Avaliação de diferentes doses de inseticida e fungicida no tratamento de sementes de trigo sob a influência no desenvolvimento da cultura nas fases iniciais

The objective of the work was to evaluate the effect of insecticide and fungicide in the treatment of wheat seeds. The treatments were, T1: control, T2: thiamethoxam (1.5 ml / kg of seed), T3: thiamethoxam (3 ml / kg of seed), T4: pyraclostrobin + methyl thiophanate + fipronil (PTF) (2.0 ml / kg of seed) and T5: PTF (4.0 ml / kg of seed). The treatment with TPF in the dose of 4.0 ml / kg of seed stood out over the other treatments, providing positive effects on the development of the culture, since thiametoxam in the dose of 3.5 ml / kg of seed, showing no difference between treatments, and provided a negative effect on the initial development of the plants.

Accessing the relevance of tests for estimating the physiological quality of wheat grains

The objective of this work was to investigate, before and after chemical treatment, the interrelationships of the physiological quality tests in wheat grains. Following the chemical treatments with (i) carboxin thiram; (ii) carboxin thiram + thiamethoxam; (iii) carboxin thiram + thiamethoxam + bio-stimulant; (iv) pyraclostrobin + methyl thiophanate + fipronil, and (v) pyraclostrobin + methyl thiophanate + fipronil + bio-stimulant, subsequently the grains were assessed for their physiological potential. The physiological potential of the grains could be differentiated based on the electrical conductivity, seedling growth, and emergence in sand tests. In conclusion, the use of the active ingredients changed the correlation between laboratory tests with crop emergence in the sand as well as altered the relevance of the tests for sorting the treated grains into different physiological potential. But, the seedling growth tests and the electrical conductivity were, together, the parameters most relevant for explaining the data variability.

Effect of the Storage Period and Fungicide Treatment on the Physiological and Sanitary Quality of Soybean Seeds

This study evaluated the effect of storage period on the physiological and health quality of soybean seeds. The experiment was arranged in a factorial scheme (4 x 2 x 2) with four periods of storage (0, 2, 4 and 6 months), two soybean cultivars (‘BRS Pintado’ and ‘MSOY 8866’) and treated and untreated seeds with the formulated mixture of active ingredients pyraclostrobine (25 g i.a L-1) + Methyl-Thiophanate (225 g i.a L-1) + fipronil (250 g i.a L-1) in a 0,1 L.ha-1 dosage of the commercial product. Concerning health, there was a reduction of Aspergillus spp., Cercospora kikuchii, Colletotrichum dematium var. truncata and Fusarium spp fungus when periods of storage were increased independently if storage interactions occurred due to cultivar, treatment and/or all analyzed factors. cv. ‘BRS Pintado’ stood out by presenting lower results on the occurrence of fungi. The isolated cultivar factor presented a significant result concerning the physiological quality and c.v. ‘BRS Pintado’ showed better results in the variables: germination of seeds from the speed aging test, germination, shoot lenght from the speed emergence test, and both shoot dry matter and root dry matter of germination. There was an interaction for the speed emergence index variable between storage versus cultivar, in which cv. ‘BRS Pintado’ achieved better average results in all periods of storage. The storage factor alone was significant for shoot length of plants from the speed emergence index, the shoot plant dry matter from the emergency speed index, root dry matter of seedling germination and germination of seeds subjected to accelerated aging. The isolated treatment factor was significant in the germination variable and the untreated seeds showed better results in relation to the treated ones. However, the difference of these values would not be significant at the field. Treated seeds showed better results compared to untreated ones in most of the analyzed variables and their association with seeds storage did not affect the physiological quality evaluation during six months of evaluation, enabling the maintenance of the health quality of seeds.