The productivity of upland rice is very low because of a host of problems, among which soil moisture stress, poor native soil fertility, and high weed infestation are the most important ones. Under upland situations, moisture stress is likely to occur during any of the growth stages of the crop, which may adversely affect growth and yield. Presowing treatment improves germination, promotes plant and root growth, and increases crop survival under water-stress conditions. A field experiment was conducted at the Instructional Farm in Vellayani of Kerala Agricultural University, India, during the late first crop season of 1999 to examine the response of upland rice to different levels of irrigation, nutrient management, and seed priming.
Soil characteristics at the trial site were a sandy clay loam texture, organic C 1.7% (Walkley and Black’s rapid titration method, Jackson 1973), pH 4.8 (pH meter with glass electrode, Jackson 1973), and available N, P2O5, and K2O of 238 (alkaline potassium permanganate method, Subbiah and Asija 1956), 32.8 (Bray 1 method, Jackson 1973), and 160 kg ha-1 (ammonium acetate method, Jackson 1973), respectively. Treatments consisted of three irrigation levels (irrigation water [IW]/cumulative pan evaporation [CPE] ratio of 1.5 [I1], 0.1 [I2], and rainfed [I3]; three nutrition levels (20-10-15 [F1], 40-20-30 [F2], and 60-30-45 [F3] kg NPK ha-1); and two seed priming methods (1% [S1] and 2.5% (KCl) [S2]. The experimental layout was a split-split-plot design with three replications: irrigation levels in main plots, nutrientmanagement in subplots, and seed priming in sub-subplots. Irrigation was given to a depth of 50 mm. Upland rice variety Matta Triveni (PTB45) was dibbled at a spacing of 20 × 10 cm. This variety was released from RARS, Pattambi, Kerala. It has a duration of 95–105 d. The grains are red, long, and bold.