No abstract

To evaluate the relative potential for survival of fungicide-cadmium succinate and benomyl, in an alternating criss-cross tolerant isolates of Sclerotinia homoeocarpa in pattern to exert a selection pressure on the extant fungus nature, equal populations of tolerant and sensitive isolates population. In the presence of selection pressure from were introduced into a disease-free, geographically isolated fungicide, the population was predominantly benomylturf plot area in the fall of 1973 and the populations were tolerant in areas where benomyl was applied, and allowed to increase naturally. Dollar spot leaf lesions were predominantly cadmium-tolerant where cadmium was sampled from infection centers monthly from the following applied. Six weeks after the fungicide applications were July through November, and 1,411 isolates obtained stopped, the benomyl-tolerant population rapidly decreased, subsequently were tested for fungicide tolerance on cadmium whereas the cadmium-tolerant population remained high. succinate-and benomyl-amended potato-dextrose agar. In These results indicate that even though benomyl-tolerant the absence of fungicides, benomyl-tolerant isolates dropped populations were low in the absence of benomyl, the to a small percentage of the total S. homoeocarpa application of benomyl resulted in a rapid resurgence of population, whereas sensitive and cadmium succinate benomyl-tolerant population. With cadmium-tolerant tolerant isolates increased to approximately equal high isolates, the use of cadmium fungicides resulted in an almost frequencies. In 1975, the plot again was sampled onaregular complete predominance of the cadmium-tolerant basis. In August 1975, when infection centers were very population, which persisted even when cadmium sprays were numerous, the area was sprayed with the fungicides, curtailed.

The effect of two benzimidazole fungicides, 2-(4-thiazolyl) benzimidazole (thiabendazole) and methyl l-(butylcarbamoyl)-2-benzimidazole carbamate (benomyl) on growth and foliar element accumulation of 'Penncross' and 'Seaside' cultiyars of. Agrostis palustris Huds. and 'Merion' cultivar of Poa pratensis L: was investigated ina series ,of greenhouse and field plot experiments. In the greenhouse, soils.with varying concentrations of the materials were seeded. with 'Penncross,' and 'Merion.In the field a 2 year old plant ing of the 'Seaside' cultivar (Agrostis palustris) was sprayed with thiabendazole, and benomyl formulations. Criteria employed for determining growth effectswere dry weight of foliage, dry weight of roots, and macro-and micro-element accumulation by the. foliage, Dry foliar weights of both Poa and Agrostis were increased by soil amendment with benomyl and thiabendazole, With Agrostis benomyl soil amendment increased foliar Κ and decreased P, Ca, Mg, Mn, B, and Na.Thiabendazole amendment increased Κ while decreasing Mg, Μn, and Na.In the field repeated foliar spray applications of benomyl increased Κ and Mg and decreased Cu and B.

No abstract

Insecticides were evaluated for the control of Japanese beetle grubs on an infested Kentucky bluegrass fairway. A randomized complete block design with 4 replications per treatment (10 x 12 ft) was utilized. Insecticides were applied on September 1, 1977. Sprayable formulations were applied with a hand-hold CO2 powered boom sprayer at 40 psi in 3 gal of water per 1000 sq ft. Granular formulations were applied with a Gandy 36-inch spreader.