Importance of Agronomic Practice on the Control of Wheat Leaf Diseases

Abstract

Soil tillage and crop rotation are considered important tools in wheat leaf disease control; however, the results of investigations are inconsistent. The aim of the present study was to determine the effect of the soil tillage system and cropping sequence on the development of winter wheat leaf diseases in 2012-2017. The disease development was assessed in a two-factor experiment: (a) soil tillage system; and (b) crop rotation. Foliar fungicides were used uniformly in all variants. The results showed that tan spot (caused by Pyrenophora tritici-repentis) dominated in 2012, 2013, and 2016, but the level of Septoria tritici blotch (Zymoseptoria tritici) was essentially lower and exceeded the severity of tan spot only in 2015. The agronomic practice used significantly influenced only the development of tan spot. Reduced soil tillage and continuous wheat sowing substantially increased tan spot severity, especially when both practices were used simultaneously. Short crop rotation (only wheat and oilseed rape) provided sufficient control of tan spot in ploughed fields, whereas in non-ploughed fields, the level of this disease did not decrease. The results could be explained by differences in the pathogens' life cycle: P. tritici-repentis ascospores in wheat debris is the main source of infection; in contrast, Z. tritici spreads by conidia from living plants.

Winter wheat leaf diseases and several steps included in their integrated control: A review

“…Most studied cultural methods are crop rotation and tillage; however, the results are contradictory. They show that crop rotation and an efficient residue management are effective tools for reducing tan spot in winter wheat (Cotuna et al, 2015); however, in a study conducted in Latvia, the previous crop did not significantly affect the level of Septoria leaf blotch (Bankina et al, 2018). In a repeated wheat sowing, tan spot infection started earlier (Bankina et al, 2018) (Bankina et al, 2018).…”

“…The level of Septoria leaf blotch was significantly lower and exceeded the severity of tan spot only in 2015. Powdery mildew was observed every year; however, the disease severity never reached 2% during the evaluation (Bankina et al, 2018).…”

“…tritici is a polycyclic pathogen reproducing both sexually and asexually, resulting in infections initiated by two types of spores (ascospores and conidia). The research results show that the incidence and severity of Septoria leaf blotch depends on meteorological conditions (Kuzdralinski et al, 2015;Bankina et al, 2018. ) Under field conditions, the latent stage of Z. tritici persists for approximately 14 days; in colder weather, this time protracts up to 28 days (Fones & Gurr, 2015;Suffert & Thompson, 2018), but in other literature sources -up to 36 days (Steinberg, 2015).…”

“…Wheat leaf diseases are widespread throughout the world and are an important risk factor for obtaining high and stable grain yields. The most economically important wheat leaf diseases are Septoria leaf blotch (caused by Zymoseptoria tritici), tan spot (caused by Pyrenophora triticirepentis) (Ronis & Semaškiene, 2011;Fernandez et al, 2016;Bankina et al, 2018), yellow rust (caused by Puccinia striiformis), and powdery mildew (caused by Blumeria graminis) Fernandez et al, 2016).…”

Yield and quality of winter wheat, depending on crop rotation and soil tillage

“…It is reported that one of the main reasons why farmers do not want to grow pulses is unstable and more variable yield in comparison to non-legume crops in Europe (Cernay et al, 2015). Traditional soil tillage helps to limit harmful organisms like wheat leaf diseases (Bankina et al, 2018) and weeds (Ausmane, Melngalvis, & Ruža, 2017), but is more time and energy consuming if compared to minimum soil tillage treatments (Strašil, Vach, & Smutný, 2015). In different studies, contradictory results are reported on advantages of soil tillage method (traditional or reduced) to ensure a higher yield and/or quality of wheat (e.g.…”