Md. Rashedur Rahman
Department of Agronomy, Bangladesh Agricultural University, Mymensingh-2202, BANGLADESH
Md. Rakibur Rahman
Department of Agronomy, Bangladesh Agricultural University, Mymensingh-2202, BANGLADESH
Md. Jahid Fazal
Department of Agronomy, Bangladesh Agricultural University, Mymensingh-2202, BANGLADESH
Md. Parvez Anwar
Agro Innovation Laboratory, Department of Agronomy, Bangladesh Agricultural University, Mymensingh-2202, BANGLADESH
Phenology, Yield performance, Black rice, Plain land ecosystem Bangladesh
Variety and Species
2.1 Description of the experimental site The study was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from June 2018 to October 2019. The experimental site is located at 240 75´ N latitude and 900 50´ E longitude in the south-west part of the Brahmaputra at an elevation of 18 m above sea level. This site belongs to non-calcareous dark grey floodplain soil under the agro-ecological zone Old Brahmaputra Floodplain. The experimental area was a fairly leveled well-drained medium-high land belonging to the Sonatola series of non–calcareous dark grey floodplain soil under the Old Brahmaputra Floodplain agro-ecological zone (UNDP and FAO, 1988). The experimental soil was silt loam having a bulk density of 1.35 g cc-1 and pH 5.70. The soil contained 0.09% total nitrogen, 1.02% organic matter, 5.68 ppm available phosphorus, and 49.12 ppm exchangeable potassium and 8.28 ppm available sulphur. 2.2 Agro-climatic condition of the site Bangladesh is located in the tropical monsoon region. It has hot and humid summer season starting from March to October and a cool winter season from November to February. Rice can be grown year-round in Bangladesh. There are three rice-growing season in Bangladesh name Aus, aman and boro. Monthly weather data during the experimental period (June 2018 to October 201) is presented in Table 2. 2.3 Characteristics of test varieties Three hilly rice cultivars named Kongnam ene, Gelong ni and Gelong se, were used as the test crop in this experiment. The seeds of the three black rice varieties were collected from Bandarban hill district of Bangladesh. The main characteristic features of the rice cultivars are discussed below: Kongnam ene is a black rice variety that includes a long history of cultivation in Southeast Asian countries such as China, India and Thailand (Kong et al., 2008). The pericarp (outer part) of kernel of this rice color is black due to a pigment known as anthocyanin, an antioxidant. Brown rice has also many health benefits. It is a transplant aman rice cultivar and matures after 90 days after transplanting with average yield 3.0-3.5 t ha-1. Life cycle of this variety ranges from 95-105 days, which however may vary due to changes in climatic condition. The plant height is 90-95 cm and the cultivar is of non-lodging type. It is somewhat resistant to pests and diseases and especially blast disease. Gelong ni and Gelong se are rice variety traditionally cultivated in hilly upland area. These rice varieties are short-duration varieties. It matures after 110-120 days of transplanting when planted in the summer season in hilly areas. Plant height is usually around 120 cm. The hull and bran around the kernel are brown in color Yield is about 3.5 t ha-1. Both these rice varieties are a good source of magnesium, phosphorus, selenium, thiamin, niacin and vitamin B6, and an excellent source of manganese, with 88 percent of our daily manganese in just one cup cooked. The morphological and nutritional characteristics are almost same for these two varieties except the thousand-grain weight. The thousand-grain weight of variety Gelong ni is little higher than that of Gelong se. 2.4 Experimental treatment and design The experiment was comprised of two factors viz. A) Three rice cultivars: Kongnam ene, Gelong ni and Gelong se; and B) Twelve date of transplanting: The transplanting of rice seedlings was done at the beginning of every month starting from 01 July 2018 to 01 June 2019. The experiment was laid out in a split plot design where date of transplanting was distributed in main plots and rice cultivars were allocated in subplots. Thus, the total number of plots was 108 (12×3×3). The size of each plot was 10 m2 (4 m × 2.5 m). 2.5 Preparation of the experimental land and layout The land was first opened with a tractor-drawn disc plough on 01 June 2018. After two days, the land was irrigated slightly and subsequent ploughings and cross ploughings were given and leveled by laddering. The field layout was made on 01 July 2018 according to experimental specification immediately after final land preparation. 2.6 Crop husbandry After the layout of the experiment was completed the rice seedlings were carefully uprooted from nursery bed and transplanted in the plots maintaining a spacing of 25 cm × 15cm. First and last transplanting of rice seedlings were done on July 01, 2018 and June 01, 2019, respectively, according to the experimental treatments. Three healthy seedlings were transplanted in each hill. The experimental plots were fertilized with urea (200 kg ha-1), triple superphosphate (100 kg ha-1), muriate of potash (70 kg ha-1), gypsum (60 kg ha-1) and zinc sulphate (10 kg ha-1). The full dose of triple superphosphate (TSP), muriate of potash (MoP), gypsum and zinc sulphate was applied at the time of land preparation. Urea was top-dressed in three equal splits, at 15, 30 and 45 days after transplanting. Various intercultural operations viz. irrigation, weeding, disease and pest management etc. were done as and when necessary to ensure and maintain the favorable condition for normal plant growth and development of crop. 2.7 Observation and data collection The crop was harvested at full maturity. The date of harvesting was confirmed when 90% of the grain became golden yellow in color. Five rice hills were selected randomly from each individual plot and uprooted before harvesting for recording data. During the growth period the data collected were days required to panicle initiation, flowering and harvesting after transplanting. Total growth duration from seed to seed was also recorded. After harvesting the data on plant height (cm), number of total tillers per hill, number of effective tillers per hill, number of non-effective tillers per hill, panicle length (cm), number of sterile spikelets per panicle, number grains per panicle, 1000-seed weight, grain yield (t/ha) and straw yield (t/ha) was collected. 2.8 Statistical analysis of data Data were compiled and tabulated in proper form for statistical analysis. The recorded data were statistically analyzed to find out the significance of variation resulting from the experimental treatments. All the collected data were analyzed using the statistical software R.
Tropical Agrobiodiversity (TRAB) 1(2) (2020) 49-54
Journal