Castor (Ricinus communis L.) is an important industrial crop used in the production of nylon, cos... more Castor (Ricinus communis L.) is an important industrial crop used in the production of nylon, cosmetics, and many industrial lubricants. Currently, castor production in the USA has nearly ceased for > 45 years, resulting in vast imports of castor oil to meet US demands. Renewed interest in this crop, especially the possibility of its use as a biolubricant, has increased the desire to learn more about where it can be produced. This study evaluated possible locations for castor production through site suitability analysis. This analysis determined potential sites for castor production by evaluating geospatial climatic, soils/geophysical, and disease data, the major drivers of castor growth and yields. The site suitability analysis determined that 12% of the contiguous USA is highly suitable for castor production. The state of Illinois has the highest percentage of arable land highly suitable for castor production (56%/8 million ha). However, due to its large size, Texas has the most land area highly suitable for castor production (~ 15 million ha). Validation of the site suitability analysis was obtained through ground-truthed data obtained from recent environmental studies testing various castor genotypes. For the southern USA (< 40 • N latitude), the regression analysis interested in site suitability point data versus performance (oil yield) at known growing sites resulted in a significant result (R 2 = 0.46, p < 0.01). Geospatial averaging site suitability values for 1-km buffer of those growing sites further improved regression analysis (R 2 = 0.57, p < 0.01). T he findings of this study provide a method to perform site suitability for novel crops such as castor using data associated with agronomic and disease characteristics. Moreover, the analysis provides suggestion that castor could easily be reintroduced to US agricultural practices.
This study aimed to evaluate the quality of Hevea brasiliensis seedlings, a GT1 clone, produced i... more This study aimed to evaluate the quality of Hevea brasiliensis seedlings, a GT1 clone, produced in protected environments in a variety of substrates. The treatments consisted of 13 substrates composed of combinations of cattle manure, soil from a ravine, medium vermiculite, superfine vermiculite and washed fine sand and two environments: a greenhouse with 50% shade using aluminized screen and a plant nursery with 50% shade using a Sombrite® screen. There were no replications of the environments; therefore, each one was considered an experiment. For each environment, a completely randomized experimental design with five replications was used to evaluate the substrates. Subsequently, the average squares of the residuals of individual variance analyses of these treatments (substrates) were evaluated, and because they did not exceed an approximate ratio of 7:1, a combined analysis of experiments was performed with Sisvar software. Two hundred eighty days after sowing, the dry weight, pl...
Improving environmental conditions in the production of seedlings by expanding the distribution o... more Improving environmental conditions in the production of seedlings by expanding the distribution of photosynthetically active radiation in abaxial leaves and protecting the substrate with straw can promote the production of higher quality seedlings. This study aimed to evaluate the reflective materials over the cultivation bench and the use of rice straw over the substrate in the formation of papaya seedlings of the group ‘Formosa’. The joint analysis was performed considering a completely randomized experimental design in a 3 x 2 factorial scheme, with five replications and six seedlings per plot. The use of aluminized screen (Aluminet®) and aluminum foil with an area of 1 m x 1.2 m as reflective material on the cultivation bench and treatment without reflective material were evaluated. Also, the presence and absence of a rice straw layer with 5 cm height, as covering over the substrate were evaluated. In the benches with aluminum foil and without reflective material, the seedling p...
Stress events or leaf damage can alter the redistribution of photoassimilates and modify the mor... more Stress events or leaf damage can alter the redistribution of photoassimilates and modify the morphological traits directly related to grain yield. This study aimed to evaluate the influence of agronomic traits on grain yield in soybean crop in function of leaf defoliation. The experiment consisted of a randomized block design with three replications, arranged in a 6 x 3 + 1 factorial scheme. The factors were composed by six reprodutive stages (R1, R2, R3, R4, R5, and R6) and three defoliation levels (33%, 66%, and 99%), and one additional treatment without defoliation (control). The following traits were evaluated: plant height, number of pods per plant, number of grains per pod, thousand grain weight, and grain yield. The magnitudes of the correlations between the same traits showed high oscillation according to the defoliation level. Results revealed the potential for the indirect selection for grain yield by the traits plant height and number of grains per pods under 0% of defol...
O objetivo do trabalho foi estimar o custo de produção da soja transgênica, em sistema de semeadu... more O objetivo do trabalho foi estimar o custo de produção da soja transgênica, em sistema de semeadura direta na região oeste do estado da Bahia. A pesquisa foi conduzida, na forma de estudo de caso, em uma propriedade rural localizada no município São Desidério (BA). Para levantamento do custo de produção utilizou-se a metodologia do sistema de Custo Operacional Total (COT). Os dados relativos aos coeficientes técnicos da cultura, utilizados no cálculo do custo de produção, foram levantados de uma planilha de controle administrativo, na safra 2015/2016. Foram calculadas médias e porcentagens de cada item do custo de produção de soja em um hectare. O Custo Operacional Total foi de R$ 2001,37 ha-1, contribuindo com maior impacto os herbicidas (33,82%) e adubos (29,73%). A soja transgênica cultivada em sistema de semeadura direta alcançou menor custo do que outros sistemas de cultivo. A produção com métodos conservacionistas, como o plantio direto e a terceirização das operações agrícola...
O preparo de solo é condição essencial para receber a cultura. A resistência do solo à penetração... more O preparo de solo é condição essencial para receber a cultura. A resistência do solo à penetração tem sido um dos parâmetros mais utilizados na avaliação de sua estrutura física. O objetivo deste trabalho foi determinar a resistência do solo à penetração mediante o preparo com diferentes implementos agrícolas. O ensaio foi composto pelo preparo do solo com cinco implementos (grade leve, grade intermediária, subsolador, arado de discos e arado de aiveca). Cada implemento foi utilizado para preparar uma faixa de 10 metros de comprimento por 5 metros de largura. Para a realização das avaliações foi descartado 1,0 metro em cada extremidade da faixa preparada. Foi realizada avaliação de resistência do solo à penetração antes de realizar o preparo do solo e outra avaliação 10 dias após o preparo do solo. Também aos dez dias após o preparo do solo realizou-se a avaliação de cobertura vegetal do solo. A resistência do solo à penetração é menor quando o preparo é realizado com o arado de dis...
Understanding the influence of row spacing and plant density on grain yield and yield components ... more Understanding the influence of row spacing and plant density on grain yield and yield components of crambe is critical in order to obtain higher grain yields. Therefore, the objective of this study was to evaluate the effects of row spacing and plant density on grain yield and its components in crambe in two distinct regions of Brazil (Marechal Candido Rondon-PR, MCR-PR, and Botucatu-SP, BTU-SP). Narrow and wide row spacing (0.20 and 0.40 m) combined with four plant densities (15, 25, 35, and 45 plants m-1) were evaluated in a randomized block layout with four replications in a 2 × 4 factorial design. The experiment at BTU-SP was run under rainfed conditions with supplementary irrigation, whereas the experiment at MCR-PR was run under rainfed conditions without supplementary irrigation. Both experiments were run in soils classified as Oxisols. There was no interaction between row spacing and plant density. Highest grain yield with supplementary irrigation was observed at 0.20 m row ...
Phosphorus (P) and potassium (K) fertilization can maximize the profitability of peanut cultivati... more Phosphorus (P) and potassium (K) fertilization can maximize the profitability of peanut cultivation. Therefore, the aim of this study was to evaluate the basic fertilization with P and K on the grain yield and production components of creeping peanut. The experiment was performed in a randomized block design, in a 2 x 3 + 1 factorial scheme. Two doses of K (30 and 60 kg ha-1 of K2O) and three levels of P (60, 90 and 120 kg ha-1 of P2O5) at sowing and an additional treatment without the basic fertilization were used, with four replicates. The cultivar Runner IAC 886was adopted. The following traits were evaluated: pod yield, grain yield, number of pods per plant, number of pods with grains per plant, the percentage of pods without grains, 100 grains weight and number of seeds per pod. P and K fertilization at sowing promote an increase in creeping peanut of about 38 and 49% in pod yield and grain yield, respectively. The highest values of pods with grains are observed with the application of 120 kg ha-1 P.
The cherry tomato (Lycopersicon esculentum var. cerasiforme) is gaining importance as an alternat... more The cherry tomato (Lycopersicon esculentum var. cerasiforme) is gaining importance as an alternative crop, mainly for small farms that use family hand labor and organic management. In this study, we investigated the effects of organic substrate combinations of cattle manure (M), vermicompost (VC), and vermiculite (V) on the yield and quality of cherry tomato fruits. Cherry tomato plants of the cultivar Carolina were grown under greenhouse conditions in 5-L pots. The five investigated substrate combinations were as follows: (T1) 80% M + 10% VC + 10% V; (T2) 70% M + 15% VC + 15% V; (T3) 60% M + 20% VC + 20% V; (T4) 50% M + 25% VC + 25% V; and (T5) 40% M + 30% VC + 30% V. Plant growth, tomato yield, and physicochemical properties of the fruits were measured. The results showed that combinations of 50% M + 25% VC + 25% V and 40% M + 30% VC + 30% V led to the best growth and adaptation of cherry tomato plants, resulting in larger and more rounded fruits. The substrate containing 40% M + 30% VC + 30% V resulted in higher numbers of fruits per plant. Different substrate combinations did not affect the chemical quality of the fruit. Therefore, our study has provided valuable information on the use of organic substrates in cherry tomato production under protected environment conditions. Based on our results, the different combinations of cattle manure, vermicompost, and vermiculite used in this study represent excellent options for reducing production costs and re-using organic byproducts.
O aumento da profundidade de semeadura afeta a germinação da semente, promovendo um prolongamento... more O aumento da profundidade de semeadura afeta a germinação da semente, promovendo um prolongamento no período para a emergência de plantas, com o uso de regulador vegetal a planta sofre estímulos de crescimento acelerando seu desenvolvimento, amenizando efeitos adversos na cultura. Com base nisto o objetivo deste estudo consistiu em analisar o efeito da inteiração do uso de Stimulate® e da profundidade de semeadura na emergência e no crescimento inicial amendoim em solos arenosos. O delineamento experimental utilizado foi de blocos ao acaso com quatro repetições em esquema fatorial 2 x 4. O primeiro fator foi composto pela do Stimulate® nas sementes. O segundo fator foi composto pelas diferentes profundidades de semeadura do amendoim. A utilização de Stimulate® promove menor porcentagem de emergência de plantas de amendoim. O volume e a massa seca do sistema radicular aumentaram de acordo com aumento da profundidade de semeadura. A profundidade de 6 cm promoveu menor tempo médio de e...
O presente trabalho foi desenvolvido com o objetivo de avaliar a influência dos modos de inoculaç... more O presente trabalho foi desenvolvido com o objetivo de avaliar a influência dos modos de inoculação de Azospirillum brasilense no crescimento inicial do triticale. O delineamento utilizado foi de blocos casualizados com quatro repetições, em esquema fatorial 4x2. O primeiro fator foi composto por quatro modos de inoculação de A. brasilense (sem inoculação, inoculação na semente, inoculação no sulco de semeadura e inoculação via foliar sendo esta última realizada aos 10 dias após a emergência). O segundo fator foi composto por dois cultivares de triticale (IPR Aimoré e BRS Harmonia). A inoculação de A. brasilense na semente pode reduzir a porcentagem de emergência e o índice de velocidade de emergência do triticale, dependendo do genótipo. Os modos de inoculação de A. brasilense de forma geral não influenciaram o crescimento inicial do triticale. A resposta das plantas a inoculação de A. brasilense é variável, dependendo basicamente do genótipo de triticale.
The Azospirillum brasilense inoculation is usually carried out via seed. However, this bacterium ... more The Azospirillum brasilense inoculation is usually carried out via seed. However, this bacterium presents passive penetration in the plant, what makes it possible to inoculate the crops using other methods. This study aimed to evaluate the influence of A. brasilense inoculation methods on the emergence and initial growth of corn and sorghum, under greenhouse conditions. A randomized block design, with four replications, in a 4 x 2 factorial scheme, was used. The first factor consisted of a control treatment (without inoculation) and three inoculation methods: via seed, via sowing furrow and via leaf spray. The second factor was composed by two hybrids of corn and two of sorghum. The application of A. brasilense to the seed can reduce the emergence percentage and the emergence speed index of corn seedlings, depending on the genotype, but its application does not influence the initial growth of the plants. The A. brasilense inoculation via seed and via sowing furrow can reduce the eme...
Seed size is an important indicator of physiological quality, since it may affect seed germinatio... more Seed size is an important indicator of physiological quality, since it may affect seed germination and seedling growth, especially under stress conditions. This study aimed to investigate the effects of seed size on germination and initial seedling growth, under salinity and water stress conditions. The treatments were arranged in a completely randomized design, in a 3 × 3 factorial scheme: three seed size classes (small, medium and large) and three stress treatments (control, saline or water stress), with four replicates. Water and salt stresses do not reduce the germination rate of medium and large seeds; however, the germination rate of small seeds is reduced under salt stress conditions. Drought stress drastically reduces the shoot growth of seedlings regardless of seed size, whereas root growth is higher in seedlings from medium and large seeds under water stress conditions. Under non-stressful environments, the use of large seeds is preferable, resulting in more vigorous seedl...
Seeds of wheat (Triticum aestivum L., cv. Jadeíte 11) and black oat (Avena strigosa Schreb., cv. ... more Seeds of wheat (Triticum aestivum L., cv. Jadeíte 11) and black oat (Avena strigosa Schreb., cv. Agro Planalto) were submitted to different osmotic potential levels induced by polyethylene glycol (PEG) with the objective of evaluate the effects of drought stress on seed germination and early seedling growth. Seeds were arranged in paper rolls and soaked in PEG solutions prepared with osmotic potentials from 0.0 (control),-0.2,-0.4, and-0.8 MPa and kept into a seed germinator, at 25°C for 15 days. A completely randomized design in a 2 × 4 factorial scheme with four replications of 50 seeds each was used. The results showed that by increasing of the osmotic potential level, germinated seeds number, germination rate index, root and shoot length, shoot and root dry matter, and seedling vigor index decreased, while mean germination time (MGT) and root:shoot ratio (RSR) increased in both crops. Additionally, black oat is more susceptible than wheat to drought stress, with germination response declining more rapidly with decreasing osmotic potential. Wheat crop tolerates water stress of up to-0.8 MPa, without reducing germination of the seeds; however, the growth of shoots and roots is drastically inhibited by the highly negative osmotic potential. The initial growth of black oat crop is progressively reduced with the rise of osmotic potential levels.
ABSTRACT: The germination and growth of melon (Cucumis melo L.) plants can be severely affected b... more ABSTRACT: The germination and growth of melon (Cucumis melo L.) plants can be severely affected by excess salts in the soil or irrigation water; however, negative effects of salt stress can be attenuated using appropriate methods of seed priming. Thus, effects of osmopriming as inducer of salt stress tolerance in melon seeds exposed to salinity levels were investigated in this study. Seeds were soaked for 22 h at 25 °C in the dark in distilled water (hydropriming) or 0.5% KNO3 solution (osmopriming), and after drying, were distributed in plastic boxes with blotter paper containing different NaCl solutions prepared with osmotic pressure of 0.0 MPa (control), -0.3 MPa (mild stress), and -0.6 MPa (severe stress). Unprimed dry seeds were taken as control. The plastic boxes were kept into a seed germinator, at 25 °C for 14 days. A completely randomized design in a 3 × 3 factorial schemes with four replicates of 25 seeds was used. Results showed that the seed priming with water and KNO3 m...
In recent years, peanut (Arachis hypogaea L.) cultivation has increased in the humid subtropical ... more In recent years, peanut (Arachis hypogaea L.) cultivation has increased in the humid subtropical areas of Brazil. However, there is little technical information for its cultivation under these conditions. The objective of this study was to evaluate the agronomic performance of cultivar RUNNER IAC 886, when grown in different row spacing and plant populations. The experiment was a randomized block design in a 2 x 4 factorial with two plant densities (seven and ten plants per meter) and four row spacings (0.40, 0.60, 0.80, 1.00 m), with four replications. The grain yield with ten plants per meter was approximately 32.1, 16.7, 13.7 and 11.5% higher than seven plants per meter for the row spacings of 0.40, 0.60, 0.80 and 1.00 m, respectively. The highest peanut grain yield was observed in the 0.6 m row spacing.
A adequada distribuição das plantas e a adubação nitrogenada são práticas de manejo que afetam a ... more A adequada distribuição das plantas e a adubação nitrogenada são práticas de manejo que afetam a produtividade do milho. Para o cultivo de milho segunda safra são necessárias informações quanto à resposta do arranjo das plantas à adubação nitrogenada. Sendo assim, o objetivo desse trabalho foi avaliar a interação entre densidade populacional, espaçamento entrelinhas e aplicação de nitrogênio (N) em semeadura na cultura do milho de segunda safra, cultivado em sistema de semeadura direta. O delineamento experimental empregado foi de blocos ao acaso, dispostos em parcelas subsubdivididas, com quatro repetições. Nas parcelas foram alocadas as densidades populacionais (60.000 e 75.000 plantas ha-1); nas subparcelas os três espaçamentos entrelinhas (0,40; 0,60 e 0,80 m) e nas subsubparcelas foram aplicadas quatro doses de N (20, 35, 50 e 65 kg ha-1) em semeadura. A adubação de cobertura foi realizada aplicando-se 100 kg ha-1 de N para todos os tratamentos na forma de ureia. Independenteme...
Castor (Ricinus communis L.) is an important industrial crop used in the production of nylon, cos... more Castor (Ricinus communis L.) is an important industrial crop used in the production of nylon, cosmetics, and many industrial lubricants. Currently, castor production in the USA has nearly ceased for > 45 years, resulting in vast imports of castor oil to meet US demands. Renewed interest in this crop, especially the possibility of its use as a biolubricant, has increased the desire to learn more about where it can be produced. This study evaluated possible locations for castor production through site suitability analysis. This analysis determined potential sites for castor production by evaluating geospatial climatic, soils/geophysical, and disease data, the major drivers of castor growth and yields. The site suitability analysis determined that 12% of the contiguous USA is highly suitable for castor production. The state of Illinois has the highest percentage of arable land highly suitable for castor production (56%/8 million ha). However, due to its large size, Texas has the most land area highly suitable for castor production (~ 15 million ha). Validation of the site suitability analysis was obtained through ground-truthed data obtained from recent environmental studies testing various castor genotypes. For the southern USA (< 40 • N latitude), the regression analysis interested in site suitability point data versus performance (oil yield) at known growing sites resulted in a significant result (R 2 = 0.46, p < 0.01). Geospatial averaging site suitability values for 1-km buffer of those growing sites further improved regression analysis (R 2 = 0.57, p < 0.01). T he findings of this study provide a method to perform site suitability for novel crops such as castor using data associated with agronomic and disease characteristics. Moreover, the analysis provides suggestion that castor could easily be reintroduced to US agricultural practices.
This study aimed to evaluate the quality of Hevea brasiliensis seedlings, a GT1 clone, produced i... more This study aimed to evaluate the quality of Hevea brasiliensis seedlings, a GT1 clone, produced in protected environments in a variety of substrates. The treatments consisted of 13 substrates composed of combinations of cattle manure, soil from a ravine, medium vermiculite, superfine vermiculite and washed fine sand and two environments: a greenhouse with 50% shade using aluminized screen and a plant nursery with 50% shade using a Sombrite® screen. There were no replications of the environments; therefore, each one was considered an experiment. For each environment, a completely randomized experimental design with five replications was used to evaluate the substrates. Subsequently, the average squares of the residuals of individual variance analyses of these treatments (substrates) were evaluated, and because they did not exceed an approximate ratio of 7:1, a combined analysis of experiments was performed with Sisvar software. Two hundred eighty days after sowing, the dry weight, pl...
Improving environmental conditions in the production of seedlings by expanding the distribution o... more Improving environmental conditions in the production of seedlings by expanding the distribution of photosynthetically active radiation in abaxial leaves and protecting the substrate with straw can promote the production of higher quality seedlings. This study aimed to evaluate the reflective materials over the cultivation bench and the use of rice straw over the substrate in the formation of papaya seedlings of the group ‘Formosa’. The joint analysis was performed considering a completely randomized experimental design in a 3 x 2 factorial scheme, with five replications and six seedlings per plot. The use of aluminized screen (Aluminet®) and aluminum foil with an area of 1 m x 1.2 m as reflective material on the cultivation bench and treatment without reflective material were evaluated. Also, the presence and absence of a rice straw layer with 5 cm height, as covering over the substrate were evaluated. In the benches with aluminum foil and without reflective material, the seedling p...
Stress events or leaf damage can alter the redistribution of photoassimilates and modify the mor... more Stress events or leaf damage can alter the redistribution of photoassimilates and modify the morphological traits directly related to grain yield. This study aimed to evaluate the influence of agronomic traits on grain yield in soybean crop in function of leaf defoliation. The experiment consisted of a randomized block design with three replications, arranged in a 6 x 3 + 1 factorial scheme. The factors were composed by six reprodutive stages (R1, R2, R3, R4, R5, and R6) and three defoliation levels (33%, 66%, and 99%), and one additional treatment without defoliation (control). The following traits were evaluated: plant height, number of pods per plant, number of grains per pod, thousand grain weight, and grain yield. The magnitudes of the correlations between the same traits showed high oscillation according to the defoliation level. Results revealed the potential for the indirect selection for grain yield by the traits plant height and number of grains per pods under 0% of defol...
O objetivo do trabalho foi estimar o custo de produção da soja transgênica, em sistema de semeadu... more O objetivo do trabalho foi estimar o custo de produção da soja transgênica, em sistema de semeadura direta na região oeste do estado da Bahia. A pesquisa foi conduzida, na forma de estudo de caso, em uma propriedade rural localizada no município São Desidério (BA). Para levantamento do custo de produção utilizou-se a metodologia do sistema de Custo Operacional Total (COT). Os dados relativos aos coeficientes técnicos da cultura, utilizados no cálculo do custo de produção, foram levantados de uma planilha de controle administrativo, na safra 2015/2016. Foram calculadas médias e porcentagens de cada item do custo de produção de soja em um hectare. O Custo Operacional Total foi de R$ 2001,37 ha-1, contribuindo com maior impacto os herbicidas (33,82%) e adubos (29,73%). A soja transgênica cultivada em sistema de semeadura direta alcançou menor custo do que outros sistemas de cultivo. A produção com métodos conservacionistas, como o plantio direto e a terceirização das operações agrícola...
O preparo de solo é condição essencial para receber a cultura. A resistência do solo à penetração... more O preparo de solo é condição essencial para receber a cultura. A resistência do solo à penetração tem sido um dos parâmetros mais utilizados na avaliação de sua estrutura física. O objetivo deste trabalho foi determinar a resistência do solo à penetração mediante o preparo com diferentes implementos agrícolas. O ensaio foi composto pelo preparo do solo com cinco implementos (grade leve, grade intermediária, subsolador, arado de discos e arado de aiveca). Cada implemento foi utilizado para preparar uma faixa de 10 metros de comprimento por 5 metros de largura. Para a realização das avaliações foi descartado 1,0 metro em cada extremidade da faixa preparada. Foi realizada avaliação de resistência do solo à penetração antes de realizar o preparo do solo e outra avaliação 10 dias após o preparo do solo. Também aos dez dias após o preparo do solo realizou-se a avaliação de cobertura vegetal do solo. A resistência do solo à penetração é menor quando o preparo é realizado com o arado de dis...
Understanding the influence of row spacing and plant density on grain yield and yield components ... more Understanding the influence of row spacing and plant density on grain yield and yield components of crambe is critical in order to obtain higher grain yields. Therefore, the objective of this study was to evaluate the effects of row spacing and plant density on grain yield and its components in crambe in two distinct regions of Brazil (Marechal Candido Rondon-PR, MCR-PR, and Botucatu-SP, BTU-SP). Narrow and wide row spacing (0.20 and 0.40 m) combined with four plant densities (15, 25, 35, and 45 plants m-1) were evaluated in a randomized block layout with four replications in a 2 × 4 factorial design. The experiment at BTU-SP was run under rainfed conditions with supplementary irrigation, whereas the experiment at MCR-PR was run under rainfed conditions without supplementary irrigation. Both experiments were run in soils classified as Oxisols. There was no interaction between row spacing and plant density. Highest grain yield with supplementary irrigation was observed at 0.20 m row ...
Phosphorus (P) and potassium (K) fertilization can maximize the profitability of peanut cultivati... more Phosphorus (P) and potassium (K) fertilization can maximize the profitability of peanut cultivation. Therefore, the aim of this study was to evaluate the basic fertilization with P and K on the grain yield and production components of creeping peanut. The experiment was performed in a randomized block design, in a 2 x 3 + 1 factorial scheme. Two doses of K (30 and 60 kg ha-1 of K2O) and three levels of P (60, 90 and 120 kg ha-1 of P2O5) at sowing and an additional treatment without the basic fertilization were used, with four replicates. The cultivar Runner IAC 886was adopted. The following traits were evaluated: pod yield, grain yield, number of pods per plant, number of pods with grains per plant, the percentage of pods without grains, 100 grains weight and number of seeds per pod. P and K fertilization at sowing promote an increase in creeping peanut of about 38 and 49% in pod yield and grain yield, respectively. The highest values of pods with grains are observed with the application of 120 kg ha-1 P.
The cherry tomato (Lycopersicon esculentum var. cerasiforme) is gaining importance as an alternat... more The cherry tomato (Lycopersicon esculentum var. cerasiforme) is gaining importance as an alternative crop, mainly for small farms that use family hand labor and organic management. In this study, we investigated the effects of organic substrate combinations of cattle manure (M), vermicompost (VC), and vermiculite (V) on the yield and quality of cherry tomato fruits. Cherry tomato plants of the cultivar Carolina were grown under greenhouse conditions in 5-L pots. The five investigated substrate combinations were as follows: (T1) 80% M + 10% VC + 10% V; (T2) 70% M + 15% VC + 15% V; (T3) 60% M + 20% VC + 20% V; (T4) 50% M + 25% VC + 25% V; and (T5) 40% M + 30% VC + 30% V. Plant growth, tomato yield, and physicochemical properties of the fruits were measured. The results showed that combinations of 50% M + 25% VC + 25% V and 40% M + 30% VC + 30% V led to the best growth and adaptation of cherry tomato plants, resulting in larger and more rounded fruits. The substrate containing 40% M + 30% VC + 30% V resulted in higher numbers of fruits per plant. Different substrate combinations did not affect the chemical quality of the fruit. Therefore, our study has provided valuable information on the use of organic substrates in cherry tomato production under protected environment conditions. Based on our results, the different combinations of cattle manure, vermicompost, and vermiculite used in this study represent excellent options for reducing production costs and re-using organic byproducts.
O aumento da profundidade de semeadura afeta a germinação da semente, promovendo um prolongamento... more O aumento da profundidade de semeadura afeta a germinação da semente, promovendo um prolongamento no período para a emergência de plantas, com o uso de regulador vegetal a planta sofre estímulos de crescimento acelerando seu desenvolvimento, amenizando efeitos adversos na cultura. Com base nisto o objetivo deste estudo consistiu em analisar o efeito da inteiração do uso de Stimulate® e da profundidade de semeadura na emergência e no crescimento inicial amendoim em solos arenosos. O delineamento experimental utilizado foi de blocos ao acaso com quatro repetições em esquema fatorial 2 x 4. O primeiro fator foi composto pela do Stimulate® nas sementes. O segundo fator foi composto pelas diferentes profundidades de semeadura do amendoim. A utilização de Stimulate® promove menor porcentagem de emergência de plantas de amendoim. O volume e a massa seca do sistema radicular aumentaram de acordo com aumento da profundidade de semeadura. A profundidade de 6 cm promoveu menor tempo médio de e...
O presente trabalho foi desenvolvido com o objetivo de avaliar a influência dos modos de inoculaç... more O presente trabalho foi desenvolvido com o objetivo de avaliar a influência dos modos de inoculação de Azospirillum brasilense no crescimento inicial do triticale. O delineamento utilizado foi de blocos casualizados com quatro repetições, em esquema fatorial 4x2. O primeiro fator foi composto por quatro modos de inoculação de A. brasilense (sem inoculação, inoculação na semente, inoculação no sulco de semeadura e inoculação via foliar sendo esta última realizada aos 10 dias após a emergência). O segundo fator foi composto por dois cultivares de triticale (IPR Aimoré e BRS Harmonia). A inoculação de A. brasilense na semente pode reduzir a porcentagem de emergência e o índice de velocidade de emergência do triticale, dependendo do genótipo. Os modos de inoculação de A. brasilense de forma geral não influenciaram o crescimento inicial do triticale. A resposta das plantas a inoculação de A. brasilense é variável, dependendo basicamente do genótipo de triticale.
The Azospirillum brasilense inoculation is usually carried out via seed. However, this bacterium ... more The Azospirillum brasilense inoculation is usually carried out via seed. However, this bacterium presents passive penetration in the plant, what makes it possible to inoculate the crops using other methods. This study aimed to evaluate the influence of A. brasilense inoculation methods on the emergence and initial growth of corn and sorghum, under greenhouse conditions. A randomized block design, with four replications, in a 4 x 2 factorial scheme, was used. The first factor consisted of a control treatment (without inoculation) and three inoculation methods: via seed, via sowing furrow and via leaf spray. The second factor was composed by two hybrids of corn and two of sorghum. The application of A. brasilense to the seed can reduce the emergence percentage and the emergence speed index of corn seedlings, depending on the genotype, but its application does not influence the initial growth of the plants. The A. brasilense inoculation via seed and via sowing furrow can reduce the eme...
Seed size is an important indicator of physiological quality, since it may affect seed germinatio... more Seed size is an important indicator of physiological quality, since it may affect seed germination and seedling growth, especially under stress conditions. This study aimed to investigate the effects of seed size on germination and initial seedling growth, under salinity and water stress conditions. The treatments were arranged in a completely randomized design, in a 3 × 3 factorial scheme: three seed size classes (small, medium and large) and three stress treatments (control, saline or water stress), with four replicates. Water and salt stresses do not reduce the germination rate of medium and large seeds; however, the germination rate of small seeds is reduced under salt stress conditions. Drought stress drastically reduces the shoot growth of seedlings regardless of seed size, whereas root growth is higher in seedlings from medium and large seeds under water stress conditions. Under non-stressful environments, the use of large seeds is preferable, resulting in more vigorous seedl...
Seeds of wheat (Triticum aestivum L., cv. Jadeíte 11) and black oat (Avena strigosa Schreb., cv. ... more Seeds of wheat (Triticum aestivum L., cv. Jadeíte 11) and black oat (Avena strigosa Schreb., cv. Agro Planalto) were submitted to different osmotic potential levels induced by polyethylene glycol (PEG) with the objective of evaluate the effects of drought stress on seed germination and early seedling growth. Seeds were arranged in paper rolls and soaked in PEG solutions prepared with osmotic potentials from 0.0 (control),-0.2,-0.4, and-0.8 MPa and kept into a seed germinator, at 25°C for 15 days. A completely randomized design in a 2 × 4 factorial scheme with four replications of 50 seeds each was used. The results showed that by increasing of the osmotic potential level, germinated seeds number, germination rate index, root and shoot length, shoot and root dry matter, and seedling vigor index decreased, while mean germination time (MGT) and root:shoot ratio (RSR) increased in both crops. Additionally, black oat is more susceptible than wheat to drought stress, with germination response declining more rapidly with decreasing osmotic potential. Wheat crop tolerates water stress of up to-0.8 MPa, without reducing germination of the seeds; however, the growth of shoots and roots is drastically inhibited by the highly negative osmotic potential. The initial growth of black oat crop is progressively reduced with the rise of osmotic potential levels.
ABSTRACT: The germination and growth of melon (Cucumis melo L.) plants can be severely affected b... more ABSTRACT: The germination and growth of melon (Cucumis melo L.) plants can be severely affected by excess salts in the soil or irrigation water; however, negative effects of salt stress can be attenuated using appropriate methods of seed priming. Thus, effects of osmopriming as inducer of salt stress tolerance in melon seeds exposed to salinity levels were investigated in this study. Seeds were soaked for 22 h at 25 °C in the dark in distilled water (hydropriming) or 0.5% KNO3 solution (osmopriming), and after drying, were distributed in plastic boxes with blotter paper containing different NaCl solutions prepared with osmotic pressure of 0.0 MPa (control), -0.3 MPa (mild stress), and -0.6 MPa (severe stress). Unprimed dry seeds were taken as control. The plastic boxes were kept into a seed germinator, at 25 °C for 14 days. A completely randomized design in a 3 × 3 factorial schemes with four replicates of 25 seeds was used. Results showed that the seed priming with water and KNO3 m...
In recent years, peanut (Arachis hypogaea L.) cultivation has increased in the humid subtropical ... more In recent years, peanut (Arachis hypogaea L.) cultivation has increased in the humid subtropical areas of Brazil. However, there is little technical information for its cultivation under these conditions. The objective of this study was to evaluate the agronomic performance of cultivar RUNNER IAC 886, when grown in different row spacing and plant populations. The experiment was a randomized block design in a 2 x 4 factorial with two plant densities (seven and ten plants per meter) and four row spacings (0.40, 0.60, 0.80, 1.00 m), with four replications. The grain yield with ten plants per meter was approximately 32.1, 16.7, 13.7 and 11.5% higher than seven plants per meter for the row spacings of 0.40, 0.60, 0.80 and 1.00 m, respectively. The highest peanut grain yield was observed in the 0.6 m row spacing.
A adequada distribuição das plantas e a adubação nitrogenada são práticas de manejo que afetam a ... more A adequada distribuição das plantas e a adubação nitrogenada são práticas de manejo que afetam a produtividade do milho. Para o cultivo de milho segunda safra são necessárias informações quanto à resposta do arranjo das plantas à adubação nitrogenada. Sendo assim, o objetivo desse trabalho foi avaliar a interação entre densidade populacional, espaçamento entrelinhas e aplicação de nitrogênio (N) em semeadura na cultura do milho de segunda safra, cultivado em sistema de semeadura direta. O delineamento experimental empregado foi de blocos ao acaso, dispostos em parcelas subsubdivididas, com quatro repetições. Nas parcelas foram alocadas as densidades populacionais (60.000 e 75.000 plantas ha-1); nas subparcelas os três espaçamentos entrelinhas (0,40; 0,60 e 0,80 m) e nas subsubparcelas foram aplicadas quatro doses de N (20, 35, 50 e 65 kg ha-1) em semeadura. A adubação de cobertura foi realizada aplicando-se 100 kg ha-1 de N para todos os tratamentos na forma de ureia. Independenteme...
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