Planting date can affect crop yield and is an important management decision for practitioners. Although wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] can be effectively double-cropped in North Carolina, if commodity prices and projected economic returns are higher for crops other than soybean, growers might consider a nontraditional, double-crop system. Direct comparisons of major agronomic crops with different planting dates or in a double-crop system with wheat are limited in North Carolina. Therefore, research was conducted in North Carolina from 2013 through 2017 to determine yield potential of corn (Zea mays L.), cotton (Gossypium hirsutum L.), grain sorghum [Sorghum bicolor (L.) Moench], peanut (Arachis hypogaea L.), and soybean planted at two dates within the recommended planting window for full-season production versus planting these crops after wheat harvest.The experimental design was a split plot, with summer crop serving as the whole plot unit and planting date within a crop serving as the subplot unit. Yield of corn, cotton, grain sorghum, peanut, and soybean in full-season production exceeded that of double-cropping with wheat in 5, 5, 2, 4, and 5 yr out of 5 yr of the study, respectively. Estimated economic returns were generated using the 10-yr average (2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017) summer crop prices with the 10-yr average wheat price. When considering all possible combinations of years and crops (n = 25), in only 20% of the possible combinations was the economic return of the double-cropping system greater than economic return of full-season crop production when compared with at least one of the planting dates within the traditional planting window. 1972wileyonlinelibrary.com/journal/agj2 Agronomy Journal. 2020;112:1972-1980.

Irrigation has the potential to increase crop yield and financial return on coarse-textured, coastal plain soils in the mid-Atlantic region of the United States. Although the majority of irrigation is delivered through overhead sprinkler irrigation, subsurface drip irrigation (SDI) has been shown to be a reasonable alternative to sprinkler irrigation because of its efficiency on small, irregularly shaped fields (Bosch et al., 1992(Bosch et al., 1998O'Brien et al., 1998). Increased yield and/or water use efficiency are often cited as benefits of SDI over overhead sprinkler irrigation (

Field studies were conducted in 2016 and 2017 at two locations in North Carolina to evaluate common ragweed (Ambrosia artemiisifolia L.) (Lewiston-Woodville) and Palmer amaranth (Amanthus palmeri S. Wats) control (Rocky Mount), peanut (Arachis hypogaea L.) yield, and estimated economic return when herbicides were applied postemergence (POST) at 2 or 6 weeks after planting (WAP); 2 and 4 WAP; 4 and 6 WAP; and 2, 4, and 6 WAP. During the following growing season, cotton (Gossypium hirsutum L.) was planted directly into the same plots to determine the impact of weed management during the previous season on weed density. In absence of herbicides, peanut yield was 880 and 1110 kg/ha at Lewiston-Woodville and Rocky Mount, respectively. When weed control depended on a single herbicide application, yield ranged from 1760 to 2660 kg/ha at Lewiston-Woodville, and 2080 to 2480 kg/ha at Rocky Mount. When herbicides were applied twice, peanut yield ranged from 2690 to 3280 kg/ha at Lewiston-Woodville and 3420 to 3840 kg/ha at Rocky Mount. The greatest yields were recorded when herbicides were applied two or three times. Applying herbicides increased the estimated economic return of peanut compared to the non-treated control (NTC). In cotton the following year, common ragweed populations at Lewiston-Woodville were greater following the NTC or a single herbicide application 2 WAP compared to more intensive herbicide programs. Palmer amaranth density at Rocky Mount the following year in cotton was not affected by weed management the previous year in peanut. These results illustrate the relative importance of timing and duration of weed management for peanut and how they influence weed emergence in the following cotton rotational crop.