Fungicides were evaluated for control of Phytophthora root rot for five growing seasons in two field plantings of Fraser fir (Abies fraseri) affected by Phytophthora cinnamomi in western North Carolina. At the first site, which had a fairly well-drained soil, treatment programs with Aliette (5 lb/100 gal, three applications per year), Subdue Maxx (3.7 fl oz/1.15 gal/1000 ft2, two applications per year), and Subdue GR (5.75 lb/1000 ft2, two applications per year) maintained low rates of mortality (< 10%) for three growing seasons, whereas tree mortality in the untreated plots reached 13 and 37% by the second and third growing seasons, respectively. At the second site, which was in a flood plain, disease did not develop during the first 2.5 years, even in untreated control plots. However, mortality increased rapidly following several high-rainfall events, but none of the fungicides had any effect on disease development. Apparently, at least under conditions not overly conducive to the disease, the fungicide treatment programs can delay the onset of high mortality rates caused by P. cinnamomi in Fraser fir for up to three growing seasons. Accepted for publication 23 February 2006. Published 31 March 2006.

If registered for use on vegetable soybean, pyroxasulfone would expand the options for weed management systems in the crop. In order to determine the potential crop injury risk of pyroxasulfone on vegetable soybean, the objective of this work was to quantify vegetable soybean tolerance to pyroxasulfone applied PRE and EPOST. Twenty-one vegetable soybean and two grain-type soybean cultivars were treated with pyroxasulfone at 417 gaiha−1 (twice the recommended field use rate) PRE, EPOST, or not treated. Plant population density was unaffected by pyroxasulfone. Only low levels (<10%) of crop injury were observed within a few weeks after PRE and EPOST treatments. Soybean cultivars were not differentially affected by pyroxasulfone, as evidenced by the lack of interactions between cultivar and treatment for any crop response variable. The low amount of risk of crop injury associated with pyroxasulfone is no different for vegetable soybean cultivars grown in the US for commercial production than grain-type soybean.

Herbicides registered in vegetable soybean often fail to control waterhemp. The objective of this research was to quantify vegetable soybean tolerance to preemergence herbicides for early-season waterhemp control, including flumioxazin applied alone PRE or in mixture with chlorimuron, metribuzin, or pyroxasulfone at use rates in grain-type soybean. Crop tolerance to the herbicides was tested in field trials with 20 vegetable soybean cultivars and four grain-type cultivars through 4 wk after treatment (WAT). Flumioxazin-based treatments were equally safe, resulting in only minor, transitory crop response (&lt;5% injury 2 WAT) and no effect on crop emergence or early season growth. Flumioxazin mixtures provided greater than 99% control of waterhemp 4 WAT, as evidenced by reduced weed density from 29.7 plants m−2 in the nontreated control to no waterhemp. Flumioxazin applied alone or in tank mixture with chlorimuron, metribuzin, or pyroxasulfone were as safe in vegetable soybean as previously reported in grain-type soybean. Registration of these products in vegetable soybean would provide the industry with additional options for managing waterhemp.

Little is known about the potential benefits of cereal rye (Secale cereale L.) in combination with various weed management tactics in processing vegetable legume crops such as edamame, lima bean, and snap bean. Field experiments were conducted over 3 yr to determine the extent to which early-terminated rye (ETR) and integrated weed management (IWM) tactics, including pre-and post-emergence herbicides with (augmented) or without (standard) hand weeding, suppress weed density and biomass. Possible drawbacks on crop establishment and yield were also investigated. Early-terminated rye (cereal rye terminated 4 wk before vegetable crops planting; i.e., Feekes growth stage 8.00 to 9.00) reduced total weed biomass 53 and 73% compared with stale seedbed (SSB) in edamame and snap bean, respectively. In contrast, total weed density and biomass were increased by 67 and 39%, respectively, in lima bean under ETR compared with SSB treatment. Early-terminated rye did not influence edamame establishment or yield; however, snap and lima beans had reduced yield. Soil nitrate-nitrogen 4 wk after planting was negatively correlated with soil moisture in all vegetable legume crops tested. The application of pre-and post-emergence herbicides, particularly when followed by hand weeding, reduced weed density and biomass and improved yield in all crops, except snap bean, compared with weedy plots. Results show that ETR can serve as an important component of IWM in edamame.