Influence of Long-term Use of Organic and Inorganic Nutrients on HLB Disease of Wheat under Rice-Wheat Cropping Pattern

Abstract

Helminthosporium leaf blight (HLB) is one of the most destructive diseases of wheat in terai (plain) region of Nepal. This study was conducted to determine the effect of long-term application of various levels of nitrogen (N), phosphorus (P), potassium (K) and organic nutrients on HLB disease of wheat. The experiment was superimposed on long-term fertility experiment conducted in RCB design with three replications under rice-wheat cropping pattern at National wheat research program (NWRP), Bhairahawa, Nepal. The treatments include various combinations of nitrogen 100 kg ha -1 , phosphorus 0 and 60 kg ha -1 , and potash 0, 50 and 100 kg ha -1 with or without Sesbania (Sesbania cannabina) and farm yard manure (FYM). Area under disease progress curve (AUDPC) was calculated using the disease scores and yield parameters were recorded. Among the inorganic nutrients, long-term deficiency of potash in the field markedly enhances the HLB disease. Application of phosphorus in various doses increased the HLB severity in absence of potash. Regular application of at least potash 50 kg ha -1 in wheat noticeably reduced the HLB disease. Regular use of FYM 10 ton ha -1 for long-term considerably reduced the HLB disease but long-term use of Sesbania as green manure did not show any impact on HLB severity. Inclusion of potash in nutrients considerably increased the yield and thousand grain weight (TGW) of wheat. In long term, balanced use of inorganic and organic nutrients with special attention on regular inclusion of potash and FYM in the nutrient combinations is vital in suppression of HLB disease under rice-wheat cropping pattern.

Occurrence and characterization of Bipolaris setariae associated with leaf blight of browntop millet (Brachiaria ramosa) in India

“…Increased crop resilience due to agronomic interventions such as crop residue management and application of fungicide (mancozeb @ 2.5 gm/lt of water) at the time of disease emergence may have contributed to the minimum disease severity of 18% (Mandya) and 26% (Chikkaballapura). The current study's findings on disease severity are similar to those observed by Bhandari (2010). When compared to healthy plants, the incidence of wheat spot blotch ( B. sorokiniana ) disease is more severe under stress conditions and in weak plants.…”

Identification of best spray schedules for Propiconazole fungicide against spot blotch disease in Wheat

“…The losses due to the disease in Nepal ranged from 23 -40 % depending on genotypes and other environmental factors (Shrestha et al, 1998;Bhandari and Tripathi, 2005;Sharma and Duveiller, 2006). Resistant genotypes, foliar spray of fungicides and nutrients management are effective against the disease (Duveiller, 2002;Regmi et al, 2002;Bhandari, 2010). Application of Triazoles fungicides can suppress the disease effectively (Bhandari and Gharti, 2002;De-Viedma and Kohli, 1997).…”