Efeito da densidade de tubérculos de tiririca (Cyperus rotundus) sobre o crescimento inicial de plantas de algodão
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Data
2002-12-01
Autores
Salgado, T.P. [UNESP]
Alves, P.L.C.A. [UNESP]
Rossi, C.V.S. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
O objetivo deste trabalho foi avaliar a interferência de densidades de tubérculos de tiririca no crescimento inicial de plantas de algodão, cultivar Delta Opal. Para isso, utilizaram-se caixas de cimento-amianto (0,60 x 0,60 x 0,25 m) com Latossolo Vermelho Escuro, no centro das quais foram semeadas seis sementes de algodão, em linha, espaçadas de 0,10 m; em seguida, plantaram-se tubérculos de tiririca nas densidades de 0, 5, 10, 15, 25, 50, 75, 100, 125, 150, 175 e 200 tubérculos por caixa, que foram nestas distribuídos aleatoriamente. O delineamento experimental foi o de blocos casualizados, em quatro repetições. Aos 50 dias após a semeadura, foram determinados, nas plantas de algodão, a altura e o teor relativo de clorofila total. Ao término do período experimental (65 dias após a emergência do algodão), foram determinados: altura, teor relativo de clorofila total, área foliar e matéria seca do caule e das folhas. Nas plantas de tiririca foi feita a contagem do número final de plantas (partes aéreas) por caixa. A interferência da tiririca no crescimento inicial do algodoeiro iniciou-se a partir de 5 tubérculos/caixa, reduzindo em até 71% as características analisadas na mais alta densidade (200 tubérculos/caixa). A competição intra-específica na tiririca acentuou-se a partir de 75 tubérculos/caixa, quando obteve mais do que 1,86 brotação por tubérculo. As características avaliadas nas plantas de algodão mais sensíveis ao efeito dos tubérculos de tiririca foram: área foliar, massa seca de folhas, caule e altura das plantas, nesta ordem.
The aim of this research was to evaluate the effect of purple nutsedge (Cyperus rotundus) tuber density on the initial growth of cotton (Gossypium hirsutum) plants, cultivar Delta Opal. Boxes (0.60 x 0.60 x 0.25 m) containing red Latosol were used as recipients, where six cotton seeds were seeded in the center of the boxes spaced by 0.10 m; followed by the purple nutsedge tuber density in the boxes (0, 5, 10, 15, 25, 50, 75, 100, 125, 150, 175, 200 tubers per box), planted randomly. The experiment was arranged in a randomized complete block design with four replications. Height and the total chlorophyll content were determined 50 days after cotton seeding. At the end of the experiment (65 days after cotton emergence), height, total relative chlorophyll content, leaf area and dry weight of shoots and leaves were determined. The final number of shoots per box was evaluated in the purple nutsedge plants. The interference of the purple nutsedge in the initial growth of cotton initiated with 5 tubers/box, reducing up to 71% of the characteristics analyzed under the highest density (200 tubers/box). The intra specific competition was more intense in 75 tubers/box, when over 1.86 sprouts per tuber were obtained. The cotton characteristics most sensitive to the interference of purple nutsedge were: leaf area, leaf dry matter and plant stem and height.
The aim of this research was to evaluate the effect of purple nutsedge (Cyperus rotundus) tuber density on the initial growth of cotton (Gossypium hirsutum) plants, cultivar Delta Opal. Boxes (0.60 x 0.60 x 0.25 m) containing red Latosol were used as recipients, where six cotton seeds were seeded in the center of the boxes spaced by 0.10 m; followed by the purple nutsedge tuber density in the boxes (0, 5, 10, 15, 25, 50, 75, 100, 125, 150, 175, 200 tubers per box), planted randomly. The experiment was arranged in a randomized complete block design with four replications. Height and the total chlorophyll content were determined 50 days after cotton seeding. At the end of the experiment (65 days after cotton emergence), height, total relative chlorophyll content, leaf area and dry weight of shoots and leaves were determined. The final number of shoots per box was evaluated in the purple nutsedge plants. The interference of the purple nutsedge in the initial growth of cotton initiated with 5 tubers/box, reducing up to 71% of the characteristics analyzed under the highest density (200 tubers/box). The intra specific competition was more intense in 75 tubers/box, when over 1.86 sprouts per tuber were obtained. The cotton characteristics most sensitive to the interference of purple nutsedge were: leaf area, leaf dry matter and plant stem and height.
Descrição
Palavras-chave
Weed, interference, Development, Leaf area, Plantas daninhas, Interferência, Desenvolvimento, área foliar
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 20, n. 3, p. 405-411, 2002.