Leilson Costa Grangeiro

Acúmulo de nutrientes por três cultivares de alface cultivadas em condições do Semi-Árido

The objective of this work was to determine the accumulation of nutrients by lettuce cultivars in conditions of Semi-arid. The experiment was carried in the field of University Federal Rural do Semi-Arido, in Mossoro, Rio Grande do North State, Brazil, in soil Alfissol. The experimental design was of randomized complete blocks, with four replications, in a 3 x 5 factorial scheme, being evaluated the cultivars of lettuce: Baba de Verao, Taina and Veronica and sampling times 7, 12, 17, 22 and 27 days after transplanting (DAT). The maximum accumulation of dry mass occurred at 27 DAT, being of 8.9; 6.9 and 6.4 g/plant, respectively to cultivars Baby de Verao, Taina and Veronica. The period of larger demand for N, P, K and Mg occurred from 22 to 27 DAT and for Ca of 17 the 22 DAT in all to cultivars. The nutrients in decreasing order of accumulation by the lettuce cultivars were: K, N, P, Mg e Ca.

Viabilidade agronômica do consórcio de alface e rúcula, em duas épocas de cultivo

The productivity of different lettuce groups and roquette was evaluated when sown in two different periods and cultivated either singly or intercropped. Theses experiments were carried out in Jaboticabal, Sao Paulo State, Brazil. The first growing period was from May to August (Autumn-Winter) and the second from September to November (Spring) of 2001. The experimental design was a randomized complete block with four replications. The treatments consisted of the combination of the following factors levels: lettuce groups (crisp, cv. Vera; looseleaf, cv. Elisa; and crisphead lettuce, cv. Taina), cropping systems (intercropping and sole crop) and roquette sowing times [0; 7, and 14 days after lettuce transplantating (DAT)]. The highest fresh and dry matter production were observed for crisphead lettuce in the Spring. The cropping systems did not affect the lettuce groups productivity. The highest roquette fresh matter production was observed in the Autumn-Winter period at 0 DAT, with the crisp and looseleaf lettuce, and at 7 DAT with crisphead lettuce. For the Spring period the highest roquette fresh matter production was observed at 7 DAT with crisp lettuce and at 0 DAT with looseleaf and the crisphead lettuce. Roquette dry matter was reduced in the intercropping at 14 DAT. The intercropping system yielded 5 to 93% more than the single system according to the land equivalent ratio. The highest land equivalent ratio was observed in the roquette-crisp lettuce intercropping at 0 DAT the crisp variety (1.93) in the Autumn-Winter, while the highest ratio was observed at 7 DAT (1.84) in the Spring.

Acúmulo e exportação de nutrientes em beterraba

O objetivo do presente trabalho foi determinar o acumulo e exportacao de nutrientes pela cultura da beterraba em condicoes de altas temperaturas e luminosidade. O delineamento experimental utilizado foi em blocos casualizados completos com quatro repeticoes, sendo os tratamentos constituidos pelas epocas de coleta de plantas (20, 30, 40, 50 e 60 dias apos semeadura). Em cada coleta foram utilizadas quatro plantas por repeticao. O maximo acumulo de massa seca ocorreu aos 60 DAS, sendo de 21,35 g/planta. A maior demanda de nutriente aconteceu no periodo de 50 a 60 DAS para N e Mg, 30 a 50 DAS para P, 30 a 40 para K e 40 a 50 DAS para Ca. A ordem decrescente dos nutrientes acumulados pela beterraba foi: N, K, Mg, Ca e P. As quantidades totais de N, P, K, Ca e Mg exportadas pelas raizes foram respectivamente de 88,0; 6,1; 93,2; 12,1 e 16,8 kg/ha.

Crescimento de pimentão em diferentes arranjos espaciais

The objective of this work was to evaluate the growth of green pepper cv. Atlantis under different spatial arrangements. Three spacing arrangements between double and simple planting rows (1.5x0.5 m, 1.6x0.4 m and 1.7x0.3 m) and four spacing distances between plants in the rows (0.2, 0.3, 0.4 and 0.5 m) combined in factorial scheme were evaluated. A randomized block design in split-plots divided in time with three replicates was used. The growth assessment was done in nine occasions, 14 days apart, and the first one was performed 14 days after transplanting (DAT). Leaf area (LA), leaf area index (LAI), dry masses of leaves (LDM), stem (SDM), fruit (FrDM) and total shoot (TDM); absolute growth rate (AGR), rates of net assimilation (NAR) and relative growth (RGR); and leaf area (LAR) and leaf mass (LWR) ratios were evaluated until 126 DAT. The changes in LA, RGR, LWR and LAR did not depend on row spacing, but spacing influenced LDM, SDM, FrDM and TDM, LAI and AGR. The increase in spacing reduces LAI and LAR, and increases LA, LDM, SDM, FrDM, TDM, AGR and NAR, but does not influence RGR and LWR.

Qualidade de frutos de melancia em função de fontes e doses de potássio

Two field experiments were carried out in Borborema, Sao Paulo State, Brazil, from October to December 2001 and from February to April 2002, to evaluate the quality of watermelon fruits, hybrid Tide, as a result of potassium sources and doses. The experimental design was a randomized complete blocks, in a 3 x 4 factorial scheme with three replications. The treatments consisted of the three potassium sources (chloride, nitrate and sulphate) and four potassium doses (50; 100; 200 and 300 kg ha-1 of K2O). Total soluble solids (TSS), total titratable acidity (TTA) and TSS/TTA ratios were evaluated. Soluble solids were influenced by the growing season with higher values from February to April. Total titratable acidity increased and TSS/TTA ratio decreased when increasing the potassium doses.

Eficiência no uso da água e interferência de plantas daninhas no meloeiro cultivado nos sistemas de plantio direto e convencional

The objective of this work was to evaluate the effect of the conventional and no-tillage systems and weed management strategies on water use efficiency in melon crop (Cucumis melo). Thus, an experiment was carried out in a randomized block design in split-plots in Mossoro-RN. The plots were constituted of two tillage systems (conventional and no-tillage) and the sub-plots of three weed management systems (plastic mulch, weeding, and no weeding). Density and dry weight of the weeds at 30 days after transplanting, commercial and total yield and daily consumption of water were evaluated. Irrigation management was performed by the characteristic soil water curve for each cropping system at 15 and 30 cm of depth and water control by daily reading a set of tensiometers installed to keep the soil above 75% of field capacity. Water use efficiency (USA), given in kg of fruit per m3, was determined based on the crops yield and water consumption. It was found that the no-tillage system reduced weed density and dry matter in 86.7 and 61%, respectively, compared to conventional tillage, and weed interference reduced commercial yield by 100% under conventional tillage and 36.5% under no-tillage. Soil with plastic mulch under no-tillage and conventional systems, and straw mulching under no-tillage reduced water consumption by 23% (388.8 m3 ha-1), 21% (363.0 m3 ha-1) and 13% (215.0 m3 ha-1), respectively, compared to the weeding treatment under conventional tillage. Soil with plastic mulch under the two tillage systems, or straw mulching under no-tillage increased the efficiency of water use from the ground without cover. In the no-weeding treatment under conventional tillage, weed interference caused total productivity loss and increased water consumption by 9.6%.

Agronomic efficiency of intercropping tomato and lettuce

Four experiments were carried out at the São Paulo State University, Brazil, with the aim of determining the agronomic viability of intercropping tomato and lettuce, under greenhouse conditions. The studied intercropping systems were established by transplanting lettuce at 0, 10, 20 and 30 days after transplanting (DAT) tomato and by transplanting tomato at 0, 10, 20 and 30 DAT lettuce. Intercropped tomato and lettuce were evaluated during two seasons and compared to their sole cropping. The experimental design was a randomized complete block with nine treatments. The productivity and the classification of the tomato fruits were not influenced by having lettuce intercropped with it, but lettuce production was lowered when tomato was intercropped with it. The longer the delay in lettuce transplanting, the greater the reduction in its productivity. There was an effect of cropping season on the extent of the agronomic advantage of intercropping over sole cropping. In the first cropping season, intercropping established by transplanting lettuce during the interval between 30 days before up to 20 DAT tomato yielded land use efficiency (LUE) indices of 1.63 to 2.22. In the second period, intercropping established with the transplanting of lettuce up to 30 days before tomato yielded LUE indices of 1.57 to 2.05.

Physiological maturity in gherkin (Cucumis anguria L.) seeds

The objective of this study was to evaluate the physical and physiological changes in the maturation of gherkin (Cucumis anguria L.) seeds since these aspects are important for high quality seed production and reducing seed deterioration in the field. Seeds were collected from fruits of the Norte cultivar at five-day intervals from the 15th to the 40th day after anthesis. The statistical design was completely randomized with six treatments (fruit ages) and four replications. For each fruit age, the fruits were evaluated visually and the mean weight determined. The seeds were evaluated regarding: moisture content, seed dry mass, germination, first count of ermination, electrical conductivity, accelerated aging, and emergence speed index. The maximum physiological quality was found in seeds collected 32 days after anthesis but the best time to harvest the fruits was from 35 to 40 days after anthesis when the seeds showed the lowest moisture content.

Weed interference in carrot yield and quality.

This work aimed to evaluate weed interference in yield and quality of carrots (Daucus carota). An experiment was carried out in a randomized block design, with four replications. The treatments were composed of six periods of weed control (0-12, 0-24, 0-36, 0-48, 0-60 and 0-72 days after emergence (DAE)). The characteristics evaluated were: yield of commercial roots, total soluble solids (TSS), total titratable acidity (TTA), vitamin C, TSS/TTA ratio and pH of roots. The commercial root yields decreased with weed interference, with weed control being required until 36 DAE. Root TSS rates and vitamin C did not vary with weed interference. The presence of weeds for a longer period increased pH and TSS and decreased TSS/TTA ratios.

Características qualitativas de genótipos de cebola

Objetivou-se, com o trabalho, avaliar alguns atributos de qualidade de diferentes genotipos de cebola (Allium cepa L.), cultivados em Mossoro-RN. O experimento foi realizado na horta experimental no Departamento de Ciencias Vegetais da Universidade Federal Rural do Semi-Arido, em delineamento de blocos casualizados completos e quatro repeticoes. Os tratamentos foram constituidos pelos genotipos de cebola CNPH 6415, CNPH 6047, CNPH 6244, CNPH 6400 Chata, CNPH 6400 Redonda, CPACT 1, CPACT 2, CPACT 3, Granex 429, Belem IPA 9, BRS Cascata, Crioula Alto Vale, Bola Precoce, Primavera, Regia, Valeouro IPA-11, Brisa e Alfa Sao Francisco. As caracteristicas avaliadas foram teor de solidos soluveis totais, acidez total titulavel, teor de vitamina C e teor de acido piruvico (pungencia). Foram observadas diferencas significativas entre os genotipos para todas as caracteristicas avaliadas. Os genotipos apresentaram uma variacao significativa para todas as caracteristicas avaliadas, confirmando dessa forma que o fator genetico e determinante na caracterizacao de cada material. O teor de solidos soluveis totais variou de 6,67 a 11,63 (o Brix), vitamina C de 22,7 a 46,81 (mg acido ascorbico/100 ml de suco) e a acidez total titulavel de 0,19 a 0,45 (% de acido piruvico). Os genotipos apresentaram pungencia intermediaria com variacao de 5,0 a 12,73 (µmol/g), sendo os menos pungentes Granex 429, CNPH 6047, Regia, Primavera e Belem IPA 9.