Comunicata Scientiae
Not a member yet
996 research outputs found
Sort by
Morphological and physiological changes in papaya seedlings irrigated with saline water and application of humic substances
No full textIn the northeast semiarid region water with high salt content is very common, which may negatively affect crops growth and development. Thus using possible salt stress attenuators is extremely important because it allows the use of saline waters for agricultural purposes. Among the possible attenuators of salt stress, humic substances stand out. This work was driven in order to evaluate the effect of the application of humic substances as a possible attenuator of salt stress from papaya seedlings irrigation. The experiment was conducted under entirely randomized design with five replications in a 4 x 4 factorial, regarding the four doses of humic substances (5, 10, 15 and 20g), and the electrical conductivity of the irrigation water (ECw 1.5; 3.0; 4.5 and 6 dS m-1). When it irrigates the papaya seedlings with water of 6.0 dS m-1 is recommended dose of 20 g of humic substances, which provided growth. Irrigation of papaya seedlings with high salinity (3.0 and 4.5 dS m-1) allied with application of 20 g of humic substances provide increased CO2 concentration, transpiration rate, instantaneous water use efficiency, carboxylation efficiency and chlorophyll b content, however, stomatal conductance, net photosynthesis and chlorophyll a content are reduced with increase of the ECw.In the northeast semiarid region water with high salt content is very common, which may negatively affect crops growth and development. Thus using possible salt stress attenuators is extremely important because it allows the use of saline waters for agricultural purposes. Among the possible attenuators of salt stress, humic substances stand out. This work was driven in order to evaluate the effect of the application of humic substances as a possible attenuator of salt stress from papaya seedlings irrigation. The experiment was conducted under entirely randomized design with five replications in a 4 x 4 factorial, regarding the four doses of humic substances (5, 10, 15 and 20g), and the electrical conductivity of the irrigation water (ECw 1.5; 3.0; 4.5 and 6 dS m-1). When it irrigates the papaya seedlings with water of 6.0 dS m-1 is recommended dose of 20 g of humic substances, which provided growth. Irrigation of papaya seedlings with high salinity (3.0 and 4.5 dS m-1) allied with application of 20 g of humic substances provide increased CO2 concentration, transpiration rate, instantaneous water use efficiency, carboxylation efficiency and chlorophyll b content, however, stomatal conductance, net photosynthesis and chlorophyll a content are reduced with increase of the ECw
Phytomass and quality of yellow passion fruit seedlings under salt stress and silicon fertilization
Get PDFThe semiarid region of Northeastern Brazil is characterized by long drought periods, and the use of saline waters appears as an alternative for the expansion of irrigated areas. Associated with the use of these waters, silicon fertilization constitutes an important attenuator of salt stress. In this perspective, this study aimed to evaluate the phytomass production and quality of the passion fruit cultivar ‘Gigante Amarelo’ grown with saline water and silicon fertilization. The experiment was conducted in a plant nursery belonging to the Center of Agrifood Science and Technology, in the municipality of Pombal-PB. A completely randomized block design in a 5 x 5 factorial scheme was used, referring to five levels of electrical conductivity of the irrigation water (0.3, 1.0, 1.7, 2.4, and 3.1 dS m-1) and five doses of silicon fertilization (0; 25; 50; 75, and 100 g of potassium silicate/plant), with four replications and two plants per plot. The phytomass accumulation (leaves, stem, and roots), as well as the total dry phytomass, shoot dry phytomass, root/shoot ratio, and the quality index of Dickson were evaluated. The data obtained were subjected to the F-test at 0.01 and 0.05 level of probability. The electrical conductivity of water from 0.3 dS m-1 caused the decrease of phytomass production in seedlings of the passion fruit cultivar ‘Gigante Amarelo’, although it is possible to produce good quality passion fruit seedlings with water salinity up to 3.1 dS m-1. The doses of silicon fertilization mitigated the effect of salt stress on the root/shoot ratio of plants of the passion fruit cultivar ‘Gigante Amarelo’.The semiarid region of Northeastern Brazil is characterized by long drought periods, and the use of saline waters appears as an alternative for the expansion of irrigated areas. Associated with the use of these waters, silicon fertilization constitutes an important attenuator of salt stress. In this perspective, this study aimed to evaluate the phytomass production and quality of the passion fruit cultivar ‘Gigante Amarelo’ grown with saline water and silicon fertilization. The experiment was conducted in a plant nursery belonging to the Center of Agrifood Science and Technology, in the municipality of Pombal-PB. A completely randomized block design in a 5 x 5 factorial scheme was used, referring to five levels of electrical conductivity of the irrigation water (0.3, 1.0, 1.7, 2.4, and 3.1 dS m-1) and five doses of silicon fertilization (0; 25; 50; 75, and 100 g of potassium silicate/plant), with four replications and two plants per plot. The phytomass accumulation (leaves, stem, and roots), as well as the total dry phytomass, shoot dry phytomass, root/shoot ratio, and the quality index of Dickson were evaluated. The data obtained were subjected to the F-test at 0.01 and 0.05 level of probability. The electrical conductivity of water from 0.3 dS m-1 caused the decrease of phytomass production in seedlings of the passion fruit cultivar ‘Gigante Amarelo’, although it is possible to produce good quality passion fruit seedlings with water salinity up to 3.1 dS m-1. The doses of silicon fertilization mitigated the effect of salt stress on the root/shoot ratio of plants of the passion fruit cultivar ‘Gigante Amarelo’
Performance of the root system of tomato plants inoculated with arbuscular mycorrhizal fungi and submitted to the grafting technique
Get PDFInformation about the combined use of arbuscular mycorrhizal fungi (AMF) in grafted horticultural crops are scarce, as is the case of tomato. Therefore, we investigated if the association between AMF and the grafting technique modifies the performance of the root system of tomato plants grown on substrate. The treatments, outlined in a two-factorial scheme, were absence of inoculation and two inoculants of AMF (Rhizophagus clarus and mycorrhizal community) inserted in grafted and non-grafted tomato plants. The experiment was designed entirely at random, with five replications. The evaluations in the root system of the plants were carried out at 30 and 120 days after transplantation (DAT). Grafted plants evaluated at 30 DAT showed greater mycorrhizal colonization when cultivated with R. clarus. However, in the 120 DAT evaluation, the greatest mycorrhizal colonization was observed in non-grafted plants produced with the mycorrhizal community. At 120 DAT, the plants produced with the mycorrhizal community showed a more developed root system in relation to non-mycorrhized plants. The root system of plants non-grafted at 120 DAT was more robust when compared to grafted plants. In conclusion, the AMF-grafting interface interferes in the mycorrhizal colonization of the root system of tomato plants. The grafting technique does not improve the development of the root system. The inoculation of tomato plants with the mycorrhizal community enhances the development of roots at 120 DAT.Information about the combined use of arbuscular mycorrhizal fungi (AMF) in grafted horticultural crops are scarce, as is the case of tomato. Therefore, we investigated if the association between AMF and the grafting technique modifies the performance of the root system of tomato plants grown on substrate. The treatments, outlined in a two-factorial scheme, were absence of inoculation and two inoculants of AMF (Rhizophagus clarus and mycorrhizal community) inserted in grafted and non-grafted tomato plants. The experiment was designed entirely at random, with five replications. The evaluations in the root system of the plants were carried out at 30 and 120 days after transplantation (DAT). Grafted plants evaluated at 30 DAT showed greater mycorrhizal colonization when cultivated with R. clarus. However, in the 120 DAT evaluation, the greatest mycorrhizal colonization was observed in non-grafted plants produced with the mycorrhizal community. At 120 DAT, the plants produced with the mycorrhizal community showed a more developed root system in relation to non-mycorrhized plants. The root system of plants non-grafted at 120 DAT was more robust when compared to grafted plants. In conclusion, the AMF-grafting interface interferes in the mycorrhizal colonization of the root system of tomato plants. The grafting technique does not improve the development of the root system. The inoculation of tomato plants with the mycorrhizal community enhances the development of roots at 120 DAT
Morphophysiology of the passion fruit ‘BRS Rubi do Cerrado’ irrigated with saline waters and nitrogen fertilization
Get PDFThis study aimed to evaluate the gas exchanges and growth of the purple passion fruit cultivar ‘BRS Rubi do Cerrado’ as a function of the salinity levels of the irrigation water and nitrogen fertilization. The research was conducted in pots adapted as drainage lysimeters, placed within a plant nursery, using a Regolithic Neosol of sandy texture, in the municipality of Pombal-PB, Brazil. A randomized block design was used, testing five levels of electrical conductivity of irrigation water (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1) associated with four doses of nitrogen (50, 75, 100, and 125% of the recommendation). The irrigation water salinity above 0.3 dS m-1 compromised the leaf area and the relative water content of the purple passion fruit ‘BRS Rubi do Cerrado’. High doses of nitrogen enhance the deleterious effects of irrigation water salinity on stomatal conductance, transpiration, internal CO2 concentration, CO2 assimilation rate, number of leaves, stem diameter, and height of purple passion fruit plants. When waters with salinity levels of up to 1.3 dS m-1 are used, the dose of 125 mg of N kg-1 of soil is recommendation for providing increases in the CO2 assimilation rate of the purple passion fruit ‘BRS Rubi do Cerrado’ at 70 days after sowing (DAS). Water salinity increases electrolyte leakage, regardless of nitrogen doses.This study aimed to evaluate the gas exchanges and growth of the purple passion fruit cultivar ‘BRS Rubi do Cerrado’ as a function of the salinity levels of the irrigation water and nitrogen fertilization. The research was conducted in pots adapted as drainage lysimeters, placed within a plant nursery, using a Regolithic Neosol of sandy texture, in the municipality of Pombal-PB, Brazil. A randomized block design was used, testing five levels of electrical conductivity of irrigation water (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1) associated with four doses of nitrogen (50, 75, 100, and 125% of the recommendation). The irrigation water salinity above 0.3 dS m-1 compromised the leaf area and the relative water content of the purple passion fruit ‘BRS Rubi do Cerrado’. High doses of nitrogen enhance the deleterious effects of irrigation water salinity on stomatal conductance, transpiration, internal CO2 concentration, CO2 assimilation rate, number of leaves, stem diameter, and height of purple passion fruit plants. When waters with salinity levels of up to 1.3 dS m-1 are used, the dose of 125 mg of N kg-1 of soil is recommendation for providing increases in the CO2 assimilation rate of the purple passion fruit ‘BRS Rubi do Cerrado’ at 70 days after sowing (DAS). Water salinity increases electrolyte leakage, regardless of nitrogen doses
Pruning management of ‘Marselan’ grapevines in the Serra do Sudeste region, in Southern Brazil
Get PDFThe agronomical behavior of the ‘Marselan’ grapevine, indicated for the production of high-quality fine wines, is related to the management of the vineyard and the edaphoclimatic conditions of the cultivation region. This work aimed to evaluate the vegetative, productive, and qualitative behavior of ‘Marselan’ grapevines subjected to the Spur Pruning and Double Guyot pruning systems, cultivated in a municipality belonging to the Serra do Sudeste region, RS state, Brazil. The ‘Marselan’ grapevines were conducted in a vertical shoot positioning training system over a ‘Paulsen 1103’ rootstock, in a commercial vineyard located in Encruzilhada do Sul, RS, Brazil. During the 2016/2017 and 2017/2018 cropping seasons the vegetative vigor, the mass of pruned shoots, Ravaz Index, production, and chemical-physical composition of the must were evaluated. The double Guyot pruning system in the ‘Marselan’ grapevines induced a lower plant vigor, promoted an increase in the number of bunches per plant, bunch mass, production, and yield. The pruning type interferes with the vigor and yield of the ‘Marselan’ grapes without altering must quality. In the management of the cv. ‘Marselan’ in the Serra do Sudeste region, Brazil, the double Guyot pruning system is the most indicated.The agronomical behavior of the ‘Marselan’ grapevine, indicated for the production of high-quality fine wines, is related to the management of the vineyard and the edaphoclimatic conditions of the cultivation region. This work aimed to evaluate the vegetative, productive, and qualitative behavior of ‘Marselan’ grapevines subjected to the Spur Pruning and Double Guyot pruning systems, cultivated in a municipality belonging to the Serra do Sudeste region, RS state, Brazil. The ‘Marselan’ grapevines were conducted in a vertical shoot positioning training system over a ‘Paulsen 1103’ rootstock, in a commercial vineyard located in Encruzilhada do Sul, RS, Brazil. During the 2016/2017 and 2017/2018 cropping seasons the vegetative vigor, the mass of pruned shoots, Ravaz Index, production, and chemical-physical composition of the must were evaluated. The double Guyot pruning system in the ‘Marselan’ grapevines induced a lower plant vigor, promoted an increase in the number of bunches per plant, bunch mass, production, and yield. The pruning type interferes with the vigor and yield of the ‘Marselan’ grapes without altering must quality. In the management of the cv. ‘Marselan’ in the Serra do Sudeste region, Brazil, the double Guyot pruning system is the most indicated
Increase of nutrients export and production of pitaya whit potassium fertilization
Get PDFCharacterization works of pitayas show that the potassium (K) is the nutrient most exported, thus, influences in the productivity and quality of this fruit. However, these researches do not report the nutrients export by pitaya\u27s associating the fertilization carried out in the orchard, information that is relevant to make the nutrients reposition adequate at the time of fertilization. The research was carried out to evaluate the supply of K2O in the export of nutrients and productivity of the Hylocereus undatus and Hylocereus polyrhizus pitaya species. The analysis was carried out in the mature fruits harvested in two harvests. Potassium fertilization was performed at doses of 0; 50; 100 and 200 g of K2O per plant. Nutrient export per ton of fruit was calculated from the determination of the nutrient levels and the dry matter of the pitaya pulp. The export of nutrients by the pitaya of the species H. undatus and H. polyrhizus occurs in the following order: K>N>P>Ca>Mg> and Mn>Fe>Cu>Zn>B. These species of pitaya have similar nutritional requirements, enabling them to be receive same fertilization management. The amount of nutrients exported was higher in plants fertilized with potassium due to the higher productivity achieved. Orchards of pitaya that reach high productivity require a greater quantity of nutrients, due to the increase export by the fruits.Characterization works of pitayas show that the potassium (K) is the nutrient most exported, thus, influences in the productivity and quality of this fruit. However, these researches do not report the nutrients export by pitaya\u27s associating the fertilization carried out in the orchard, information that is relevant to make the nutrients reposition adequate at the time of fertilization. The research was carried out to evaluate the supply of K2O in the export of nutrients and productivity of the Hylocereus undatus and Hylocereus polyrhizus pitaya species. The analysis was carried out in the mature fruits harvested in two harvests. Potassium fertilization was performed at doses of 0; 50; 100 and 200 g of K2O per plant. Nutrient export per ton of fruit was calculated from the determination of the nutrient levels and the dry matter of the pitaya pulp. The export of nutrients by the pitaya of the species H. undatus and H. polyrhizus occurs in the following order: K>N>P>Ca>Mg> and Mn>Fe>Cu>Zn>B. These species of pitaya have similar nutritional requirements, enabling them to be receive same fertilization management. The amount of nutrients exported was higher in plants fertilized with potassium due to the higher productivity achieved. Orchards of pitaya that reach high productivity require a greater quantity of nutrients, due to the increase export by the fruits
Organic compost as a conditioner of soils cultivated with yellow passion fruit
Get PDFThis research aimed to evaluate the effect of doses of organic compost on the yield and economic profitability of organic yellow passion fruit grown in sandy-loam and clay-loam soils. Two experiments were installed in the field, in different soil types and municipalities in the state of Acre. The experimental design was in randomized blocks with five treatments, four replications, and four plants per experimental unit. The treatments consisted of adding the compost as a replacement for 1/3 of the volume of cylindrical planting holes with 40 cm, 80 cm, 120 cm, 160 cm, and 200 cm, corresponding to the addition of 6.3; 25.1; 56.5; 100.4, and 156.9 liters per planting hole, respectively. The mean fruit mass and the yield of the yellow passion fruit were higher in sandy-loam soil. The total revenue was R 5,841.9 ha-1 in the sandy soil. The total cost was higher in the clayey soil than in sandy soil. Both soils responded in quadratic function with an increase in the cost as the volume of organic compost was increased, ranging from R 26,249.63 ha-1 with 156.9 liters of compost per hole. Net income was negative for all compost volumes in both types of soil, responding linearly, with a reduction in revenue of R 4,311.6 ha-1 in the clayey soil and R 12,736.00 ha-1 with 6.3 liters of compost per hole up to R 80.82 ha-1 with the addition of each liter of compost in the pit due to the low yield caused by period long drought
Quality of guava fruits bagged with different materials in an organic system
Get PDFThis study aimed to evaluate the interference of bagging materials on the incidence of insect larvae and the physical and chemical quality of the guava cv. Paluma in an organic system. The experimental design was in randomized blocks with seven treatments and four replications of 25 fruits each. The bagging materials (treatments) were: nonwoven fabric (TNT), transparent plastic bag, white plastic bag, parchment paper, kraft paper, and non-bagged fruits (control). The titratable acidity (TA), ascorbic acid, soluble solids (SS), SS/TA ratio, fresh mass, fruit diameter, fruit length, appearance, and fruit fly incidence were evaluated. Fruit bagging increased the fresh fruit mass, except the tulle bag, which did not change fruit diameter but increased fruit length. There was a high incidence of fruit flies in the non-bagged fruits (100%) and in those with tulle bags (56.53%), reduced to 2.15% when using parchment paper, and reaching the absence of bored fruits when using nonwoven fabric, transparent plastic, and white plastic bags, materials that provided the highest percentages of marketable fruits. All bagging materials did not change the total titratable acidity content and the SS/TA ratio; however, all of them reduced the content of total soluble solids, except the tulle bag. Fruit bagging with nonwoven fabric and parchment paper increased the content of ascorbic acid. Fruit bagging with parchment paper, plastic bag, and nonwoven fabric are efficient in the organic production of guavas for preventing the infection by insect larvae and maintaining the physical and chemical quality of the fruit.This study aimed to evaluate the interference of bagging materials on the incidence of insect larvae and the physical and chemical quality of the guava cv. Paluma in an organic system. The experimental design was in randomized blocks with seven treatments and four replications of 25 fruits each. The bagging materials (treatments) were: nonwoven fabric (TNT), transparent plastic bag, white plastic bag, parchment paper, kraft paper, and non-bagged fruits (control). The titratable acidity (TA), ascorbic acid, soluble solids (SS), SS/TA ratio, fresh mass, fruit diameter, fruit length, appearance, and fruit fly incidence were evaluated. Fruit bagging increased the fresh fruit mass, except the tulle bag, which did not change fruit diameter but increased fruit length. There was a high incidence of fruit flies in the non-bagged fruits (100%) and in those with tulle bags (56.53%), reduced to 2.15% when using parchment paper, and reaching the absence of bored fruits when using nonwoven fabric, transparent plastic, and white plastic bags, materials that provided the highest percentages of marketable fruits. All bagging materials did not change the total titratable acidity content and the SS/TA ratio; however, all of them reduced the content of total soluble solids, except the tulle bag. Fruit bagging with nonwoven fabric and parchment paper increased the content of ascorbic acid. Fruit bagging with parchment paper, plastic bag, and nonwoven fabric are efficient in the organic production of guavas for preventing the infection by insect larvae and maintaining the physical and chemical quality of the fruit
Industrial residues as substrate components for the production of Ilex paraguariensis seedlings
Get PDFIlex paraguariensis is an important forest species in Brazil. Recently, the development of new products has increased seedlings demand and consequently, the interest in new products to use as substrates like residues from industries. We aimed to evaluate the viability of using industrial residues as substrates to produce yerba mate seedlings. We formulated thirteen substrates with coconut fiber, carbonized and decomposed yerba mate industrial residues in different ratios, which were compared to two commercial substrates, in a completely randomized design. The stratified seeds were placed in 110 cm³ tubes filled with the substrates. Plants were kept in a greenhouse for 135 days, shade house (70%) for 30 days, and rustification area in full sunlight for 15 days, under fertigation after 30 days of sowing. We evaluated montlhy the survival, height, and stem diameter, and at the end of the production period, we evaluated shoot and root dry mass. From the data obtained, we calculated the total dry mass and ‘Dickson quality index’. The substrates formulated with coconut fiber and decomposed yerba mate industrial residue can be used to produce yerba mate seedlings, but it depends on the ratio of the substrate components. Substrates with higher total porosity and microporosity provided seedlings with biometric characteristics similar to those produced in commercial substrates. The carbonized yerba mate residue reduced seedling growth when used in a percentage equal to or higher than 50% in the substrate.Ilex paraguariensis is an important forest species in Brazil. Recently, the development of new products has increased seedlings demand and consequently, the interest in new products to use as substrates like residues from industries. We aimed to evaluate the viability of using industrial residues as substrates to produce yerba mate seedlings. We formulated thirteen substrates with coconut fiber, carbonized and decomposed yerba mate industrial residues in different ratios, which were compared to two commercial substrates, in a completely randomized design. The stratified seeds were placed in 110 cm³ tubes filled with the substrates. Plants were kept in a greenhouse for 135 days, shade house (70%) for 30 days, and rustification area in full sunlight for 15 days, under fertigation after 30 days of sowing. We evaluated montlhy the survival, height, and stem diameter, and at the end of the production period, we evaluated shoot and root dry mass. From the data obtained, we calculated the total dry mass and ‘Dickson quality index’. The substrates formulated with coconut fiber and decomposed yerba mate industrial residue can be used to produce yerba mate seedlings, but it depends on the ratio of the substrate components. Substrates with higher total porosity and microporosity provided seedlings with biometric characteristics similar to those produced in commercial substrates. The carbonized yerba mate residue reduced seedling growth when used in a percentage equal to or higher than 50% in the substrate
Physiological characteristics of endive, lettuce and chicory seeds as a function of spectral quality
Get PDFSeedling production is a critical step in the establishment of vegetables. This work aimed to evaluate the effect of different spectral qualities on the germination and vigor of endive, lettuce, and chicory seeds. The experiment was carried out in three stages. The first stage, two cultivars of lettuce (‘Crespa Repolhuda’ and ‘Vera’) and six spectral qualities (blue LED, red LED, blue + red LED, white LED, fluorescent and dark) were evaluated; the second stage, two cultivars of chicory (‘Lisa Escarola’ and ‘Palla Rosa’) and the same spectral qualities were evaluated. In the third stage, the spectral quality of the endive cultivar ‘Pão de Açúcar’ was evaluated. The experiments were performed in a completely randomized design, with four replications of 50 seeds each. The evaluated parameters were: germination percentage, first count, germination speed index, seedling length, and fresh and dry mass. Endive, lettuce and chicory seeds germinated both in the presence or not of light so that they can be classified as neutral photos. A spectral LED of red quality fostered the development of the most significant volume of fresh mass on the endive, lettuce, and chicory. All the spectral qualities stimulated root growth. The dark, on the other hand, promoted the most significant length of the aerial part, promoting seedlings etiolation.Seedling production is a critical step in the establishment of vegetables. This work aimed to evaluate the effect of different spectral qualities on the germination and vigor of endive, lettuce, and chicory seeds. The experiment was carried out in three stages. The first stage, two cultivars of lettuce (‘Crespa Repolhuda’ and ‘Vera’) and six spectral qualities (blue LED, red LED, blue + red LED, white LED, fluorescent and dark) were evaluated; the second stage, two cultivars of chicory (‘Lisa Escarola’ and ‘Palla Rosa’) and the same spectral qualities were evaluated. In the third stage, the spectral quality of the endive cultivar ‘Pão de Açúcar’ was evaluated. The experiments were performed in a completely randomized design, with four replications of 50 seeds each. The evaluated parameters were: germination percentage, first count, germination speed index, seedling length, and fresh and dry mass. Endive, lettuce and chicory seeds germinated both in the presence or not of light so that they can be classified as neutral photos. A spectral LED of red quality fostered the development of the most significant volume of fresh mass on the endive, lettuce, and chicory. All the spectral qualities stimulated root growth. The dark, on the other hand, promoted the most significant length of the aerial part, promoting seedlings etiolation