Pepelnica pšenice (Blumeria graminis (DC.) Speer f. sp. tritici (Em. Marchal)) sve češći problem u usjevima pšenice na Unsko-sanskom kantonu u BiH

Abstract

In 2018. wheat fields on the territory North-western part of Bosnia and Herzegovina were regularly inspected. Occurrence of the causal agent of wheat powdery mildew, Blumeria graminis (DC) f. sp. tritici Speer (syn. Erysiphe graminis DC f. sp. tritici Marchal)) was registered in a large number of localities. In vegetation period, symptoms characteristic for this fungus were observed on all green plant organs, but it was most commonly present on leaves and basal leaf sheaths of wheat plants. Microscopic preparations were made from samples of diseased parts of wheat in the laboratory of the Biotechnical Faculty. Chasmothecia and conidia were observed under the microscope. Chasmothecia and conidia were registered under the microscope. In 2018, presence of the pathogen was registered on about 60% of the total wheat sowed. Disease Index (DI) was calculated using the McKinney formula. The disease index represents the percentage of the disease.The intensity of plant infection was ranged on a scale 0-9. The disease index above 35% was registered on about 56.6% of the infected plants and 40% total wheat plants. After harvest, grains from infected wheat plants were measured for absolute and hectoliter weigts, which were found to range from 25 to 42 g and from 60 to 67 kg, respectively. To improve the effectiveness of crop protection, it is necessary to apply the required agricultural practices: long-term crop rotation, control of volunteer wheat and grassy weeds of the family Poaceae, deep plowing, balanced fertilization, optimum sowing time and others. The main strategy to control powdery mildew is by using resistant cultivars the disease can also be controlled by fungicide treatments.