Simone da Costa Mello

Métodos de avaliação da qualidade fisiológica de sementes de brócolos

The work was carried out to compare methods of evaluation of broccoli seed physiological quality, including tests of germination, seedling emergence, accelerated aging (24, 48, 72 and 96 hours at 42°C) and electrical conductivity (0.5, 2, 4, 12 and 24 hours of imbibition at 25°C with 25, 50 and 75 ml of water). The tests of germination, seedling emergence and electrical conductivity (imbibition for 24 h with 25 ml of water) agreed in discriminating the vigour of seed lots. A acelerated aging at 42°C for 48 hours can also be used to distinguish vigour among seed lots.

Quality of mini tomatoes harvested at two maturity stages and kept chilled in three packages

The economic importance of small tomato fruits has been increased considerably due to the significant levels of lycopene and sugars. However, to achieve these compounds, the harvest is limited to a ripening stage demanded by consumers, which could reduce this marked period. Harvesting at an early stage and use of conservation techniques are desirable to amplify the marketing period. The aim of this study was to evaluate the quality of small tomato fruits, Sweet Grape cultivar, harvested at two stages of ripening (light red and red), kept in three types of package (perforated PET, PEBD 30 μ and Vegetal Pack 18 μ) at a temperature of 20±1oC and a relative humidity (RH) of 85±5% during 20 days. During this period, gas composition inside the packaging (O 2 , CO 2 and ethylene), peel color, fresh mass loss, soluble solids content (SS), titratable acidity (TA), SS/TA and ascorbic acid levels were evaluated every 5 days. The lycopene content was determined at the beginning and the end of conservation. The experimental design was completely randomized in a split plot with four replications. Mass loss, peel color and gas composition were affected by both stage of harvest and package. The total SS/TA increased 4.74 during the conservation for two stages, regardless of package. The light red fruits reached after 20 days of conservation, mean levels of lycopene of 16.47 mg 100 g -1 and SS/TA of 18.43; on the other hand the red fruits achieved 15.30 mg 100 g -1 of lycopene and 16.80 of SS/TA. There was a mean increase of 8.4 mg 100 g -1 of lycopene in light red fruits, while in red fruits, the increase was 0.9 mg 100 g -1 . The PEDB film was the best to maintain the fresh mass and peel color, therefore it was indicated for the maintenance of these attributes. The Vegetal Pack film showed no advantage in relation to the PET perforated packaging.

Produtividade e podridão parda em couve-flor de inverno influenciadas pelo nitrogênio e boro

The hollow stem disorder is a common problem in cauliflower, resulting in similar symptom to B deficiency. Its occurrence is associated, specially to nitrogen and boron rates. There is few information about this subject in Brazil. The experiment was carried out from March to June/2006 in a randomized complete block design with 4 replications. The objective was to evaluate rates of nitrogen (100, 150, 200 and 250 kg ha-1) and B aplication (0 and 3 kg ha-1) on yield and hollow stem disorder of the cauliflower x91Juliax92 cultivated in Kandiustalf at Tiete region, Sao Paulo State, Brazil. The curd diameter was not influenced by treatments and corresponding mean value was 17.74 cm. Nitrogen levels increased mean weight, yield and N content of curds. Fertilization increased boron contents in curds, commercial yield and reduced hollow stem disorder. There was a negative correlationship between B concentration at curds and hollow stem disorder incidence. Therefore, to reduce this physiological disorder the boron fertilization is required when cauliflower is grown even in soil with average B level.

Crescimento e absorção de nutrientes pelo Aster ericoides cultivado em solo sob estufa

Aster ericoides is a cut flower crop with great market and production potential that was only recently introduced into Brazil. Thus, little information is available regarding fertilization and nutrition under tropical conditions. The growth, dry matter production and nutrient absorption of Aster ericoides (cv. White Master) cultivated in an UDOX soil under greenhouse conditions was evaluated. Seedlings were transplanted 30 days after sowing date, in October 99. Plant samples were taken at 15; 30; 45; 60; 75; 90 and 96 days after transplanting. Plant growth and dry matter production were slow in the beginning but at 60 days (before flowering) 69% of the height, 27% of the top and 50% of the roots dry matter was reached. Plants reached 137 cm in height and 24.21 g of dry weight at the end of cycle. Flowering began after 75 to 90 days after transplanting date. Macronutrients uptake (kg ha-1) at 96 days was 316,32 of K > 230,52 N > 35,30 P > 18,39 S > 16,12 Mg > 8,57 Ca and micronutrients uptake (g ha-1) was 3464,89 Mn > 1603,23 Fe > 1104 Zn > 308 B > 61 Cu.

Temperatura inicial de germinação no desempenho de plântulas e mudas de tomate

Seedling production is an important step for the tomato production and can be influenced by the initial temperature of germination. The aim of this study was to evaluate the effect of this factor in the tomato germination and seedling growth. It was used four seed lots which were tested for germination, accelerated aging and electrical conductivity to evaluate the physiological potential. After lots characterization, seeds were exposed to initial germination temperatures (20-30, 30, 33 and 35°C) and were analyzed by the SVIS® software. The seedling performance was evaluated using the emergence speed index and percentage, height and dry weight of shoots and roots. In general, the higher temperatures decreased the seedlings development. However, 28 days after sowing, the seedlings growth was similar among temperatures.

Boro e nitrogênio na incidência de hastes ocas e no rendimento de brócolis

A incidencia de hastes ocas em brocolis (Brassica oleracea L. var. italica Plenck) depende de varios fatores que afetam a absorcao e o transporte de B, elemento responsavel pelo aparecimento dessa desordem fisiologica. O trabalho avaliou os efeitos de quatro niveis de nitrogenio e dois niveis de boro e da interacao entre eles na incidencia de hastes ocas e na producao de brocolis. As doses de N (100, 150, 200 e 250 kg ha-1) foram divididas em quatro aplicacoes iguais aos 15, 30, 45 e 60 dias apos o transplante. O boro (0, 4 e 8 kg ha-1) foi aplicado metade no plantio e a outra metade em cobertura aos 45 dias apos o transplante. A massa media das inflorescencias e a producao total foram diminuidas com a aplicacao de B em funcao do crescimento mais lento das plantas provocado pela toxicidade desse elemento. Contudo, nas areas nao adubadas com B, a porcentagem de plantas com hastes ocas foi, em media, de 44,14%, sendo que a incidencia dessa anomalia sofreu drastica reducao com a aplicacao de B, onde a maior dose (8 kg ha-1) resultou em apenas 4,52% de inflorescencias afetadas. Doses de N superiores a 215,4 kg ha-1 aumentaram o numero de plantas com hastes ocas somente nas areas que nao receberam B.

Vertical growth of mini watermelon according to the training height and plant density

A melancia e uma especie tradicionalmente conduzida em campo no sistema rasteiro. As cultivares de frutos pequenos (1 a 3 kg), que adquirem melhores precos de mercado, vem sendo cultivadas tambem em ambiente protegido, onde sao conduzidas no sistema vertical, com poda de ramos e raleio de frutos. Essas praticas possibilitam aumentar o adensamento das plantas, a qualidade e a produtividade de frutos em comparacao ao sistema rasteiro. Objetivou-se com este trabalho avaliar a influencia de tres alturas de conducao (1,7; 2,2 e 2,7 m) e duas densidades de plantas (3,17 e 4,76 plantas m-2) sobre as caracteristicas produtivas e qualitativas da mini melancia Smile cultivada em ambiente protegido. A poda da haste principal foi realizada aos 43, 55 e 66 dias apos o transplante (DAT) para as alturas de conducao de 1,7; 2,2 e 2,7 m, respectivamente. A massa seca dos ramos, dos peciolos, das folhas e total foram afetados pela altura de conducao, cujos maiores valores foram obtidos para as plantas conduzidas a 2,2 e 2,7 m de altura. A area foliar, a area foliar especifica e o indice de area foliar nao foram influenciados pela altura de conducao das plantas. A altura de conducao de 2,7 m elevou a produtividade total. Entretanto, a produtividade comercial, a massa media dos frutos e todas as caracteristicas qualitativas nao foram significativamente diferentes das obtidos pela altura de poda de 2,2 m. Em relacao a densidade de plantas, a melhor opcao foi a de 4,76 plantas m-2, pois elevou a produtividade comercial em 37,4% sem reduzir a massa media dos frutos.

Nitrogênio e boro na produção e incidência de haste oca em couve-flor 'Sharon'

NITROGEN AND BORON ON YIELD AND INCIDENCE OF HOLLOW STEM DISORDER IN CAULIFLOWER ‘SHARON’ The objective was evaluate nitrogen (100, 150, 200 and 250 kg ha -1 ) and boron rates (0; 1.5 kg ha -1 at planting and 1.5 kg ha -1 after 45 transplanting days and 3.0 kg ha -1 at planting) on yield and hollow stem disorder of cauliflower ‘Sharon’ in blocks randomized in factorial design with four replications. The experiment was carried out in field conditions, in Piracicaba, Sao Paulo State, at Nitossolo Vermelho Eutrofico soil during November/2005 until March/2006. The nitrogen and boron did not effect on commercial and total yield, inflorescence mass, N and B levels of leaves and inflorescences. Hollow stem incidence was reduced by B application.

Adubação nitrogenada e potássica do Aster ericoides cultivado em ambiente protegido

The Aster ericoides is a cut flower crop recently introduced into Brazil. It has great production potential and acceptation by consumer market but exist little information about fertilization management, essential to its development and quality. In this work we evaluated the nitrogen and potassium fertilization on dry matter yield and nutrient absorption by Aster ericoides (White Master) growing in a Typic Hapludox soil under greenhouse conditions. The experiment was set up in a completely randomized design factorial scheme (4 x 4) with 4 rates of N (0; 50; 75 and 100 kg ha-1 N), 4 rates of K (0; 52; 78; 104 kg ha-1 K2O) and 4 replicates at second cycle of culture. The population was maintained at 400,000 plants per hectare. After 105 days, ten stems of each plot were harvested. The stem and leaf dry matter production, number of flowers in each stem and number of principal lateral shoots in each stem were not influenced by treatments. The rate of 46 kg ha-1 of N resulted in maximum flower dry matter production (19.40 g plant-1) and potassium fertilization did not influence the evaluated characteristics. These results showed how necessary it is to be careful with N and K fertilization in this type of soil, to avoid reduced flower dry matter production. More studies about nitrogen and potassium fertilization should be done to define adequate recommendations for Aster ericoides planting under tropical conditions.

Yield and incidence of hollow stem disorder of cauliflower 'Sharon' influenced by the application of nitrogen and boron.

The hollow stem disorder is a common problem in cauliflower, resulting in similar symptoms as those caused by B deficiency. Its occurrence in cauliflower is related to nitrogen and boron levels. There exist little information about this subject in Brazil. The effect of nitrogen rates and boron application periods were evaluated on the cauliflower production and incidence of hollow stem. The experiment was carried out from November 2005 through February 2006 in a Kandiustalf soil (0.54 mg B kg-1, BaCl2 1.25 mg L-1) at Tiete region, Sao Paulo State, Brazil, in a randomized complete block design with four replicates, four N levels (100; 150; 200 and 250 kg ha-1) and two periods of B application (one and two applications) and a control (without application). Cauliflower curd diameter ranged from 16.45 to 22.03 cm and the commercial yield from 15.71 to 29 t ha-1; these two traits were not influenced by treatments. Nitrogen rates increased linearly in leaves and curds. The hollow stem and curd browning were reduced and commercial yield was increased with B fertilization. The correlation between B concentration on leaves (r= 0.66; p<0.05) and curds (r= 0.76; p<0.05) with hollow stem disorder was negative. Boron fertilization is necessary to reduce the symptoms of hollow stem when cauliflower is grow in soil with medium B level (0.54 mg B dm-3). More studies are needed using other types of soil and other cauliflower cultivars in order to reduce this physiological disorder in tropical conditions and increase the efficiency of boron fertilization.