Regional Farmers Field Trial (RFFT)

The Regional Farmers Field Trial (RFFT) was conducted at 5 locations of Jhapa, Morang and Sunsari during 2015/16 and 2016/17. Plot size was 100 m2 . BL 3555, BL 3978, BL 3264, BL 4341, BL 4347 and Aditya were evaluated under natural epiphytotic conditions at farmers field. Fertilizers were applied at the rate of 100:30:30 N:P2O5:K2O kg ha-1. All P2O5 and K2O and half Nitrogen were applied during final land preparation. The remaining half N was top dressed into two splits at tillering and panicle initiation stage of wheat crop. All the other cultural practices were followed as per the requirement. Foliar blight disease was scored using the scale developed by Saari and Prescott (1975). The double digit scale was used to measured foliar blight where the first digit equated to the height of infection and second digit with the infection severity. The scale gradations were 1 to 9. Similarly, leaf rust was scored using modified Cobb scale and the scores were then converted to average coefficient of infection (ACI) as described by the U.S. Department of Agriculture for the International Rust Nurseries (Stubbs et al 1986). Similarly, growth stages of wheat were recorded using the scale developed by Zadoks et al (1974). Finally, grain yield was recorded. Data were analyzed by using Microsoft Excel and MSTAT-C (MSTAT, Michigan State Univ., USA). Mean comparisons were done using Duncan’s multiple range test. Descriptive analysis was also performed. Aditya showed trace resistance to leaf rust. BL 4341, BL 3978, BL 3264 and BL 4347 were moderately susceptible to leaf rust (Table 43) but their ACI was low (8). All the genotypes except Aditya showed susceptible reaction to foliar blight. Severity of foliar blight in BL 4341, BL 3555, BL 3978, BL 3264, BL 4347 and Aditya was 45.9%, 39.5%, 46.1%, 40.3%, 40.3% and 29.6%, respectively (Table 19). Tested genotypes did not differ significantly in grain yield (Table 43). However, highest grain yield was recorded in BL 4341 (2.83 t/ha), which was followed by BL 3555 (2.78 t ha-1), BL 3264 (2.73 t ha-1), BL 3978 (2.70 t ha-1) and BL 4347 (2.63 t ha-1). The lowest yield was observed in Aditya (2.33 t ha-1).

Table 19: Grain yield and severity of leaf rust and foliar blight in wheat genotypes in RFFT in the Eastern plains of Nepal  

Note: R= Resistant, MR= Moderately Resistant, MS= Moderately Susceptible, S= Susceptible, ACI= Average Coefficient of Infection.