The effect of adjuvants and nozzle type on the control of volunteer corn by clethodim

Abstract

Volunteer corn is a problematic weed in soybean fields in the USA, where it causes harvest problems and reduces the yield and seed quality of soybean crops. It is a competitive weed, as it grows taller than the soybean plants, and like many other weeds, causes yield reduction by competing with the crop for light, moisture, nutrients and space. There are a number of herbicide inhibitors of the enzyme ACCase, such as clethodim, which are a possible control substance for volunteer corn in soybean. The objective of this study was to determine the influence of adjuvants (crop oil concentrates 3.33% v/v (COC), non-ionic surfactants 0.25% v/v (NIS), methylated seed oil 3.33% v/v (MSO), high surfactant oil concentrate 1.67% v/v (HSOC)), spray nozzles (XR110015, AIXR110015 or TTI110015) and carrier volumes (66 l ha-1 and 132 l ha-1) with clethodim in the control of volunteer corn. The experiment was conducted in controlled conditions at the Department of Agronomy and Horticulture, West Central Research and Extension Center, University of Nebraska - Lincoln, Lincoln, NE 69101, USA. The treatments were in a factorial arrangement, with a randomized complete block design with eight replicates, in two experimental repetitions. Visual injury assessments were recorded at 7, 14, 21 and 28 days after the treatment (DAT). The results have indicated that control of the volunteer corn was maximal (100%) at 66 l ha-1, in clethodim+COC treatments, with the nozzle selection not influencing control at this carrier volume. At greater carrier volume (132 l ha-1), the selection of adjuvants, as well as nozzles, has influenced the clethodim efficacy. The highest efficacy (98%), at greater carrier volume, was recorded in cases where clethodim+COC and clethodim+HSOC treatments were applied by a XR spray nozzle, and in the clethodim+COC treatment, applied by a TTI spray nozzle. Data from this study will be useful to agricultural producers attempting to control volunteer corn (grass weeds) in broadleaf cropping systems.

Samonikli kukuruz je problematična korovska vrsta u usevu soje u USA, gde izaziva velike probleme tokom žetve, utiče na prinos i kvalitet zrna soje. To je izrazito kompetitivan korov zato što nadrasta usev soje, i poput drugih korova, utiče na prinos putem kompeticije za svetlost, vodu, hraniva i životni prostor. Postoji veći broj herbicida inhibitora enzima ACC-aza sa kojima je moguće suzbijati samonikli kukuruz u soji kao što je npr. kletodim. Stoga cilj istraživanja je bio da se utvrdi da li dodavanjem ađuvanata (koncentrat biljnog ulja 3,33% v/v (COC), nejonski surfaktant 0,25% v/v (NIS), metilisano ulje semena 3,33% v/v (MSO), koncentrovano biljno ulje 1,67% v/v (HSOC)) u kombinaciji sa različitim tipovima rasprskivača (XR110015, AIXR110015, TTI110015) i pri različitom utrošku radne (zaštitne) tečnosti (66 l ha-1, 132 l ha-1) je moguće povećati efikasnost kletodima u suzbijanju samoniklog kukuruza. Eksperiment je izveden u kontrolisanim uslovima u Department of Agronomy and Horticulture, West Central Research and Extension Center, University of Nebraska - Lincoln, Lincoln, NE 69101, USA. Tretmani su organizovani po potpuno slučajnom blok rasporedu sa osam ponavljanja i ceo ogled je ponovljen dva puta. Vizuelne ocene oštećenja su rađene 7, 14, 21 i 28 dana nakon tretiranja (DNT). Najbolja efikasnost u suzbijanju samoniklog kukuruza je postignuta pri manjem utrošku radne tečnosti (66 l ha-1) u tretmanu kletodim+COC, dok izbor rasprskivača nije imao uticaja na postignutu efikasnost (100%). Pri većoj zapremini radne tečnosti (132 l ha-1) izbor ađuvanta, kao i izbor rasprskivača su imali uticaja na efikasnost kletodima. Sa najboljom efikasnošću (98%) pri većoj zapremini radne tečnosti su bili tretmani kletodim+COC i kletodim+HSOC primenjeni XR rasprskivačem, kao i tretman kletodim+COC primenjen sa TTI rasprskivačem. Rezultati ovih istraživanja mogu biti od koristi poljoprivrednim proizvođačima pri suzbijanju samoniklog kukuruza (travnih korova) u širokolisnim usevima.