MANEJO DA ADUBAÇÃO POTÁSSICA NA CULTURA DO MILHO (Zea mays)

Abstract

Maize is an annual monocotyledonous Monocotyledonous belonging to the family Poaceae (Gramineae), classified as Zea mays L. Maize is one of the most important crops in Brazil. To increase crop productivity, a limiting factor is adequate mineral nutrition, through fertilization, assessing the nutritional need of the vegetable, observing the total amount of nutrients absorbed. The lack of potassium macronutrient results in a series of damages to the plant, so the present work aims precisely to evaluate the response of potassium fertilization in different doses and times of application. The experiment was conducted in the experimental area belonging to the Department of Plant Science and Agricultural Sciences - CCA - Campus II of the Federal University of Paraíba located in the city of Areia-Pb. The experimental area was composed of 4 replicates, composed of 10 treatments previously randomized, each treatment with 4 grooves, and 2 times of application of K (sowing, V5 stage). The following variables were evaluated: plant height, stem diameter, number of leaves, leaf length of the middle third. The height (m) of Hybrid Corn AG1051 plants was influenced by periods of potassium fertilizer application. When AG1051 Hybrid Corn plants were submitted to potassium fertilization in the V5 stage of crop development, the average height of the plants tended to increase. In the case of the diameter of the stem (cm) of Hybrid Corn AG1051 plants, it was influenced by the periods of application of the potassic fertilizer independent of the period of application of the fertilizer, the diameter of the stem of the plants tended to increase up to the amount of 150 kg / There are 1. The number of leaves of plants of Hybrid Corn AG1051 was influenced by the periods of application of the fertilizer the number of leaves of the plants tended to increase in a quadratic form, presenting the average values of 8.8 and 8 leaves at the forty five days after planting For the plants that received fertilization in the planting and in the stage V5 of development of the culture respectively. The average leaf size of AG1051 Hybrid Corn plants was influenced by the periods of application of the fertilizer, this variable behaved in a quadratic way, independent of the period of fertilization, presenting the average values of 81 cm in length for the plants that received fertilization In the planting and 78.6 in the treatment in which the fertilization was carried out in stage V5 of crop development. Thus 50 kg ha-1 of KCl applied at corn sowing AG 1051, provides better plant height values. The fertilization season did not influence the diameter of the stem, with the best dose being 150 kg ha-1. The time of fertilization does not influence the variable number of leaves, the best dose being 200 kg ha-1. The highest value of the average third of leaves size is verified in the fertilization done at the planting applied to the dose of 100 kg ha-1 of KCl.