Resistance against phomopsis leaf blight disease induced by potassium salts in strawberry plants

Abstract

Background Growing interest of strawberry cultivation in Egypt necessitates more efforts towards its severe phomopsis leaf blight disease caused by Phomopsis obscurans. Synthetic fungicides could control this fungus but due to their critical impact on human beings and the environment, we are in dire need of safe alternatives for its control. Therefore, the leverage of the potassium bicarbonate and dipotassium phosphate on P. obscurans suppression on strawberry plants was examined. Results Full inhibition of the fungal linear growth was achieved at the highest concentration (2%) of the two salts. Under field conditions, 87.5, 81.3, and 81.3% were the best decreases in disease severity gained by the two salts at 2% of both salts and the fungicide Amstar, respectively. Potassium bicarbonate at 1.5% reduced severity by 68.8%. Concentrations 1, 1.5, and 2% of each salt considerably enhanced strawberry yield. The increases were 66.7 and 61.7%, at 2% concentration by the two salts, respectively. Increments by 126.7 and 150% of peroxidase activity in plant leaves and by 140 and 148% of chitinase activity were noted by the two salts, respectively, at 2%. Conclusions The examined bicarbonate and phosphate salts could suppress P. obscurans growth and spread. The more the used salt concentration, the better it suppresses the fungal growth with consequent effect on the plants which apparently promoted their field yield. Potential implications of the two salts on enhancing activities of the two enzymes reflected their role in suppressing the disease. Further research is needed to integrate these salts in management strategies of P. obscurans in Egypt to foster strawberry yield utilizing ecofriendly approaches.

Strawberry (<i>Fragaria</i> spp.): Cultivation, Production, Consumption, and Marketing in Cameroon

“…White leaf spots (Figure 5D) (Cérès Agricole, Red Gold of Africa, Mbidjoro Sustainable Living Environment, and KAFFO Farm); leaf yellowing (Figure 5E) (Cérès Agricole, Red Gold of Africa, BIO Farm of Lolodorf, and Bafoussam Farm), and whitish down on the upper and lower leaf surfaces (Figure 6F) (KAFFO Farm) were also recorded. Melinda [27], Baroncelli [28], Abd-El-Kareem [29], and Mykhailenko [30] attribute these black spot symptoms to anthracnose caused by Colletotricum acutatum or Colletotricum gloeosporioides, or Cercospora fragariae, and purple blight caused by Diplocarpon earlianum, while the common leaf spots are caused by Mycosphaerella fragariae. On the other hand, white leaf spots are thought to be the result of Ramularia grevilleana attacks [29] [30].…”

“…The varieties of Fragaria x ananassa ("Madame Moutot", "Charlotte", "Elsanta", "Ruby gem", "Ostara", and "San Andreas") and Fragaria vesca ("Maestro" and "Mara des bois"), have presented the crown rot in some plants (Figure 7). Abd-El-Kareem [29], and Mykhailenko [30], attributed this symptom of crown rot to Phytophthora fragariae attacks.…”

Genes and Loci Controlling the Resistance of Strawberry (F. ananassa Duch.) to Pathogens

“…Phytophthora (red stele root rot) of strawberries is caused by two species of pseudo fungi of the Phytophthora genus (Abd- El-Kareem et al, 2020). The first one, Phytophthora fragariae Hickman, causes Phytophthora root rot or so-called « redness of the central root cylinder ».…”

The Efficiency of some Control Agents in Resisting the Okra Root Rot Disease Caused by the Fungus Pythium aphanidermatum

“…fungi are one of the most important pathogens, especially the semi-pathogenic fungus pythium aphanidermatum, which causes the disease of rotting seeds and roots and the fall of seedlings, as well as a wide family range and is known for the rapid destruction of the plant host and can stay in the soil for a long time on plant remains [7].chemical pesticides have been widely used to reduce losses caused by pathogens, as it has been found that excessive use of these pesticides causes an impact on human health and pollution of the environment [8] [9].therefore, researchers have turned to finding alternative environmentally friendly and safer methods that replace chemical pesticides, such as biological control methods using microbiology and the use of substances that induce resistance in the plant.trichoderma harzianum is one of the most widely used microorganisms in this field [10].the plant's defense system can also be induced as a response to environmental or biological stresses, depending mainly on its genetic and physiological characteristics. melatonin n -acetyl-5-methoxytyptamine derived from the amino acid tryptophan is one of the most important of these compounds [11].due to the interest of researchers in the resistance of plant pathogenic fungi using chemical compounds that do not have negative effects on living organisms, interest has increased in the use of sodium bicarbonate (NAHCO 3 ) to resist plant pathogenic fungi, as it works to reduce the growth of fungal pathogens as well as its use in the food industry [12] [13].therefore, this study aimed to identify the role of the biological control agent trichoderma harzianum., and inducing agents melatonin and sodium bicarbonate in the fight against the semi-pathogenic fungus pythium aphanidermatum, the cause of okra root rot disease, laboratory and field.…”