Management strategies for three difficult to control weeds found in tea ecosystem

Abstract

Goose grass (Eleusine indica (L.) Gaertn.), Crab grass (Digitaria sanguinalis (L.) Scop.) and a new weed identified as Indian Muraina grass (Ischaemum indicum (Houtt.) Merr.), could not be effectively controled with the PPC approved herbicides. Goose grass covers the ground by tillers, exhibit high seeding capability (roughly 10,000 seeds/plant) and tough root system (24 roots/ plant). Mixing of Paraffinic oil @ 1% as adjuvant with Glyphosate 41% SL @ 2L and 3L ha-1 was found to have hastened the control. Glyphosate 71% SG @ 2kg ha-1 + 1% Paraffinic oil recorded 100 per cent control at 28 DAS (Days After Spray). Another new herbicide (HEB -A) from Propaquizafop group, HEB-A@600ml/ha + 1% Paraffinic oil recorded 100 % control for 77 DAS with no regrowth. Crab grass, an annual erect for semi erect grass is another hardy species of weed as reported by tea plantations. Flowering starts from May and remains upto September. Tank mixing of a new herbicide Indaziflam 500 SC @ 75 ml ha-1 + Glufosinate Ammonium 13.5%SL @ 1650 ml ha-1 + 1% Soybean oil + non ionic wetting agent recorded 100 % control within 14 DAS with no regeneration even after 63 DAS. Glyphosate 41%SL @ 2L ha-1 + Indaziflam 500 SC @ 75ml ha-1+1% Soybean Oil + non ionic wetting agent brought satisfactory control. Paraquat Dichloride 24% SL @ 1320 ml ha -1 can control upto 21 DAS. Indian Muraina grass is a hardy weed, covers ground by profuse branching from each node, inflorescence is 2-digitate spikes; November – May is the period of flowering, propagated by seed and old root stock. Tank mix of Glyphosate 71% SG @ 1.5 kg ha -1 + Glufosinate Ammonium 13.5% SL @ 1.0L ha -1 + non ionic wetting agent recorded 100% control. Paraquat Dichloride 24% SL @ 2.0 L ha -1 also found effective.

Keywords: Goose grass, Crab grass, Indian Muraina grass