Efeito da aplicação foliar de silicato de potássio e de fungicida na severidade da ferrugem da folha e da mancha amarela do trigo

Abstract

Effect of foliar application of potassium silicate and fungicide on the severity of leaf rust and yellow leaf spot in wheatThe occurrence of diseases such as leaf rust (Puccinia triticina) and yellow spot (Drechslera tritici-repentis) can decrease wheat yield. This study aimed to evaluate the effect of foliar application of potassium silicate (PS) and fungicide on the control of leaf rust and yellow spot in the cultivars Safira and Quartzo. The experiment was carried out in a randomized complete block split-split plot design with four replications. The cultivars were randomly assigned to the main plot, and in the subplots, the treatments T1 -control, T2 -fungicide (azoxystrobin 60 g a.i/ha + ciproconazole + 24 g a.i/ha) sprayed at the growth stages 45 (booting) and 58 (heading), T3 -PS (40 g/L) sprayed at growth stages 45 and 58, T4 -PS (40 g/L) and fungicide sprayed, respectively, at growth stages 45 and 58 and T5 -potassium hydroxide (6.5 g/L) sprayed in the growth stages of 45 and 58. The volume used in the sprays was 250 L/ha. The evaluation of leaf rust and yellow spot severity started at 7 days after the first spraying and then every week, in a total of five assessments. Data of disease severity were used to calculate the area under leaf rust progress curve (AULRPC) and the area under yellow spot progress curve (AUYSPC). The PS, at the rate and the number of sprayings, was not efficient to decrease both AUYSPC and AULRPC in the two cultivars.

Influence of silicon on wheat tan spot severity in the State of Goiás

“…In this attribute, both cultivars that received silicon exhibited higher quality and yield, when compared to treatments without the addition of the micronutrient, which once again indicates the beneficial effect of its use. These results also corroborate those presented by Soratto et al (2012), Wordell Filho et al (2013, Telaxka et al (2019) and Galindo et al (2021).…”

“…Regarding tan spot, Wordell Filho et al (2013) reported that the association of fungicides and potassium silicate provided smaller areas under the progress curve in an experiment carried out in Chapecó in the state of Santa Catarina, Brazil. The results of the present work also corroborate those of Pazdiora et al (2017), where in an experiment under controlled conditions, there was greater resistance to tan spot even in susceptible cultivars; however, the greatest reduction in tan spot was in moderately resistant cultivar.…”

“…Later, Cruz & collaborators (2011) analyzed potassium silicate in reducing the severity of wheat blast (Pyricularia grisea Cooke ex Sacc.). In this same sense, Wordell Filho et al (2013) studied the effect of potassium silicate on leaf rust (Puccinia triticina Erikss) and tan spot (P. tritici-repentis) in Chapecó-SC. Pazdiora et al (2018) studied the effect of silicon on tan spot under controlled conditions.…”