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Allometry and morphophysiology of papaya seedlings in a substrate with polymer under irrigation with saline water
Get PDFThe availability and quality of the irrigation water are among the limitations for the development of agriculture in the semiarid. Aiming at gathering information on these limitations, this work aimed to evaluate the association between a water-absorbing polymer and water salinity in irrigation frequencies, as well as container volumes on the allometric and morphophysiological indices of seedlings of the papaya (Carica papaya) cultivar ‘Sunrise Solo’. The treatments were obtained from the combination between the water-absorbing polymer (0.0; 0.2; 0.6; 1.0, and; 1.2 g dm-3), the electrical conductivity of the irrigation water (0.3; 1.1; 2.7; 4.3, and; 5.0 dS m-1), and irrigation frequencies (daily and alternate), plus two additional treatments (0.75 and 1.30 dm3) to study the effects of the container volume, distributed in a randomized block design. At 55 days after sowing, the following characteristics were evaluated: ratio between stem height and diameter; ratio between shoot and root dry matter; root density; leaf blade area; ratio between total leaf area and root dry mass; specific leaf area; leaf area ratio; leaf mass ratio; and Dickson quality index. The allometric and morphophysiological indices were damaged by the increase of water electrical conductivity and favored by the application of the polymer and a higher irrigation frequency. In the production of papaya seedlings, a daily irrigation frequency must be prioritized, using containers of 0.75 or 1.30 dm-3, water with electrical conductivity up to 2.6 and 1.9 dS m-1 when irrigated daily or in alternate days, respectively, and 0.6 g dm-3 of polymer.The availability and quality of the irrigation water are among the limitations for the development of agriculture in the semiarid. Aiming at gathering information on these limitations, this work aimed to evaluate the association between a water-absorbing polymer and water salinity in irrigation frequencies, as well as container volumes on the allometric and morphophysiological indices of seedlings of the papaya (Carica papaya) cultivar ‘Sunrise Solo’. The treatments were obtained from the combination between the water-absorbing polymer (0.0; 0.2; 0.6; 1.0, and; 1.2 g dm-3), the electrical conductivity of the irrigation water (0.3; 1.1; 2.7; 4.3, and; 5.0 dS m-1), and irrigation frequencies (daily and alternate), plus two additional treatments (0.75 and 1.30 dm3) to study the effects of the container volume, distributed in a randomized block design. At 55 days after sowing, the following characteristics were evaluated: ratio between stem height and diameter; ratio between shoot and root dry matter; root density; leaf blade area; ratio between total leaf area and root dry mass; specific leaf area; leaf area ratio; leaf mass ratio; and Dickson quality index. The allometric and morphophysiological indices were damaged by the increase of water electrical conductivity and favored by the application of the polymer and a higher irrigation frequency. In the production of papaya seedlings, a daily irrigation frequency must be prioritized, using containers of 0.75 or 1.30 dm-3, water with electrical conductivity up to 2.6 and 1.9 dS m-1 when irrigated daily or in alternate days, respectively, and 0.6 g dm-3 of polymer
O Cultivation of safflower flower stems with seeds treated by thermotherapy: Hastes florais de cártamo
No full textThe floral stems of safflower (Carthamus tinctorius L.) present an ornamental character due to their rusticity and versatility of use. The propagation via seeds shows high incidence of pathogens, negatively affecting the establishment of plants in the field, requiring treatments. Thus, the objective of this study was to evaluate the cultivation of safflower flower stems from seeds treated by thermotherapy and sown at different seasons in the year. The experiment was carried out in a completely randomized, 4 x 3 factorial design (sowing dates and thermotherapy treatments), with four replications. Sowings took place in the first seasonal fortnights (spring and summer of 2016, and autumn and winter of 2017), after undergoing thermotherapy treatment or not: control (without treatment), moist heat thermotherapy (45º C 15 min-1) and heat dry thermotherapy (45º C 24 h-1). It was evaluated the emergence of seedlings for plant stand formation, the phenological stages until flowering, the duration of the cultivation cycle, phyllochron, anthochron, the biometry of flower stems and inflorescences. It was observed that the seed treatments via thermotherapy were beneficial for the initial establishment of seedlings in the field. The development and duration of the cultivation cycle of the flower stems were different for all sowing dates, with the maintenance of the ornamental characteristics and the quality of the flower stems.The floral stems of safflower (Carthamus tinctorius L.) present an ornamental character due to their rusticity and versatility of use. The propagation via seeds shows high incidence of pathogens, negatively affecting the establishment of plants in the field, requiring treatments. Thus, the objective of this study was to evaluate the cultivation of safflower flower stems from seeds treated by thermotherapy and sown at different seasons in the year. The experiment was carried out in a completely randomized, 4 x 3 factorial design (sowing dates and thermotherapy treatments), with four replications. Sowings took place in the first seasonal fortnights (spring and summer of 2016, and autumn and winter of 2017), after undergoing thermotherapy treatment or not: control (without treatment), moist heat thermotherapy (45º C 15 min-1) and heat dry thermotherapy (45º C 24 h-1). It was evaluated the emergence of seedlings for plant stand formation, the phenological stages until flowering, the duration of the cultivation cycle, phyllochron, anthochron, the biometry of flower stems and inflorescences. It was observed that the seed treatments via thermotherapy were beneficial for the initial establishment of seedlings in the field. The development and duration of the cultivation cycle of the flower stems were different for all sowing dates, with the maintenance of the ornamental characteristics and the quality of the flower stems
Radish production under different shading screens and mulching
Get PDFShading Screens and mulching may provide a favorable environment for radish growing in regions of adverse climates. This work aimed to evaluate the radish productivity under the influence of different shading screens associated with the presence and absence of mulch in two different years. The experiment was carried out in two different seasons (2017 dry season and 2018 rainy season), in the vegetable garden of Liberdade campus, at the University of International Integration of Afro-Brazilian Lusophony (Unilab), municipality of Redenção-CE. The experimental design was in randomized blocks in a split-plot arrangement, with four repetitions, in which the plots consisted of growing with and without mulching and in the subplots, five shading screens: 50% Black Shading Screen (50% BSS), 50% Red Shading Screen (50% RSS), 30% White Shading Screen (30% WSS), 70% Black Shading Screen (70% BSS) ), and full sunlight (FS). The red shading screens 50% and white 30%, in addition to cultivation under full sunlight, provide higher performance in terms of the number of leaves, tuberous root diameter, tuberous root matter, and the radish crop productivity, regardless of the evaluated period. The applied mulch does not influence the productivity of the rabante, influencing only the gain of dry mass of the aerial part, soluble solids and length of the tuberous root.Shading Screens and mulching may provide a favorable environment for radish growing in regions of adverse climates. This work aimed to evaluate the radish productivity under the influence of different shading screens associated with the presence and absence of mulch in two different years. The experiment was carried out in two different seasons (2017 dry season and 2018 rainy season), in the vegetable garden of Liberdade campus, at the University of International Integration of Afro-Brazilian Lusophony (Unilab), municipality of Redenção-CE. The experimental design was in randomized blocks in a split-plot arrangement, with four repetitions, in which the plots consisted of growing with and without mulching and in the subplots, five shading screens: 50% Black Shading Screen (50% BSS), 50% Red Shading Screen (50% RSS), 30% White Shading Screen (30% WSS), 70% Black Shading Screen (70% BSS) ), and full sunlight (FS). The red shading screens 50% and white 30%, in addition to cultivation under full sunlight, provide higher performance in terms of the number of leaves, tuberous root diameter, tuberous root matter, and the radish crop productivity, regardless of the evaluated period. The applied mulch does not influence the productivity of the rabante, influencing only the gain of dry mass of the aerial part, soluble solids and length of the tuberous root
Three species of Colletotrichum are associated with anthracnose of pomegranate in Brazil
Get PDFPomegranate is a fruit rich in vitamins and secondary metabolites used in traditional medicine and industry. However, production losses have been associated the anthracnose, disease caused by Colletotrichum species. This is an important disease of the pomegranate, as it affects the yield and the quality of the fruits. The present study aimed to investigate which species of Colletotrichum are associated with anthracnose disease in pomegranate in the Northeast region of Brazil, using multi-locus phylogenetic analysis and morpho-cultural characteristics. The total DNA extracted was amplified with GAPDH, TUB2, CAL, ACT genes and the ITS-rDNA region. The sequences obtained were used for the construction of phylogenetic trees of Bayesian inference. The mycelial growth rate, size and shape of the conidia and appressories were evaluated for the morpho-cultural characterization of the species. Six isolates were analysis and three species belonging to the C. gloeosporioides complex were identified in this study. This is the first report of C. theobromicola (2) in pomegranate fruit in Brazil and C. siamense (2) and C. fructicola (2) in the world.Pomegranate is a fruit rich in vitamins and secondary metabolites used in traditional medicine and industry. However, production losses have been associated the anthracnose, disease caused by Colletotrichum species. This is an important disease of the pomegranate, as it affects the yield and the quality of the fruits. The present study aimed to investigate which species of Colletotrichum are associated with anthracnose disease in pomegranate in the Northeast region of Brazil, using multi-locus phylogenetic analysis and morpho-cultural characteristics. The total DNA extracted was amplified with GAPDH, TUB2, CAL, ACT genes and the ITS-rDNA region. The sequences obtained were used for the construction of phylogenetic trees of Bayesian inference. The mycelial growth rate, size and shape of the conidia and appressories were evaluated for the morpho-cultural characterization of the species. Six isolates were analysis and three species belonging to the C. gloeosporioides complex were identified in this study. This is the first report of C. theobromicola (2) in pomegranate fruit in Brazil and C. siamense (2) and C. fructicola (2) in the world
Sugar apple seedling production as a function of substrates and slow-release fertilizer
Get PDFThere is still a lack of studies on the effect of slow-release fertilizers and substrates on the production of high-quality sugar apple seedlings. In this context, the present study aimed to evaluate the quality and biomass of sugar apple seedlings grown in organic substrates at doses of slow-release fertilizer. The experimental design was randomized blocks in split-plot scheme, with four replicates and eleven plants per plot. Substrates were evaluated in the plots (fresh sugarcane bagasse; enriched sugarcane bagasse; coconut powder; commercial organic substrate Tropstrato®), whereas the doses of the slow-release fertilizer Osmocote® were evaluated in the subplots (0; 3; 6; 9; 12 and 15 kg m-3 of substrate). Substrates and slow-release fertilizer doses had effect on the formation of sugar apple seedlings. The effect of slow-release fertilizer is influenced by the substrate used in the formation of sugar apple seedlings. The substrate coconut powder showed the best performance for E%, NL and LAI in sugar apple plants, which reinforces its recommendation to be used in seedling production. For the studied conditions, based on the DQI, we recommend coconut powder associated with the slow-release fertilizer dose of 9 kg m-3 to produce sugar apple seedlings.There is still a lack of studies on the effect of slow-release fertilizers and substrates on the production of high-quality sugar apple seedlings. In this context, the present study aimed to evaluate the quality and biomass of sugar apple seedlings grown in organic substrates at doses of slow-release fertilizer. The experimental design was randomized blocks in split-plot scheme, with four replicates and eleven plants per plot. Substrates were evaluated in the plots (fresh sugarcane bagasse; enriched sugarcane bagasse; coconut powder; commercial organic substrate Tropstrato®), whereas the doses of the slow-release fertilizer Osmocote® were evaluated in the subplots (0; 3; 6; 9; 12 and 15 kg m-3 of substrate). Substrates and slow-release fertilizer doses had effect on the formation of sugar apple seedlings. The effect of slow-release fertilizer is influenced by the substrate used in the formation of sugar apple seedlings. The substrate coconut powder showed the best performance for E%, NL and LAI in sugar apple plants, which reinforces its recommendation to be used in seedling production. For the studied conditions, based on the DQI, we recommend coconut powder associated with the slow-release fertilizer dose of 9 kg m-3 to produce sugar apple seedlings
In vitro germination of pollen grains of three native species from Pampa biome with ornamental potential
Get PDFThe aim of this work was to verify the in vitro germination of pollen grains of Angelonia integerrima L., Campomanesia aurea O. Berg and Sesbania punicea (Cav.) Benth in different culture medium and temperatures. For this purpose, flower buds from which pollen was collected and sprayed on plates containing the three evaluated culture medium: M1 - agar and sucrose; M2 - agar, sucrose and H3BO3; M3 - agar, sucrose, H3BO3, Ca(NO3), MgSO4 and KNO3; and two incubation temperatures (20 °C and 30 °C). Data was subjected to analysis of variance after its transformation to square root and means were compared by Fisher’s test (LSD). For the three species, the temperature of 30 ºC provided the highest percentage of pollen grain germination. For A. integerrima, M1 and M3 promoted the highest germination percentages (40.7 % and 56.5 %, respectively). On the other hand, for C. aurea, M2 provided the highest germination average (43.7 %). At last for S. punicea, M3 was the one that provided the highest average (31.62 %). It was concluded that the evaluated species differ in micronutrient requirements for in vitro germination of pollen grains. The temperature of 30 °C was suitable for all three species.The aim of this work was to verify the in vitro germination of pollen grains of Angelonia integerrima L., Campomanesia aurea O. Berg and Sesbania punicea (Cav.) Benth in different culture medium and temperatures. For this purpose, flower buds from which pollen was collected and sprayed on plates containing the three evaluated culture medium: M1 - agar and sucrose; M2 - agar, sucrose and H3BO3; M3 - agar, sucrose, H3BO3, Ca(NO3), MgSO4 and KNO3; and two incubation temperatures (20 °C and 30 °C). Data was subjected to analysis of variance after its transformation to square root and means were compared by Fisher’s test (LSD). For the three species, the temperature of 30 ºC provided the highest percentage of pollen grain germination. For A. integerrima, M1 and M3 promoted the highest germination percentages (40.7 % and 56.5 %, respectively). On the other hand, for C. aurea, M2 provided the highest germination average (43.7 %). At last for S. punicea, M3 was the one that provided the highest average (31.62 %). It was concluded that the evaluated species differ in micronutrient requirements for in vitro germination of pollen grains. The temperature of 30 °C was suitable for all three species
Ecophysiology of the Southern Highbush blueberry cv. Biloxi in response to nitrogen fertigation
Get PDFIn Brazil, the nutritional requirements of the blueberry are not sufficiently known, thus requiring further research on the management of mineral fertilization. In this perspective, this work aimed to evaluate physiological attributes of Southern Highbush blueberry plants cv. Biloxi as a function of nitrogen fertigation in Brasília-DF. The experiment was conducted from August 2018 to July 2019, in the Fruit Sector of the Experimental Biology Station of the University of Brasilia (UnB), Federal District. This experiment adopted a randomized block design, with four treatments: 10; 20; 30, and 40 g of N plant-1, 8 replications, and 5 plants per experimental plot. The following variables were measured: net photosynthesis rate (A), transpiration (E), stomatal conductance (gs), internal CO2 concentration (Ci), instantaneous water-use efficiency (WUE), carboxylation efficiency (CE), SPAD index (SPAD) and leaf nitrogen (N). There was an effect of the different nitrogen doses applied on the physiological attributes. The plants of the blueberry cultivar Biloxi increased their photosynthetic rates at doses up to 30 g of N plant-1. Nitrogen rates did not influence stomatal conductance nor did they provide improvements in the carboxylation efficiency of the blueberry plants. Under the conditions of the present work, the highest N leaf contents were obtained with the application of 30 g N plant-1, and values above this concentration did not correspond to higher net photosynthesis rates, transpiration, and CO2 concentration in the leaf mesophyll.In Brazil, the nutritional requirements of the blueberry are not sufficiently known, thus requiring further research on the management of mineral fertilization. In this perspective, this work aimed to evaluate physiological attributes of Southern Highbush blueberry plants cv. Biloxi as a function of nitrogen fertigation in Brasília-DF. The experiment was conducted from August 2018 to July 2019, in the Fruit Sector of the Experimental Biology Station of the University of Brasilia (UnB), Federal District. This experiment adopted a randomized block design, with four treatments: 10; 20; 30, and 40 g of N plant-1, 8 replications, and 5 plants per experimental plot. The following variables were measured: net photosynthesis rate (A), transpiration (E), stomatal conductance (gs), internal CO2 concentration (Ci), instantaneous water-use efficiency (WUE), carboxylation efficiency (CE), SPAD index (SPAD) and leaf nitrogen (N). There was an effect of the different nitrogen doses applied on the physiological attributes. The plants of the blueberry cultivar Biloxi increased their photosynthetic rates at doses up to 30 g of N plant-1. Nitrogen rates did not influence stomatal conductance nor did they provide improvements in the carboxylation efficiency of the blueberry plants. Under the conditions of the present work, the highest N leaf contents were obtained with the application of 30 g N plant-1, and values above this concentration did not correspond to higher net photosynthesis rates, transpiration, and CO2 concentration in the leaf mesophyll
Dormancy overcoming in seeds of cajá-manga (Spondias dulcis)
Get PDFThe propagation of ‘cajá-manga’ (Spondias dulcis) is usually performed by seeds. The presence of dormancy is an obstacle for seedling production and the commercial use of its main product, the fruit. This research aimed to evaluate the use of phytoregulators associated with the scarification of the distal region of the embryo in dormancy overcoming and in the standardization of germination of ‘cajá-manga’ seedlings. Endocarps extracted from fruits of six matrices were subjected to the following treatments: control (T1), mechanic scarification in the distal region of the embryonic axis (T2); all following treatments involved scarification and imbibition in a solution of: water for 6h (T3); GA3 (750 mgL-1) for 6h (T4); GA3 (350 mg L-1) for 12h (T5); Cytokinin (750 mg L-1) for 6h (T6); Cytokinin (350 mg L-1) for 12h (T7); GA3 and Cytokinin (750 mg L-1) for 6h (T8); and GA3 and Cytokinin sowing 25 endocarps in expanded polystyrene trays using a washed sand substrate. The following variables were evaluated: emergence, first emergence count, emergence speed index, mean emergence time, shoot and root length of seedlings, and relative emergence frequency. The experimental design was in randomized blocks, with 9 treatments and four replications consisting of 25 endocarps each. The data obtained were subjected to the F Test at a 1% level of probability, as well as to the Scott-Knott method. The use of mechanic scarification in the opposite region of the embryonic axis, followed by the imbibition in a solution of gibberellin + cytokinin at the concentration of 350 mgL-1 for 12 hours is promising for dormancy overcoming in seeds of Spondias dulcis.The propagation of ‘cajá-manga’ (Spondias dulcis) is usually performed by seeds. The presence of dormancy is an obstacle for seedling production and the commercial use of its main product, the fruit. This research aimed to evaluate the use of phytoregulators associated with the scarification of the distal region of the embryo in dormancy overcoming and in the standardization of germination of ‘cajá-manga’ seedlings. Endocarps extracted from fruits of six matrices were subjected to the following treatments: control (T1), mechanic scarification in the distal region of the embryonic axis (T2); all following treatments involved scarification and imbibition in a solution of: water for 6h (T3); GA3 (750 mgL-1) for 6h (T4); GA3 (350 mg L-1) for 12h (T5); Cytokinin (750 mg L-1) for 6h (T6); Cytokinin (350 mg L-1) for 12h (T7); GA3 and Cytokinin (750 mg L-1) for 6h (T8); and GA3 and Cytokinin sowing 25 endocarps in expanded polystyrene trays using a washed sand substrate. The following variables were evaluated: emergence, first emergence count, emergence speed index, mean emergence time, shoot and root length of seedlings, and relative emergence frequency. The experimental design was in randomized blocks, with 9 treatments and four replications consisting of 25 endocarps each. The data obtained were subjected to the F Test at a 1% level of probability, as well as to the Scott-Knott method. The use of mechanic scarification in the opposite region of the embryonic axis, followed by the imbibition in a solution of gibberellin + cytokinin at the concentration of 350 mgL-1 for 12 hours is promising for dormancy overcoming in seeds of Spondias dulcis
Portugûes Stability and adaptability of sweet orange using mixed models
No full textEvaluations with sweet oranges are usually performed in several harvests and places to verify the differential behavior according to the environmental variations. This makes the selection by traditional statistical methodologies more and more difficult since they have limitations in the case of data unbalanced, common in citrus during the experimental phase due to the possibility of plot loss over the years. The objective of this work was to estimate the temporal stability and adaptability of sweet orange genotypes cultivated in eight crops under the edaphoclimatic conditions of Rio Branco, Acre. The experimental design used was in randomized blocks containing 55 genotypes and three replications. Four agronomic characteristics were evaluated during eight harvests. The genetic parameters were estimated using the REML/BLUP methodology. After detecting the presence of significant interaction between genotypes and environments, stability and adaptability analyzes were conducted by the methods of the harmonic mean of the genotypic values (HMGV), the relative performance of the genetic values (RPGV) and the harmonic mean of the relative performance of the genotypic values (HMRPGV). The HMRPGV can be used to select stable, adapted and productive sweet orange genotypes. The number 48, 19, 5, 14, 2, 47 and 37 sweet orange genotypes can be selected for cultivation in an environment similar to the one studied, as they simultaneously present high stability, adaptability and productivity.Evaluations with sweet oranges are usually performed in several harvests and places to verify the differential behavior according to the environmental variations. This makes the selection by traditional statistical methodologies more and more difficult since they have limitations in the case of data unbalanced, common in citrus during the experimental phase due to the possibility of plot loss over the years. The objective of this work was to estimate the temporal stability and adaptability of sweet orange genotypes cultivated in eight crops under the edaphoclimatic conditions of Rio Branco, Acre. The experimental design used was in randomized blocks containing 55 genotypes and three replications. Four agronomic characteristics were evaluated during eight harvests. The genetic parameters were estimated using the REML/BLUP methodology. After detecting the presence of significant interaction between genotypes and environments, stability and adaptability analyzes were conducted by the methods of the harmonic mean of the genotypic values (HMGV), the relative performance of the genetic values (RPGV) and the harmonic mean of the relative performance of the genotypic values (HMRPGV). The HMRPGV can be used to select stable, adapted and productive sweet orange genotypes. The number 48, 19, 5, 14, 2, 47 and 37 sweet orange genotypes can be selected for cultivation in an environment similar to the one studied, as they simultaneously present high stability, adaptability and productivity
Liming on the growth and production of essential oil of basil grown in different light environments
Get PDFStudies about the influence of agronomic factors in the growing and production of secondary metabolites of basil plants are scarce. Among the existing factors, the soil fertility and the light quality has a great influence in the vegetative production of this group of plants. This study aims to evaluate the impacts of different combinations of light quality and the absence and presence of liming on growth, content and yield of essential basil oil. The experimental design was completely randomized in a 5x2 factorial design arranged in subdivided plots. Five light environments were used: black mesh, thermo-reflective mesh, blue mesh, red mesh, and full sun, and two soil acidity correction conditions. We performed the analysis of plants growth at 50 days after thinning (DAT), besides the determination of the essential oil content and yield. We observed significant interaction between the light environment and the soil acidity correction for the variables root volume and dry mass, and trunk dry mass. Regarding the essential oil production, the greater content and yield were obtained in plats grown under thermo-reflective mesh and with limestone application, increasing the soil base saturation. The basil plants are influenced by the light quality and limestone application on the growth, and essential oil content and yield.Studies about the influence of agronomic factors in the growing and production of secondary metabolites of basil plants are scarce. Among the existing factors, the soil fertility and the light quality has a great influence in the vegetative production of this group of plants. This study aims to evaluate the impacts of different combinations of light quality and the absence and presence of liming on growth, content and yield of essential basil oil. The experimental design was completely randomized in a 5x2 factorial design arranged in subdivided plots. Five light environments were used: black mesh, thermo-reflective mesh, blue mesh, red mesh, and full sun, and two soil acidity correction conditions. We performed the analysis of plants growth at 50 days after thinning (DAT), besides the determination of the essential oil content and yield. We observed significant interaction between the light environment and the soil acidity correction for the variables root volume and dry mass, and trunk dry mass. Regarding the essential oil production, the greater content and yield were obtained in plats grown under thermo-reflective mesh and with limestone application, increasing the soil base saturation. The basil plants are influenced by the light quality and limestone application on the growth, and essential oil content and yield