WATER USE EFFICIENCY OF RICE (ORIZA SATIVA) IN RELATION TO IRRIGATION SCHEDULE AND SOWING DATE IN THE SUDAN SAVANNA • ECOLOGICAL ZONE OF NIGERIA

WATER USE EFFICIENCY OF RICE (ORIZA SATIVA) IN RELATION TO IRRIGATION SCHEDULE AND SOWING DATE IN THE SUDAN SAVANNA • ECOLOGICAL ZONE OF NIGERIA

Abstract:

A field study was carried out to ascertain the effect of irrigation schedule and sowing date on the water use efficiency (WUE) of rice, Oryza sativa. The experiment consisted of 3 irrigation schedules (irrigating at 10, 15, and 25 Kpa suctions) 4 sowing dates (mid-Dec, mid-Jan., mid-Feb,, mid-Mar.); two lowland rice varieties (ITA 212, and ITA 123) laid out as a 4 x 3 x 2 RCB factorial with 4 replicates. The experiment was conducted at the Irrigation Research Station, Kadawa (11° 39’N, 08° 02’E and 500m above sea level), for 2 dry seasons from 1989 – 1991. The main effects of irrigation schedule and sowing date on plant height, number of seeds per unit area, and grain yield were significant (P < 0.05). These yield components and yield were highest with the March sowing date, and scheduling irrigation at 10 Kpa soil suction. The main effect of irrigation schedule on ripening grade (filled-grain percentage x 1000-grain weight) was significant (P < 0.05). The highest, ripening grade was obtained with scheduling irrigation at 10 Kpa soil suction. Sowing date had no significant effect on ripening grade. The effect of interaction between treatments on yield and yield components was not significant (P < 0.05). The differences in yield between the sowing dates, are attributable to the prevalent weather conditions during the ripening period, especially the max-min. temperature difference and solar radiation. Filled-grain percentage accounted for the highest variation in grain yield, followed by 1000-grain weight. Max.-min. temperature differences and solar radiation were lower during the ripening period in the March sowing date than the other dates. The relationship between yield, max-min. temperature difference and solar radiation was well described by the following prediction equation: Y = [31.536 – 0.765t – 0.014S] 18.5 x 10-2 where Y = estimated yield in t ha-1; t = max-min. temperature difference in °C, and S = solar radiation in Cal Cm-2. Water use pattern was monomodal with the single peak at heading, irrespective of sowing date and irrigation schedule. WUE was highest with the March sowing date, and irrigation scheduled at 10 Kpa. The estimated ETcrop was found to be described by the following prediction equation – ETcrop – 5.07 + 0.00272 Rs where ETCi-op = estimated crop evapotranspiration, in mm day-1, and Rs is the solar radiation in Cal Cm-2

WATER USE EFFICIENCY OF RICE (ORIZA SATIVA) IN RELATION TO IRRIGATION SCHEDULE AND SOWING DATE IN THE SUDAN SAVANNA • ECOLOGICAL ZONE OF NIGERIA

Sharing is caring!