Impact of different sowing dates and weed management strategies on phenological development, productivity, and thermal efficiencies of direct seeded rice

Abstract

Background  Sowing dates and weed management practices could alter several phenological phases of direct seeded rice. However, limited is known about the impacts of these aspects on phenology, thermal efficiencies, and agro-meteorological indices of direct seeded rice.

Objective  The objective of the study was to evaluate the effect of sowing dates and weed management strategies on phenology, thermal efficiencies, and agro-meteorological indices of direct seeded rice.

Methods  Two sowing dates [10^th May (early) and 3^rd June (late)] and six weed management strategies [i.e., weedy-check, 4-time mechanical weeding (weed-free), bensulfuron methyl + pretilachlor as pre-emergence, oxyfluorfen as pre-emergence, bensulfuron methyl + pretilachlor as pre-emergence + 2,4-D as post-emergence, and oxyfluorfen as pre-emergence + 2,4-D as post-emergence] were included in the study.

Results  Early sowing took more days to reach various phenological phases, accumulated higher heat units, and recorded significantly higher thermal efficiencies, and yield than late sowing. Mechanical weeding took more time to complete different developmental stages, hence, accumulated higher heat units and recorded significantly higher thermal-use efficiencies and yield followed by application of bensulfuron methyl + pretilachlor as pre-emergence + 2,4-D as post-emergence.

Conclusion  Earlier sowing with 4 mechanical weedings or successive pre-emergence application of bensulfuron methyl + pretilachlor followed by post-emergence application of 2,4-D is recommended for better phenological development and yield of direct seeded rice.

Agrometeorological Indices; Drum Direct Seeded Rice; Heat Units; Phenology