Photoynthetic and productive increase in tomato plants treated with strobilurins and carboxamides for the control of Alternaria solani

Abstract

A B S T R A C TDuring two years (2015 and 2016), an experiment was carried out to investigate the effects of the application of strobilurin and carboxamides on the photosynthetic efficiency and yield of tomato plants inoculated with A. solani grown in greenhouse in southern Brazil. The experimental design was randomized blocks with five replicates and seven treatments: inoculated control (water + inoculum), absolute control (water), boscalid (0.075 g L −1 ), boscalid (0.100 g L −1 ) + kresoxim-methyl (0.050 g L −1 ), pyraclostrobin (0.100 g L −1 ), fluxapyroxad (0.058 g L −1 ) + pyraclostrobin (0.116 g L −1 ) and methyl (1.100 g L −1 ) + pyraclostrobin (0.100 g L −1 ), applied at 15 days after transplantation, at intervals of 15 days, totaling 6 applications. The effect on plant development was evaluated by plant height, leaf area, fresh and dry mass of leaves, stem and roots. To verify the photosynthetic efficiency, gas exchange, chlorophyll a fluorescence, content of photosynthetic pigments, nitrate reductase enzyme activity, carbohydrate content and yield were evaluated. All fungicides positively affected the evaluated parameters, improving photosynthetic efficiency and fruit production, in addition to providing efficient disease control. However, treatments using fluxapyroxad with pyraclostrobin, followed by metiram with pyraclostrobin stood out for promoting high photochemical yield due to the higher levels of photosynthetic pigments, activity of the nitrate reductase enzyme and, consequently, increase in the synthesis and translocation of photoassimilates. These results demonstrate the benefits of the use of these agrochemicals in the control of A. solani in tomato.

Application of pyraclostrobin as an alternative to reduce phytotoxification of fomesafen in common bean

“…Increases in the photosynthetic rate of wheat, soybean and tomato plants after application of pyraclostrobin are also described in the literature (Grossmann et al 1997;Fagan et al 2010;Marek et al 2018).…”

Strobilurins and carboxamides in physiology and management of Alternaria sp. of tomato

“…According with the main results observed in these molecules uses, there are greater accumulations of biomass and productivity, photosynthetic increase, increased activity of the nitrate reductase enzyme, higher levels of photosynthetic pigments and reduction of oxidative stress (Amaro et al, 2020). This effect on plant physiology has been studied in different cultures such as rice (Debona et al, 2016), bananas (Lima et al, 2012), tomatoes (Marek et al, 2018), cucumbers (Amaro et al, 2018), carrots (Colombari et al, 2015). Other studies also demonstrate improvements in the post-harvest quality of tomato (Ramos et al, 2013) and melon fruits (Macedo et al, 2017).…”

Fragments of a Wheat Hevein-Like Antimicrobial Peptide Augment the Inhibitory Effect of a Triazole Fungicide on Spore Germination of Fusarium oxysporum and Alternaria solani

“…Among them, there are the negative side effects on non-target species, contamination of the environment, and the potential for the development of resistance to fungicides in the target species. Triazoles, especially formulated together with strobilurins, are usually first tested in vitro and then commonly applied to tomato cropping systems in Russia and other countries [8][9][10][11][12]. These compounds belong to antifungal agents having a medium to high risk for the development of fungicide resistance [13].…”