Reducing seed dormancy in Indian ricegrass [Oryzopsis hymenoides]

Indian ricegrass [Oryzopsis hymenoides (Roem. and Schult.) Ricker] is an excellent native species for revegetation of coal and oil shale sites. However, inadequate germination due to a high seed dormancy results in poor stand development and limits its use. This paper presents the results of a series of experiments attempting to reduce the dormancy by weakening the lemma and palea by scarification of the seed covering. Four treatments (three mechanical and one concentrated sulfuric acid) were examined, alone and in combination with gibberellic acid. Three ages of seed were tested in the greenhouse, the laboratory and the field. Concentrated sulfuric acid and a modified commercial scarifier most effectively increased germination in the greenhouse; gibberellic acid enhanced germination of the younger, fresher seeds in this environment. A rubbing machine improved emergence in the field more than the other treatments. It was, however, only a modest improvement. Concentrated sulfuric acid decreased field emergence for all 3 ages of seed. Germination studies in the laboratory indicated that none of the treatments increased mortality.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Weed Hosts of Globodera pallida from Idaho

The potato cyst nematode, Globodera pallida (PCN), a restricted pest in the United States, was first reported in Bingham and Bonneville counties of Idaho in 2006 (1). The U.S. government and Idaho State Department of Agriculture hope to eradicate it from infested fields. Eradicating PCN will require depriving the nematodes of their hosts over a protracted time period. Functional eradication might be achieved with relatively high, proven to be efficacious dosages of soil fumigants. The presence of host weeds of PCN can play a significant role in the success of the eradication program. To determine the host status of common weeds found in potato fields of the Pacific Northwest, host suitability tests were conducted in a secured greenhouse located at the University of Idaho at Moscow. Reproduction of PCN on nine weeds including hairy nightshade (Solanum physalifolium formerly S. sarrachoides) and cutleaf nightshade (S. triflorum) (biotypes from Idaho and Washington), black nightshade (S. nigrum) (Washington biotype), bittersweet nightshade (S. dulcamara) (Idaho biotype), redroot pigweed (Amaranthus retroflexus), kochia (Kochia scoparia), and common lambsquarters (Chenopodium album) were compared with reproduction on Desiree, Russet Burbank (known hosts), and Santé (poor host) potatoes (S. tuberosum). Plants were grown in 10-cm-diameter clay pots containing sandy loam soil previously fumigated with methyl bromide and inoculated with 10 to 150 cysts that were either collected from infested fields or raised in the secured greenhouse (ample diapause period elapsed). Treatments were replicated five times and each trial lasted 3 months. Cysts were extracted from soil with a Fenwick can, and the reproductive factor (RF = final cyst count ÷ initial inoculum) was determined. While both biotypes of hairy nightshade were suitable hosts of PCN (161–668 ÷ 150; RF = >1), cutleaf biotypes, black, and bittersweet nightshades were poor hosts (1–108 ÷ 150; RF = 1) proved to be suitable hosts and Santé (1–20 ÷ 150; RF = <1) a poor host of Idaho PCN. Although some cysts were recovered from pots containing the remaining weed species, they may have been part of the original inoculum. The significance of nightshade species (whether suitable or poor hosts) in eradication of potato cyst nematode from infested fields cannot be overemphasized. Reference: (1) A. M. Skantar et al. J. Nematol. 39:133, 2007

Registration of ‘UI Darwin’ Wheat

‘UI Darwin’ (Reg. No. CV-1022, PI 639953) is a hard white winter wheat (Triticum aestivum L.) developed by the Idaho Agricultural Experiment Station and released in February 2006. UI Darwin (pedigree IDO445/‘Manning’) was tested under the experimental numbers A93151W-85 and IDO604. It is a tall semidwarf wheat released for crop-fallow rotations of the Intermountain West, where few hard white wheat cultivars are available. UI Darwin has improved resistance to stripe rust (Puccinia striiformis Westend.) relative to ‘Bonneville’ hard red winter wheat with resistance to dwarf bunt (Tilletia controversa Kühn in Rabenh) at similar levels to Bonneville. In 16 rainfed yield trials grown in Idaho from 2001 to 2005, UI Darwin had an average grain yield of 3200 kg ha-1, similar to Bonneville (3050 kg ha-1) and ‘Weston’ (3190 kg ha-1) but less than ‘Gary’ (3560 kg ha-1 UI Darwin has improved bread baking quality compared with current hard white winter wheat cultivars and has excellent color in akaline noodle products. UI Darwin had an average pup-loaf volume of 1075 mL, similar to hard red winter wheat cultivars Bonneville (1044 mL) and Weston (1064 mL) but greater than the hard white wheat cultivar Gary (963 mL)

Registration of ‘Juniper’ Wheat

‘Juniper’ (Reg. No. CV-1021, PI 639951) is a hard red winter wheat (Triticum aestivum L.) developed by the Idaho Agricultural Experiment Station and released in February 2006. Juniper was tested under the experimental numbers A91013W-1 and IDO575. It is a full-stature wheat released for very low rainfall, crop-fallow rotations of the Intermountain West and was released for its improved resistance to stripe rust (Puccinia striiformis Westend) and dwarf bunt (Tilletia controversa Kühn in Rabenh) and bread-baking quality compared with current full-stature cultivars. Juniper had an average yield in rainfed trials of 3290 kg ha−1, compared with the other tall cultivars for this region, ‘Weston’ and ‘Bonneville’, which had grain yields of 3050 and 3180 kg ha−1, respectively. Weston has undesirable baking quality due to short dough mixing time. Juniper has nearly a full minute longer mixograph mixing time compared with Weston (p \u3c 0.01). Juniper also has similar snow mold tolerance (causal organism Typhula spp.) to Bonneville without the undesirable characteristic of late heading date and maturity. Juniper heads 3 d earlier than Bonneville