Influence of sugarcane straw on weed germination control

Abstract


 This research studied the effectiveness of herbicide treatments in weed control and during different periods of emergence, when applied to varying amounts of straw. The experiment was conducted in a greenhouse with pre-emergent herbicides: amicarbazone, metribuzin, indaziflam, isoxaflutole, amicarbazone + indaziflam, metribuzin + indaziflam, and isoxaflutole + indaziflam, against three species (Sorghum halepense, Rottboellia exaltata, and Mucuna aterrima). The experimental design was completely randomized in a 5x4 factorial scheme, with five amounts of straw (0, 1, 2, 3, and 5 t/ha) and four periods of weed emergence (0, 30, 60, and 90 days after treatments). The residual control of indaziflam was influenced by the amount of straw. Metribuzin presented a low residual control, while isoxaflutole was not affected by the amount of straw. Amicarbazone offered residual control for Mucuna aterrima. The association between indaziflam + isoxaflutole displayed a suitable residual control against Sorghum halepense and Rottboellia exaltata. The association of indaziflam + metribuzin adequately controlled Mucuna aterrima and Sorghum halepense. herbicide physical-chemical characteristics can influence their performance, and the association of products may increase residual and weed spectrum control.
 Highlights
 
 This partial or total removal of remaining sugarcane straw from the soil surface alters weeds dynamics in sugarcane fields. In this situation we have monocot and dicot weeds infesting the sugarcane crops.
 Among these species, some plants are even more difficult to control, such as Sorghum halepense, Rottboellia exaltata, and Mucuna aterrima
 Indaziflam herbicide presented a better performance in controlling monocotyledonous plants than eudicot plants.
 The herbicides amicarbazone and metribuzin presented adequate control of Mucuna aterrima despite having lower residual control.
 The association of indaziflam + metribuzin, resulted in satisfactory results for Mucuna aterrima, Sorghum halepense, and Rottboellia exaltata.

Managing itchgrass and morningglory in plant cane: a strong decision on associating herbicides for pre-emergence control

“…During the initial evaluation period in our study, the low control percentage of both weeds, mainly in the association of umioxazin and diclosulan treatment, is related to the low soil moisture during the rst 7 days after application (Fig. 1), so that to achieve the herbicide bioavailability in the soil solution, soil moisture is necessary in the rst week after application (Silva et al 2021). On the other hand, when there is high soil moisture, the umioxazin provides satisfactory weed control (Correia et al 2013).…”

“…Rodrigues et al (2022) stated that R. exaltata was controlled by the herbicide indazi am at dosages of 75, 150, and 225 mL in pre-emergence, as the control percentages remained high (above 91%) after 84 DAA compared with the control treatment, a fact that expresses the long residual effect of indazi am (Rodrigues et al 2022). Control of R. exaltata by isolated indazi am, in the emergence periods at 0, 30, and 60 DAT was over 80% in ratoon cane (Silva et al 2021). The results obtained by Silva et al (2021) indicated that the isolated application of indazi am achieves better control over monocotyledonous species than over eudicot ones.…”

“…Control of R. exaltata by isolated indazi am, in the emergence periods at 0, 30, and 60 DAT was over 80% in ratoon cane (Silva et al 2021). The results obtained by Silva et al (2021) indicated that the isolated application of indazi am achieves better control over monocotyledonous species than over eudicot ones. Furthermore, when the indazi am is associated with other molecules, as adopted in our study using diclosulan, tebuthiuron or sulfentrazone association, control of both itchgrass and morningglory increases signi cantly.…”

“…Very vigorous and proli c, a single plant is capable of issuing up to 100 tillers and producing 15,000 seeds, which remain dormant in the soil for up to four years (Lorenzi 2000;Freitas et al 2004;Correia et al 2013). The seeds are small and exhibit rapid germination and eld colonization (Silva et al 2021). In Brazilian sugarcane elds (Oliveira and Freitas 2009; Correia 2016), the occurrence of R. exaltata promoted losses of up 80% in ratoon cane and 100% in plant cane (Arévalo and Bertoncini 1994;Sousa et al 2020).…”

“…Against the morningglory species Ipomoea quamoclit, (Toledo et al 2015) observed that pre-emergence sulfentrazone and sequential tebuthiuron application provided an excellent level of control (100%). Therefore, nding e cient herbicides against monocot and eudicot weeds that are selective for sugarcane has become necessary (Silva et al 2021). The association of amicarbazone + isoxa utole + indazi am applied in pre-emergence provided a satisfactory level of control over itchgrass, namely 92% at 120 DAA, while also ensuring good selectivity for sugarcane.…”