Legume Genomics and Genetics 2024, Vol.15, No.6, 303-314 http://cropscipublisher.com/index.php/lgg 307 weed competition in soybean is between 14 and 42 Days After Sowing (DAS). During this period, weeds must be controlled to prevent significant yield losses. Delayed weed management beyond this critical period results in a steady decline in growth and yield, with each day of delay causing yield losses of 32~37 kg·ha-1 (Table 2). Table 2 Soybean growth response to different period of weed interference in 2016 and 2017 (Adopted from Daramola, 2020) Weed interference Crop vigor score Canopy height (cm) Number of branches Number of leaves Leaf area index Dry weight (g·plant-1) Crop growth rate 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 2017 WI14 6.4 a 7.4 a 96.5 a 95.0 a 8.0 a 7.6 a 32.0 a 27.6 a 2.8 a 2.7 a 36.4 a 36.2 a 0.5 a 0.4 a WI28 5.9 b 6.2 c 90.0 b 89.5 b 7.1 b 7.2 b 23.4 b 20.0 b 2.4 b 2.1 c 33.6 b 33.3 b 0.4 b 0.3 b WI42 5.5 c 5.4 d 81.9 c 80.9 c 6.5 c 6.9 c 18.7 c 20.3 b 2.1 c 1.9 d 30.8 c 30.1 c 0.3 c 0.2 c WI56 5.4 c 5.8 d 80.6 c 80.4 c 6.5 c 6.7 c 18.1 c 16.2 c 2.1 c 1.9 d 30.1 c 30.6 c 0.3 c 0.2 c WIhar 5.2 c 5.6 d 80.0 c 77.2 c 6.4 c 6.9 c 19.9 c 16.1 c 2.0 c 1.9 d 29.5 c 28.8 c 0.3 c 0.2 c WF14 5.3 c 5.6 d 82.9 c 80.0 c 6.5 c 6.6 c 19.3 c 17.8 c 2.0 2 2.0 c 29.9 c 29.5 c 0.3 c 0.2 c WF28 5.8 d 7.0 b 90.8 b 88.0 b 7.1 b 7.1 b 25.7 b 21.3 b 2.5 b 2.4 b 32.4 b 33.2 b 0.4 b 0.3 b WF42 6.5 a 7.4 a 100.7 a 91.0 a 7.7 a 7.5 a 31.2 a 28.8 a 2.8 a 2.7 a 34.9 a 34.9 a 0.5 a 0.4 a WF56 6.2 a 7.8 a 101.6 a 94.0 a 7.9 a 7.5 a 34.6 a 28.3 a 2.9 a 2.8 a 36.4 a 36.6 a 0.5 a 0.4 a WFhar 6.6 a 7.6 a 102.3 a 100.0 a 8.0 a 7.5 a 34.6 a 30.2 a 3.0 a 2.9 a 36.4 a 36.0 a 0.5 a 0.4 a SE±(p<0.05) 0.32 0.43 5.82 5.74 0.43 0.37 4.3 3.6 0.23 0.18 2.2 2.6 0.06 0.06 Moreover, integrated weed management practices have been shown to reduce weed biomass and density effectively, thereby enhancing soybean yield. For instance, the use of a combination of herbicides and mechanical weeding can maintain weed biomass below critical levels, ensuring higher crop productivity (Jadhav, 2013; Snyder et al., 2016). Additionally, early planting and narrow row spacing can expedite canopy closure, further reducing the competitive advantage of weeds (Datta et al., 2017; Arsenijevic et al., 2021). 5 Pest and Disease Management 5.1 Major pests affecting soybean yield Soybean crops are susceptible to a variety of pests that can significantly impact yield. Among the most detrimental pests are stink bugs, which have become a major concern in regions like the Neotropics, where they account for up to 60% of insecticide applications (Bueno et al., 2023). Other notable pests include soil pests such as Coleoptera larvae and dipterans like Delia platura, which can cause substantial damage to the crop (Mureșanu et al., 2020). Additionally, aphids and leaf-eating insects such as Vanessa cardui and Autographa gamma are prevalent and can lead to significant yield losses if not managed effectively (Wang et al., 2000). 5.2 Disease management strategies Effective disease management in soybean cultivation involves a combination of chemical and non-chemical strategies. Chemical control measures, including the use of fungicides, are commonly employed to manage diseases such as downy mildew (Peronospora manshurica) and bacterial blight (Pseudomonas glycinae) (Mureșanu et al., 2020). However, there is a growing emphasis on integrated disease management approaches that combine cultural practices, such as crop rotation and resistant cultivars, with reduced chemical applications to minimize environmental impact (Khan et al., 2019). For instance, the use of pre-emergence herbicides in conjunction with early planting and narrow row spacing has been shown to enhance canopy closure and reduce disease incidence (Arsenijevic et al., 2021). 5.3 Role of biocontrol in pest and disease management Biological control (biocontrol) plays a crucial role in the integrated pest management (IPM) of soybean crops. Conservation Biological Control (CBC) strategies, which focus on preserving natural enemies of pests, have been effective in maintaining pest populations below economic threshold levels. For example, reducing insecticide use and prioritizing biopesticides can enhance the presence of natural enemies, thereby reducing the need for chemical interventions. Augmentative Biological Control (ABC) programs, involving the mass release of biocontrol agents,
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