Management of strawberry leaf blight disease caused by Phomopsis obscurans using silicate salts under field conditions

Abstract

Background: Due to the increased economic and social benefits of the strawberry crop yield in Egypt, more attention has been paid to control its pests and diseases. Leaf blight, caused by the fungus Phomopsis obscurans, is one of the important diseases of strawberry plants. Therefore, effect of silicon and potassium, sodium and calcium silicates, and a fungicide on Phomopsis leaf blight of strawberry under laboratory and field conditions was examined. Results: Four concentrations, i.e., 0, 2, 4, and 6 g/l of silicon as well as potassium, sodium and calcium silicates could significantly reduce the linear growth of tested fungus in the laboratory test where complete inhibition of linear growth was obtained with 6 g/l. The other concentrations showed less but favorable effects. The highest reduction of disease severity was obtained with potassium silicate and calcium silicate separately applied as soil treatment combined with foliar spray which reduced the disease incidence by 83.3 and 86.7%, respectively. Other treatments showed significant (P ≤ 0.05) but less effect. The highest yield increase was obtained with potassium silicate and calcium silicate applied as soil treatment combined with foliar spray which increased fruit yield by 60 and 53.8%, respectively. All tested treatments increased (P ≤ 0.05) the activities of the peroxidase, polyphenol oxidase, and chitinase enzymes. Conclusions: All tested concentrations of silicon salts have suppressed the fungal growth and disease spread but with different degrees. The more the concentration, the better it suppresses the fungal growth and consequent effect on damaging strawberry plants. Potassium silicate and calcium silicate separately applied as soil treatment combined with foliar spray were the best in reducing the disease incidence and increasing crop yield. Potential implications of silicate salts on enhancing activities of the tested enzymes reflected their role in protection against such a plant disease.

Molecular reassessment of diaporthalean fungi associated with strawberry, including the leaf blight fungus, Paraphomopsis obscurans gen. et comb. nov. (Melanconiellaceae)

“…Geographic distribution: Australia (Cook and Dubé 1989 ; Shivas 1989 ; Cunnington 2003 ), Brazil (Mendes et al 1998 ), Brunei Darussalam (Peregrine and Bin Ahmad 1982 ), Bulgaria (Bobev 2009 ), China (Jinping 2011 ; Shi et al 2013 ), Egypt (Haggag 2009 ; Abd-El-Kareem et al 2019 ), Malawi (Peregrine and Siddiqi 1972 ), Myanmar (Thaung 2008 ), South Africa (Crous et al 2000 ), Tonga (Dingley et al 1981 ), USA: Florida, Maryland, North Carolina, Ohio, Oregon, Washington, West Virginia (Alfieri Jr et al 1984 ; Cash 1953 ; Shaw 1973 ; Maas 1998 ; Farr and Rossman 2020 ).…”

Optimizing Safe Approaches to Manage Plant-Parasitic Nematodes

“…The 1, 3-dithicyclobutane-N-chitosan oligosaccharide could decrease M. incognita egg hatching by up to 90% at 2 mg/mL and cause 94% mortality of M. incognita J 2 at 4 mg/mL [93]. The role of silicon to support plant resistance against a variety of harmful bacterial and fungal invasions was recently reviewed [94]. As its salts can also suppress Meloidogyne paranaensis populations on coffee seedlings [95], silicates should be further tried in IPM programs in specific sites with various groups of pathogens.…”

Identification of Important Fungal Diseases of Strawberry in Purbalingga Regency, Central Java, Indonesia

“…Hawar daun pada mulanya berwarna ungu kemerah-merahan, berkembang menjadi coklat tua atau merah-kecokelatan di bagian tengahnya dan dikelilingi oleh pembatas berwarna kuning. Infeksi sering berkembang menjadi menyerupai huruf V (El-Kareem et al 2019). Selain penyakit tersebut di atas, penyakit penting lain misalnya empulur merah disebabkan oleh cendawan tular tanah Phytophthora fragariae (CABI 2019), layu Verticillium disebabkan oleh cendawan Verticillium albo-atrum (Bolda dan Koike 2013), dan busuk akar hitam yang disebabkan oleh Rhizoctonia sp.…”