ENHANCING THE YIELD POTENTIAL OF RICE (ORYZA SATIVA L.) THROUGH DIFFERENT AGRONOMIC TECHNIQUES UNDER THE AGRO-CLIMATIC CONDITIONS OF DERA ISMAIL KHAN-PAKISTAN

Abstract

A research project was initiated at Gomal University, Dera Ismail Khan, and NWFP, PAKISTAN during 2004 - 2005; to provide appropriate rice cultivation technologies that are agronomically practicable and economically viable under the agro-climatic conditions of the area. The research project was based on field-oriented problems faced by the paddy growers. Four field experiments were conducted and were laid out in a Randomized Complete Block Design (RCBD) with split-plots arrangements, replicated 4 times. 1 st experiment was “Effect of Phosphorus Levels and Irrigation Regimes on the Yield and Yield Components of Transplanted Coarse Rice” in which five P 2 O 5 levels were maintained in main plots while the four irrigation regimes were kept in sub- plots. The sub-plot size was 3 × 5 m 2 . The 2 nd trial pertaining to “Effect of Plant Growth Regulator (NAA) Levels and Irrigation Regimes on the Yield and Yield Components of Transplanted Coarse Rice” was also laid out in RCBD with split plot arrangement, keeping four levels of NAA plant growth regulator in main plots while the four irrigation regimes were kept in sub-plots. Third experiment was on “Effect of Phosphorus and Plant Growth Regulator (NAA) Levels on the Yield and Yield Components of Transplanted Coarse Rice” having four levels of NAA plant growth regulator in main plots and in sub plots five P 2 O 5 levels maintained. In forth experiment “Effect of Plant Growth Regulator (NAA) Levels at Different Growth Stages of Transplanted Coarse Rice” the growth stages of rice of crop were kept in main plots and four levels of (NAA) plant growth regulator were kept in sub plots. Well-adapted coarse rice variety IR-6 was used in the research project. Thirty-five days old rice nursery was used in the all experiments. Data were recorded on various growth and yield parameters like plant height (cm), productive tillers m -2 , unproductive tillers m -2 , panicles m -2 , spikelets panicle -1 , sterility and normal kernels percentage, 1000-grain weight (g), paddy yield (t ha -1 ), straw yield (t ha -1 ) and harvest index. In experiment 1, the combination P 3 I 2 (150 kg ha -1 P 2 O 5 with 10 irrigations containing 750 mm water (distributed in 10 irrigations)), proved the best combination for getting maximum paddy yield. In experiment 2, it was determined that significantly higher (8.50 and 8.60 t ha -1 ) paddy yield was recorded in the plots treated with G 2 I 2 (90 ml ha -1 level of plant growth regulator and 10 irrigations) during 2004 and 2005, respectively and the lowest paddy yield was recorded in treatment G 0 I 1 (without plant growth regulator level with 8 irrigations) with the values of 3.60 and 3.75 t ha -1 during 1 st and 2 nd year, respectively. While in experiment 3, it was observed that the treatment G 2 P 2 (90 ml ha -1 plant growth regulators level with 100 kg ha -1 phosphatic fertilizer was on top with maximum paddy yield (8.70 and 8.90 t ha -1 ) during 2004 and 2005, respectively. In forth experiment it was found that paddy yield of the treatment S 2 G 2 (panicle initiation stage with plant growth regulator level of 90 ml ha -1 ) produced maximum paddy yield of (9.00 and 9.20 t ha -1 ) during both the years of study On the basis of research findings, it is concluded that for getting maximum yield of paddy under agro climatic conditions of Dera Ismail Khan the farmer should apply 750 mm water, 90 ml plant growth regulator (NAA) on panicle initiation stage. However while applying the plant growth regulator the farmer can reduce the P 2 O 5 dose up to 100 kg ha -1 instead of 150 kg ha -1 and vice versa.