Timing of Glyphosate Application on Control of Silverleaf Nightshade and Glyphosate-Resistant Cotton Yield

Abstract

A 3-yr dryland study was initiated in 1999 at Munday, TX, on an Altus fine sandy loam to determine the most appropriate cotton growth stage or stages at which to apply glyphosate. The objectives were: (1) to evaluate control of silverleaf nightshade in the cotton and (2) to determine the effect on yield. Treatments were: (1) control (C; two cultivations), (2) early glyphosate at the four-leaf stage (E), (3) early glyphosate followed by a midseason application 21 d later (E+M), (4) two cultivations plus late glyphosate at 20% open bolls (L), (5) treatment E+L, and (6) treatment E+M+L. In fall 1999 and 2001, silverleaf nightshade stem numbers decreased in the plots sprayed early and midseason, and increased in plots receiving only late or no applications when compared with the counts in the spring of those years. However, in fall 2000, nightshade numbers were less than in early spring 2000 regardless of treatment, probably because of hot and dry weather. In fall 2001, silverleaf nightshade populations had increased 13-fold and twofold for the C and L treatments, respectively, when compared with populations at the beginning of the study. Other treatments had population decreases of 10 to 90%. Three-year average lint yields were higher with early or early plus midseason applications. Lint yields were similar with early or early plus midseason sprays. Lint yields were higher when nightshade/cotton biomass competition was lower. Early application of glyphosate can effectively control silverleaf nightshade populations and can increase yield when compared to no application or a late application.

Are Mediterranean forest ecosystems under the threat of invasive species Solanum elaeagnifolium?

“…For example, the allelopathic mechanisms can be incorporated in agro-ecosystems for weed control through several ways such as the inclusion of allelopathic crops in crop rotations, the use of their residues for cover cropping, or by selection of the most active allelochemicals to be used as bioherbicides ). In the case of S. elaeagnifolium, it may also be combined with current chemical control methods (Cambardella & Elliott 1992, Choudhary & Bordovsky 2006, Gitsopoulos et al 2017.…”

CHEMICAL OPTIONS FOR THE CONTROL OF SILVERLEAF NIGHTSHADE (Solanum elaeagnifolium)

“…Applying glyphosate at the end of summer can enhance rootbank control, because during this period the carbohydrates and the nutrients move into the root system and this contributes to increased movement of the herbicide towards roots (Kidston et al, 2007). However, Choudhary and Bordovsky (2006) found that applying glyphosate late in the season was not effective on silverleaf nightshade. Previous research has provided variable results related to the most appropriate growth stage of silverleaf nightshade to apply glyphosate (Feuerherdt, 2010).…”

“…It can be used in fruit orchards, vineyards, and other row-seeded crops with directed-spray applications. It has been reported to efficiently control silverleaf nightshade in glyphosateresistant cotton (Choudhary and Bordovsky, 2006;Joy et al, 2008).…”

“…Concerning the appropriate growth stage for maximum control of silverleaf nightshade with the application of herbicides, there is conflicting information (Choudhary and Bordovsky, 2006). For silverleaf nightshade control, it is important to target rootbank with systemic herbicides, but when the seeds are the start of new infestations it is essential to control seedbank as well.…”

Early detection, herbicide resistance screening, and integrated management of invasive plant species: a review

“…12 Some key attributes favor its growth and colonization potential in new regions; namely: (i) high seed production potential with up to 60 berries per plant accounting up to 120 seeds per berry, 21 (ii) rhizome fragmentation after tillage may generate multiple new stems, 29 (iii) extended root system, that makes conventional tillage insufficient, 29 (iv) low efficacy of systemic herbicides, 30 (v) tolerance to various biotic and abiotic stresses, 31 and (vi) high adaptability dynamics to various soil and environmental conditions. Solanum elaeagnifolium has been reported to compete with wheat (Triticum aestivum L.), maize (Zea mays L.), cotton (Gossypium hirsutum L.), sorghum (Sorghum bicolor L.), pepper (Capsicum annuum L.), peanut (Arachis hypogaea L.), and alfalfa (Medicago sativa L.), 22,25,32 while it has been also observed in olives and citrus orchards. It is present in forest edges but not inside a forest environment.…”