Produção e qualidade da moranga híbrida em resposta a doses de nitrogênio Yield and quality of hybrid squash (pumpkin) in response to nitrogen doses

Foram avaliados os efeitos de doses de N na produção e qualidade da moranga hibrida cv. Tetsukabuto (Takaima F1) em experimento na EPAMIG Centro Oeste, Prudente de Morais (MG), de 25/08 a 03/12/2008. Foram avaliadas cinco doses de nitrogênio (0; 37,5; 75; 150; 300 kg ha-1), na forma de uréia, divididas em quatro aplicações (30% no plantio, 20% aos 20 dias, 30% aos 40 dias e 20% aos 60 dias após a emergência), num delineamento experimental de blocos casualizados com quatro repetições. As doses de N influenciaram significativamente as características avaliadas. O número de frutos aumentou de 2.498 ao ponto de máximo de 6.794 frutos ha-1 com a aplicação de 219 kg ha-1 de N. O diâmetro e a espessura da polpa do fruto aumentaram de 14,97 e 2,33 cm, até atingirem os pontos máximos de 17,74 e 2,80 cm nas doses de 171 e 128 kg ha-1 de N, respectivamente. O teor de sólidos solúveis na polpa de frutos de moranga híbrida aumentou com o aumento das doses de N observando-se com a aplicação de 300 kg ha-1 de N teor de 8ºBrix. A produtividade de frutos foi também influenciada pelas doses de N estimando-se como valor máximo 11,55 t ha-1 de frutos com a aplicação de 300 kg ha-1 de N. A dose estimada de N relativa à máxima eficiência econômica foi obtida com a aplicação de 262 kg ha-1, considerando os preços de R$2,41 kg-1 de N e de R$ 560,00 t-1 de moranga.<br>An experiment was carried out at EPAMIG Centro Oeste, Prudente de Morais, Minas Gerais state, Brazil, from August 25 to December 2, 2008, to evaluate the effects of N rates on production and quality of hybrid squash cv. Tetsukabuto (Takaima F1). The treatments were five N rates (0, 37.5, 75, 150, 300 kg ha-1), as urea, split in four applications (30% at planting date, 20% at 20 days, 30% at 40 days and 20% at 60 days after emergence) in a randomized complete block design, with four replications. The N rates significantly affected the characteristics evaluated. The number of fruits increased from 2,498, reaching the fruit maximum number (6,794 ha-1) when applying 219 kg ha-1 N. The fruit yield was also influenced by N rates, the maximum yield (11.55 t ha-1) being achieved when 300 kg ha-1 of N were applied. The diameter and thickness of fruit pulp increased from 14.97 and 2.33 cm to achieve maximum points of 17.74 and 2.80 cm with N doses of 171 and 128 kg ha-1, respectively. The soluble solids content in the fruit pulp increased with increasing N doses and the content of 8ºBrix was observed with the application of 300 kg ha-1 N. Fruit yield was also influenced by N rates being estimated 11.55 kg ha-1 as maximum yield with the application of 300 kg ha-1 N. The estimated dose of N on the maximum economic efficiency was obtained with the application of 262 kg ha-1, considering the prices of R$2.41 kg-1 of N and R$ 560.00 t-1 of hybrid squash fruits

Influence of the N/K ratio on the production and quality of cucumber in hydroponic system

The objective of this work was to evaluate the quality of fruits and the nutritional status of cucumber CV. Aodai cultivated in nutrient solutions with different N:K ratios. The hydroponic cultivation was initially performed, during the vegetative growth, in nutrient solution with 1:2.0 mmol L-1 N:K, and, later, during fruit setting, in four different nutrient solutions with N:K (w/w) at the ratios 1:1.4, 1:1.7, 1:2.0 and 1:2.5. An additional treatment with a nutrient solution containing the ratio 1:2.2 (w/w) N:K during the vegetative growth and N:K 1:1.4 (w/w) during fruit setting, both with 10% ammonium (NH4+) was included. The treatments were arranged in a randomized design with six replicates. Irrigation was carried out with deionized water until seed germination, and then with nutrient solution until 30 days after germination, when plants were transplanted. Plants in the hydroponic growing beds were irrigated with the solutions for vegetative growth, and, after 21 days, the solutions were replaced by solutions for fruit setting. At 45 and 60 days after transplanting, the fresh weight, length, diameter, volume and firmness of the fruit were evaluated, and, at 45 days after transplanting, the macronutrient concentrations in the leaves were determined. The use of different N:K ratios during fruit setting influenced the cucumber production. The ratio of 1.0:1.7 N: K (w/w), with 10% of N in the form of ammonia, is recommended for the whole cycle

Desempenho de cultivares de cebola em cultivo orgânico e tipos de solo no Vale do São Francisco Evaluation of onion cultivars under organic cultivation in two soil types in the São Francisco Valley, Brazil

Com o objetivo de avaliar a produtividade de cultivares de cebola em cultivo orgânico no Vale do São Francisco, conduziram-se dois experimentos, de maio a outubro de 2005, nos Campos Experimentais de Bebedouro, Petrolina-PE, e Mandacaru, Juazeiro-BA, em ARGISSOLO e VERTISSOLO respectivamente. O delineamento experimental utilizado foi em blocos ao acaso, utilizando-se dezoito e quatorze cultivares de cebola, respectivamente e quatro repetições. Em ARGISSOLO a produtividade total de bulbos variou de 13,52 a 39,52 t/ha. A produtividade comercial oscilou de 7,45 a 38,32 t/ha, sobressaindo-se como mais produtivas as cultivares Brisa IPA-12 (38,32 t/ha) e São Paulo (35,86 t/ha) que não evidenciaram diferenças significativas entre si, assim como as cultivares Botucatu-150 (26,41 t/ha) e Pira Ouro (26,37 t/ha), e menos produtivas as cultivares Conquista (7,45 t/ha) e Crioula Alto Vale (7,81 t/ha). Em VERTISSOLO a produtividade total de bulbos variou de 6,87 a 24,68 t/ha. Sobressairam-se com produtividade comercial as cultivares Texas Grano PRR (21,56 t/ha) e IPA-10 (17,50 t/ha), que não diferiram entre si. As cultivares Crioula Alto Vale, CNPH-6348, CNPH- 6436 e CNPH-6206 não tiveram produção comercial de bulbos.<br>In this research were evaluated the yield of onion cultivars under organic growth in the São Francisco Valley. Two field trials were evaluated, one at the Experimental Farm Station of Embrapa Tropical Semi-Arid, in Petrolina, in an ultisol type and the other at the Experimental Farm Station of Mandacaru, in Juazeiro, in a vertisol type, from February to October of 2005. The experimental design was of randomized complete blocks, with 18 and 14 cultivars, respectively, and four replications. In the ultisol, the total yield of bulbs ranged from 13.52 to 39.52 t/ha. The commercial yield ranged from 7.45 to 38.32 t/ha where the cultivars Brisa (38.32 t/ha) and São Paulo (35.86 t/ha) showed the highest yield without statistical difference; Cultivars Botucatu-150 (26.41 t/ha) and Pira Ouro (26.37 t/ha) also stood out with high yield without statistical difference. The cultivars Conquista (7.45 t/ha) and Crioula Alto Vale (7.81 t/ha) presented the worst performance. In the vertisol the total yield of bulbs ranged from 6.87 to 24.68 t/ha. The cultivars Texas Grano PRR (21.56 t/ha) and IPA-10 (17.50 t/ha) presented the highest yield, without statistical differences. The cultivars Crioula Alto Vale, CNPH-6348, CNPH-6436 and CNPH- 6206 presented no commercial yield