Effects of water stress at different critical growth stages on the growth and yield of paddy varietytrs

• Main Author: Corin John
• Format: Academic Exercise
• Language: English
• Published: Universiti Malaysia Sabah
• Subjects: QK Botany; SB Plant culture
• Online Access: https://eprints.ums.edu.my/id/eprint/23939/1/Effects%20of%20water%20stress%20at%20different%20critical%20growth%20stages.pdf; https://eprints.ums.edu.my/id/eprint/23939/

A field study was conducted to investigate the effects of water stress occurrence during critical growth stages of TR8 paddy variety. This study was carried out at Faculty of Sustainable Agriculture rain shelter in Universiti Malaysia Sabah, Sandakan, located at latitude s-0 55' N and longitude 118° 02' E for four months (24th June 2016 to 24th October 2016). The objectives of this study were to determine the effects on vegetative growth and yield component of TR8 paddy variety due to the occurrence of water stress at different critical growth stages and to identify the most susceptible critical growth stage of TR8 paddy variety towards water stress. In this study, there were three critical growth stages of TR8 paddy variety that were induced with water stress. The selected critical growth stages were active tillering, panicle initiation and heading. Meanwhile, the rate of water stress was at 30% field capacity. There were 16 pots with dimension 29 cm diameter were used in this study. Each treatment had four replications and was laid out using Completely Randomized Design. The effects were measured through vegetative growth and yield components of paddy. The parameters of vegetative growth included plant height (cm), culm height (cm), number of tillers, and percentage of productive tillers. The yield components included number of panicles per hill, percentage of grains per panicle, percentage of filled grains (%), percentage of empty grains (%), lQOO-grains weight and extrapolated yield per hectare in one session while the soil fertility included soil pH, percentage of nitrogen content(%), and phosphorus content (ppm). Data was analysed with one-way ANOVA test. In term of vegetative components, the results showed there was significant difference among all the treatments except the number of tillers. T2 had the lowest means of plant height (93.63 cm), culm height (50.83 cm) and percentage of productive tillers (59.63%). Meanwhile, Tl had the lowest mean of number of tillers (29 tillers) among the treatments. Overall, panicle initiation growth stage (T2) was more susceptible with water stress compared to other critical growth stages. In term of yield components, the results showed that there was significant difference among all the treatments except in number of panicles per hill, panicle length and lOQO-grains weight. T2 had the lowest means of number of panicles per hill (19 panicles), panicle length (22.45 cm), percentage of filled grains (73.25%), lQOO-grains weight (20.08g) and extrapolated yield per hectare for a season (5.63 ton/ha). However, T2 had the highest mean of empty grains (31.65%). Overall, panicle initiation growth stage (treatment two) was more susceptible with water stress compared to other critical growth stages. In term of soil fertility, there was no significant difference among all the treatments. Control (C) had the lowest mean of soil pH value (5.47) after planting while T3 had the lowest mean of percentage of nitrogen content (2.39%) after planting. Last but not least, the results showed that Tl had the lowest mean of phosphorus content (0.11 ppm) after planting. Overall, soil fertility was not affected by water stress at different critical growth stages of paddy.Thus, when water shortage occurs, farmers should save water during heading growth stage (T3) instead of panicle initiation growth stage (T2) in order to minimize the reduction of paddy yield.