Multifunctional Adjuvants Affect Sulfonylureas with Synthetic Auxin Mixture in Weed and Maize Grain Yield.

A field study in the years 2017-2019 was carried out to evaluate the impact of novel adjuvant formulations on the efficacy of sulfonylurea and synthetic auxin herbicides. Treatments included nicosulfuron + rimsulfuron + dicamba (N+R+D) at full and reduced rates with three multicomponent (TEST-1, TEST-2, TEST-3) as well as standard (MSO, S) adjuvants. In this greenhouse study, Echinochloa crus-galli seeds were planted and treated with N+R+D at 2-3 leaf stages. The water with the desired pH (4, 7, and 9) for the preparation of the spray liquid was prepared by incorporating citric acid or K3PO4 to either lower or raise the pH of the water. Adjuvant TEST-1 added to the spray liquid at pH 4 increased the effectiveness to 68%, TEST-2 to 81%, and TEST-3 to 80%, compared to 73% and 66% with the MSO and S. The efficacy of N+R+D at pH 7 with TEST-1 increased to 83%, TEST-2 to 82%, and TEST-3 to 77%, but with MSO, it increased to 81%, and 71% with S. Adjuvants TEST-1, TEST-2, and TEST-3 in the liquid at pH 9 increased efficacy to 76 and 80%, compared to 79 and 63% with MSO or S adjuvants. N+R+D applied with TEST-1, TEST-2, and TEST-3 provided greater weed control than herbicides with surfactant (S) and similar or even better than with standard methylated seed oil (MSO) adjuvants. Maize grain yield after herbicide-with-tested-adjuvant application was higher than from an untreated check, and comparable to yield from herbicide-with-MSO treatment, but higher than from S treatment.

Impact of novel herbicide based on synthetic auxins and ALS inhibitor on weed control.

Delayed sowing of winter cereals or unfavorable weather conditions in autumn may make it impossible to carry out herbicide treatment in autumn. In such cases, weed control should be started in the spring. During this time, the plantation should be protected as effectively as possible because the weeds are at an advanced stage of growth. Therefore, they are less sensitive to applied herbicides. In the treatment, it is worth using a mixture of different mechanisms of action. Studies were conducted to evaluate the effectiveness of a band of tribenuron-methyl, and MCPA applied as soluble granules in spring control of dicotyledonous in winter cereals. The biological efficacy of herbicides was estimated in the 25 field experiments on winter cereals in Poland. Postemergence, a spring application of tribenuron-methyl + MCPA, effectively controls the majority of weed species present in spring: Anthemis arvensis, Brassica napus, Capsella bursa-pastoris, Centaurea cyanus, Lamium purpureum, Matricaria chamomilla, Tripleurospermum inodorum, Stellaria media and Thlaspi arvense. Satisfactory control was confirmed for Veronica persica, Viola arvensis, and Galium aparine. Tribenuron-methyl with MCPA is recommended for application to winter cereals in spring. To prevent the development of resistance in weeds, it is advantageous to combine two active substances.

The Dynamics of Sugar Maize (Zea mays saccharata Sturt.) Infestation of Field Pansy (Viola arvensis).

Field pansy infestation can lead to a decrease in the species diversity of plant communities and to the disappearance of other species. Field pansy infestation is fairly common in many crops, including maize. Understanding the ecology and management strategies for field pansy in maize is essential for effective weed control. This research into sugar maize was conducted from 1992 to 2019 in the Research and Education Center Gorzyn, Zlotniki branch, which belongs to the Poznan University of Life Sciences. The assessment of weed infestation was carried out in experiments that focused on chemical weed control in maize. The experiments were established as single-factor randomized block designs with four field replications. The aim of the study was to evaluate dynamic changes in the status and the degree of field pansy infestation in sugar maize that was cultivated after various other crops in the Wielkopolska region, with a focus on weather conditions. The results indicated that the probability of field pansy individuals occurring among the total number of weeds was highest when maize was cultivated after wheat, but the probability of such infestation did not significantly differ when maize was sown in a crop rotation after winter triticale.

Impact of Multifunctional Adjuvants on Efficacy of Sulfonylurea Herbicide Applied in Maize (Zea mays L.).

To reduce the cost of intensive herbicide application and environment pollution and enhance biological effectiveness, effective multifunction adjuvants should be used. A field study was conducted in 2017-2019 in midwestern Poland in order to assess the effects of new adjuvant formulations on the activity of herbicides. Treatments included the herbicide nicosulfuron at recommended (40 g ha-1) and reduced rates (28 g ha-1) alone and with the addition of tested MSO 1, MSO 2, and MSO 3 (differing in the type and amount of surfactants), as well as standard (MSO 4 and NIS) adjuvants. Nicosulfuron was applied once during the 3-5 leaf stage of maize. Results indicate that nicosulfuron with the tested adjuvants provided satisfactory weed control equivalent to that provided by standard MSO 4 and better than that provided by NIS. Nicosulfuron applied with the tested adjuvants led to a similar grain yield of maize as that achieved with standard adjuvant treatments and much higher than that measured in untreated crops.