The effect of integrated weed management using mulch, cover plants and the use of Treflan herbicide on the yield of Dragon’s head (Lallemantia iberica Fischer & C.A. Meyer)

Introduction: Agriculture has always struggled with weeds throughout history and has achieved considerable progress in this regard. Humans started fighting weeds by hand and also by using animals, and now they continue this way mainly through mechanical and chemical methods. Weeds not only reduce the production of crops and increase the cost of agricultural products, but also cause problems to the public in various ways. Weeds compete with agricultural plants to receive nutrients, soil moisture and sunlight and lead to a decrease in the yield of agricultural plants. Manual weed control is time-consuming and expensive. Chemical weed control method is one of the important methods used in weed control. but these herbicides can have a serious impact on the environment. Non-chemical weed control such as the use of mulch and cover plants are the preferred methods for weed control. Considering the importance of weed control and the existence of few studies on the comparison of different L. iberica weed control methods, this experiment was conducted with the aim of comparing the effect of different weed control methods in L. iberica fields.
Materials and Methods: The field experiment was carried out in the research farm of the Faculty of Agriculture of Tabriz University, located eight kilometers east of Tabriz. According to meteorological maps, the climate of this region is classified as steppe and semi-arid. The height of this area is 1360 meters above sea level, and the latitude and longitude are 17°46′ east and 5°38′ north, respectively. The experimental design used in this study was a split plot based on a randomized complete block design with three replications. In this experiment, two levels of herbicides (use and non-use of Treflan herbicide) were placed in the main plots and the pure cultivation treatments of infected and weed-free L. iberica and cultivation along with the use of mulch and cover plants were placed in the secondary plots. In the process of the plants after removing the marginal effect, the number of 10 plants from each plot was taken as a sample and the number of flower cycles in the main and secondary branches, the number of nodes of the main and secondary branches and the number of leaves of the main branch were determined and then their average was determined. Calculated and recorded. Also, harvest index and soil moisture after harvest were calculated.
Results and Discussion:Weed contamination caused a decrease in the biological yield per unit area and the yield index of the Dragon’s head plant. Based on the results of the variance analysis table of traits related to the medicinal plant L. iberica, the simple effect of treflan herbicide on grain yield per unit area at the level of one percent probability and on the biological yield per unit area at the probability level of five percent and in the rest of the traits was insignificant. Also, the simple effect of weed management methods, as well as the mutual effect of Treflan herbicide and management methods on all measured traits was significant at the 1% probability level. By using mulch of straw and stubble as well as the cover plant Vicia villosa, the number of seeds in the capsule of L. iberica plants infected with weed increased significantly compared to the pure cultivation of this plant. Weed contamination reduced the number of seeds per plant and the use of straw and stubble mulch and cover plants increased the number of seeds per plant infected with weeds. With weed infestation, the weight of 1,000 seeds decreased, and the weight of 1,000 seeds increased with the use of Treflan herbicide and weed management methods. Seed yield per unit area in plants grown under weed interference conditions was significantly lower than weed-free treatments.
Conclusions
Weed infestation decreased the number of seeds per capsule, number of seeds per plant, seed yield per plant, weight of 1000 seeds, biological yield per plant and biological yield per plant area of L. iberica. Among the management methods applied in this experiment, the use of straw and stubble mulch and the treatment of the cover plant V. villosa along with the use of the herbicide Treflan had the greatest effect in increasing the yield and yield components of L. iberica.