This work is devoted to the development of ways to prevent emergence of herbicide resistance in weeds. The only way to prevent the emergence of resistance is the integrated use of herbicides with different mechanisms of phytotoxicity. To prevent the emergence of resistance, potential components of the formulations should have a common spectrum of controlled weed species, and to ensure high efficiency of crop protection, the spectrum of action each component should be wide as possible. These requirements are met by herbicides from the classes of carotenoid synthesis inhibitors, inhibitors of electron transport in photosystem II (PS II) chloroplasts, protoporphyrinogen oxidase inhibitor (PPO).
The main limiting factor for the integrated use certain herbicides is the effect of their interaction. Therefore, the aim of this work was to study the effects of interaction and select combinations with synergistic and additive interaction. Since among these classes of herbicides there are preparations selective for corn (Zea mays L.), winter wheat (Triticum aestivum L.) and sunflower (Helianthus annuus L.), it was planned to develop mixtures for the protection of these crops based on the data obtained. The research was conducted under vegetation and field experiments.
Mixtures acetolactate synthase (ALS) inhibitor herbicides with HPPD inhibitor herbicides are used to protect corn crops and control resistance. In vegetation experiments conducted with oil radish (Raphanus sativus var. oleifera), a model of annual dicotyledonous weeds, it was shown that interaction of herbicide HPPD inhibitor tolpyralate with the ALS inhibitor rimsulfuron is antagonistic. The change from antagonistic to additive interaction was achieved only when the application rate of rimsulfuron was doubled. At the same time, when using a mixture of tolpyralate with electron transport inhibitor terbutylazine, the interaction is synergistic. It was shown that the synergism is due to an increase in the efficiency of electron transport blocking and an increase in the intensity reactive oxygen species (ROS) formation. In field experiments, it was found that the mixture of tolpyralate with rimsulfuron, even at an increased rate of rimsulfuron application, does not guarantee effective control of individual resistant to the components of the mixture of weed species.
Due to changes in climatic conditions, the development of herbicide mixtures for use in the fall in winter wheat crops is of particular importance. In this regard, we studied the effects of interaction when combining herbicides of three different classes - the phytoendesaturase inhibitor diflufenican, the TE inhibitor metribuzin and the PROTO inhibitor carfentrazone. The results of the research showed that only in the mixture of carfentrazone and metribuzin the interaction has signs of antagonism, while in others the interaction is additive. Field tests of weed control efficiency and crop selectivity showed that the triple tank mixture was the most effective in controlling weeds throughout the growing season. When used in winter wheat sowing, the mixture of diflufenican with metribuzin and the triple tank mixture were not inferior in terms of protection and yield preservation to the effectiveness of the complex herbicide preparation Marathon, the active ingredients of which are the microtubule polymerization inhibitor pendimethalin and the electron transport inhibitor isoproturon, as well as the experimental preparation GF-2202, which contains diflufenican and ALS inhibitors. The results obtained indicate that the use of mixtures of diflufenican with metribuzin and a triple mixture allows achieve high efficiency of winter wheat crop protection without the use ALS inhibitor herbicides.
In order to develop a herbicide composition that would provide effective protection of sunflower crops from weeds and be an effective means of preventing the emergence of resistant weed biotypes, a mixture of the herbicide inhibitor of carotenoid synthesis aclonifen with the electron transport (PS II) inhibitor prometryn. As a result the studies, it was shown that when applied during the sunflower growing season, the interaction of aclonifen with prometryn is synergistic. However, severe plant damage was observed, which did not decrease even when the rate of prometryn was reduced to sub-herbicidal. Therefore, mixture of aclonifen and prometryn was further applied to the soil after sowing the crop. With this application, the interaction of aclonifen with prometryn is additive. As a result of the research, the application rates of aclonifen and prometryn were determined, which are not inferior to the action the complex herbicide Primekstra TZ Gold. At the same time, it is an effective factor in preventing the emergence of herbicide-resistant weed biotypes.
As a result of the research, we have identified combinations that meet the requirements necessary to prevent the emergence of herbicide resistance in weeds.
