scholarly journals QUANTUM YIELD, PHOTOSYNTHETIC PIGMENTS AND BIOMASS OF MINIWATERMELON UNDER IRRIGATION STRATEGIES AND POTASSIUM1

2021 ◽  
Vol 34 (3) ◽  
pp. 659-669
Author(s):  
SAULO SOARES DA SILVA ◽  
GEOVANI SOARES DE LIMA ◽  
VERA LÚCIA ANTUNES DE LIMA ◽  
LAURIANE ALMEIDA DOS ANJOS SOARES ◽  
HANS RAJ GHEYI ◽  
...  

ABSTRACT This study was conducted with the objective of evaluating the quantum yield, photosynthetic pigments and biomass accumulation of mini watermelon cv. Sugar Baby, under strategies of irrigation with saline water and potassium fertilization. The experiment was conducted in a randomized block design, in a 8 × 3 factorial scheme, with three replicates, corresponding to eight strategies of irrigation with saline water applied at different phenological stages of the crop (control - irrigation with low-salinity water throughout the crop cycle, and salt stress in the vegetative, vegetative/flowering, flowering, flowering/fruiting, fruiting, fruiting/ fruit maturation and fruit maturation stage) and three potassium doses (50, 100 and 150% of the recommendation). The dose of 100% corresponded to 150 mg of K2O kg-1 of soil. Two levels of electrical conductivity of water were used: 0.8 and 4.0 dS m-1. Irrigation with water of 4.0 dS m-1 continuously in the vegetative and flowering stages increased the initial fluorescence and decreased the quantum efficiency of photosystem II of mini watermelon fertilized with 100 and 150% of K recommendation. Fertilization with 50% recommendation did not interfere in the fluorescence parameters of the mini watermelon, regardless of the irrigation management strategy. Chlorophyll a synthesis is inhibited by salt stress in the vegetative/flowering, flowering, flowering/fruiting, fruiting/maturation stages, as well as for total chlorophyll, except for the flowering stage. Application of 4.0 dS m-1 water in the flowering, fruiting/maturation and maturation stages promoted greater biomass accumulation in mini watermelon.

2020 ◽  
Vol 33 (2) ◽  
pp. 509-517
Author(s):  
TARSO MORENO ALVES DE SOUZA ◽  
VANDER MENDONÇA ◽  
FRANCISCO VANIES DA SILVA SÁ ◽  
MEDSON JANER DA SILVA ◽  
CAÍQUE SANTOS TOMÉ DOURADO

ABSTRACT Salt stress causes losses in the yields of crops, especially those of great economic and social-food importance, such as passion fruit. The objective of this study was to evaluate the effects of fertilization with calcium silicate on the mitigation of salt stress in yellow passion fruit seedlings. The experiment was conducted in a protected environment, in a randomized block design, arranged in a 4 x 3 factorial scheme, referring to four concentrations of calcium silicate (0; 2.22; 4.44 and 6.66 g per plant) and three levels of irrigation water salinity - ECw (0.5; 1.7 and 4.0 dS m-1), with four replicates, considering five plants as experimental unit. BRS GA1 seedlings were produced in 0.5-dm3 containers filled with a mixture of soil, washed sand and aged bovine manure, in a ratio of 1:1:1 (v:v:v). Plants received calcium silicate applications according to the studied doses in three plots, at 30, 45 and 60 days after sowing. At 90 days after sowing, plants were evaluated for growth and biomass accumulation. The use of water with salinity of 4.0 dS m-1 restricted the growth and biomass accumulation of passion fruit seedlings. The use of calcium silicate at dose of 3.5 g per plant mitigates salt stress in seedlings of passion fruit cultivar BRS GA1 when irrigated with saline water.


2018 ◽  
Vol 31 (4) ◽  
pp. 963-971 ◽  
Author(s):  
WELSON LIMA SIMÕES ◽  
MARCELO CALGARO ◽  
MIGUEL JULIO MACHADO GUIMARÃES ◽  
ANDERSON RAMOS DE OLIVEIRA ◽  
MÍRIAN PAULA MEDEIROS ANDRÉ PINHEIRO

ABSTRACT Sugarcane is one of the most affected crops by water scarcity. The efficient use of the irrigation water is an alternative to minimize this problem. The objective of this work was to evaluate biometric parameters, yield, and technological quality of sugarcane plants subjected to different controlled water deficit regimes in the sub-middle São Francisco Valley, Brazil. The experiment was conducted in a randomized block design, in two crop cycles, with three replications, with ten treatments consisted of three controlled water deficits (15%, 30%, and 45% of the crop evapotranspiration - ETc), applied at three development stages of the plant - sprouting and tillering (Stage I), grand growth (Stage II), and maturation (Stage III) - and a control with 100% of the ETc throughout the entire crop cycle. The controlled water deficit did not affect the technological quality of the sugarcane in any development stage. The sugarcane yield was higher when using a controlled water deficit of 30% of ETc in the sprouting and tillering stages of the plants. The water deficit of 15% of ETc is recommended for the grand growth, or maturation stages of the sugarcane plants for a greater water use efficiency of the production system.


Author(s):  
Luderlândio A. Silva ◽  
Marcos E. B. Brito ◽  
Pedro D. Fernandes ◽  
Francisco V. da S. Sá ◽  
Rômulo C. L. Moreira ◽  
...  

ABSTRACT This study aimed to evaluate the growth and physiology of citrus scion/rootstock combinations irrigated with saline water until the pre-flowering stage. The experiment was conducted in drainage lysimeters with capacity for 150 dm3, in randomized block design in a 2 x 10 factorial scheme, corresponding to two electrical conductivities of water (S1 = 0.3 and S2 = 3.0 dS m-1) and ten scion/rootstock combinations (nine hybrids and one commercial variety) grafted with Tahiti lime, in three repetitions and one plant per plot. Grafted seedlings were transplanted one year after sowing, subjected to salt stress from 15 days after transplanting until the pre-flowering period, and evaluated for gas exchanges and growth. The irrigation with 3.0 dS m-1 saline water did not influence the photosynthetic activity of the studied citrus scion/rootstock combinations until the pre-flowering. The genotype Santa Cruz Rangpur lime (LCRSTC) was more sensitive to irrigation water salinity in terms of growth. The least sensitive combinations to salinity were Tahiti lime grafted onto TSKFL x (LCR x TR) - 018, TSKFL x TRBK - 011 and TSKFL x TRBK - 30.


2021 ◽  
Vol 42 (6) ◽  
pp. 3219-3234
Author(s):  
Giordanio Bruno Silva Oliveira ◽  
◽  
Francisco de Assis de Oliveira ◽  
Sandy Thomaz dos Santos ◽  
Mychelle Karla Teixeira de Oliveira ◽  
...  

The use of saline water is one of the major challenges of agriculture, as it can cause nutritional imbalances and thus reduce crop yield. This study proposes to examine the efficiency of potassium nutrition as a salt stress-mitigating agent in melon grown in a protected environment. The experiment was laid out in a randomized-block design with ten treatments in a 2 × 4 factorial arrangement represented by two melon cultivars (McLaren and SV1044MF) and four nutrient solutions (S1 - standard nutrient solution, 2.5 dS m-1; S2 - nutrient solution salinized with NaCl, 5.0 dS m-1; S3 - nutrient solution salinized with NaCl + 50% K, 6.5 dS m-1; and S4 - nutrient solution salinized with NaCl + 100% K, 7.5 dS m-1). Yield (average fruit weight, production, fruit diameter, internal cavity, and pulp thickness), quality (pulp firmness, total sugars, soluble solids [SS], vitamin C, pH, titratable acidity [TA] and SS/TA ratio) and nutritional (K, Na and K/Na ratio) variables were evaluated. Plants fertigated with standard nutrient solution showed the highest values for fruit weight (1,190.6 g), production (2,381.3 g per plant), fruit diameter (13.6 cm) and pulp thickness (2.6 cm). Cultivar McLaren produced heavier fruits (931.4 g) with larger diameter (12.4 cm) and pulp thickness (2.4 cm). The addition of NaCl to nutrient solution induced a reduction in the yield variables but did not influence fruit quality. The addition of extra K to salinized nutrient solution did not mitigate the deleterious effect of salinity on the yield of melon.


Author(s):  
Jônatas R. M. de Sousa ◽  
Hans R. Gheyi ◽  
Marcos E. B. Brito ◽  
Claudivan F. de Lacerda ◽  
Francisco V. da Silva ◽  
...  

ABSTRACT This study aimed to evaluate the salt tolerance of 'Mimo do Céu' orange grafted onto three rootstocks using physiological parameters such as maximum quantum efficiency of photosystem II (PSII) and the production of fruits. It also evaluated the effectiveness of increased nitrogen (N) fertilization in reducing the effects of salt stress. Two concomitant experiments were carried out under controlled conditions, using drainage lysimeters. The Experiment I evaluated the effects of the application of five levels of saline water on three combinations of scion-rootstocks grafted with 'Mimo de Ceu' orange, in a randomized block design with three replicates in a 5 x 3 factorial scheme. The Experiment II evaluated the application of two N levels (100 and 200% of recommendation) in three scion-rootstock combinations irrigated with water of electrical conductivity of 3.0 dS m-1, in a 3 x 2 factorial scheme, with three replicates. The maximum quantum efficiency of PSII was inhibited in citrus plants under salt stress. 'Mimo do Ceu' orange grafted onto 'Common' Rangpur lime has higher yield potential. The increase in N dose did not reduce the deleterious effects of water salinity on fruit production.


Author(s):  
Geovani Soares de Lima ◽  
Adaan Sudario Dias ◽  
Leandro De Pádua Souza ◽  
Francisco Vanies da Silva Sá ◽  
Hans Raj Gheyi ◽  
...  

Due to the scarcity of water in the semi-arid region of Northeast Brazil, in both quantitative and qualitative terms, the use of saline water in agriculture should be considered as one alternative for irrigated agriculture. This study therefore aimed to evaluate the photosynthetic pigments, growth and production of West Indian Cherry as a function of irrigation using waters with different salinity levels and potassium (K) fertilization, after grafting. The study was carried out in drainage lysimeters under greenhouse conditions, in a eutrophic Regolithic Neosol with sandy loam texture, in the municipality of Campina Grande, PB. The experiment was set in a randomized block design, to test two levels of irrigation water electrical conductivity - ECw (0.8 and 3.8 dS m-1) and four K2O doses - KD (50, 75, 100 and 125% of recommendation), with three replicates. The dose relative to 100% corresponded to 79.2 mg K2O kg-1 of soil. Irrigation with high salinity water stimulated the biosynthesis of chlorophyll b and carotenoids, while the chlorophyll a content and the growth of the cherry were reduced markedly in the post-grafting phase. The harmful effects of salinity on the total number of fruit and fresh mass of West Indian Cherry fruit were minimized with potassium fertilization.


2020 ◽  
Vol 43 ◽  
pp. e48565
Author(s):  
Jéssica Pontes Rangel ◽  
Daniel Marçal de Queiroz ◽  
Francisco de Assis de Carvalho Pinto ◽  
Cleonice Campos Teixeira ◽  
Fábio Lúcio Santos ◽  
...  

The search for alternative energy sources has fomented the study of several crops. The macauba palm crop, for instance, has been highlighted because of its particular relevance in Brazil due to its wide distribution across Brazilian territory and its potential for yielding high amounts of oil per cultivated hectare. However, the species is still most commonly harvested via extractivism, which results in low yields. Therefore, we aimed to analyze the dynamic behavior of the fruit-rachilla system when subjected to mechanical vibration to gather baseline information for the subsequent development of macauba harvesting machines. The fruit-rachilla system of the species was modeled for different fruit maturation stages and plant accessions. Natural frequencies and modes of vibration were determined by the stochastic finite element method (FEM), adopting the specific mass and the modulus of elasticity of the system as random variables, which enabled us to compile a dataset of natural frequencies based on the variability of the system properties. The mean values of the natural frequencies obtained in the vibration assays were 26.02 Hz at the green maturation stage and 21.22 Hz at the ripe maturation stage. The mean values of natural frequencies found in the simulation by stochastic FEM, referring to the third mode of vibration, were 26.05 Hz at the green maturation stage and 21.23 Hz at the ripe maturation stage. We concluded that the natural frequencies of the macauba fruit-rachilla system on the basis of different plant accessions showed a decreasing behavior during fruit maturation. The modes of vibration characterized by pendulum displacement did not differ among plant accessions or between fruit maturation stages.


Author(s):  
Geovani S. de Lima ◽  
Francisco W. A. Pinheiro ◽  
Hans R. Gheyi ◽  
Lauriane A. dos A. Soares ◽  
Pedro F. do N. Sousa ◽  
...  

ABSTRACT The objective of this study was to evaluate the effects of saline water irrigation management strategies and potassium doses on the concentration of photosynthetic pigments, gas exchange, and fruit production of ‘BRS GA1’ yellow passion fruit. The experiment was carried out under field conditions using a randomized block design, with treatments based on a 6 × 2 factorial scheme, related to six management strategies for irrigation with saline water (irrigation with low-salinity water throughout the crop cycle-WS; irrigation with high-salinity water in the vegetative stage-VE; flowering stage-FL; fruiting stage-FR; and successively in vegetative/flowering stages-VE/FL and vegetative/fruiting stages-VE/FR) and two doses of potassium (60 and 100% of the recommendation), with four replicates. The dose of 100% recommendation corresponded to 345 g of K2O plant-1 year-1. High electrical conductivity irrigation water (4.0 dS m-1) was used in different phenological stages according to treatment, alternating with water of low electrical conductivity (1.3 dS m-1). The synthesis of chlorophyll a and b, stomatal conductance, instantaneous carboxylation efficiency and water use efficiency of ‘BRS GA1’ yellow passion fruit were reduced under irrigation with water of 4.0 dS m-1 in all strategies adopted. Fertilization with 60% of the K recommendation promoted greater number of fruits and yellow passion fruit yield. Irrigation with 4.0 dS m-1 water in the vegetative/flowering and flowering stages reduced the yield of yellow passion fruit.


Author(s):  
Aline D. A. de L. Marcelino ◽  
Pedro D. Fernandes ◽  
Jean P. C. Ramos ◽  
Wellison F. Dutra ◽  
José J. V. Cavalcanti ◽  
...  

ABSTRACT Two multivariate methods were adopted to classify salt-tolerant cotton genotypes based on their growth and physiological traits. The genotypes were cultivated in a greenhouse and subjected to 45 days of irrigation with saline water from the V4 phase onwards. Irrigation was performed with saline water with electrical conductivity (ECw) of 6.0 dS m-1. A factorial-randomized block design was adopted with nine cultivars, two treatments of ECw (0.6 as the control, and 6.0 dS m-1), and four replicates. Plants were evaluated for growth, gas exchange, and photosynthesis. The data were statistically analyzed using univariate and multivariate methods. For the latter, non-hierarchical (principal component, PC) and hierarchical (UPGMA) models were used for the classification of cultivars. Significant differences were found between cultivars based on univariate analyses, and the traits that differed statistically were used for multivariate analyses. Four groups were identified with the same composition in both the PC and UPGMA methods. Among them, one contained the cultivars BRS Seridó, BRS 286, FMT 705, and BRS Rubi, which were tolerant to salt stress imposed on the plants. Photosynthesis, transpiration, and stomatal conductance data were the main contributors to the classification of cultivars using the principal component method.


Author(s):  
Genilson L. Diniz ◽  
Reginaldo G. Nobre ◽  
Geovani S. de Lima ◽  
Leandro de P. Souza ◽  
Hans R. Gheyi ◽  
...  

ABSTRACT Abiotic stresses are responsible for the loss of agricultural production in different regions, especially in semiarid regions, which have long periods of drought and high evapotranspiration, leading to the use of saline water as an alternative for the expansion of irrigated areas. In this context, the objective was to evaluate the physiological indices and the growth of the ‘Gigante Amarelo’ passion fruit as a function of the salinity of irrigation water and fertilization with silicon. A randomized block design was used in a 5 x 2 factorial scheme, whose treatments consisted of five electrical conductivities of irrigation water - ECw (0.3; 1.0; 1.7, 2.4 and 3.1 dS m-1) associated with two doses of silicion (150 and 300 g of silicon plant-1) with four repetitions. Salt stress causes changes in gas exchange, chlorophyll a and b synthesis and growth of ‘Gigante Amarelo’ passion fruit plants, 60 days after transplanting. Fertilization with silicon dose of 300 g plant-1 promotes increments in CO2 assimilation rate and instantaneous water use efficiency, being able to mitigate the deleterious effects of salinity. Passion fruit plants fertilized with silicon dose of 300 g plant-1 attained greater growth in stem diameter and relative growth rate in stem diameter, from 30 to 60 days after transplanting.


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