Emanoela P. de Paiva ◽  
Pedro D. Fernandes ◽  
...  

This study aimed to evaluate the interaction between the fertilization with nitrogen (N) and phosphorus (P) and irrigation with saline water on the water relations, gas exchanges and chlorophyll a fluorescence in West Indian cherry in the vegetative stage. The study was carried out in protected environment, using lysimeters filled with clay loam Regolithic Neosol, with low P content, installed in a randomized block design, arranged in a factorial scheme with five levels of electrical conductivity of irrigation water (ECw), and four managements of P and N fertilization, with three replicates and one plant per plot. Along the experiment, water relations, gas exchanges and chlorophyll a fluorescence were evaluated in West Indian cherry plants. The increase in irrigation water salinity reduces the gas exchanges of the plants, but the increment of 40% in N supply increases the photosynthetic activity of West Indian cherry at recommendation levels higher than 100:100% of the P/N ratio, when irrigated with ECw of up to 3.0 dS m-1. The combined action of N and P, at doses of 140:140% N/P recommendation, increases leaf turgor in the plants, regardless of the ECw level. The increment of 40% in N dose reduces the effects of salinity on the initial fluorescence of chlorophyll a in West Indian cherry irrigated with up to 2.2 dS m-1.


2020 ◽  
Vol 9 (7) ◽  
pp. e130973911
Author(s):  
Roberto Cleiton Fernandes de Queiroga ◽  
Zaqueu Lopes da Silva ◽  
Odair Honorato Oliveira de ◽  
Elidayane da Nóbrega Santos ◽  
Higínio Luan Oliveira Silva ◽  
...  

The objective of this study was to evaluate the productivity and quality of melon fruits as a function of the dose and time of application of biostimulant in the conditions of the semi-arid region of Paraíba. The experiment was carried out at the Federal University of Campina Grande, campus of Pombal - PB, Brazil, in a randomized block design in a 4 x 5 split plot scheme, with doses of biostimulant (0; 0.5; 1.0; 1, 5 and 2.0 L ha-1) and in the subset of the biostimulant application times (15; 20; 25 and 30 days before harvest - DAC), in four replications. Characteristics related to fruit production and quality were evaluated. There was no interaction between the factors of dose and application time of the biostimulant in any of the evaluated characteristics. Thus, the highest estimated values of number of fruits per plant, fruit mass and total melon production were obtained with the application of doses ranging from 0.9 to 1.5 L ha-1 and at the time of application it varied from 22,5 to 23.6 DAC. The content of soluble solids increased 5.5% when the biostimulant dose of 2.0 L ha-1 was used and 4.4% when the product was applied 15 days before harvest.


2012 ◽  
Vol 36 (5) ◽  
pp. 951-960
Author(s):  
Paulo Sérgio Lima e Silva ◽  
Alexandre Emanuel Régis Holanda ◽  
Haroldo Nogueira de Paiva ◽  
Fábio Henrique Tavares de Oliveira ◽  
Odaci Fernandes de Oliveira

Planting densities influence several aspects of forest formation, including management practices, timber yield, quality, and extraction, and consequently its production costs. The objective of this study was to evaluate Mimosa caesalpiinifolia and Gliricidia sepium growth as a function of planting density (400, 600, 800, 1000, and 1200 plants ha-1) and plant age. The species were evaluated every 90 days for plant height (PH), crown diameter (CD) and root collar diameter (RCD) (10 cm above the ground), with the first evaluation performed at 90 days and the last at 720 days. When plants were one year of age and beyond, evaluations were conducted also for stem diameter at breast height (DBH) (1.30 m above the ground). A randomized block design with split-plots and three replicates was adopted. Species were assigned to plots, planting densities were assigned to subplots, and evaluation ages were assigned to subsubplots. The four traits in both species had their values decreased as planting density increased, but continually increased as plant age increased. For PH and RCD there was an alternation between species superiority, with gliricidia being superior to sabiá at some ages, while the opposite occurred at other ages. As to CD the species only differed in the last measurement, gliricidia being superior. With regard to DBH, gliricidia was superior starting from the second measurement. There was an effect of the species × ages interaction for the four traits and also an effect of the densities × ages interaction for CD and DBH.


2019 ◽  
Vol 11 (9) ◽  
pp. 83
Author(s):  
Jackson de M. Alves ◽  
Alex S. de Lima ◽  
Cesenildo de F. Suassuna ◽  
Francisco R. A. Figueiredo ◽  
Toshik Iarley da Silva ◽  
...  

Zucchini (Cucurbita pepo L.) is a horticultural crop of great socioeconomic importance in Brazil and in the world. However, inappropriate fertilization management, such as over-fertilization of soils, may become a limiting factor for its development. Thus, the aim of this study was to evaluate the morpho-physiological behavior of zucchini submitted to nitrogen (N) doses applied via soil and foliar application of silicon (Si). The treatments were distributed in split-plot scheme in a randomized block design, with three replications. The plot was formed by silicon levels (0.0 and 6.0 g plant-1) and the subplots constituted by five nitrogen levels (30, 60, 90, 120 and 150 kg ha-1), adding up to 30 experimental units. Gas exchanges and growth parameters were assessed at 35 days after planting. The data were submitted to analysis of variance by the F test and in the cases of significance was performed a polynomial regression analysis for the nitrogen factor and Tukey test for the silicon factor. The supply of Si positively enhances the effects of N on growth characteristics and gas exchanges of zucchini. The simultaneous application of Si and N does not influence the leaf area of zucchini. The N dose of 93.9 kg ha-1 provides greater assimilation of CO2 in zucchini plants under the conditions in which the experiment was performed.


2012 ◽  
Vol 12 ◽  
pp. 29-34 ◽  
Author(s):  
Dhruba R Bhattarai ◽  
Krishna P Poudyal ◽  
Shanta Pokhrel

Inorganic fertilizers alone cannot sustain high levels of productivity. It may cause deterioration of soil environment leading to low productivity. An investigation was carried out to develop integrated nutrient management technology for fruit yield of bell pepper (Capsicum annuum L.). The experiment was conducted at Horticulture Research Division, Nepal Agricultural Research Council Khumaltar, Lalitpur during 2010/011. The experiment was laid out in a randomized block design with three replications and having seven treatments viz., Control (100% NPK), Azotobacter + 25% N + PK, Azotobacter + 50% N + PK, Azotobacter + 75% N + PK, Azotobacter + FYM + 25% N + PK, Azotobacter + FYM + 50% N + PK, Azotobacter + FYM + 75% N + PK. Among the tested treatments, T7 (Azotobacter + FYM + 75 % N + PK) recorded the maximum plant height (66.18 cm), number of primary branches (8.20) and fruit yield (18.08 kg) per plot.DOI: http://dx.doi.org/10.3126/njst.v12i0.6475 Nepal Journal of Science and Technology 12 (2011) 29-34 


2020 ◽  
Vol 41 (4) ◽  
pp. 1135
Author(s):  
Francisco Gonçalo Filho ◽  
Miguel Ferreira Neto ◽  
Cleyton dos Santos Fernandes ◽  
Francisco Vanies da Silva Sá ◽  
Nildo da Silva Dias ◽  
...  

Because of climatic problems in the Brazilian semi-arid region, it is of fundamental importance to seek a culture that considers water scarcity and available natural resources. Thus, a randomized block design, with subdivided plots and six replications, was carried out in the experimental area of the treatment and wastewater reuse station of the Milagres Settlement, Apodi, Brazil, with the objective of evaluating cultivation of herbaceous cotton (Gossipyum hirsutum) fertigated with domestic sewage treated in a semi-arid environment. Two cultivation cycles were carried out, and the cotton plants were fed with three different solutions containing treated domestic sewage (TDE) plus supply water (PSW), to supply the crop evapotranspiration (ETc) (100% PSW – control, 50% PSW + 50% TDE and 100% TDE), with and without phosphate fertilization in pre-planting. The contribution of nutrients to the soil and plant growth were analyzed. The results indicated that the wastewater presents potential fertilizer, reaching to the soil amounts of some nutrients exceeding the cotton’s needs, when 100% of the ETc was supplied via fertigation with domestic effluent, resulting in an increase in the growth rates of the plants. There was no interaction between the percentages of wastewater and phosphate fertilization in pre-planting. Phosphorus alone promoted significant variation only in the first cycle, indicating that there is a residual fertigation effect with domestic effluent on the nutrient supply.


2018 ◽  
Vol 31 (4) ◽  
pp. 798-807 ◽  
Author(s):  
Francisco Ronaldo Alves de Oliveira ◽  
Henrique Antunes de Souza ◽  
Marco Antônio Rosa de Carvalho ◽  
Mirian Cristina Gomes Costa

ABSTRACT The objective of this study was to evaluate the effects of the addition of parts of leguminous trees on the growth and nutrition of maize (Zea mays L.), as well as on the chemical attributes of a degraded soil, 65 days after applying the residues. The experiment was conducted in pots, in a randomized block design with ten treatments and four replicates. The evaluated treatments were: T1 - No residues of leguminous trees, T2 - Leaves of Mimosa caesalpiniifolia, T3 - Branches of Mimosa caesalpiniifolia, T4 - Leaves + branches of Mimosa caesalpiniifolia, T5 - Leaves of Mimosa hostilis, T6 - Branches of Mimosa hostilis, T7 - Leaves + branches of Mimosa hostilis, T8 - Leaves of Gliricidia sepium, T9 - Branches of Gliricidia sepium and T10 - Leaves + branches of Gliricidia sepium. Pots were filled with soil from a degraded area and residues were added in the form of green mass after sowing the maize. Residues of leguminous trees positively influenced maize growth at 65 days after application and favored the accumulation of nitrogen, phosphorus and potassium in the shoots. Green fertilizers improved soil chemical attributes at 65 days after application, especially nitrate-N (NO3 --N), ammonium-N (NH4 +-N), total inorganic N (NO3 --N + NH4 +-N) and K, demonstrating that these species are good options for recovering degraded areas in the semi-arid region of Ceará.


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