Evaluation of nutritional amendments and fungicides against brown leaf spot of rice

Abstract

Helminthosporium oryzae, the causal organism of bacterial leaf spot (BLS) has brought a tremendous loss of rice crop in the field. Rice seedlings of four commercial varieties (Nayab basmati, Kiran 434, Super basmati, and Pak 386) were screened against BLS in the field by using a randomized complete block design (RCBD). The present experiment was encompassed the evaluation of fermented farmyard manure, leaf manure, Boron, and NPK solution against BLS. The effect of different fungicides (Score, Flumax, Melodyduo, and Polyram) was also checked on the mycelial growth of Helminthosporium oryzae in-vitro and in-vivo. The results showed that Pak 386 was highly resistant with 17.22% disease severity and Super Basmati was found moderately resistant with 22.31% disease severity; variety Kisan 434 was found moderately susceptible (24.15%) and Nayab Basmati (24.82%) was susceptible. Among all NPK solutions showed the best results in growth enhancement, plant vigor as well as reduction in disease severity followed by FFYM, boron and leaf manure. Under in-vitro conditions, all the fungicides performed best at 150 ppm in terms of colony growth reduction. The maximum growth inhibition was recorded in Score followed by Flumax, Melodyduo, and Polyram. Score gave a significant reduction in BLS disease severity and maximized the agronomic attributes. The fungicides performed best at 150 ppm in terms of colony growth reduction. The maximum growth inhibition was recorded in Score followed by Flumax, Melodyduo, and Polyram. Score gave a significant reduction in BLS disease severity and maximized the agronomic attributes. Keywords: HBV, HCV, ICT, PCR, Risk factors, Mansehra