Mychelle Karla Teixeira de Oliveira

Desempenho de cultivares de alface submetidas a diferentes níveis de salinidade da água de irrigação

This study was carried out in greenhouse to evaluate the performance of different cultivars of lettuce under saline conditions. The experimental design was a completely randomized in factorial scheme, with five cultivars of lettuce (Monica SF31, Grandes Lagos 659, Veneranda, Folha Roxa Quatro Estacoes e Stella) and five levels of water salinity (0.5 , 1.5, 2.5, 3.5 and 4.5 dS m-1) and three replications. The plants were harvested at 35 days after transplanting and the main morphophysiological growth parameters, that is, the number of leaves, leaf area, stem length, fresh weight and dry weight of plants were evaluated. Significant effect of the isolated factors and of the interaction for all parameters was found. The best performance was obtained in cultivar Folha Roxa Quatro Estacoes. The number of leaves, leaf area and biomass of shoots were reduced linearly with increasing salinity, with higher values in cultivars Folha Roxa Quatro Estacoes and Stella.

Interação entre salinidade e bioestimulante na cultura do feijão caupi

Objetivou-se, neste trabalho, avaliar a interacao entre salinidade e o uso de bioestimulante (Stimulate®) sobre o desenvolvimento do feijao caupi. A semeadura foi feita em vasos utilizando-se, como substrato, um Argissolo Vermelho Amarelo. O experimento obedeceu a um delineamento inteiramente casualizado em esquema fatorial 2 x 7. Os tratamentos se constituiram da combinacao de dois niveis de sais da agua de irrigacao e seis formas de aplicacao de bioestimulante (Ausencia, Tratamento de sementes, Foliar aos 20 dias apos semeadura (DAS), Foliar aos 40 DAS, Tratamentos de sementes + Foliar aos 20 DAS, Tratamento de sementes + foliar aos 40 DAS e Aplicacao foliar aos 20 e 40 DAS). Foram realizadas duas avaliacoes nao destrutivas (20 e 40 DAS) e uma destrutiva (60 DAS) e avaliados a altura, o numero de folhas, a area foliar e a massa seca de folhas, de caule e da parte aerea. Todos os parâmetros fisiologicos avaliados foram afetados pela salinidade. Nas formas de aplicacao adotadas o bioestimulante nao proporcionou melhorias no desenvolvimento das plantas quando submetidas ao estresse salino; a salinidade inibiu o efeito benefico do bioestimulante sobre o desenvolvimento do feijao caupi; enfim, o uso de bioestimulante nao e viavel em plantas cultivadas sob estresse salino.

Desempenho agronômico da cenoura adubada com jitirana antes de sua semeadura

The scarlet starglory is an herbaceous plant native that is presented as a potential source for green manure in the semi-arid northeast of Brazil, and generates many benefits, especially the increased availability of nutrients for crops. The objective of this present study was to evaluate the agronomic performance of carrot fertilized with scarlet starglory before carrot sowing. An experiment was conducted at the teaching garden of the Plant Sciences Department, Universidade Federal Rural do Semi-Arido (UFERSA), Mossoro-RN, from September to December 2008. The experimental design used was a randomized complete block with treatments arranged in a 4 x 4 + 1 factorial scheme, with 3 replications. The first factor was composed of the quantities of scarlet starglory incorporated into the soil (5.4; 8.8; 12.2 and 15.6 t ha-1 on a dry basis), and the second factor by the times of scarlet starglory incorporation into the soil (0; 10; 20 and 30 days before sowing of carrot - DBS). The additional treatment (control) was fertilized with 80 t ha-1 of cattle manure. The characteristics evaluated were: plant height, leaf number per plant, dry mass of shoot, commercial productivity, scrap productivity, classified productivity. There was no significant interaction between the quantities of scarlet starglory incorporated into the soil and its times of incorporation before carrot sowing on any of those evaluated characteristics. The highest productive performance of carrot was obtained in the amount of 15.6 t ha-1 of scarlet starglory incorporated into the soil at the time of 20 days prior to the carrot planting time.

Interação entre salinidade da água de irrigação e adubação nitrogenada na cultura da berinjela

The objective of this study was to evaluate the interaction of salinity of irrigation water levels associated with nitrogen doses on yield of eggplant crop. The experiment was conducted in a greenhouse of the Department of Environmental Sciences and Technology -UFERSA. The experiment followed a randomized block design in a 4 x 6 factorial, with four replications, with four levels of electrical conductivity of irrigation water (0.5, 2, 4 and 6 dS m-1) and six levels of nitrogen (5, 10, 15, 20, 25 and 30 g plant-1). Six measurements were conducted, in which the following variables were analysed: number of fruits, length, diameter and mean fruit weight, and total yield per plant. After statistical analysis of the data, it was verified that there was a negative effect of salinity on all variables. Nitrogen levels above 5 g plant-1 did not increase fruit yield of eggplant, and increased the deleterious effect of salinity on the yield of eggplant. The agronomic efficiency of nitrogen is reduced with increasing dose of N and salinity.

Desempenho agroeconômico da cenoura adubada com jitirana (Merremia aegyptia)

The use of spontaneous plants of the Caatinga biome as green manure is becoming a viable option for vegetable production in northeastern Brazil. Among these plants, the scarlet starglory is a spontaneous plant adapted to the climatic and soil conditions of the region, with high biomass production, rapid growth and low C/N ratio. We evaluated the agroeconomic performance of carrot (cv. Brasilia) depending on added amounts of scarlet starglory under the ground and of its moment of incorporation. The study was carried out in a rural area, in Mossoro, Rio Grande do Norte state, Brazil, from September to December 2009. The experimental design was randomized complete blocks with the treatments arranged in a factorial scheme (4x4) + 1, with three replications. The first factor was comprised of amounts of scarlet starglory placed between the carrot rows, in a depth of 15 cm (5.4, 8.8, 12.2 and 15.6 t ha-1 on a dry basis) and the second factor, of the incorporation moment of this material (0, 15, 30 and 45 days after sowing carrots). The additional treatment (control) was 40 t ha-1 of cattle manure applied 10 days before sowing. We evaluated the marketable and total yield of roots, percentage of the different classes of roots and the economic indicators of gross income, net income, rate of return and profit margin. No significant interaction between the amounts of scarlet starglory under the soil and the incorporation moment was determined in any of the characteristics examined for carrot. The best agroeconomic performance of carrot cropping was obtained by adding 15.6 t ha-1 of scarlet starglory to the soil. The optimization of this performance was achieved with the incorporation moment of 26 days after carrot sowing.

Crescimento de mudas de moringa em função da salinidade da água e da posição das sementes nos frutos

Choosing seeds is crucial for obtaining good quality seedlings, especially when the seedlings are grown under adverse environmental conditions. This work was carried out to evaluate the influence of salinity on the development of moringa seedlings from seeds located at different positions in the pod. The design used in this study was a completely randomized design with treatments arranged in 3 x 4 factorial scheme, with four replications. The treatments resulted from a combination of three positions in the seed fruit (basal, median and apical) with four salinity levels of irrigation water (0.5, 2.0, 3.5 and 5.0 dS m-1). The growth characteristics evaluated were the following: height (ALT), stem diameter (AD), diameter of the root principal (DRP), number of leaves (NL), leaf area (LA), shoot dry mass (SDM), root dry mass (RDM) and total dry mass (MST). The data were submitted to analysis of variance by F test and means were compared by the Tukey test at 5% of probability for the effect of seed position in the fruits, and to regression analysis for data from the salinity. Interaction was significant for most traits. The salinity of irrigation water caused a reduction in all variables. Seedlings from seeds located in the basal portion of the fruits are more affected by salinity of irrigation water.

Sensibility of cotton crops to mepiquat chloride under saline conditions

This work was carried out to evaluate the effect of irrigation water at different salinity levels, and of seed treatment with plant growth regulator, on the development of the cotton plant. The experimental design used was completely randomized, arranged in a 5 x 2 factorial scheme with four replications. The treatments resulted from the combinations of five levels of salinity of the irrigation water (S1-0.5, S2-2.0, S3-3.5, S4-5.0 and 6.5 dS m-1) on seeds, both treated and not treated with growth regulator. The evaluated characteristics were: number of leaves, leaf area, height, dry mass of stems, leaves and vegetative parts, specific leaf area and leaf area ratio. There was an interaction between salinity and seed treatments with mepiquat chloride, but only for leaf area and leaf area ratio. All other characteristics decreased with the increasing salinity of the irrigation water, with greater reductions in leaf area (mean of 65.8%) and dry mass of vegetative parts (64%). Seed treatment with mepiquat chloride affected plant development, independent of salinity.

Effect of Saline Stress and Calcium Nitrate on Lettuce Grown on Coconut Fiber

This study aimed to evaluate the use of saline solutions enriched with calcium nitrate in the production of lettuce grown in coconut fiber. The experiment was carried out from July to August 2017 in a greenhouse, at the Federal Rural University of the Semi-Arid Region (UFERSA), Mossoro-RN, Brazil. A randomized block design was used, in 2 × 5 factorial scheme, with three replicates. Treatments resulted from the combination of two lettuce cultivars [Elba (Curly) and Irene (Crisphead)] and five nutrient solutions (S1- standard nutrient solution; S2-S1 + NaCl (28.48 mmol L-1); S3-S2 + Ca(NO3)2 (6.89 mmol L-1); S4-S2 + Ca(NO3)2 (9.15 mmol L-1); S5-S2 + Ca(NO3)2 (11.43 mmol L-1)]. Plants were harvest 30 days after transplantation and the following variables were analyzed: head diameter, stem diameter, number of leaves, fresh weight, dry weight, leaf area, specific leaf area and leaf succulence. The cv. Irene (Crisphead) is more tolerant to nutrient solution salinity compared with the cv. Elba (Curly). Nutrient solutions enriched with 50 and 100% of Ca(NO3)2 promoted better performance of the cultivars Elba and Irene, respectively, fertigated with saline nutrient solution.

QUALIDADE DE MUDAS DE Tabebuia aurea EM DOIS AMBIENTES E DIFERENTES NÍVEIS DE FERTIRRIGAÇÃO

The quality of seedlings of tree species is crucial to succeed in reforestation project or commercial exploitation. This work was to evaluate the influence of two environments (AMB-1, greenhouse; AMB-2, plastic camera installed inside the greenhouse) and concentrations of nutrients applied by fertigation (0; 50; 100 and 150% of a patterns nutrient solution) in the production of seedlings of Tabebuia aurea using design was completely randomized, with four replications. The following growth characteristics were evaluated: height, stem diameter, number of leaves, leaf area, dry matter aerial part, dry root matter, dry root weight, total dry matter, height/stem diameter ratio, specific leaf area, leaf area ratio and Dickson quality index (IQD). Data analysis revealed that there was significant interaction between the factors for most variables. The use of the plastic chamber (AMB-2) provided greater growth of Tabebuia aurea seedlings. Fertigation solutions with nutrient concentrations varying from 80 to 100% of the standard solution provide better quality Tabebuia aurea seedlings.

Production of coriander in substrate fertigated with increasing nutrient concentrations

Coriander is one of the most popular vegetables in the cuisine of the northeastern region of Brazil and its leaves are used in the composition and decoration of various regional dishes. However, its cultivation has been little studied, especially in hydroponic systems. This study aimed to evaluate the effect of increasing nutrient concentrations in the nutritive solution applied to coriander plants grown on fertigated substrate. A completely randomized design with five treatments and six replications was used. Each experimental unit was represented by a PVC channel (1.0 x 0.1 x 0.1 m). Treatments represented five nutrient concentrations in the nutritive solution (25, 50, 75, 100 and 125% of the standard solution recommended for lettuce cultivation). Plants were harvested 35 days after sowing. The evaluated variables were plant height, number of leaves, fresh and dry matter (root, shoot and whole plant), and N, P and K content. All variables were affected by the increased nutrient concentration in the nutritive solution used forfertigation. The ionic concentration of 75% of the nutrients contained in the standard formulation recommended for hydroponic production of lettuce can be used for coriander crop.