Sanitary and Physiological Quality of Soybean Seeds Treated With Ozone

Vitor O Rodrigues,Amanda C Penido,Diego De S Pereira,Alan Eduardo S Mendes,João Almir Oliveira,Ariadne M S Oliveira

doi:10.5539/jas.v11n4p183

Abstract

Widely used, the seeds chemical treatment can cause physiological quality loss due to phytotoxicity that the active principles may cause. In this context, the ozone gas stands out (O3) as efficient agent biocide, however its use in the pathogens control and their effects on the seeds physiological quality are still little studied. In this context, the objective was to evaluate the ozone gas efficiency as a controller agent of plant pathogens and its effect on the physiological quality of soybean seeds. For this, seeds of two soybean cultivars were treated with ozone gas in two concentrations (15 and 25 g/m&sup3;) and in five exposure times (0, 20, 40, 60 and 120 minutes). After the treatments, the seeds quality was evaluated by tests of sanity, tetrazolium, first germination count, germination percentage, initial stand, emergence percentage, emergence speed index, electrical conductivity, accelerated aging and enzymatic activity. Six pathogens were found in seeds of soybeans evaluated, namely: Phomopsis sp., Penicillium sp., Aspergillus sp., Fusarium sp., Cercospora kikuchi and Alternaria sp. It was concluded that the sanitary treatment with ozone gas reduces the incidence of these fungi and does not compromise the physiological quality of soybean seeds.

Highlights

Due to the importance that soybean crop has acquired for the Brazilian economy, cultivars with higher yields are increasingly sought
Showed an incidence of around 40%. This value was reduced to values below 10%, except for Phomopsis sp., which despite of being reduced remained with higher values of incidence (20%), in relation to the others
The fungi Fusarium sp., Cercospora kikuchi and Alternaria sp, with an average of incidence at around 20%, were reduced to values below 10%, regardless of the ozone concentration used (Figure 1)

Summary

Introduction

Due to the importance that soybean crop has acquired for the Brazilian economy, cultivars with higher yields are increasingly sought. Intensive cultivation has generated a greater selection pressure of pests and diseases, which make the use of treated seed essential, mainly to ensure the plants survival at the beginning of cycle, once the seeds are characterized as sources of inocula in the diseases spread, caused mostly by fungi. The fungi occurrence in soybean seeds has been reported in several countries where culture is exploited, being some of them of greater economic importance as, Phomopsis spp., Colletotrichum truncatum, Fusarium spp., Sclerotinia sclerotiorum, Cercospora kikuchii, Aspergillus spp. and Rhizoctonia solani. The seeds chemical treatment can cause physiological quality loss, depending on the active principle the dose of the product used and the time between the application of the treatment and the sowing, which leads to the search for alternative treatments that are efficient and with less phytotoxicity. Disinfectant processes as a preventive measure can reduce the chemical products use

Methods

Results

Conclusion