Confronting Dual Threats: Management of Tylenchulus semipenetrans Cobb and Fusarium oxysporum in Citrus Orchards causing Decline

Abstract

Citrus decline is a multifaceted challenge affecting citrus orchards worldwide as well as Pakistan, poses a significant threat to the citrus industry. This decline is often attributed to the synergistic effects of various pathogens, Fusarium oxysporum and Tylenchulus semipenetrans emerging as key contributors. The present study was conducted during 2018-2021to investigate the different chemicals for the management of citrus decline under natural field conditions. The experiment was designed in RCBD with five replicates. Each treatment was applied twice a year at time of new flushes Data were collected each year before treatment application on the basis of no. of infected roots piece/ 100 pieces of roots for fungi, no. of juveniles/ 100 grams of soil and  no. of females/ gram of roots for nematodes, and After six month of last application, as compared to pretreatment data, maximum percent inhibition of fungus, number of juveniles and number of females were found in T₁ 89.67%, 89.87% & 90.39 followed by T₂ 84.61%, 83.91% & 82.82%, T₃ 79.54%, 88.17% & 89.45%, and T₄ 76.78%, 81.92% & 83.04% respectively. While in the control treatment the no. of infected roots piece/ 100 pieces of roots (36.96%), no. of Juveniles/ 100 grams of soil (94.11%) and no. of females/ gram of roots (109.78%), percent increased many fold which caused citrus decline. All chemicals treatments reduced significantly in nematode and fungal infestations