Alcione Guimarães Freire

Produção do algodoeiro em função da salinidade e tratamento de sementes com regulador de crescimento

This study was conducted to evaluate the effect of different salinity levels of irrigation water and seed treated with growth regulator on the yield of cotton. It was used an entirely statistical randomized design, in a factorial scheme 5 x 2, with four replications. The treatments resulted from the combination of four salinity levels of irrigation water (S1-0.5; S2-2.0; S3-3.5; S4-5.0 and S5-6.5 dS m-1) in treated and untreated seeds with growth regulator. The variables were: production of cotton, seed and fiber, 100 seed weight and percentage of fiber. There was not interaction between salinity levels and seed treated. The parameters of cotton production are reduced with the use of water salinity from 3.5 dS m-1, independent of seed treated or not with growth regulators. Agronomic traits 100 seed weight, percentage of fiber and seed cotton production are not influenced by mepiquat chloride. The seed treatment with growth regulator do not affects the adverse effect of salinity.

Interação entre salinidade e fósforo na cultura do rabanete

Resumo - O uso de agua salina, na irrigacao, tem sido um desafio para os pesquisadores e produtores rurais, sendo constantemente desenvolvidos estudos que possibilitem o uso de agua, de qualidade inferior, sem afetar o rendimento e qualidade dos produtos agricolas. Este trabalho foi realizado com o objetivo de avaliar o efeito de diferentes niveis de salinidade da agua de irrigacao e doses de fosforo na cultura do rabanete. O delineamento experimental adotado foi inteiramente ao acaso, arranjados em esquema fatorial 4 x 4 com tres repeticoes. Os tratamentos resultaram da combinacao de quatro niveis de salinidade da agua de irrigacao (S 1 -0,5; S 2 -2,0; S 3 -3,5 e S 4 -5,0 dS m -1 ) com quatro doses de fosforo (0; 100; 200 e 300 mg dm -3 ). As variaveis avaliadas foram: numero de folhas, area foliar, massa fresca e seca das raizes. A cultura do rabanete respondeu significativamente a interacao entre salinidade e fosforo para area foliar, massa fresca e seca das raizes; e de forma isolada para numero de folhas. Doses crescentes de fosforo reduziram a sensibilidade da cultura do rabanete a salinidade de ate 3,5 dS m -1 . O manejo da adubacao fosfatada e uma alternativa

Produção e qualidade do meloeiro cultivado com filmes plásticos em respostas à lâmina de irrigação

A demanda por tecnicas que aumentem a produtividade do melao e proporcionem a padronizacao dos frutos nas caracteristicas desejaveis pelos consumidores como, elevado teor de solidos soluveis e firmeza de polpa, bom sabor e boa aparencia externa, e uma realidade. A cobertura do solo com filmes plasticos e uma tecnica que foi introduzida no agro-polo Assu-Mossoro-Barauna para suprir essa demanda. Por outro lado, o uso de cobertura do solo com filmes plasticos modifica a evapotranspiracao das areas cultivadas, necessitando de ajustes da lâmina de irrigacao. Objetivou-se com este trabalho avaliar o efeito de quatro lâminas de irrigacao (L1 -100%; L2 - 91%; L3 - 82% e L4 - 72% da lâmina padrao de 452 mm, a qual foi determinada pela metodologia do Kc dual da FAO) e tres tipos de filmes de polietileno (branco-preto, prata-preto e preto-preto) na cobertura do solo, comparando com o cultivo sem cobertura, na producao e qualidade dos frutos do meloeiro. A utilizacao dos filmes de polietileno proporcionou um aumento expressivo na produtividade, sendo o aumento no peso dos frutos de 20% em media em relacao ao tratamento com solo descoberto; os filmes de polietileno de coloracao branco-preto e preto-preto sobressairam em relacao ao de cor prata-preto; a lâmina padrao de 452 mm pode ser reduzida em ate 28% sem alterar a producao mesmo havendo reducao do peso medio dos frutos em 11%; a concentracao de solidos soluveis diminuiu a medida que a lâmina de irrigacao foi reduzida, devido ao intenso ataque de pragas.

Qualidade física de um cambissolo sob sistemas de manejo

The Apodi Tableland is becoming known as a promising center of irrigated fruit production because of the agricultural potential of its soils. The physical properties of these soils are modified by different management types. The purpose of this study was to evaluate the physical properties of an Inceptisol under papaya (Carica papaya L.) in two tillage systems, compared to the same soil type under secondary forest. Samples of disturbed and undisturbed soil were collected for analysis of texture, clay dispersed in water, bulk density, particle density, aggregate stability, organic carbon, and penetration resistance. The clay flocculation degree and organic matter content were calculated. The soil hydraulic conductivity was tested in the field. The 3 x 3 x 5 factorial scheme consisted of two soil management systems (papaya planted in furrow and ridge) and native secondary forest; three soil layers (0-0.1; 0.1-0.2, and 0.2-0.3 m), in five replications, except for the hydraulic conductivity, for which a factorial 3 x 2 x 5 (two soil management systems and secondary forest; two tensions - 0 and 5 hPa; five replications) was used, in a completely randomized design. The Kolmorogov-Smirnov Test was used to verify the normality of data distribution, the F Test for analysis of variance and Tukeys test for mean comparison, all at p=0.05. It was concluded that: a) the hypothesis that the tillage systems worsen the physical soil quality was refuted, indicating that the quality of the cultivated soil was generally maintained or improved in relation to the status of the native soil; b) the decrease of the organic matter content, percentage of stable aggregates (diameter class 4.76-2.00 mm) and the mean weighted diameter in cultivated soil, although still far from critical limits, indicate the need for management practices that avoid soil degradation; c) the soil quality indices were sensitive to changes caused by soil management systems and can therefore be used as a basis of interpretation of the dynamics of soil physical processes in time.

Rede de poros de um Cambissolo sob diferentes usos e índice S relativizado como indicador da qualidade física do solo

The objective of this work was to evaluate soil porous media quality under different uses, as well as to propose a new index to monitor changes in its structure due to management: the Srelative index. An Inceptisol under irrigated banana cultivation and secondary forest, in the Brazilian Apodi Plateau, was evaluated at three soil layers (0.0–0.1, 0.1–0.2, and 0.2–0.3 m) as to: particle size, particle and bulk density, organic matter content, intrinsic permeability to air, and water retention curve. Total porosity, index for pore continuity (defined by the ratio between soil intrinsic permeability to air and aeration porosity), volume of blocked pores, and the S and Srelative indices were determined. The Srelative index was calculated as the ratio between S-index values from undisturbed and disturbed samples of the same soil (Sundisturbed/Sdisturbed). Under the studied conditions, the Srelative index is a good quantifier of the changes imposed by soil use and management. Soil cultivation maintains or improves the quality of the evaluated attributes, except for blocked porosity, when compared with the soil under native secondary forest with ten years of regeneration after agricultural use.

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.

Soil Physical Quality Indicators and Refinement of the Evaluation Method through the Srelative

This study aimed to verify the efficiency of indicators of measure of physical attributes’ alterations and to refine the S relative determination method in order to increase its sensitivity to soil physical alterations. Soils under Ficus carica L. cultivation (with 0, 20, 40 and 60% of liquid bovine biofertilizer in the irrigation depth) and under forest were used. Parameters evaluated included soil granulometry, soil bulk and particle density, soil water retention curve (SWRC), porosity and the indices S and S relative . The experimental design was completely randomized with four replicates. For S relative refinement, with the SWRC containing only textural porosity, the soil was dispersed in water and with the addition of 1 N sodium hydroxide (with and without removal of sodium through washing). An ANOVA was performed for 0, 20, 40 and 60% of biofertilizer in 0-10, 10-20 and 20-30 layers; Dunnett test was used to compare the mean values of S-index and S relative -index. With respect to four methods to obtain the S relative -index the means were compared by Tukey test. Tests of line parallelism and intercept were performed for the regressions between each of the soil physical variables and S relative -index obtained. It was found that S and S relative indices were sensitive to soil physical alterations caused by the application of the biofertilizer; Srelative-index was sensitive to variation in soil bulk density and total porosity and the S relative -index obtained from the method of soil dispersion in water is more sensitive to soil physical alterations in comparison to S relative -index obtained through ADFE.