Proexadiona cálcica na fisiologia e produtividade da batata
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Data
2020-08-25
Autores
Oliveira, Luan Santos de
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Universidade Estadual Paulista (Unesp)
Resumo
O uso de regulador de crescimento na batateira pode ser uma alternativa para reduzir o porte da planta e aumentar a produtividade de tubérculos. Esta técnica em associação com a adubação nitrogenada pode ser uma estratégia para potencializar a produção de tubérculos das classes com tubérculos maiores. Assim, o objetivo deste trabalho foi avaliar o efeito da adubação nitrogenada e de doses e épocas de aplicação da proexadiona cálcica (PCA) sobre as características morfofisiológicas da planta, partição de matéria seca, produtividade e qualidade de tubérculos das cultivares de batata Ágata e Mondial. Foram conduzidos quatro experimentos, sendo dois em condições de casa de vegetação (um com Ágata e outro com Mondial) e dois em campo (um com Ágata e outro com Mondial). Na casa de vegetação o delineamento experimental adotado foi o de blocos ao acaso com quatro repetições. Os tratamentos foram representados por um controle (sem regulador) e seis diferentes manejos da aplicação de PCA (50g: 50 g ha-1 aplicados uma vez, 50+50g: 50 g ha-1 aplicados duas vezes, 50+50+50g: 50 g ha-1 aplicado três vezes, 100g: 100 g ha-1 aplicados uma vez, 100+100g: 100 g ha-1 aplicados duas vezes, 100+100+100g: 100 g ha-1 aplicados três vezes). Nos experimentos de campo o delineamento foi o de blocos ao acaso em esquema de parcela subdividida, com quatro repetições. As parcelas foram representadas por dois níveis de fornecimento de N (Recomendado = 120 kg ha-1 e Alto = 240 kg ha-1) e as subparcelas por sete manejos de aplicação de PCA (controle: sem regulador, 50g: 50 g ha-1 aplicados uma vez, 50+50g: 50 g ha-1 aplicados duas vezes, 50+50+50g: 50 g ha-1 aplicado três vezes, 100g: 100 g ha-1 aplicados uma vez, 100+100g: 100 g ha-1 aplicados duas vezes, 100+100+100g: 100 g ha-1 aplicados três vezes). Os resultados obtidos em casa de vegetação indicaram que o manejo da PCA com três aplicações sequenciais de 100 g ha-1 do i.a. foi mais eficiente em reduzir o comprimento das hastes de ambas cultivares. Na cultivar Ágata, a aplicação de PCA não afetou a produtividade de tubérculos, mas alterou o tamanho dos tubérculos formados. Na cultivar Mondial, os tratamentos com duas e três aplicações de 100 g ha-1 de PCA aumentaram a produtividade de tubérculos, mas o incremento obtido foi reflexo do aumento no número de tubérculos de menor tamanho. Os resultados obtidos em campo indicaram que os níveis de fornecimento de N (Recomendado = 120 kg ha-1 e Alto = 240 kg ha-1) pouco influenciou as características analisadas para as duas cultivares. Na cultivar Ágata houve maior redução no comprimento das hastes das plantas quando foram realizadas duas ou três aplicações de 100 g ha-1 de PCA ou três aplicações de 50 g ha-1 de PCA. Porém, a aplicação de PCA não alterou a produtividade total, comercial e especial de tubérculos, bem como o formato dos tubérculos produzidos. Na cultivar Mondial foi preciso fazer mais de uma aplicação de PCA para reduzir significativamente o comprimento das hastes das plantas, e as maiores reduções ocorreram com três aplicações sequenciais de 100 g ha-1 de PCA. A aplicação de PCA não alterou o formato dos tubérculos e a produtividade comercial, mas os tratamentos com duas aplicações de 50 ou 100 g ha-1 de PCA aumentaram a produtividade de tubérculos da classe especial.
The use of plant growth regulator (PGR) in potato crop can be an alternative practice to reduce plant size and increase tuber yield. This technique in association with nitrogen (N) fertilization can be a strategy to enhance production of larger tuber classes. Thus, the objective of this study was to evaluate the effect of nitrogen N fertilization and rates and times of prohexadione-calcium (PCA) application on plant morphophysiological features, dry matter partition, tuber yield and tuber quality of Agata and Mondial potato cultivars. Four experiments were carried out, two in greenhouse conditions (one with Agata and other with Mondial) and two in field (one with Agata and the other with Mondial). In greenhouse, the experimental design adopted was randomized blocks with four replications. Treatments were represented by a control (without PGR) and six different managements of PCA application (50g: 50 g ha-1 applied once, 50+50g: 50 g ha-1 applied twice, 50+50+50g: 50 g ha-1 applied three times, 100g: 100 g ha-1 applied once, 100+100g: 100 g ha-1 applied twice, 100+100+100g: 100 g ha-1 applied three times). In field experiments, the design was randomized blocks in a split-plot scheme, with four replications. Plots were represented by two levels of N supply (Recommended = 120 kg ha-1 and High = 240 kg ha-1) and subplots were represented by seven managements of PCA application (control: without PGR, 50g: 50 g ha-1 applied once, 50+50g: 50 g ha-1 applied twice, 50+50+50g: 50 g ha-1 applied three times, 100g: 100 g ha-1 applied once, 100+100g: 100 g ha-1 applied twice, 100+100+100g: 100 g ha-1 applied three times). The results obtained in greenhouse indicated that the management of PCA with three sequential applications of 100 g ha-1 a.i. was more efficient in reducing stem length of both cultivars. In the Ágata cultivar, PCA application did not affect tuber yield, but changed the size of the formed tubers. In the Mondial cultivar, treatments with two and three applications of 100 g ha-1 PCA increased tuber yield, but the increase obtained was a reflection of a increase in the number of smaller tubers. The results obtained in field indicated that the levels of N supply (Recommended = 120 kg ha-1 and High = 240 kg ha-1) had little influence on the features analyzed in both cultivars. In the Ágata cultivar, there was a greater reduction in plant stem length when two or three applications of 100 g ha-1 PCA or three applications of 50 g ha-1 PCA were performed. However, PCA application did not change total, marketable and special tuber yield or the shape of tubers produced. In the Mondial cultivar, it was necessary to make more than one application of PCA to significantly reduce the length of plant stems, and the greatest reductions was observed with three sequential applications of 100 g ha-1 PCA. PCA application did not change tuber shapes or marketable yield, but treatments with two applications of 50 or 100 g ha-1 PCA increased yield of tubers of special class.
The use of plant growth regulator (PGR) in potato crop can be an alternative practice to reduce plant size and increase tuber yield. This technique in association with nitrogen (N) fertilization can be a strategy to enhance production of larger tuber classes. Thus, the objective of this study was to evaluate the effect of nitrogen N fertilization and rates and times of prohexadione-calcium (PCA) application on plant morphophysiological features, dry matter partition, tuber yield and tuber quality of Agata and Mondial potato cultivars. Four experiments were carried out, two in greenhouse conditions (one with Agata and other with Mondial) and two in field (one with Agata and the other with Mondial). In greenhouse, the experimental design adopted was randomized blocks with four replications. Treatments were represented by a control (without PGR) and six different managements of PCA application (50g: 50 g ha-1 applied once, 50+50g: 50 g ha-1 applied twice, 50+50+50g: 50 g ha-1 applied three times, 100g: 100 g ha-1 applied once, 100+100g: 100 g ha-1 applied twice, 100+100+100g: 100 g ha-1 applied three times). In field experiments, the design was randomized blocks in a split-plot scheme, with four replications. Plots were represented by two levels of N supply (Recommended = 120 kg ha-1 and High = 240 kg ha-1) and subplots were represented by seven managements of PCA application (control: without PGR, 50g: 50 g ha-1 applied once, 50+50g: 50 g ha-1 applied twice, 50+50+50g: 50 g ha-1 applied three times, 100g: 100 g ha-1 applied once, 100+100g: 100 g ha-1 applied twice, 100+100+100g: 100 g ha-1 applied three times). The results obtained in greenhouse indicated that the management of PCA with three sequential applications of 100 g ha-1 a.i. was more efficient in reducing stem length of both cultivars. In the Ágata cultivar, PCA application did not affect tuber yield, but changed the size of the formed tubers. In the Mondial cultivar, treatments with two and three applications of 100 g ha-1 PCA increased tuber yield, but the increase obtained was a reflection of a increase in the number of smaller tubers. The results obtained in field indicated that the levels of N supply (Recommended = 120 kg ha-1 and High = 240 kg ha-1) had little influence on the features analyzed in both cultivars. In the Ágata cultivar, there was a greater reduction in plant stem length when two or three applications of 100 g ha-1 PCA or three applications of 50 g ha-1 PCA were performed. However, PCA application did not change total, marketable and special tuber yield or the shape of tubers produced. In the Mondial cultivar, it was necessary to make more than one application of PCA to significantly reduce the length of plant stems, and the greatest reductions was observed with three sequential applications of 100 g ha-1 PCA. PCA application did not change tuber shapes or marketable yield, but treatments with two applications of 50 or 100 g ha-1 PCA increased yield of tubers of special class.
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Palavras-chave
Solanum tuberosum, Proexadiona cálcica, Giberelina, Nutrição mineral, Prohexadione-calcium, Gibberellin, Mineral nutrition