A regional-scale study of the contribution of local, management and climate factors to the infestation of processing tomato fields with Amaranthus species

Unraveling the reasons for failure to control Amaranthus albus: insights into herbicide application at different growth stages, temperature effect, and herbicide resistance on a regional scale

“…51 In this context, an important finding of this study was that, despite reduced rimsulfuron efficacy under elevated temperatures at the 4-6-TL stage, all populations were effectively controlled by the herbicide when applied at the 5-TL stage under a colder temperature regime, resembling the conditions during the planting season in the eastern growing areas. 7 This observation highlights the benefit of applying rimsulfuron under lower temperatures, such as in the fields of the Beit She'an Valley, which are typically planted in late winter and early spring. Similarly, Godar et al 20 showed that the reduced sensitivity of A. palmeri to mesotrione, a 4-hydrosyphenylpyruvate dioxygenase (HPPD) inhibitor, at warmer temperatures, was a result of increased metabolism.…”

“…Agricultural systems exhibit remarkable complexity, necessitating the consideration of diverse abiotic, biotic, and anthropogenic factors for effective weed management in agroecosystems. 7,33 To understand the reasons behind the failure to control A. albus in processing tomato fields within a study region characterized by significant climatic variability, we therefore seek to break down this complexity. We started by positing that the primary factor determining herbicide efficacy would be the timing of weed control application in relation to the plants' growth stage.…”

“…However, it is important to note that despite these clear instructions, the diverse climate conditions in different growing areas can make the actual practice more complex. 7 Another aspect that should be taken into consideration is the variation in germination patterns among populations across the region, with potential implications for the observed range of growth stages in the fields. Gafni et al 22 recently identified variations in germination dynamics among the same A. albus populations as those examined in this study.…”

“…51 The introduction of new herbicides, which are currently under consideration for regulatory approval for use in processing tomato, should be considered in accordance with local climate conditions, and in accordance with the timing and intensity of application. 7 Applying herbicides before substantial weed germination and emergence, either pre-planting or during the early stages of the crop, could prove effective. Recent assessments have explored the pre-emergence application of herbicides like metribuzin 52 and pendimethalin 53 along with the utilization of a finger weeder for mechanical intra-row weed control.…”

“…5,6 In Israel, most processing tomatoes are grown in the northern region, which is characterized by a significant climate gradient extending from east to west. This climatic diversity not only dictates the planting dates of processing tomatoes, but also impacts the growth rates of both the crop and the weeds, 7 with A. albus being the predominant species. Israel's northern region hosts four major tomato growing areas: the Beit She'an Valley in the east (semi-arid climate); the Jezreel Valley in the south (with a climate that transitions gradually from semi-arid in the east to Mediterranean in the west); the Zevulun Valley in the west (Mediterranean climate); and the Hula Valley in the north (Mediterranean climate) (Fig.…”