Evaluation of Fungicide for the Management of Leaf and Fruit Spot (Phaeoramularia angolensis) of Sweet Orange in West & Kellem Wollaga Zones

Abstract

Sweet orange (Citrus sinensis) is an important fruit crop in the daily diet, good source of food nutrients, cash to the farmers. The leaf and fruit spot disease caused by Phaeoramularia angolensis is one of the most devastating airborne diseases and also the main constraints contributing to the low productivity of citrus plantation in 20 African countries including Ethiopia. The experiment was conducted to evaluate three fungicide (Unizeb 80% WP, Trust-cymocop 439.5 WP, and Benomyl 500 WP) and combination of the two each fungicide under field conditions for the management of leaf and fruit spot disease and also to assess the yield losses. Not significant different in disease incidence between treatments and there was a significant difference in the leaf and fruit spot disease severity and Area under Disease Progressive Curve (AUDPC) among treatments. On the final date of disease assessment, among the fungicide, Unizeb sprayed was recorded the lowest disease severity (17.33%) and (18.17%), whereas the highest disease severity of (46.67%) and (45.83 %) were recorded on leaf and fruit spot on control plots, respectively. The highest fruit yield of 6.14 and 5.94 t/ha were also recorded from plots sprayed with Unizeb 80% WP and Benomyl 500 WP fungicide. Unizeb 80% WP fungicide applied exhibited maximum partial cost net benefit from all plots that means the highest (123970.00 ETB ha^-1) was recorded and followed by Benomyl 500 WP (111520.00 ETB ha^-1) fungicide treated plots. The results of the present study revealed that the novel possibility of using Unizeb foliar spray with four times which was found to be an effective in decreasing leaf and fruit spot disease symptoms on sweet orange in Kellem Wollega, Western Oromiya and increased yield.

Keywords: Sweet Orange, Leaf and Fruit spot disease, Fungicides, Yield and Cost benefit.

DOI: 10.7176/JBAH/9-5-01

Publication date:March 31^st 2019