ASSESSING THE STATUS OF YELLOW LEAF ROOT ROT DISEASE ON SANH ORANGE IN HAM YEN DISTRICT, TUYEN QUANG PROVINCE

Abstract

The purpose of this study was to evaluate the status of yellow leaf root rot on Sanh orange, identify the caused of yellow leaf root rot and propose solutions to increase the effectiveness of Sanh orange in Ham Yen district, Tuyen Quang province. We collected the information from farmers about the current farming situation, production conditions and taked the soil samples from the survey sites to analyze and determine the cause of yellow leaf root rot disease in Ham Yen district, Tuyen Quang. The survey results show that the majority of orange-growing households get seedlings from places with no clear origin (82%), the use of organic fertilizer for orange trees in the locality has not been noticed by the people. In terms of use, up to 61.67% of households do not use organic fertilizers or decaying manure, the remaining 38.33% of households use but the amount of organic fertilizer for plants is quite low, the amount of fertilizer Inorganic plants have not yet complied with the technical process of producing earthen orange trees. The results of analysis of soil samples for orange production in Ham Yen, which have pH ranging from 3.81 to 5.54, EC from 0.41 to 0.88 mS/cm are acidic or very acidic soil. Measures to improve soil, help plants can better absorb nutrients. The analysis results showed that the number of fungal spores in the soil samples ranged from 408 to 595 spores/100g of soil and the characteristics of some nematode species were identified specifically: T.semipenetrans, H. .cavenessi, C.magnifica.