Control of brown blotch disease caused by Pseudomonas tolaasii by some chemical and biological treatments and its effect on some productive traits of the edible mushroom Agaricus bisporus

Abstract

The research was carried out in a mushroom farm, College of Agriculture, Tikrit University, five microelements were tested, namely, iron, manganese, molybdenum, Zinc and boron, and a combination of these five elements, in addition biological agent, Pseudomonas fluva, to control of the brown blotch disease caused by pathogenic bacteria Pseudomonas tolaasii on the edible mushroom Agaricus bisporus. The results showed that all the treatments of the micro-elements as well as the growth-promoting bacteria P. fluva led to a significant superiority in the higher productivity of A. bisporus fruit bodies compared to the treatment of the pathogenic bacteria P. tolaasii only. The highest productivity of the fruit bodies was reached in the treatment of the elements mixture with beneficial bacteria P. fluva, which amounted to 2675.6 g / 20 kg compost, with a biological efficiency of 79.59%. At the level of elements, molybdenum (without bacteria) and with P. fluva outperformed the other elements by recording the highest productivity of 2533.2 and 2527.4 g / 20 kg compost with a biological efficiency of 80.26 and 79.0% , respectively, compared to the lowest productivity of 1404.3 g / 20 kg compost with a biological efficiency of 45.7 in the pathogenic bacteria P. tolaasii. The results showed that all treatments of the elements individually and in combination led to a significant decrease in the infection rate,  no infection rate was recorded in the treatments of the elements mixture with the presence of pathogenic bacteria P. tolaasii with beneficial P. fluva compared to the highest infection rate of 32% in the treatment of P. tolaasii.