Fontes e doses de nitrogênio antes e após a indução floral em abacaxi cv. Smooth Cayenne, na região noroeste do estado de São Paulo
2010; Linguagem: Inglês
ISSN
2639-6459
Autores Tópico(s)Banana Cultivation and Research
ResumoPineapple plant is demanding in fertility of soil, and N is the most important nutrient for the development of plant and increase of size and mass of fruits. The objective of this work was to evaluate quantity and quality of fruits of pineapple cv. Smooth cayenne in the northwest area of Sao Paulo State, using sources and doses of N, applied before and after the flowering induction, in soil fertilized with potassium. The work was conducted at Agua Limpa farm, in Guaracai-SP, in a Red-yellow Latosol. The seedlings were planted in furrows at soil surface, in 03/17/2009, with spacing of 1.10m between double lines, 0.40m between single lines and 0.40m among plants, with approximate density of 33,000 plants ha, being each plot composed of four double lines with 56 plants/plot in the total. The flowering induction was accomplished in two times, due to little percentage of plants induced in the first time, in other words, in 02/21/2009 and 05/05/2009, with the respective crops of the fruits accomplished in 09/12/2009 (203 days after the induction) and 11/27/2009 (206 days after the induction). The evaluations were: two nutritional analyses in D leaf, one before and other after the flowering induction, and two analyses of fruits, due to the accomplishment of two crops. A randomized block design with four repetitions in a factorial scheme 3x5 (for 1st leaf analysis without time effect) and 2x3x4 (for 2nd leaf analysis and two fruit analyses), being composed by two times of N application: the total dose accomplished in 10/06/2008 (before the floral induction) or total dose in 06/12/2009 (after the floral induction), 3 sources of N, ammonium sulfate, urea and ammonium nitrate, and four N doses (7.5; 15; 22.5 and 30 g plant) was used. Ammonium sulfate provided higher leaf N and S content as applied on pineapple plant before or after the floral induction. For the fruits harvested in 09/03/2009, the application of ammonium nitrate increased the dimensions of fruits; however, it increased the acidity and reduced the IM. Already, for the fruits harvested in 11/27/2009, the sources ammonium sulfate and ammonium nitrate increased the productivity. The application of N before the floral induction provided fruits with larger dimensions and better quality in the two times of floral induction, and it increased the productivity for the fruits from 2 floral induction. Nitrogen doses applied before floral induction provided lineal increments on leaf N content; however, by dilution effect, they reduced the P, K, Ca and Mg content. For the fruits harvested in 09/03/2009, the increment on N doses, increased in a lineal way the SS content; however, for the fruits harvested in 11/27/2009, the increment on N doses applied after the floral induction decreased in a lineal way the productivity of pineapple fruits 'Smooth Cayenne'. Key-word: Urea. Ammonium sulfate. Ammonium nitrate. Mass of fruits. Lista de Ilustracoes Figura 1 – Tratos culturais com as suas respectivas datas de realizacao, dados de precipitacao pluvial (mm) e temperatura media (oC) durante a conducao do experimento. Guaracai, 2008 e 2009 Foto 1 – Area experimental com a cultura do abacaxi com aproximadamente 1 ano de idade, apos a 1a adubacao e 1a inducao floral (10/04/2009). Guaracai – SP, 2009 Foto 2 – Area experimental com a cultura do abacaxi no dia (03/09/2009), apos a 2a adubacao e 2a inducao floral, mostrando frutos empapelados colhidos na 1a colheita, e frutos sendo formados colhidos na 2a colheita. Guaracai – SP, 2009 Foto 3 – Area experimental com a cultura do abacaxi no dia (10/11/2009), proximo a 2a colheita, mostrando a maior quantidade de frutos colhidos nesta epoca. Guaracai – SP, 2009 Foto 4 – Area experimental com a cultura do abacaxi no dia da 2a colheita (27/11/2009), mostrando os frutos colhidos dentro sacos plasticos. Guaracai – SP, 2009 Foto 5 – Frutos colhidos dentro de sacos plasticos previamente identificados com o numero da parcela (27/11/2009). Guaracai – SP, 2009 Pagina
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