Yellow nutsedge control and nursery crop tolerance with manage as affected by adjuvant choice

• Published in: Journal of environmental horticulture 1999-09, Vol.17 (3), p.114-119
• Main Authors: McDaniel, G.L, Fare, D.C, Witte, W.T, Flanagan, P.C
• Format: Article
• Language: English
• Subjects: adjuvants; application rate; chlorosis; Cyperus esculentus; Forsythia intermedia; growth; halosulfuron; herbicide resistance; Ilex; Ilex crenata; Ilex meserveae; leaves; Liriope muscari; oils; phytotoxicity; planting stock; species differences; sulfonylurea herbicides; surfactants; weed control; Weigela florida
• ISSN: 0738-2898; 2573-5586
• DOI: 10.24266/0738-2898-17.3.114

Adjuvants combined with one-half rate (18 g ai/ha, 0.26 oz ai/A) of Manage (MON 12051, halosulfuron) were evaluated for phytotoxicity on five species of landscape plants grown in containers and for effectiveness of yellow nutsedge (Cyperus esculentus L.) control. Adjuvants tested at 0.25 and 0.5% (v/v) were: X-77 (non-ionic), Scoil (methylated soybean seed oil), Sun-It II (methylated sunflower seed oil), Agri-Dex (paraffin crop oil concentrate), and Action “99” (non-ionic organosilicone). Manage combined with each adjuvant injured Japanese holly (I. crenata Thunb. ‘Bennett's Compacta’), forsythia (Forsythia x intermedia Zab. ‘Lynwood Gold’), green liriope (Liriope muscari Bailey ‘Big Blue’), and weigela (Weigela florida Bunge ‘Pink Lady’), but not ‘Blue Girl’ holly (Ilex x meserveae S.Y. Hu ‘Blue Girl’). Manage with Scoil produced moderate phytotoxicity on forsythia and weigela and reduced growth of all landscape plants. Manage plus Action “99” caused severe phytotoxicity to weigela and reduced growth on all plants tested. Manage plus Agri-Dex treatment resulted in moderate to severe growth reduction to all plants, with severe marginal necrosis of foliage on forsythia and weigela. Manage with Sun-It II resulted in less growth reduction and fewer phytotoxic symptoms of the test species, compared to other adjuvant plus Manage combinations. Initially, foliar chlorosis was observed on all species except ‘Blue Girl’ holly with the Manage plus Sun-It II treatment, but most plants had recovered by 8 weeks after treatment (WAT). Yellow nutsedge control at 4WAT was greater when Manage (18 g ai/ha, 0.26 oz/A) was combined with Scoil, Sun-It II, Agri-Dex, or Action “99” adjuvants. By 8WAT, Manage combined with Sun-It II resulted in 98–100% control of nutsedge. Manage plus the adjuvants Scoil or Sun-It II resulted in superior yellow nutsedge control compared to X-77, Action “99”, or Agri-Dex and had little effect on growth of these landscape plants.