ISOLATING AND DIAGNOSING THE FUNGI RESPONSIBLE FOR PALM LEAF SPOT DISEASE IN CERTAIN ORCHARDS IN AL NAJAF GOVERNORATE, AND CHEMICALLY CONTROLLING THEM

Abstract

This study has been conducted in the Laboratory Association in the Directorate of Agriculture of Najaf Al-Ashraf. The study aims to isolate the fungi that present with the symptoms of palm leaf spot disease in certain orchards in Al- Najaf Governorate. The study indicates that various species of fungi have emerged through the process of isolation, including Fusarium oxysporum; Aspergillus sp; Alternaria spp; Alternaria alternate; Thielaviposis paradora; Cladosporium herbarum; Fusarium solani; Mucor sp; and Aspergillus spp. Furthermore, during the researchers' testing, it is discovered that isolated fungi such as Lind Gar Cladosporium herbarum, keissler Alternaria alternate, F.solani (Mort.)sacc, and Fusarium oxyporum schelecht  possess the pathogenic capability to induce palm leaf spot disease. The results of an experiment have assessed the efficacy of two different chemical pesticides. It has been observed that the chemical pesticide Othello top 32.5% SC TM effectively reduces the rate of fungal infection. Specifically, after spraying in the orchards of Al-Mishkhab district, the infection rate decreased to 2.33%. In contrast, the infection rate remained higher at 20.67% after spraying in the orchards of Al-hira district. Similarly, the results of spraying Al Najaf district orchards with the chemical pesticide (Brak 24 EC) for infection severity show that the lower infection rate after spraying is %1.9. However, in the orchards of Al-Haydaria district, the infection rate increased to 18.5% after spraying. There is no significant difference in infection severity between the two types of pesticide used in the orchards of Al Najaf and Al-Mishkhab districts. Furthermore, the chemical pesticide (Othello top 32.5% SC ^TM) is more efficient in pesticide spraying. It achieves an efficiency rate of 85.1% in Al-Kufa orchards and a lesser rate of 61.66% in Al-Hira orchards. In addition, the chemical pesticide (Brak 24 EC) demonstrates a higher level of effectiveness in orchards located in the Al Najaf district, with an efficiency rate of 70%. Conversely, orchards in the Al Abbasia district show a lower efficiency rate of 57.27%.  Besides, the chemical pesticide, (Othello top 32.5% SC ^TM), is superior in terms of spraying efficiency. It effectively reduces the percentage of pests in four different orchards, with an average spraying efficiency of 78.67%.