EFFECT OF HIGHER DOSES OF UREA FERTILIZER OVER RECOMMENDED DOSE ON MUSTARD

Abstract

The experiment was conducted at the research field of the Department of Agricultural Botany, Sher-e Bangla Agricultural University, Dhaka during the period from November 2019 to February 2020 to observe the effect of high doses urea on three different cultivars of mustard (BARI sarisha 11, BARI sarisha 16 and BARI sarisha 17). Three different levels of urea fertilizer was used such as T1 (250 kg/ha), T2 (312.50 kg/ha) and (375 kg/ha). The experiment was laid out under two factors Randomized Complete Block Design (RCBD) with 3 replications. Under T1, the tallest plant height at harvest was 131.86 cm (BARI recommended dose). Lowest plant height was observed 100.59 cm under treatment T3. Overdoes of urea may cause plant height to decrease. The highest number of leaves was recorded 38.43 under T3. So, we can see that plant became bushier when an excess amount of urea was applied. Seed per siliqua was also affected by different quantities of urea. Under the recommended dose, the highest number of seed per siliqua (21.44) was recorded. Higher urea doses (T3) most likely had a negative impact on seed output. In the case of seed dry weight and pod length, there was no significant association. As a result, the total influence on yield components was negligible. The physiological indicators were significantly affected by varying levels of urea administration. Significant differences were seen between the SPAD reading and the Leaf porometer reading. T3 obtained the highest SPAD measurement (49.88) and T1 recorded the highest Leaf porometer reading (336.95). Results indicate that Overdose of urea had detrimental effect on yield of mustard plant though vegetative growth was higher in case of higher dose. Number of seed per siliqua was found highest (21.44) under treatment T1 (250kg/ha).