Influência de doses e épocas de aplicação de magnésio na nutrição, crescimento, produtividade e qualidade de cultivares de batata
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Data
2022-09-06
Autores
Garreto, Francisca Gyslane de Sousa
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Universidade Estadual Paulista (Unesp)
Resumo
O magnésio (Mg) é um nutriente importante na produção e transporte de carboidratos na planta, interferindo na produtividade e na qualidade dos tubérculos de batata. Apesar da importância deste nutriente, no Brasil, são escassos os estudos científicos sobre sua aplicação na cultura da batata (Solanum tuberosum L.). Dessa forma, o objetivo do presente trabalho foi definir a dose e a época de aplicação de Mg capazes de suprir a necessidade da planta, bem como avaliar o efeito de doses e épocas de aplicação de Mg na nutrição da planta, produtividade, qualidade dos tubérculos e partição de fotoassimilados nas cultivares Agata, Asterix e Orchestra. Neste trabalho de pesquisa foram realizados três estudos. O estudo I consistiu em um experimento em casa de vegetação com duas cultivares (Agata e Asterix) no ano de 2021 e os estudos II e III foram realizados em campo com as cultivares Agata, Asterix e Orchestra, sendo cada um deles conduzido em dois locais/anos distintos (Itaí-SP e Botucatu-SP) nos anos de 2019 e 2020. A fonte de Mg utilizada foi o sulfato de magnésio monohidratado (kieserita). O estudo I foi conduzido no delineamento experimental de blocos casualizados, em esquema fatorial 6×2, com seis repetições. Os tratamentos foram constituídos por seis manejos (doses/épocas de aplicação) de Mg (T0: controle, sem adubação com Mg; T1: 2,1 mmolc dm-3 de Mg aplicado no plantio; T2: 4,1 mmolc dm-3 de Mg aplicado no plantio; T3: 8,2 mmolc dm-3 de Mg aplicado no plantio; T4: 4,1 mmolc dm-3 de Mg aplicado aproximadamente 10 dias após a emergência (DAE) (amontoa); T5: 2,1 mmolc dm-3 de Mg aplicado no plantio e 2,1 mmolc dm-3 de Mg aplicado aos 10 DAE) e duas cultivares de batata (Agata e Asterix). Nos experimentos de campo foi utilizado o delineamento experimental de blocos casualizados, com quatro repetições. O estudo II, denominado “estudo de doses e épocas de aplicação de Mg”, foi instalado no esquema fatorial 4×2+1, cujos tratamentos foram constituídos por quatro doses de Mg (12,5; 25,0; 50,0 e 100,0 kg ha-1) em duas épocas de aplicação, no sulco de plantio ou por ocasião da amontoa, e um tratamento sem aplicação de Mg (controle). O estudo III, denominado “estudo de formas de manejo da aplicação de Mg”, foi constituído por cinco formas de parcelamento/épocas de aplicação da mesma dose de Mg e um tratamento sem aplicação de Mg (controle). Os resultados indicaram que a aplicação de Mg mantém maiores índices relativos de clorofila (SPAD) na folha, proporcionando maior produção de matéria seca (MS) e acúmulo total de Mg, independente da cultivar. A maior parte do Mg absorvido é translocado para os tubérculos. A aplicação de Mg, via sulfato de magnésio monoidratado (kieserita), pode aumentar a produtividade e a qualidade dos tubérculos de batata, mesmo em solos com elevado teor de Mg trocável no solo (9-14 mmolc dm-3). A época de aplicação do Mg (plantio ou amontoa) tem pouca influência na nutrição, produtividade e qualidade dos tubérculos das cultivares de batata. As cultivares de batata apresentam responsividade a adubação magnesiana na seguinte ordem: Agata > Asterix > Orchestra. O fornecimento de Mg aumenta teor de amido e reduz os teores de açúcares redutores e totais nos tubérculos de batata.
Magnesium (Mg) is an important nutrient in the production and carbohydrate transport in the plant, interfering with the yield and quality of potato tubers. Despite the importance of this nutrient, in Brazil, there are few scientific studies on its application in the potato (Solanum tuberosum L.) crop. Thus, the objective of the present work was to define the rate and timing of Mg application capable of supplying the need of the plant, as well as to assess the impact of rates and timing of Mg application on nutrition, yield, tuber quality and partition of photoassimilates in potato of three cultivars (Agata, Asterix, and Orchestra). In this research work, three studies were carried out. Study I consisted of an experiment in a greenhouse with two cultivars (Agata and Asterix) in the year 2021 and studies II and III were carried out in the field with the cultivars Agata, Asterix, and Orchestra, each one being conducted in two locations/different years (Itaí-SP and Botucatu-SP) in the years 2019 and 2020. The source of Mg used was magnesium sulfate monohydrate (kieserite). Study I was carried out in a randomized block design, in a 6×2 factorial design, with six replications. The treatments consisted of six managements (rates/timing) of Mg (T0: control, without fertilization with Mg; T1: 2.1 mmolc dm-3 of Mg applied at planting; T2: 4.1 mmolc dm-3 of Mg applied at planting; T3: 8.2 mmolc dm-3 of Mg applied at planting; T4: 4.1 mmolc dm-3 of Mg applied approximately 10 days after emergence (DAE) (hilling); T5: 2.1 mmolc dm-3 of Mg applied at planting and 2.1 mmolc dm-3 of Mg applied 10 DAE) and two potato cultivars (Agata and Asterix). In the field experiments, a randomized block design was used, with four replications. Study II, called “study of rates and timing of Mg application”, was installed in a 4×2+1 factorial design, whose treatments consisted of four rates of Mg (12,5, 25, 50, and 100 kg ha-1) at two timings of application, in the planting furrow or at hilling, and treatment without Mg application (control). Study III, called “study of ways of managing the application of Mg”, consisted of five forms of splitting/timing of application of the same rate of Mg and treatment without application of Mg (control). The results indicated that the Mg application maintains higher relative levels of chlorophyll (SPAD) in the leaf, providing greater dry matter (DW) production and total Mg accumulation, regardless of the cultivar. Most of the absorbed Mg is translocated to the tubers. The application of Mg, via magnesium sulfate monohydrate (kieserite), can increase the yield and quality of potato tubers, even in soils with high exchangeable Mg content in the soil (9-14 mmolc dm-3). The application timing of Mg (planting or hilling) has little influence on the nutrition, yield, and quality of tubers of potato cultivars. Potato cultivars are responsive to magnesian fertilization in the following order: Agata > Asterix > Orchestra. The supply of Mg increases the starch content and reduces the levels of reducing and total sugars in potato tubers.
Magnesium (Mg) is an important nutrient in the production and carbohydrate transport in the plant, interfering with the yield and quality of potato tubers. Despite the importance of this nutrient, in Brazil, there are few scientific studies on its application in the potato (Solanum tuberosum L.) crop. Thus, the objective of the present work was to define the rate and timing of Mg application capable of supplying the need of the plant, as well as to assess the impact of rates and timing of Mg application on nutrition, yield, tuber quality and partition of photoassimilates in potato of three cultivars (Agata, Asterix, and Orchestra). In this research work, three studies were carried out. Study I consisted of an experiment in a greenhouse with two cultivars (Agata and Asterix) in the year 2021 and studies II and III were carried out in the field with the cultivars Agata, Asterix, and Orchestra, each one being conducted in two locations/different years (Itaí-SP and Botucatu-SP) in the years 2019 and 2020. The source of Mg used was magnesium sulfate monohydrate (kieserite). Study I was carried out in a randomized block design, in a 6×2 factorial design, with six replications. The treatments consisted of six managements (rates/timing) of Mg (T0: control, without fertilization with Mg; T1: 2.1 mmolc dm-3 of Mg applied at planting; T2: 4.1 mmolc dm-3 of Mg applied at planting; T3: 8.2 mmolc dm-3 of Mg applied at planting; T4: 4.1 mmolc dm-3 of Mg applied approximately 10 days after emergence (DAE) (hilling); T5: 2.1 mmolc dm-3 of Mg applied at planting and 2.1 mmolc dm-3 of Mg applied 10 DAE) and two potato cultivars (Agata and Asterix). In the field experiments, a randomized block design was used, with four replications. Study II, called “study of rates and timing of Mg application”, was installed in a 4×2+1 factorial design, whose treatments consisted of four rates of Mg (12,5, 25, 50, and 100 kg ha-1) at two timings of application, in the planting furrow or at hilling, and treatment without Mg application (control). Study III, called “study of ways of managing the application of Mg”, consisted of five forms of splitting/timing of application of the same rate of Mg and treatment without application of Mg (control). The results indicated that the Mg application maintains higher relative levels of chlorophyll (SPAD) in the leaf, providing greater dry matter (DW) production and total Mg accumulation, regardless of the cultivar. Most of the absorbed Mg is translocated to the tubers. The application of Mg, via magnesium sulfate monohydrate (kieserite), can increase the yield and quality of potato tubers, even in soils with high exchangeable Mg content in the soil (9-14 mmolc dm-3). The application timing of Mg (planting or hilling) has little influence on the nutrition, yield, and quality of tubers of potato cultivars. Potato cultivars are responsive to magnesian fertilization in the following order: Agata > Asterix > Orchestra. The supply of Mg increases the starch content and reduces the levels of reducing and total sugars in potato tubers.
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Palavras-chave
Solanum tuberosum, nutrição mineral, kieserita, manejo de magnésio, produtividade, transporte de carboidratos, mineral nutrition, magnesium management, yield, carbohydrate transport