and 2014 ( Allen et al., 2017 ). Seedling diseases can lead to poor crop establishment in soybean and can be managed with fungicide seed treatments ( Bradley, 2008 ; Dorrance and McClure, 2001 ; Dorrance et al., 2003 ). Fungicides with broad
Martin M. Williams II and Carl A. Bradley
Nancy W. Callan and Don E. Mathre
Biological seed treatment offers a safe, environmentally responsible option for protection of seeds and seedlings from attack by soilborne pathogens. Most effective biological seed treatments have used either bacterial or fungal agents. The efficacy of a biological seed treatment depends upon the ability of the biocontrol agent to compete and function on the seed and in the rhizosphere under diverse conditions of soil pH, nutrient level, moisture, temperature, and disease pressure. Seed treatment performance may be improved through application and formulation technology. An example of this is the bio-priming seed treatment, a combination of seed priming and inoculation with Pseudomonas aureofaciens AB254, which was originally developed for protection of sh-2 sweet corn from Pythium ultimum seed decay. Bio-priming has been evaluated for protection of seed of sweet corn and other crops under a range of soil environmental conditions.
Mark A. Bennett, Nancy W. Callan, and Vincent A. Fritz
Disease management is an important step in any crop establishment system. Emergence of field-seeded crops may take several weeks for many species and represents a vulnerable stage of plant growth. This paper considers various biological, chemical, and physical seed treatments for improved seed performance. The role of seed quality and cultural practices in seedling establishment also is reviewed. Multidisciplinary approaches to improving horticultural crop establishment are promising.
Na Zhang, Lu Han, Lixin Xu, and Xunzhong Zhang
turfgrass species ( Fry, 1991 ). Jiang and Fry (1998) indicated that foliar application of ETH could increase the turf quality of perennial ryegrass under drought. The efficacy of using ETH as a seed treatment to promote drought resistances of turfgrass
Kiersten A. Wise, Robert A. Henson, and Carl A. Bradley
different management practices is the best way to manage ascochyta blight of chickpea ( Gan et al., 2006 ). Integrated management programs include crop rotation, seed certification and testing, fungicide seed treatment, partially resistant cultivars, and
Melissa Bonham, Gerald M. Ghidiu, Erin Hitchner, and Elwood L. Rossell
, azinphos-methyl, and phosmet, until the early 1990s. Additionally, the increase in carrot weevil damage may also be attributed to limited acreage for crop rotation, an important pest management tactic for carrot weevil ( Grafius, 1984 ). Seed treatment
Giovanni Antoniaci Caputo, Sandra Branham, and Matthew Cutulle
challenge for the establishment of Brassica crops in direct-seeded production. The use of protective compounds as seed treatment could improve crop tolerance to injury from PRE herbicides, making it feasible to direct-seed Brassica crops for production
Carlos A. Parera and Daniel J. Cantliffe
Poor emergence and low seedling vigor are characteristics of many supersweet sweet corn (Zea mays L.) cultivars carrying the shrunken-2 (sh2) gene. Four sh2 sweet corn cultivar seeds [`How Sweet It Is' (HSII), `Crisp N' Sweet 711' (CNS-711), `Sweet Belle' (SB), and `Dazzle' (DZ)] were solid-matrix-primed (SMP), SMP with sodium hypochlorite (SMPcl), treated with a fungicide combination (F) (Imazalil + Captan + Apron + Thiram), or primed with the aforementioned fungicides (SMPf). The seed treatments were tested in the laboratory and the field. Seed imbibition and leachate electrical conductivity were lower in SMP seeds than in nonprimed seeds. In the field, emergence percentage and rate of CNS-711 and SB (high-vigor seeds) were not improved by the seed treatments compared to the nontreated seeds. Emergence percentage and rate of HSII and DZ (considered low-vigor seeds) were improved as a result of SMPcl, SMPf, or F treatments compared to nonprimed seeds. Compared to the F treatment, the SMPcl presowing treatment increased DZ seedling emergence rate and percentage. The combined SMP and seed disinfection via NaOCl seems to be a promising fungicide seed-treatment substitute that improves the stand establishment and seedling vigor of sh2 sweet corn cultivars. Chemical names used: 1-[2-(2,4-dichlorophenyl)-2-(2-propenyloxy)ethyl]-1 H imidazole (Imazalil); N-[(trichloromethyl)thio]-4-cyclohexene-1,2-dicarboximide(Captan); N- (2,6-dimethylphenyl)- N -(methoxyacetyl)alanine methyl ester (Apron); tetramethylthiuram disulfide (Thiram).
Rhoda L. Burrows* and Ismail Ahmed
Fungicides applied as soil drenches affect arbuscular-mycorrhizal (AM) fungal colonization of plant roots to different degrees, depending on the chemical used. However, the effect of fungicides applied as seed treatments has been less studied, and is of particular interest to growers who want to encourage beneficial mutualisms while protecting seedlings against pathogens. We tested the effects of four common seed treatments, Apron (mefenoxam), Thiram, Raxil (tebuconzaole), and Captan on colonization of `Superstar' muskmelon roots by the AM fungus Glomus intraradices in the greenhouse. By 30 days after planting, colonization was very high (>90% root length) for all treatments, with relatively minor (<10%) differences in percent length root with AM hyphae. The Apron seed treatment had the highest percent root length with hyphae, but the lowest amount of vesicles, while roots from Raxil and Captan-treated seeds had the lowest hyphal colonization and highest vesicle formation. Myconate ®, a commercial formulation of formononetin, an isoflavone previously shown to increase AM colonization, significantly increased the percent colonization of roots from the Raxil treatment, but not other treatments. Myconate also increased vesicle numbers in all but the Captan treatments, but not significantly.
Sandra A. Balch, Cynthia B. McKenney, and Dick L. Auld
Oenothera biennis, common evening primrose, is grown commercially for its seed, which contains high levels of gamma-linolenic acid (GLA), a fatty acid with pharmaceutical and dietary importance. Other native species of Oenothera are being evaluated for the presence of GLA in their seed and their potential as a commercial source of GLA. Native evening primrose species have shown slow emergence and low germination percentages. Studies were conducted to determine the effects of chilling, scarification, and priming on germination of seed for six species of native evening primrose. Overall, seed germination was improved by seed treatments. However, responses to the various treatments differed among species.