65ª Reunião Anual da SBPC

E. Ciências Agrárias - 1. Agronomia - 4. Fitotecnia

FLOWER AND FRUIT BEHAVIORS IN EGGPLANT EXPOSED TO DIFFERENT SOURCES AND LEVELS OF POTASSIUM

Odyone Nascimento da Silva - Universidade Federal Rural da Amazônia-UFRA Argemiro Pereira Martins Filho - Universidade Federal Rural da Amazônia-UFRA Maria do Bom Conselho Lacerda Medeiros - Universidade Federal Rural da Amazônia-UFRA Douglas José Marques - Departamento de Ciência do Solo, Universidade Federal de Lavras, Lavras, Brasil Fernando Broetto - Departamento de Química e Bioquímica, Universidade Estadual Paulista, Botucatu, Allan Klynger da Silva Lobato - Universidade Federal Rural da Amazônia-UFRA

INTRODUÇÃO:

Eggplant (Solanum melongena L.) is a horticultural species that has been largely consumed in world due to medical and nutritive potentials.Growth and adaptation of a species to environment is related with your reproductive efficiency, and this aspect also is linked to photosynthetic pigments, because adequate work of photosynthetic apparatus can produce greater number flowers and consequently fruits. Excessive fertilization normally promotes increase in salinity soil, and this condition can reached by the utilization frequent of large amounts of chemical compounds used in mineral nutrition of plants. Besides to represent problem for soil, there are other negative consequences for plant, such as decreases in growth, and yield. "tags"

OBJETIVO DO TRABALHO:

The aim of this study was to investigate flower and fruit behaviors in eggplant (Solanum melongena L.), and to indicate better potassium source to cultivation of this species."tags"

MÉTODOS:

Study was conducted in Departamento de Produção Vegetal, Universidade Estadual Paulista (UNESP), Botucatu, São Paulo, Brazil. The eggplant seeds of cv. Embu were placed to germinate in containers with sterile substrate denominated Plantmax® and watered with distilled water. The seedlings were transplanted from container to pot in 35thday, in which 3 or 4 definitive leaves were present. The experimental design used was factorial scheme with randomized blocks (2 x 4), 2 potassium sources (KCl and K2SO4) combined with 4 potassium levels (250, 500, 750 and 1000 kg K2O. ha-1). This experiment was composed of 5 replicates and 40 experimental units. The fertilization of surface started on 15thday after transplanting and promoted in constant intervals of 15 days. The fertilization of surface was performed using as N source calcium nitrate in amount of 22.8 g pot-1 divided in 14 applications. Flower number, aborted flower number, and aborted fruit number were measured in regular intervals of 2 days, beginning in 48th days after transplanting until harvest period. For these parameters were evaluated 5 plants by treatment. In aborted flower number was obtained by subtraction among actual evaluation and previous evaluation. Aborted fruit number was evaluated in fruit harvest period.

RESULTADOS E DISCUSSÃO:

In relation to flower number were showed similar effects independent of potassium source used.In addition, treatment with K2SO4 promoted higher flower number independently of dose used. Points with maximum value of 128 and 170 flowers produced by KCl and K2SO4 were estimated in 500 and 580 Kg ha-1, respectively.Flower aborting was showed significant interaction between factors (sources and doses). With K2SO4there are reductions in applications of 500 and 750 kg ha-1 K2O. Probably higher flower aborting in sub-optimal dose can be associated to nutritional insufficiency. By other hand, increase in aborting rate in supra-optimal dose resulted in aborting large, and this fact probably is due to negative effect produced by fertilizing in greater dose. For KCl, effect was contrary in proportion that is increased to KCl doses.Results linked to aborted fruits presented similar effects to KCl and K2SO4, and consequent increase in aborting rate produced by greater potassium fertilization. However, when used KCl occurred higher fruit aborting in all doses. This behavior induced by potassium fertilization can be attributed to competitive inhibition produced by high potassium concentrations, in which promotes decrease in Ca2+ and Mg2+ absorptions that combines in same ligation site.

CONCLUSÕES:

This study reveals that higher rates of potassium fertilization produces changes in eggplant metabolism, inducing effects normally associated to salt stress, and provoking negative interference such as higher flower and fruit aborting, in which are parameters that probably affect yield. Pesquisa científica já concluída.

Palavras-chave: Eggplant, Potassium, Flower.