EXPLORING FIELD VARIABILITY: CROP DURATION, RICE BLAST RESISTANCE, AND YIELD IN RICE BREEDING LINES

Abstract

Rice, a staple food for over half of the world's population, is a critical crop that requires ongoing improvement in disease resistance, crop duration, and yield to ensure food security and sustainability. Field variability plays a crucial role in determining the success of rice breeding programs, especially in relation to these factors. This study, conducted at ARS Baffa Mansehra, evaluated 20 rice breeding lines, developed by National Agriculture Research Centre (NARC), including the local check (Fakhre Malakand), for diversity in disease infestation, crop duration, and yield parameters. Data were collected on rice blast incidence and severity, days to panicle emergence, anthesis, grain filling, maturity, plant height, grain weight, and grain yield. The highest rice blast incidence was recorded for NARC-8 (66.7%), followed by NARC-4 (50.0%), with the lowest incidence in Fakhre Malakand (0%) and breeding lines NARC-12 and NARC-1 (14.3%). Rice blast severity increased from 28.9 to 36.4 on average. Panicle emergence days ranged from 83 (NARC-3 and NARC-6) to 119 (NARC-18). Plant height varied, with NARC-17 being the tallest (87 cm) and NARC-14 and NARC-15 the shortest (64 cm). The maximum thousand-grain weight was observed in NARC-6, NARC-10, and NARC-11 (34 g), while NARC-19 had the lowest (27 g). NARC-12 had the highest grain yield (193 g), followed by NARC-13 (182 g) and NARC14 (162 g), with the lowest yields in NARC10 (107 g), NARC-17, and NARC-6 (112 g). The overall variability observed among the advanced breeding lines of rice could be used for subsequent genetic improvement of rice, with particular emphasis on Hazara Division.