Evaluation of different weed management practices on nutrient uptake, yield and soil microbial population of wheat (Triticum aestivum L.)

Abstract

A field experiment was conducted during rabi, season of 2019-20 at the Research farm, Bihar Agricultural College, Sabour, Bhagalpur.The experiment consisting of fourteen treatments was laid out in randomized block design with three replications. The crop was infested with the divergent type of weed flora e.g. Phalaris minor, Fumaria parviflora and Cynodon dactylon of grassy, Chenopodium album, Anagallis arvensis, Melilotus alba, Argemona Mexicana and Solanum nigrum of broad-leaved and Cyperus rotundus, Cyprus iria and Cyprus difformis of sedges group.The sowing of wheat variety HD-2967 was done on 23th November 2019, and harvesting was done on 5th April, 2020. The results revealed that ready-mix application of (clodinafop-propargyl @ 60 g a.i. ha-1 + metsulfuron-methyl @ 4 g a.i. ha-1 PoE) and(mesosulfuron @ 12 g a.i. ha-1 + iodosulfuron-methyl-sodium @ 2.4 g a.i. ha-1PoE) gave higher weed control efficiency (82.02%, 79.31%), lower weed index (4.56%, 6.81%) respectively.Both of these treatments recorded 69.04 and 65.47 per cent grain yield enhancement along with the highest benefit-cost ratio (1.65 and 1.57).The maximum nutrient uptake was also noticed under T8 and T12. No any phytotoxic symptoms has been recorded under these two treatments.Among nutrient content (%), phosphorus content (%) in grain and straw has been recorded highest in weed free and it was significantly at par with T4, T5, T8 and T10 treatment respectively.Based on all the observation recorded, clodinafop-propargyl @ 60 g a.i. ha-1 + metsulfuron-methyl @ 4 g a.i. ha-1 PoE has performed better in all respects amongst all the herbicide applied treatment followed bymesosulfuron @ 12 g a.i. ha-1 + iodosulfuron-methyl-sodium @ 2.4 g a.i. ha-1 PoE.The maximum bacterial count (10.55 x 107 CFU g-1soil) was observed under the treatment T8 while fungi and actinomycetes population were found higher under weedy check.