Ground ivy is a common broadleaf weed that disrupts turf uniformity and is difficult to control. The objective of this field research was to evaluate cultural and chemical control of ground ivy. Increasing annual nitrogen fertilizer applications from 0 to 196 and 293 kg·ha-1 reduced ground ivy cover by 24% and 32%, respectively. At 26 weeks after treatment, 1.1 kg·ha-1 isoxaben applied in May limited ground ivy spread by 34% compared to the control. Triclopyr, 2,4-D, or fluroxypyr applied at the highest-labeled rate in October provided superior ground ivy control by the following May. Combining an annual fertility program of 196 kg·ha-1 nitrogen and an application of 1.1 kg·ha-1 isoxaben with or after an application of 2,4-D, fluroxypyr, or triclopyr in the fall can maximize ground ivy control. Chemical names used: N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide (isoxaben); [(3,5,6-trichloro-2-pyridinyl)oxy]acetic acid (triclopyr); (2,4-dichlorophenoxy)acetic acid (2,4-D); [(4-amino-3,5-dichloro-6-fluoro-pyridyl)oxy]acetic acid (fluroxypyr).

Ground ivy is a stoloniferous, perennial weed that persists in lawn turf. With the widespread use of 2,4-D on turf sites, the development of 2,4-D–tolerant ground ivy is a possibility. Ground ivy populations showed a highly variable response to foliar 2,4-D application. Ground ivy from Nebraska (NE) was tolerant to 2,4-D, whereas Ohio (OH) ground ivy was susceptible. The 2,4-D–susceptible OH population absorbed 37% more foliar-applied14C–2,4-D than the 2,4-D–tolerant NE population. Although OH and NE populations total translocation of applied14C was similar and averaged 5%, the OH population translocated 42% more toward the apical meristem of the primary stolon than the NE population, primarily because of the OH population's higher14C–2,4-D absorption. The variation in response to 2,4-D found between these two populations occurred after exposure of roots to 2,4-D, but the effect was less pronounced. These results suggest that the difference in foliar uptake may partially contribute to differences in response to 2,4-D between these two populations. Likewise, differences in acropetal translocation may contribute to the differential sensitivity of 2,4-D–tolerant and –susceptible ground ivy populations.

The effectiveness of Trichogramma dendrolimi, Trichogramma embryophagum, Trichogramma sp. strain 45 and Trichogramma sp. strain 48 to control the codling moth Cydia pomonella L. and the summer fruit tortrix moth Adoxophyes orana F.R. was tested in 4 field trials (1984)(1985)(1986). Four to six Trichogramma treatments (depending on the temperature) each at 400 (pillar trees) to 9,000 (round tops) parasites per tree were carried out between June and August to insure the continuous presence of Trichogramma in the plots. The monitoring was done by examining 3,000 to 10,000 apple fruits per plot.T. dendrolimi reduced the damage of C. pomonella by 61.35 %, of A. orana by 72.85 %. T. embryophagum reduced the damage of C. pomonella by 50.06 %, of A. orana by 50.8 %. Trichogramma strain 45 reduced the damage of C. pomonella by 41.6 % and of A. orana by 87.9 %, Trichogramrna strain 48 by 57.2 % and 51.2 % respectively.The reduction of 67.1% in the number of apple fruits damaged by C. pomonella and A. orana obtained by the inundative releases of T. dendrolimi in these experiments is considered economically and the use of this species in practice is recommended.

Site of uptake, absorption, translocation, and metabolism of ethofumesate were studied to determine the differential responses of annual bluegrass, creeping bentgrass, and perennial ryegrass. Using barriers to isolate foliage or soil, the primary site of ethofumesate absorption was found to be the foliage. Symptoms resulting from foliar and over-the-top spray applications of ethofumesate to annual bluegrass included stunting of growth, epinasty, swelling of the crown, darker green color, and fusing of expanding leaf blades. Averaged over the course of the experiment, annual bluegrass, creeping bentgrass, and perennial ryegrass absorbed 33, 11, and 13% of ethofumesate applied. No ethofumesate was detected distally from the treated leaf, but overall translocation of 14C 14 d after treatment (DAT) was 2.2, 5.8, and 2.2% of the absorbed 14C for annual bluegrass, creeping bentgrass, and perennial ryegrass, respectively. Ethofumesate was rapidly metabolized in each species with half-lives ranging from 4.5 to 7 d. The three grasses had metabolized, on average, 67% of the absorbed ethofumesate 14 DAT.

Ground ivy is an invasive, perennial, broadleaf weed common in turf sites. A recent survey of lawn care professionals suggests ground ivy populations respond differently to herbicides. Our study was conducted to determine the variation in response among and within ground ivy populations to 2,4-D or triclopyr application. Ground ivy populations were sampled from nine sites in the United States and Canada. Leaf width, petiole length, and internode length varied by population by as much as 31, 36, and 45%, respectively. In a greenhouse study, applying 4.5 kg/ha 2,4-D or 0.9 kg/ha triclopyr to all populations resulted in a phytotoxic response that varied according to population by as much as 47% for 2,4-D and 31% for triclopyr. Random-amplified polymorphic DNA analysis identified 52 genotypes in the nine populations, and these genotypes varied in response to 2,4-D application in some populations. Difficulty in control of ground ivy with 2,4-D or triclopyr may be because of the presence of ecotypes and biotypes.

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