Weed control in maize crops with various schemes of herbicide application

Abstract

Goal. Carry out a comparative evaluation of the effectiveness of different schemes of application of modern herbicides in maize crops. Methods. Field, phenological, statistical. Conducted spraying of corn crops to seedlings (ВВСН 00) with herbicides Adengo 465 SC, hp (thiencarbazone-methyl, 90 g/l + isoxaflutol, 225 g/l + cyprosulfamide, 150 g/l), 0.5 l/ha, Primextra TZ Gold 500 SC, (S-metachlor. 312.5 g/l + terbuthylazine, 187.5 g/l), 4.5 l/ ha, Merlin Flex Duo 475 SC, (isoxaflutop, 50 g/l + cyprosulfamide, 50 g/l + terbuthylazine, 375 g/l, 2.0 l/ha. After germination in the phase of 4—5 leaves (ВВСН 14—15) applied insurance herbicides Milagro 040 SC, (nicosulfuron, 40 g/l), Basis 75 v.g. rimsulfuron, 500 g/kg + thifensulfuron-methyl, 250 g/l), MаisTer Power OD (foramsulfuron, 31.5 g/l + iodosulfuron-methyl sodium, 1.0 g/l + thiencarbazone-methyl, 10 g/l + cyprosulfamide, 15 g/l), Laudis 30 WG, VG (tembotrione, 200 g/kg + isoxadifen-ethyl, 100 g/kg) and Stellar, RK (topramezone, 50 g/l + dicamba, 160 g/k) in the recommended consumption rates. The experimental plots were 1000 m2 in the first experiment, the recurrence of 3-fold and 25 m2 in the second experiment, the recurrence of 4-fold. Observations were made for meteorological indicators. Statistical processing of the results was performed according to computer «Statgraphic plus» programs. Results. Mixed type of segetal vegetation prevailed in the experimental plots. Among the perennial weeds dominated by Sonchus arvensis L., Cirsium vulgare Savi Ten., Convolvulus arvensis L., among annuals — Setaria glauca L., Setaria viridis L., Echinochloa crus-galli L., Polygonum convolvulus L., Calinsoga parviflora L., Stellaria media (L.) Vill.), Chenopodium album L., Raphanus raphanistrum L., Thlaspi arvense L., Amaranthus retroflexus L. The application of pre-emergence herbicides effectively inhibited the growth and development of weeds. 60 days after application, the effectiveness of herbicides was 87—97% against cereals and 89—98% against dicotyledonous weeds, which did not require the application of insurance herbicides. During the critical periods of maize development, a sufficient level of soil moisture was recorded during the research years. After 60 days, the effectiveness of herbicides applied after crop germination was 65—95% against dicotyledonous and 65—92% against cereal weeds. The highest effect in killing weeds was provided by MaysTer Power, 1.5 l/ha, Laudis 30 WG, VG, 0.5 kg/ha + surfactant Mero, 2.0 l/ha and Stellar, RK, 1.25 l/ha + surfactant Metholate, 1.25 l/ha. The application of herbicides has significantly reduced the aboveground mass of weeds and increased crop yields. Maize grain yield from weed-protected areas was at the level of 8.0—9.7 t/ha against 4.1—4.9 t/ha in the control. Conclusions. Both herbicide application schemes under favorable weather conditions provide effective weed control of maize crops The efficiency of pre-emergence herbicides was at the level of 87—98%, post-emergence — 65—95%. At the same time, the reduction of aboveground mass of weeds was 75—95%, and crop yields increased by 1.6—2.2 times depending on the drug.