Growth Responses of Direct Seeded Upland Rice (Oryza species) Varieties to Seed Rates at Different Sampling Stages

Abstract

Field trials were conducted at Samaru and Maigana during the 2011 and 2012 wet seasons on the experimental farm of the Institute for Agricultural Research, Ahmadu Bello University Samaru, Zaria and on the Research Farm of the Kaduna State Agricultural Development Programme, Maigana both in the Northern Guinea Savannah agro-ecological zone of Nigeria to determine the growth responses of direct seeded upland rice varieties to seed rates. The treatments consisted of three upland rice varieties (NERICA 4, 8 and JAMILA), three sowing methods (broadcasting, drilling and dibbling) and three seed rates (40, 80 and 120 kg ha^-1). The treatments were laid out in a split plot design and were replicated three times with factorial combinations of sowing methods and seed rates in the main plot and three rice varieties in the sub plots. Results revealed that an increase in seed rates resulted in decrease in plant height at 6WAS in both locations. At Maigana significant reduction was observed on number of tillers at all the sampling periods and at 9WAS, number of leaves as well as leaf area index also decreases as seed rates increased. At Samaru, no significant effect was recorded on number of tillers, number of leaves and leaf area index.) Theree was no significant influence of sowing methods on plant height, number of leaves, tillers and leaf area index throughout the study at both locations. However, there were significant variation and similarity among the varieties used in this study. It was observed that at Samaru, JAMILA produced the tallest plant, more number of leaves and tiller number at all the growth periods while NERICA 8 had the tallest plants, more number of leaves, tiller number and leaf area index. However, NERICA 4 and 8 displayed similarities in number of tillers and number of leaves at one growth stage to another. Based on the result obtained from the study, it can be inferred that JAMILA had better growth performance in Samaru while NERICA 8 Perform better in Maigana. Consequently broadcast or drilled rice performed better at 40 kg ha^-1 seed rate.

Keywords: Growth, direct seeded, rice varieties and seed rates.