Author(s)

Thu Zar Win¹, Kyaw Ngwe¹, Swe Swe Mar¹, Aye Aye Khaing²

¹Department of Soil and Water Science, Yezin Agricultural University, Naypyitaw, Myanmar.
²Department of Agronomy, Yezin Agricultural University, Naypyitaw, Myanmar.

The aim of this research was to explore the optimum nitrogen (N) fertilizer rate for yield and quality of rainfed cotton under respective PAWC. A two-year field experiment was conducted in 2019 and 2020 during post-monsoon season at two sites, Pawaingyoe and Kokkokhahla, having different PAWC. Each year at both sites, six levels of N rate (T1 = 0, T2 = 60, T3 = 90, T4 = 120, T5 = 150 and T6 = 180 kg N ha^-1) were laid out in randomized complete block design with four replications and cotton variety Ngwechi-6 was tested. Results showed significant response of cotton to N fertilizer application in each year in both sites and it was consistently lower in 2020 compared to 2019. The DUL, CLL and PAWC of Pawaingyoe were higher than Kokkokhahla. Each year, all yield components and yield were superior in Pawaingyoe than Kokkokhahla. At Pawaingyoe in 2019, maximum values of yield components, seed cotton yield and NUE were achieved by T2. In 2020, all the yield components and yield were non-significant in all N applied treatments and the maximum NUE was found in T2. At Kokkokhahla in 2019, maximum values of yield components and seed cotton yield were obtained in T4, but, maximum NUE was observed in T3 and it gave 90.43% of maximum yield. In 2020, maximum values of yield components, seed cotton yield and NUE were achieved from T3. For fiber quality, T2 gave significantly higher fiber strength in Pawaingyoe, while T4 provided maximum fiber length and strength in Kokkokhahla during 2019. This study suggested that T2 (60 kg N ha^-1) would be the suitable rate for Pawaingyoe in both high and low rainfall condition (2019 and 2020). For Kokkokhahla, within the range between T3 and T4 (90 to 120 kg N ha^-1) would be appropriate in favorable rainfall condition as 2019 and T3 (90 kg N ha^-1) might be the most suitable rate in low rainfall such as 2020.

Cotton, Nitrogen, Plant Available Water Capacity, Yield, Yield Components

Win, T.Z., Ngwe, K., Mar, S.S. and Khaing, A.A. (2021) Yield and Quality of Rainfed Cotton (Gossypium hirsutum L.) in Response to Nitrogen Rates under Different Plant Available Water Capacity Sites in Central Dry Zone of Myanmar. Open Access Library Journal, 8, 1-15. doi: 10.4236/oalib.1107891.