Maria Zuleide de Negreiros

Estimativa da área foliar do meloeiro

The leaf area of the Gold Mine melon was estimated when submitted to irrigation water levels varying from 55% to 130% of the hydric necessity of the crop, utilizing low and high salinity water. One plant per plot was collected at 19; 26; 34; 40 and 50 days after sowing, obtaining data of length, width, total leaf area, number of leaves, and individual leaf areas up to 24 leaves per plant. The results indicated that a partial correlation between the total plant leaf area (AF) and the number of leaves (NF) exists, with r2 = 0.95**, and the regression equation AF = 108NF - 516, with r2 = 0.95. The comparison of the models showed that at least one relation between leaf width (L) and leaf area (AF) differentiated from the others, even though the relation that assumes the whole data set (AF=0,826L1,89; r2 = 0.97) has a high determination coefficient.

Qualidade de híbridos de melão amarelo em diferentes densidades de plantio

The aim of this work was to evaluate the fruit quality of yellow melon hybrids. The experiment was carried out at the Fazenda Santa Julia Agro Comercial Exportadora de Frutas Tropicais Ltda in Mossoro, Brazil. The experimental design was a randomised complete block with four replicates, in a 3 x 4 factorial scheme, with the following factors: hybrids (Gold Mine, AF 646 e XPH 13096) and plant density (10,000; 20,000; 30,000 and 40,000 plants/ha). Firmness, total soluble solids, total titratable acidity, total sugars and shape ratio were evaluated. Shape ratio was affected by plant density. The hybrid AF 646 had highest total soluble solids (10.33%) and total sugars (8.45%). Gold Mine presented the best firmness (40.50 N) and shape ratio. Hybrid XPH 13096 had the highest total titratable acidity (14.38 mg/100 ml suco). In general, the three hybrids had oblong fruits. Fruits tended to become rounded with increasing plant density.

Desempenho agroeconômico do bicultivo de alface em sistema solteiro e consorciado com cenoura

Two experiments were carried out from September to May 2002, in Mossoro, Rio Grande do Norte State, Brazil, to evaluate the agrieconomic performance of two lettuce groups under bicropping, sole crop and intercropping system with two carrot cultivars (Alvorada and Brasilia) in a strip-intercropping arrangement. The experimental design was of group balanced blocks with four replications. The evaluated lettuce cvs. were from the crispleaf group (Lucy Brown, Taina, Laurel and Veronica) and looseleaf group (Baba de Verao, Maravilha das Quatro Estacoes, Elisa and Carolina). In the intercropping experiment, the split-plot scheme was used. In the plots the carrot cvs. were assigned and in the subplots the lettuce cvs. of both groups. From the lettuce cvs. were obtained data of leaf yield and, for the carrot cvs. were obtained total and commercial yield, besides the root classes. Agrieconomic indices such as land equivalent ratio, gross and net income, monetary advantage, rate of return and profit margin were used to measure the efficiency of intercropping systems. No significant interaction was obtained between carrot and lettuce cvs. in yield of both crops. Carrot cvs. did not influence crop yield and lettuce cvs. had no influence on carrot yield. In the bicropping of lettuce with carrot, the cvs. Lucy Brown and Taina (crispleaf group) and Baba de Verao and Maravilha das Quatro Estacoes (looseleaf group) had presented the best yield performance in the first planting. In the second planting, only cv. Maravilha das Quatro Estacoes of looseleaf lettuce group had presented the best performance under intercropping. Lettuce cvs. of crispleaf group intercropped with carrot had presented the best yield performance when compared to those of the looseleaf group. The intercropping systems of carrot Alvorada x lettuce Lucy Brown and carrot Brasilia x lettuce Maravilha das Quatro Estacoes in a strip arrangement of four carrot rows alternated with four lettuce rows resulted in the best agrieconomic indicators, with land equivalent ratios of 2.16 and 2.15, rates of return of 2.05 and 2.33, and profit margins of 53.92% and 59.83%, respectively.

Produção e valor agroeconômico no consórcio entre cultivares de coentro e de alface

The experiment was carried from October to December 2003, in the field, to evaluate the production and agrieconomic performance of coriander cultivars intercropped with lettuce cultivars. The experimental design was of randomized complete blocks in a 5 x 2 factorial scheme, with three replications. The treatments consisted of the combination of five coriander cultivars (Verdao, Superia, Portugues, Asteca and Santo) with two lettuce cultivars (Taina and Baba de Verao). Evaluations of plant height, number of stalks/plant, shoot dry matter, number of marketable bunches/m2 and estimated yield of green mass were made from the coriander crop. Plant height and diameter, number of leaves/plant, leaf dry matter and estimate yield were obtained from the lettuce crop. Agrieconomic indicators were used to measure the efficiency of intercropping systems. There was a significant interaction between coriander and lettuce cultivars on plant height, number of marketable bunches/m2 and green mass estimated yield, with coriander cv. Portugues presenting the best performance in yield, in combination with both lettuce cultivars. The lettuce cultivars presented different yield performance, with lettuce cv. Baba de Verao being the most productive. Agrieconomic efficiencies were observed in all intercropping systems, but the highest efficiencies were registered in the combination of Taina/Asteca and Baba de Verao/ Portugues.

Produtividade de alface em função de condições de sombreamento e temperatura e luminosidade elevadas

The effect of three types of polyethylene screens (white, green and black) under four heights from the soil surface (20; 30; 40 and 50 cm) was evaluated on the yield of lettuce (Great Lakes cv) under high temperature and luminosity conditions of Mossoro, Rio Grande do Norte State, Brazil. The control treatment consisted of the cultivation of the lettuce under open sky. The experimental design was of randomized complete blocks in a 3x4+1 factorial scheme, with four replications. Three types of shading-net colors (white, green and black) and four heights in the bed (20; 30; 40 and 50 cm above soil surface) besides a control (without net) were evaluated.Plant height and diameter, number of leaves/plant, yield, shoot dry matter and plant growth rate were obtained from plants. A higher number of leaves/plant and lettuce yield was observed using the white screen. The highest lettuce yield (80,5 t.ha-1) was obtained with the screen placed 44,6 cm from the soil surface. There was a significant interaction between types of screen and screen heights from the soil surface on the quantity of shoot dry matter and plant growth rate. The highest economic indicators were registered with the white screen at 40 cm from the soil surface.

Produção de alface em função de cultivares e tipos de tela de sombreamento nas condições de Mossoró

Two experiments were carried out in the Escola Superior de Agricultura de Mossoro, in Brazil. The first experiment, from October to November 1999, evaluated the performance of three lettuce cultivars grown at the nursery stage under shading and three types of polyethylene net, and the second experiment, from December 1999 to January 2000, compared the lettuce yield under shading and no shading. The experimental design in both experiments was a randomized complete block. Treatments in the first experiment were factorial combinations of three types of polyethylene net (2 x 2 mm white and green nets and half-shade black net) and three lettuce cultivars (Great Lakes, Veronica and Regina) replicated four times. Treatments in the second experiment were these three types of polyethylene net plus one where lettuce cultivar Veronica was grown under no shading (control) replicated three times. The lettuce spacing in both experiments was 0.20 x 0.20 m. The performance of lettuce was evaluated through plant height and diameter, leaf number per plant, shoot dry matter content, yield, relative growth rate, gross and net incomes and rate of return. Shading and cultivar interaction affected plant height. Plant diameter and leaf number per plant were affected only by cultivars. Shoot dry matter content and yield were affected by shading as well as cultivars. White polyethylene net shading associated with lettuce cultivar Great Lakes provided the highest economic indices when compared to no shading.

Effects of lettuce cultivars and spacings on lettuce leaf yield under high temperature and sunlight

O comportamento de tres cultivares de alface em seis diferentes espacamentos de plantio sob temperatura e luminosidade elevadas foi avaliado no periodo de 8 de junho a 24 de julho de 1998, na Horta do Departamento de Fitotecnia da ESAM em Mossoro (RN). O delineamento experimental usado foi blocos casualizados completos com quatro repeticoes em um esquema fatorial 3 x 6 + 1 (tratamento adicional). Os tratamentos consistiram da combinacao de tres cultivares de alface (Great Lakes, Elisa e Baba de Verao) com seis espacamentos de plantio (20 x 20 cm, 20 x 25 cm, 20 x 30 cm, 25 x 25 cm, 25 x 30 cm e 30 x 30 cm) mais um tratamento adicional que foi a cultivar Great Lakes, no espacamento 20 x 20 cm, sombreada durante todo o ciclo cultural. As caracteristicas avaliadas foram altura e diâmetro de plantas, numero de folhas por planta, massa seca da parte aerea, produtividade, renda bruta, renda liquida e taxa de retorno. A cultivar Great Lakes foi a que apresentou melhor produtividade e melhores indicadores economicos. O espacamento que apresentou maior producao de massa seca da parte aerea, produtividade e os maiores indicadores economicos foi 20 x 20 cm. O numero de folhas por planta foi superior para a cultivar Elisa, mas nao foi afetado pelos espacamentos.

Performance of lettuce cultivars with and without intercropping with carrot in Mossoró

An experiment was carried out between December 1997 and March 1998, in the Escola Superior de Agricultura de Mossoro, Brazil, to evaluate the performance of five lettuce cultivars in two cropping systems (with and without intercropping with the carrot cv. Brasilia) as well as the performance of carrot treatments in these cropping systems, under high temperature and ample sunlight of Mossoro. This experiment was carried out in an Eutrophic Yellow Red Argissolo. The experimental design was of randomized complete blocks in a 2 x 5 factorial scheme with five replications. The planting systems were the first factor and the lettuce cv. (Baba de Verao, Elisa, Great Lakes, Regina and Taina) were the second factor. There was, in each block, a plot with carrot without intercropping to assess the combined indices of the intercropping systems. Two types of univariate analyses of variance were performed, one to evaluate the lettuce traits and another for the carrot characteristics. Crop production was considered suitable for the marketing. Independently of the cropping system used, higher lettuce yield was observed in the cultivar Baba de Verao. The intercropping system which gave the best economic performance and greater land equivalent ratio (1.16) was carrot plus cultivar Regina. Carrot root yield was not affected by the competition of lettuce cultivars.

Rendimento e qualidade do melão sob lâminas de irrigação e cobertura do solo com filmes de polietileno de diferentes cores

O experimento foi conduzido de abril a julho de 2002, na Fazenda Santa Julia Agro-Comercial Exportadora de Frutos Tropicais Ltda, Mossoro, para avaliar o efeito da cobertura do solo com filmes de polietileno de diferentes cores (amarelo, marrom, preto, prateado e solo descoberto) e lâminas de irrigacao (100, 86 e 71% da lâmina padrao) sobre o rendimento e qualidade do melao Gold Mine cultivado na epoca chuvosa. O delineamento experimental utilizado foi o de blocos completos casualizados em esquema fatorial 5x3, com quatro repeticoes. Foram avaliados o numero e produtividade de frutos comerciaveis, refugos e totais, massa media de frutos comercializaveis, classificacao dos frutos, firmeza da polpa, espessura da polpa e teor de solidos soluveis. Houve interacao significativa entre os tipos de coberturas de solo e lâminas de irrigacao para a massa media de frutos comercializaveis, com os filmes de polietileno registrando os maiores valores em relacao ao solo descoberto. Os maiores rendimentos de frutos comercializaveis e totais, percentagens de frutos tipo exportacao, teores de solidos soluveis e espessura de polpa foram obtidos nas coberturas com filmes de polietileno. As lâminas de irrigacao nao afetaram de modo significativo a producao e qualidade dos frutos.

Características químicas de folhas de alface cultivada sob efeito residual da adubação com composto orgânico

Um experimento foi desenvolvido durante o periodo de julho a setembro de 1996 na horta da ESAM, para avaliar o efeito residual do composto orgânico sobre as caracteristicas quimicas de folhas de alface em segundo cultivo sucessivo. As analises foram realizadas no Nucleo de Estudos em Pos-colheita da ESAM. O delineamento experimental utilizado foi em blocos casualizados completos em esquema fatorial 5 X 2, com quatro repeticoes. O primeiro fator constou de doses de composto orgânico (0; 40; 80; 120 e 160 t ha-1) e o segundo da ausencia ou presenca do adubo mineral (300; 500 e 150 kg ha-1 de sulfato de amonio, superfosfato simples e cloreto de potassio, respectivamente). Os teores de proteina bruta, fosforo, potassio e de magnesio nas folhas de alface aumentaram em funcao das doses de composto orgânico aplicadas; nao houve interacao entre as doses de composto orgânico e a presenca do adubo mineral para as caracteristicas avaliadas.