Universal Journal of Agricultural Research 3(2): 59-67, 2015 http://www.hrpub.org DOI: 10.13189/ujar.2015.030205 Seed Priming and Trichoderma Application: A Method for Improving Seedling Establishment and Yield of Dry Direct Seeded Boro (Winter) Rice in Bangladesh Moshiur Rahman * , Julfikar Ali , Mehedi Masood Department of Agronomy, Bangladesh Agricultural University, Bangladesh Copyright © 2015 Horizon Research Publishing All rights reserved. Abstract Seedling mortality is the major barrier to optimum stand establishment in dry direct seeded boro (winter) rice. Two experiments were carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh, Bangladesh during January to June 2012 and 2013 to study the effect of seed priming, Trichoderma and fungicide application on seedling establishment and yield performance of dry direct seeded Boro rice. First experiment comprised three seed priming treatments, osmopriming with 3% ZnSO 4 solution, hydropriming and no priming. There were five treatment combinations of Trichoderma and fungicides. These were seed treatment with Trichoderma (T 1 ), spraying of rice seedling with sulphur fungicide (Thiovit) (T 2 ); propiconazole fungicide (Potent) (T 3 ), and combination of Thiovit and Potent (T 4 ) and a control treatment (T 5 ) where no fungicide or Trichoderma was applied. The treatment was applied at 20 days after sowing (DAS). In year 2013, the experiment comprised ten treatment combinations of Trichoderma and fungicides viz.seed treatment with Trichoderma (T 1 ), seed treatment with Trichoderma + spraying of Thiovit (T 2 ), seed treatment with Trichoderma + spraying of Potent (T 3 ), seed treatment with Trichoderma + spraying of Thiovit and Potent (T 4 ), spraying of Thiovit (T 5 ), spraying of Potent (T 6 ), seed treatment with Thiovit + spraying of Potent (T 7 ), seed treatment with Potent + spraying of Thiovit (T 8 ), spraying of mixture of Thiovit and Potent (T 9 ), and control (no fungicide or Trichoderma) (T 10 ). Both the experiments used Randomized Complete Block Design (RCBD) with three replications. Results showed that osmopriming gave higher number of seedling, length and dry matter of shoot and root and yield than hydropriming. All these attributes were highest with seed treatment by Trichoderma. Experiment 2 revealed that seed treatment with Trichoderma harzianum followed by spraying of Thiovit gave the highest yield of rice. The study concludes that sowing of seed after osmopriming with 3% ZnSO 4 and biopriming with Trichoderma and then application of sulphur fungicide at 20 days after sowing could be practiced for ensuring high seedling establishment and yield of rice under dry direct seeded system in boro season. Keywords Rice, Boro Season, Dry Direct Seeding, Priming, Fungicide Application 1. Introduction Rice (Oryza sativa L.) is the staple food for nearly half of the world’s population.The global rice requirement has been increased by more than two folds (e.g. 150 million tones in 1961 and 350 million tones in 2011) during the last five decades [23]. In 2011-12, 33.541 million tons of rice is produced from 11.527 million hectares of land in Bangladesh [5]. Among the three rice seasons viz. Aus, Aman and Boro, rice yield is the highest in Boro season. Boro rice contributes about 56% of the total rice production in Bangladesh. Therefore, Boro rice is the main contributor to the food production and security in the country. Rainfall is practically nil during Boro season (December – March) and therefore, rice production in this season is fully dependant on irrigation. Rice is mainly cultivated in puddle transplanted flood irrigation (PTR-CI) system requiring 3000-5000 litres of water to produce one kilogram of rice. Very recently, scarcity of irrigation water is evident in many parts of the country that threatens the sustainability of boro rice production. Under this water scarce situation, farmers may be forced to shift their rice land to other crops which would cause severe food shortage in the country. Rice production could be sustained in water shortage areas by adopting technologies that ensures rice production with less water. Recent research shows that boro rice could be produced using 50-70% less water by adopting the dry direct seeded rice production technology [28, 32]. In this system rice seed is directly sown on dry cultivated land during December to January. This sowing period coincides with very low temperature which causes poor seedling establishment owing to seedling mortality. The poor seedling establishment due seedling mortality poses a serious hindrance to the rice production in this new system. Application of chemical fungicides (e.g. sulphur or