Nutritional efficiency in sunflower cultivars under dosages of potassium in semiarid region

Potassium (K) participates in critical processes in sunflower cultivation, such as osmotic regulation and translocation of photosynthesis. However, the absorption or accumulation of this nutrient occurs differently owing to edaphoclimatic factors or between cultivars. The objective of this study was to evaluate the nutritional efficiency of sunflower cultivars as a function of different dosage K dosages in a semiarid region. To this end, two experiments were conducted in 2016 and 2017. The treatments consisted of five dosages of K at 0, 30, 60, 90, and 120 kg ha-1 K2O and four sunflower cultivars, Aguará 6, Altis 99, Multissol, and BRS 122. The experimental design was a randomized block with four replications and subdivided plots. The characteristics evaluated were agronomic efficiency, physiological efficiency, recovery efficiency, utilization efficiency, and accumulation of total K in the plant. Sunflower cultivars responded to K dosages in the two crops, with variations in efficiency parameters. Crop 2 showed better nutritional efficiency compared to crop 1. Aguará 6 showed greater nutritional efficiency than the other two crops. The use of dosages between 75 and 91 kg ha-1 of K2O provided better efficiency in K usage for the cultivars.

Efficiency of Nitrogen Use in Sunflower.

The large variation in the response of sunflower to nitrogen fertilization indicates the need for studies to better adjust the optimum levels of this nutrient for production conditions. Our objectives were to analyze the agronomic yield of sunflower cultivars as a function of nitrogen fertilization; indicate the cultivar with high nitrogen use efficiency; and measure the adequate N dose for sunflower through nutritional efficiency. The completely randomized block design with split plots was used to conduct the experiments. The treatments included five nitrogen rates being allocated in the plots and the four sunflower cultivars. To estimate the nutrient use efficiency in the sunflower, we measured agronomic efficiency (AE), physiological efficiency (PE), agrophysiological efficiency (APE), apparent recovery efficiency (ARE), and utilization efficiency (UE). The results indicate that all cultivars had a reduction in AE due to the increase in N doses in the first crop. For PE, the highest values were observed for Altis 99 during the 2016 harvest. In that same harvest, Altis 99 had the highest APE. The dose of 30 kg ha-1 provided greater ARE for all cultivars in both crops, with greater emphasis on BRS 122 and Altis 99. The cultivation of cultivars Altis 99 and Multissol at a dose of 30 kg ha-1 in is recommended semiarid regions.

Efficiency of nitrogen use by sesame genotypes under brazilian semi-arid conditions

Nitrogen (N) is an essential macronutrient for plant growth and rate applications can influence the performance of sesame, and when applied in excess can cause nitrogen loss in the environment, and consequently make the cost of production more costly to the producer. Therefore, the objective of this work was to evaluate the efficiency of nitrogen use by different cultivars of irrigated sesame seeds under the edaphoclimatic conditions of the northeastern semi-arid region in two harvests. The experiments were carried out from February to May (1st harvest) and from July to October (2nd harvest) in 2016. The treatments were arranged in a split plot scheme, in which the plots were the five nitrogen doses (0, 30, 60, 90 and 120 kg ha-1), and in the subplots, the four sesame genotypes (CNPA G2, CNPA G3, CNPA G4 and BRS Seda), the design was in randomized complete blocks with four replications. The nitrogen use efficiency assessments evaluated were: agronomic efficiency (AE), physiological efficiency (PE), agrophysiological efficiency (APE), recovery efficiency (RE) and efficiency of use (EU). The rate that provided the greatest efficiency of use was 30 kg ha-1 of N applied. The cultivar BRS Seda had greater efficiency of use in relation to the other cultivars studied. The crop that had better efficiency of use was the 2nd agricultural harvest.

Economic indicators of nitrogen fertilization in sunflower cultivars / Indicadores econômicos de adubação nitrogenada em cultivares de girassol

Sunflower is one of the most important oilseeds in the world. However, cultivation in semi-arid regions requires analysis of production costs and profitability, ensuring effective decision-making, focused on farming procedures and techniques. In two agricultural crops, 2016 and 2017, experiments were conducted to evaluate the economic indicators of sunflower cultivars ('Aguará 06', 'Altis 99', 'Multissol' and 'BRS 122') submitted to nitrogen (N) doses (0; 30; 60; 90 and 120 kg ha-1) via fertirrigation under semi-arid conditions. The net margin corresponded to the increase of N doses, reaching a maximum net margin in the 2016 harvest of R$ 366.89 ha-1 at the dose of 81 kg ha-1 of N for 'BRS 122'; R$ 577.41 ha-1 with 118 kg ha-1 of N for 'Multissol'; and for 'Aguará 06' (R$ 2,124.00 ha-1) and 'Altis 99' (R$ 976.66 ha-1) at the dose of 120 kg ha-1 of N. In the 2017 harvest, 'BRS 122' obtained R$ 190.90 ha-1 in the dose of 83 kg ha-1 of N and 'Multissol' reached R$ 657.50 in the dose of 85 kg ha-1 of N; the cultivars 'Aguará 06' (R$ 1,078.00 ha-1) and 'Altis 99' (R$ 957.14 ha-1) in the dose of 120 kg ha-1 of N. The rate of return and the profitability index were positive for all cultivars in both crops.

O girassol é uma das mais importantes oleaginosas do mundo. No entanto, o cultivo em regiões semiáridas requer análise dos custos de produção e rentabilidade, garantindo tomadas de decisão eficazes, focadas em procedimentos e técnicas agrícolas. Em duas safras agrícolas, 2016 e 2017, foram conduzidos experimentos para avaliar os indicadores econômicos de cultivares de girassol ('Aguará 06', 'Altis 99', 'Multissol' e 'BRS 122') submetidos a doses de nitrogênio (N) (0; 30; 60; 90 e 120 kg ha-1) via fertirrigação em condições semiáridas. A margem líquida correspondeu ao aumento das doses de N, atingindo uma margem líquida máxima na safra 2016 de R$ 366,89 ha-1 na dose de 81 kg ha-1 de N para 'BRS 122'; R$ 577,41 ha-1 com 118 kg ha-1 de N para 'Multissol'; e para 'Aguará 06' (R$ 2.124,00 ha-1) e 'Altis 99' (R$ 976,66 ha-1) na dose de 120 kg ha-1 de N. Na safra de 2017, 'BRS 122' obteve R$ 190,90 ha-1 na dose de 83 kg ha-1 de N e 'Multissol' alcançaram R$ 657,50 na dose de 85 kg ha-1 de N; as cultivares 'Aguará 06' (R$ 1.078,00 ha-1) e 'Altis 99' (R$ 957,14 ha-1) na dose de 120 kg ha-1 de N. A taxa de retorno e o índice de lucratividade foram positivos para todas as cultivares em ambas as culturas.

Agro-economic profitability of sweet potato cultivars as a function of the harvest age and times of cultivation in the semi-arid / Rentabilidade de cultivares de batata-doce em função da idade de colheita e épocas de cultivo no semiárido

The objective of this work was to evaluate the profitability of sweet potato cultivars, harvested at different ages and cultivated in different periods (rainy and dry) in the municipality of Mossoró, semi-arid region of Rio Grande do Norte. The experimental design was a randomized complete block design with four replications and treatments arranged in split plots scheme. The plots were composed of three sweet potato cultivars (ESAM 1, Paraná and Mother of Family) and the subplots for five harvest ages (90 , 105, 120, 135 and 150 days after transplanting - DAT). Productivity of commercial roots and production costs was evaluated, as well as the economic indicators: gross income, net income, rate of return and profit margin. Independently of the growing periods, the productivity of commercial roots increased with the later harvest of the crop and differentiated the cultivars. Production costs averaged R$ 6,087.97 ha-1 in the rainy season and R$ 6,181.42 ha-1 in the dry period. Labor expenditures were the most impacting of total expenditures. The cultivars ESAM 1 and Paraná presented higher productivities of commercial roots and profitability when cultivated in the rainy season, while Paraná cultivar was superior to the other cultivars in the crop in the dry season. In both growing periods, the harvest age of 150 DAT promoted higher productivities of commercial roots and profitability to sweet potato production.

Este trabalho teve como objetivo avaliar a rentabilidade de cultivares de batata-doce, colhidas em diferentes idades e cultivadas em períodos distintos (chuvoso e seco) no município de Mossoró, semiárido do Rio Grande do Norte. O delineamento experimental foi em blocos ao acaso, com quatro repetições e tratamentos arranjados em parcelas subdivididas, sendo as parcelas formadas por três cultivares de batata-doce (ESAM 1, Paraná e Mãe de Família) e as subparcelas por cinco idades de colheita (90, 105, 120, 135 e 150 dias após o transplantio ­ DAT). Avaliaram-se produtividade de raízes comerciais e custos de produção, assim como os indicadores econômicos: renda bruta, renda líquida, taxa de retorno e índice de lucratividade. Independentemente dos períodos de cultivo, a produtividade de raízes comerciais aumentou com a colheita mais tardia da cultura e diferenciou as cultivares. Os custos de produção foram em média da ordem de R$ 6.087,97 ha-1 no período chuvoso e R$ 6.181,42 ha-1 no período seco. As despesas com mão de obra foram as mais impactantes nas despesas totais. As cultivares ESAM 1 e Paraná apresentaram maiores produtividades de raízes comerciais e lucratividades quando cultivadas no período chuvoso, enquanto a Paraná foi superior as demais cultivares no cultivo na época seca. Em ambas as épocas de cultivo, a idade de colheita de 150 DAT promoveu maiores produtividades de raízes comerciais e rentabilidade à produção de batata-doce.

Agronomic performance of carrot fertilized with roostertree [Calotropis procera (Ait.) R. BR.] in two growing seasons / Desempenho agronômico da cenoura adubada com flor-de-seda [Calotropis procera (Ait.) R. BR.] em duas épocas de cultivo

Because vegetables have a fast production cycle, they require fertilization in quantities and at ideal times to obtain maximum productivity, and green manure is an alternative practice to the use of mineral fertilizers. This study was conducted to evaluate the effects of different amounts of roostertree [Calotropis procera (Ait.) R. Br.] biomass and its incorporation times in two growing seasons, in the agronomic performance of carrots. The experiment was conducted on an experimental farm at the Universidade Federal Rural de Pernambuco (UFRPE) in the autumn-winter period (March-July 2012) and the spring-summer period (September-December 2012). The experimental design was a randomized block design with three replications. The treatments were arranged in a factorial 4 x 4 design; the first factor consists of four amounts of roostertree biomass (5.4, 8.8, 12.2 and 15.6 t ha-1 on a dry basis), and the second factor consists of four times of incorporation of this manure into the soil (0, 10, 20 and 30 days before sowing the carrots). The carrot cultivar used was Brasília. The following traits were evaluated: plant height, number of leaves per plant, root dry mass, total and commercial yield of roots. The best agronomic performance of carrot cultivar Brasília was found with the amount of roostertree biomass of 15.6 t ha-1, in the time of incorporation into the soil of 10 days before seeding. The cultivation in the autumn-winter showed higher total and commercial productivities of carrot roots fertilized with roostertree.

As hortaliças, por possuírem ciclo rápido de produção, demandam adubações em quantidades e momentos ideais para a obtenção da máxima produtividade, sendo a adubação verde uma prática alternativa ao uso de fertilizantes minerais. O presente estudo foi realizado com o objetivo de avaliar os efeitos de diferentes quantidades de biomassa de flor-de-seda [Calotropis procera (Ait.) R. Br.] e seus tempos de incorporação, em duas épocas de cultivo, no desempenho agronômico da cenoura. O experimento foi conduzido em campo experimental pertencente à Universidade Federal Rural de Pernambuco (UFRPE), nos períodos outono-inverno (março a julho de 2012) e primavera-verão (setembro a dezembro de 2012). O delineamento experimental utilizado foi em blocos casualizados, com três repetições. Os tratamentos foram arranjados em esquema fatorial 4 x 4, com o primeiro fator constituído por quatro quantidades de biomassa de flor-de-seda (5,4; 8,8; 12,2 e 15,6 t ha-1 em base seca), e o segundo fator, por quatro tempos de incorporação ao solo deste adubo (0, 10, 20 e 30 dias antes da semeadura da cenoura - DAS). A cultivar de cenoura utilizada foi a Brasília. Foram avaliados a altura de plantas, número de folhas por planta, massa seca de raízes, produtividades total e comercial de raízes. O melhor desempenho agronômico da cenoura cv. Brasília foi obtido com a quantidade de flor-deseda de 15,6 t ha-1, no tempo de incorporação ao solo de 10 dias antes da semeadura. O cultivo no outono-inverno promoveu maiores produtividades total e comercial às raízes de cenoura adubada com flor-de-seda.