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Soy is Brazil's main commodity, and due to its importance, farmers have adopted several technological innovations, such as light supplementation, to increase grain productivity and quality. However, the use of artificial light can interfere with weed dynamics and herbicide efficiency. The objective of this work was to evaluate the effect of herbicides on weed control and qualitative and quantitative attributes of soybeans grown under light supplementation. A field experiment was set up in the city of Monte Carmelo, MG, Brazil. The treatments were distributed in plots mounted under a central pivot in two environments: with light supplementation (LED panels) and without light supplementation. The treatments were distributed across four blocks, and plots were subdivided in space. The herbicides used were glyphosate, diclosulam and glyphosate, s-metolachlor and glyphosate, fomesafen + clethodim, flumioxazin + clethodim. The variables analyzed were the number of weeds, biomass, and control; chlorophyll levels; initial fluorescence; ratio of variable fluorescence to maximum fluorescence; and soybean electron transport rate—indicators of soybean yield. Light supplementation increases the density and biomass of weeds and impairs the effectiveness of herbicides. However, light supplementation with LED panels installed on the central irrigation pivot promotes increased productivity and improvements in the quantitative and qualitative parameters of soybeans. Due to these benefits, light supplementation can be considered advantageous for irrigated soybean production. [ABSTRACT FROM AUTHOR]

Seed coat cracking and green seeds threaten soybean crop production. Seed coat cracking results from a complex interplay of genetic factors, environmental stresses, and crop management practices. Green seeds, linked to water deficit, nutritional deficiencies, and environmental stresses, exhibit reduced quality and viability. The intricate relationships between seed coat integrity and seed permeability, influenced by the lignin content, porosity, and color, play a pivotal role in seed germination, storage potential, and resistance to field stresses. These issues reverberate through the soybean agricultural supply chain. Strategic interventions are crucial to address these abnormalities and ensure soybean productivity. Seed germination and vigor are reduced due to seed coat cracking and green seeds, undermining food security and necessitating additional resources for disease management. The occurrence and identification of green seeds and seeds with cracks in the seed coat were also reported by identifying the genes and QTLs (quantitative trait loci) associated with these characteristics. Herbicides, commonly used in weed management, may offer a strategic approach to mitigating seed coat cracking and green seed occurrence. Understanding the complex interactions between the genetics, environmental factors, and management practices influencing seed abnormalities is essential as global climate change intensifies. This review emphasizes the need for integrated strategies, balanced plant nutrition, and cohesive phytosanitary management to mainly alleviate seed coat cracking and greenish occurrences in soybeans and other plant species. [ABSTRACT FROM AUTHOR]

Significant losses in agricultural production are due to abiotic stresses, such as herbicide phytotoxicity. Dicamba (diglycolamine salt) is a herbicide used for post-emergent control of broadleaf weeds. It has a possibility to vapor-spread into neighboring fields causing damage to other crops. However, not every stress can be easily identified. Therefore, remote sensing has the potential as a new tool in early injury detection. This study evaluated the effects of simulated dicamba drift on the occurrence of phytotoxicity in soybeans (Glycine max). Soybean was assessed in seven dicamba doses (0, 0.056, 0.56, 5.6, 11.2, 28, 112 g ha−1) for changes in plant injury (scale of notes), spectral aspects (triangular greenness index (TGI), and shoot dry mass. The plants were photographed using a digital camera positioned at 1.2 m above the planting media level. The results indicate a positive effect of low dicamba doses (0.56 and 0.056 g a.e. ha−1) on TGI canopy distinction and shoot dry mass. Soybean TGI canopy distinction and the injury scale estimated at 45 days after sowing, and the soybean shoot dry mass observed at 99 days after sowing, presented significant and moderate Pearson's r coefficient of correlations (r = −0.609 and 0.625), indicating TGI as a valid and practical spectral index for plant dicamba-injured evaluations. [ABSTRACT FROM AUTHOR]

The recent availability of soybean cultivars with resistance to dicamba herbicide has increased the risk of injury in susceptible cultivars, mainly as a result of particle drift. To predict and identify the damage caused by this herbicide requires great accuracy. The objective of this work was to evaluate the injury caused by the simulated drift of dicamba on soybean (nonresistant to dicamba) plants assessed visually and using the Triangular Greenness Index (TGI) from images obtained from Remotely Piloted Aircraft (RPA). The study was conducted in a randomized complete block design with four replications during the 2019/2020 growing season, and the treatments consisted of the application of six doses of dicamba (0, 0.28, 0.56, 5.6, 28, and 112 g acid equivalent dicamba ha-1) on soybean plants at the third node growth stage. For the evaluation of treatments using the TGI technique, spectral data acquired through a Red Green Blue (RGB) sensor attached to an RPA was used. The variables studied were the visual estimation of injury, TGI response at 7 and 21 days after application, plant height, and crop yield. The exposure to the herbicide caused a reduction in plant height and crop yield. Vegetation indices, such as TGI, have the potential to be used in the evaluation of injury caused by dicamba, and may be used to cover large areas in a less subjective way than visual assessments. [ABSTRACT FROM AUTHOR]

Summary: Management of plant-parasitic nematodes in no-tillage systems relies on knowledge of the species, their abundance and their host range in a certain cropping area. Crop rotation is one of the most efficient techniques in the control of plant-parasitic nematodes; thus, the identification of non-host plant species is essential. Therefore, the aim of this study was to evaluate the host suitability of different cover crops used in crop rotations to control two of the most devastating plant-parasitic nematodes in the Brazilian central region, Meloidogyne javanica and M. incognita. Two experiments were conducted in a completely randomised design under glasshouse conditions. In the M. incognita experiment, seven treatments (cover crops) were evaluated: Crotalaria juncea (sunn hemp; CJ), Stylosanthes humilis (Townsville stylo; TS), Pennisetum glaucum (millet; M), Triticum aestivum (wheat; W), Mucuna aterrima (black mucuna, BM), Glycine max (soybean treated with nematicide (fluensulfona) (SN) and soybean without nematicide (SwN)). In the M. javanica experiment, nine treatments were evaluated: Cajanus cajan (pigeon pea), Brassica napus (canola), B. nigra (mustard), CJ, M, W, BM, SN and SwN. The evaluations were performed 60 days after inoculation, when eggs and juveniles were present in the plant roots and soil, and the nematode reproduction factors (RF) were determined. The results indicated that CJ, M and BM were effective in controlling M. javanica and M. incognita. The SwN and even SN resulted in high RF and were not effective in the control of M. javanica and M. incognita. [ABSTRACT FROM AUTHOR]