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- Author or Editor: Harlene Hatterman Valenti x
Greenhouse studies were conducted to evaluate simulated drift injury to annual bedding plants. Dahlia, gazania, geranium, marigold, petunia, and salvia in the early stages of flowering were sprayed with either 2,4-D (dimethylamine salt) or dicamba (diglycolamine salt) at rates one-fifth, one-tenth, or one-twentieth the lowest labeled rate of for turfgrass. Interactions between species by time, species by treatments, and treatments by time were significant for visual injury. Species sensitivity from most sensitive to least sensitive was marigold > dahlia ≫ geranium = petunia > gazania = salvia. Dahlia was more sensitive to dicamba than 2,4-D while the opposite was true for marigold. Petunia flower initiation was reduced as dicamba or 2,4-D rate was increased. The duration of the trial may have limited flowering differences among treatments with the remaining species. Dahlia loss of apical dominance as an injury response was greater with dicamba than 2,4-D. Typical injury symptoms for dahlia included stem, leaf, and petiole epinasty along with multiple shoot growth. Gazania injury included slight leaf rolling and leaf stretching. Geranium injury included leaf curling and fewer flowers per cluster. Marigold injury included leaf node swelling and stem wall rupture with massive cellular proliferation. Petunia injury included stem and pedicel epinasty, curling of the outer portion of the corolla, and lower flower production. Salvia injury included stunting, slight flower stem curvature, and partial dieback of the terminal raceme.
Assessment at North Dakota State University is considered to be a conversation about learning outcomes enriched by data with a goal of improving student learning. On the classroom level, this focuses on developing techniques to assess course-related knowledge and skills but may also include techniques to assess learner reactions to teaching and their course-related learning, study skills, and self-confidence. On the program level, this consists of an assessment plan and a corresponding assessment report. These assessment plans identify how the entire curriculum will be assessed over time, whereas the report documents plan implementation. The report consists of the activities designed to collect information on the success of each course. These activities may be direct, indirect, or non-measures of student learning. The direct measures along with a few indirect measures provide answers to the university assessment committee on student learning assessment questions: “what did you do?,” “what did you learn?,” and “what will you do differently as a result of what you learned?”
Weed control is necessary to ensure success in early stages of juneberry (Amelanchier alnifolia) orchard development; however, juneberry growers have limited chemical weed control options. A field trial was initiated at Prosper, ND, to evaluate the efficacy of physical and chemical weed control methods and their effects on juneberry growth. Woven landscape fabric most effectively eliminated weed emergence, whereas winter rye (Secale cereale) cover crop allowed the most weeds to emerge throughout the study. During both years, a hairy vetch (Vicia villosa) companion crop provided poor early- to midseason weed control, but weed suppression increased over time as hairy vetch grew to cover open areas. However, hairy vetch was very competitive with juneberry, reducing crop height, width, and overall growth. Plants within the herbicide treatments (glyphosate at 0.75 lb/acre plus oryzalin at 2 lb/acre and linuron at 1.7 lb/acre followed by flumioxazin at 1 oz/acre) and the hand-weeded control, which was weeded three times each year, had the greatest growth.
Field trials were initiated near Carrington and Absaraka, N.D., on a Heimdal clay loam and a Spottswood sandy loam, respectively to evaluate onion grade and yield in response to planting configuration, spring cover crop, and reservoir tillage. Results from the Carrington and Absaraka locations during 2002 and 2003 showed that colossal-sized onion was the largest grading size obtained (Carrington, 2003) and that the greatest number of colossal onion were from the bed configuration that had a reservoir tillage treatment. The coarser soil texture at Absaraka allowed for spring and fall formed raised bed comparison (2003) in which the fall formed raised bed tended to have greater yields and more marketable onion. Planting configuration resulting in the greatest total yield varied among locations and years but generally increased with reservoir tillage. Soil moisture and temperature monitoring during the early growing season did not differ greatly. However, differences in soil water potentials at the 6“ depth were observed during the last part of the growing season. Cover crop results indicated that a row of canola planted between onion rows for wind erosion protection will reduce onion yields even when ample water is available through routine irrigation. Herbicides for broadleaf control were not applied until onion had two true-leaves due to label restrictions. This delay enabled the canola to grow beyond the recommended stage for broadleaf control and to quickly outgrow the herbicide injury.
Blackberry (Rubus subgenus Rubus Watson) production has the potential to expand into the northern Great Plains with the development of the rotating cross-arm (RCA) trellis system that prevents winter injury by laying the plants horizontal to the ground so that they can be covered during cold periods. However, this will only occur with the evaluation of new cultivars and overwintering protection methods associated with the RCA trellis system. Ten cultivars under four rowcover treatments were evaluated for winter damage, vegetative growth, yield, and fruit quality. Thermo-couples monitored air temperature under each rowcover treatment. Results indicated that rowcovers differed in their ability to moderate winter air temperatures. However, temperature moderation differences from rowcovers did not correspond to plant growth differences. Instead, cultivar influenced plant growth differences. Plants under the thermal blanket with corn stover had greater yield and more berries, while fruit quality was unaffected by rowcover treatment. Differences were also found between cultivars for fruit quantity and quality. Although rowcovers enabled overwintering primocanes to produce fruit after winter temperatures reached −30
Greenhouse experiments were conducted to compare visible injury from sublethal rates of 2,4-D, dicamba, and a premixed product of 2,4-D + mecoprop + dicamba for eight annual flowers and to describe herbicide injury symptoms for these annual species. Herbicides were applied at rates 0.05×, 0.1×, and 0.2× of their highest labeled rate for turfgrass to simulate spray drift conditions. Visible injury varied between species, herbicide rate, and time after herbicide application. Alyssum (Lobularia maritima Desv.) showed the greatest initial injury and ageratum (Ageratum houstonianum Mill.) showed the greatest injury at 4 weeks after treatment. Symptom severity increased as herbicide rate increased, with the greatest injury from the premixed product, followed by 2,4-D, and then dicamba. The eight species varied in their degree of visible injury and flower production to dicamba, 2,4-D, and the premixed product. Reduced flowering was most obvious for prolific flowering species such as alyssum. Impatiens (Impatiens wallerana L.), salvia (Salvia splendens Sello), and snapdragon (Antirrhinum majus L.) produced more flowers in response to sublethal dicamba rates compared to the untreated plant. All rates of 2,4-D generally reduced flowering compared to untreated plants, except the lowest rate of 2,4-D for geranium (Pelargonium xhortorum Bailey) and snapdragon. Dahlia (Dahlia hortensis Cav.) sprayed with dicamba at the highest rate produced three times as many stems as plants untreated or those sprayed with 2,4-D. Overall order of species susceptibility to sublethal rates of dicamba, 2,4-D, or the premixed product from most susceptible to least susceptible was ageratum > alyssum > marigold (Tagetes erecta L.) > dahlia > geranium = salvia = snapdragon = impatiens. Differences in overall susceptibility to the plant growth regulator herbicides evaluated should provide useful information to horticulturalists designing annual flower beds and borders and lawn care applicators.
A juneberry (Amelanchier alnifolia) cultivar trial was conducted to evaluate fruit yield, quality, and other characteristics for juneberry cultivars and a native biotype. One-year old micropropagated material was transplanted and established in North Dakota in 2004. The native biotype is available as a conservation plant from Towner State Nursery (Towner, ND) and was included as a readily available juneberry for producers. Fruit diameter, soluble solids content, yield (total and marketable), and plant size measurements were taken during the 2010 and 2011 season. ‘Martin’, the native biotype, ‘Parkhill’, ‘Pembina’, ‘Regent’, and ‘Thiessen’ produced the highest total yield in 2010, whereas ‘Parkhill’ had the highest total yield in 2011, followed by ‘Thiessen’ and then ‘Martin’. Cultivars Martin, Parkhill, and Thiessen produced the highest marketable yield over the 2-year study. ‘Martin’ and ‘Thiessen’ fruit were larger and heavier than the rest of the cultivars. The largest plants were ‘Martin’, ‘Parkhill’, ‘Regent’, and ‘Thiessen’. Soluble solids concentrations were similar among all cultivars. Cultivars Martin or Thiessen should be recommended to commercial producers wanting a high yielding cultivar with uniform fruit ripening, whereas Parkhill should be recommended to producers with a you-pick operation wanting a high yielding cultivar with an extended fruit ripening period.
Vegetable soybeans (Glycine max), the same species as field-dried soybeans, have similar production requirements and good market potential for commercial producers in upper midwestern United States. Five vegetable soybean cultivars were tested for yield and quality characteristics and to assess the necessity of field irrigation during 2003 and 2004 in North Dakota. Cultivars of different maturity dates were evaluated for stand densities, pod production, seed weight, and marketable yield. Total marketable yields varied between the years, ranging from 5773 to 10,118 lb/acre. Lower yields in 2003 were attributed to significantly lower population stands caused by poor germination conditions. `Envy', the earliest maturing cultivar, produced a significantly smaller seed size, while `Sayamusume' produced a greater seed size than the other cultivars both years. `Butterbean', `IA1010', and `IA2062' yielded greater percentages of three-bean pods than the other two cultivars each growing season. Irrigation did not increase the marketable pod yield or the quality variables examined each season; thus it appears that rainfall during the growing season may be adequate for vegetable soybean production in this region.
Traditionally, the structure of higher-order data in genotype-by-environment interaction requires simplification to use bilinear reduction models. Flexible multiway reduction models have been claimed to be more informative, as they allow exploration of individual trends and account for the covariance among data modes. In complex latent traits, such as acclimation response of grapevine (Vitis sp.), these methods may offer increased insight into plant adaptive processes. In a growth chamber study, data from seven phenotypic traits at 11 photoperiodic times in the presence of two temperatures of 30 accessions were analyzed. The four-way interaction among these data modes was isolated and further examined through bilinear singular value decomposition (SVD) and multiway Tucker decomposition models. A similar set of three latent process traits were identified regardless of model used. The Tucker decomposition model led to more concise clustering of wild-type accessions, was more interpretable, as trends could be evaluated separately, and had less indication of overfitting; therefore, the multiway method was preferred over the standard SVD bilinear method in the investigation of high-order interaction in acclimation response. This methodology may offer insight into other complex traits, such as phenolic development, drought tolerance, and horizontal disease resistance to improve breeding efforts as other individual mechanisms used by the organism are separated, quantified, and compared rather than the culmination of events as an end-product.