Tiller production by bread wheat seed (Triticum aestivum L.) infected with karnal bunt (Tilletia indica Mitra)

The tiller production by infected seed with karnal bunt (KB) showing different levels of infection, and uninfected seed of bread wheat cultivar Tacupeto F2001, were evaluated during the crop season 2021-2022 at the Norman E. Borlaug Experimental Station in the Yaqui Valley, Sonora, Mexico. Plants were artificially inoculated by injection during the 2020-2021 crop season and the seed was selected based on the level of infection [level 1 (point of infection at the base of the seed), 2 (ca 30 % of the seed affected with KB), and 3 (ca 50 % of the seed affected with KB)]. Sowing was carried out on December 2 and 14, 2021 in beds 2 m long with two rows, placing 10 seeds in each row. The range of the number of tillers produced by seed with infection levels 1, 2, and 3, and the uninfected check sown on December 2 was: 15-37, 10-34, 14-28, and 15-39, while for the December 14 sowing date: 13-36, 11-33, 12-35, and 6-34, respectively. The average number of tillers produced was 24, 20, 22, and 25 for seed with levels of infection 1, 2, and 3, respectively, and the uninfected check, sown on December 2; while for December 14, it was 25, 21, 21, and 18 in the same order. The total number of tillers produced by infected seed with levels of infection 1, 2, 3, and the uninfected seed during the December 2 sowing date had a range of 391-500, while for the December 14 it was 366-490. The average temperature during the period of the evaluation was 17.4 °C with a maximum of 36.3 °C and a minimum of 2.3 °C; the average relative humidity was 64.3 %; there were 17.5 mm of precipitation, and the number of heat and cold units was 130 and 589, respectively.