Glyphosate [N-(phosphonomethyl)glycine] was applied at various stages of maturity to corn (Zea mays L. ‘Pioneer brand 3147’ and ‘Dekalb XL 394’), soybeans [Glycine max (L.) Merr. ‘Forrest’ and ‘Essex’], and johnsongrass [Sorghum halepense (L.) Pers.]. Glyphosate applied over-the-top of corn before the grain moisture level decreased to 30% (black layer will have been formed) caused various seed and subsequent progeny abnormalities. Depending on grain moisture level at the time of glyphosate application, seed weight was sometimes reduced and progeny seedling emergence, vigor, and weight were reduced. Also, abnormal seedlings, albino or straited, occurred. Glyphosate applied 2½ weeks or more before soybean maturity reduced seed weight, caused seed discoloration, and drastically reduced progeny seedling emergence, vigor, and weight. Glyphosate applied in September or early October controlled semimature johnsongrass. Later applications were less effective because of advanced senescence.

The effect of ergot (Claviceps africana) in naturally infected sorghum was assessed in feedlot rations. Thirty-two Hereford steers (Bos taurus) in individual pens with access to shade were adapted to feedlot conditions and then offered one of four rations containing 0, 4.4, 8.8 or 17.6 mg/kg of ergot alkaloids (84% dihydroergosine, 10% dihydroelymoclavine and 6% festuclavine), equivalent to ~0, 10, 20 or 40 g/kg ergot (sclerotia/sphacelia) in the rations. These rations were withdrawn at noon on the second day because of severe hyperthermia and almost complete feed refusal in ergot-fed steers. After recovery on ergot-free rations for 5 days, treatment groups were incrementally introduced, over a further 3–12 days, to rations containing 0, 1.1, 2.2 or 4.4 mg/kg of alkaloids (~0, 2.5, 5 or 10 g/kg ergot, respectively). Relative exposure to ergot was maintained, so that the zero- (control), low-, medium- and high-ergot groups remained so. Steers were individually fed ad libitum, and water was freely available. Steers in all ergot-fed groups had significantly elevated rectal temperatures at 0800–1000 hours, even when the temperature–humidity index was only moderate (~70), and displayed other signs of hyperthermia (increased respiration rate, mouth breathing, excessive salivation and urination), as the temperature–humidity index increased to 73–79 during the day. Plasma prolactin was significantly reduced in ergot-fed groups. Voluntary feed intakes (liveweight basis) of the ergot-fed groups were significantly reduced, averaging 94, 86 and 86%, respectively, of the feed intakes of the control group. Hair coats were rough. While the control steers grew from a mean initial liveweight of 275 kg to a suitable slaughter weight of 455 kg in 17 weeks (growth rate 1.45 kg/day), ergot-fed groups gained only 0.77–1.10 kg/day and took at least 5 weeks longer to reach the slaughter weight, despite removal of ergot at the same time as control steers were sent to slaughter. Sorghum ergot, even at low concentrations (1.1 mg alkaloids/kg feed) is severely detrimental to the performance of steers in the feedlot.

Three preemergence and four postemergence herbicides were compared for control of prickly sida (Sida spinosaL.) in soybeans (Glycine maxMerrill) and for level of phytotoxicity to soybeans. As a preemergence herbicide, chlorbromuron [3-(4-bromo-3-chlorophenyl)-1-methoxyl-1-methylurea] provided better control of prickly sida than did linuron [3-(3,4-dichlorophenyl)-1-methoxyl-1-methylurea] which was more consistently effective than was naptalam (N-1-naphthylphthalamic acid) plus dinoseb (2-sec-butyl-4,6-dinitrophenol). Chlorbromuron applied as a preemergence treatment caused slight crop injury. In most cases preemergence treatments followed by cultivation were effective in providing season-long control. The descending order of effectiveness for prickly sida control by the postemergence herbicides was: chlorbromuronmetribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)one] > prometryne [2,4-bis(isopropylamino)-6-(methylthio)-s-triazine] > dinoseb. Prometryne as a postemergence treatment following a preemergence herbicide increased prickly sida control more consistently than dinoseb used as the postemergence treatment. However, prometryne caused more crop injury than did dinoseb.Comparison of soybean yields from the weedy and weed free checks show that prickly sida caused only 9 to 14% yield losses in soybeans.

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