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Helen C. Harrison

This 1988–1990 field study was designed to: evaluate the effectiveness of wide width floating row covers (covers remained over the crops the entire growing season), polyethylene mulch, and mulch color--red, green, and black--on the growth, yield, quality, insect, and weed control for red (`Red Danish') and green (`Resistant Danish') cabbage cultivars. Insect control treatments included Agronet floating row covers, periodic sprays with dipel, and no insect control. Subplots for weed control were: PPI Treflan and black, green, and red polyethylene mulch. Sub–subplots were red and green cabbage cultivars. Annual rye grass was utilized as a living mulch between the polyethene strips.

One of the purposes of this research was to perfect a pesticide-free system for small-scale vegetable production. Preliminary results indicate few color effects but do show that cabbage can be grown under row covers the entire growing season. However, the covers can become brittle after 2 months of exposure to sunlight. Significant cultivar differences for insect and disease resistance were observed.

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Helen C. Harrison

The Master Gardener Program in the state of Wisconsin is growing rapidly and has been in existence since the late 1970s. There are several aspects of our program(s) that make us unique. First, we are one of the very few states to service all counties within the state, not just our heavily metropolitan areas. Second, we have two major program types along with some unique county programming. We have the basic Master Gardener Program, which covers the major aspects of horticulture—this gives the learner 36 h of training with an expectation of 36 h of volunteer work in return. We now offer the general program in districts (extension has six clusters of counties in Wisconsin)—such that the counties within a district (usually around 16) will have the chance to offer the course at least once every 3 years. That is because the general course is offered once a week (3 h in the evening) for 12 weeks; and thus the basic course is offer spring and fall. If some of the counties within a particular district do not choose to participate, then other counties around the state can take part. Most of the 12 programs are high quality 2-h video productions followed by a 1-h ETN program, which is like a big conference call—everyone has an interactive session with the specialist who developed the video. The specialized program is a series of four 36-h (six 6-h days) training over a 4-year period, which covers flowers, fruit, vegetables, and turf, along with trees and shrubs. This program is offered in our four largest metropolitan areas and is still done all by live lecture. Finally, we require update training for our MGs if they want to continue to be members in good standing (wallet-size cards are issued). This involves 10 h of specified educational opportunities and 10 volunteer hours per year. We also have a day-long educational conference each spring as well as cooperating with Iowa and Minnesota to offer a 2-1/2 day workshop on the alternating years of the international conference. This is hands-on training, held usually the end of June, and rotates among the three states. We now have a stong MG association which has nonprofit status and is an integral partner with us here at the university. Not only do MGs receive members in good standing cards annually, they also receive certificates for 150, 250, 500, 750, and 1000 h of service as well as a 10-year certificate.

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Laura K. Paine and Helen C. Harrison

Parasitic flowering plants represent a unique ecological adaptation, having evolved away from independent function and toward an increasing dependence on other higher plants for survival. Mistletoe, a common evergreen parasite of woody plants, has played a significant role in human culture for centuries. Throughout history, mistletoe species were nurtured and revered as medicinal herbs and religious symbols. But the role of mistletoe has changed. Its importance in western culture has dwindled to a minor, though enduring, association with the Christmas holiday. In contrast, its significance as a parasite of tree crops and woody ornamentals has increased in recent years. Mistletoe species are studied in efforts to control their pathogenic effects and to gain insight into the evolutionary role played by this family of parasitic flowering plants. The unique characteristics of mistletoe that challenge horticultural researchers have contributed to its enduring role in human life.

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Mary H. Meyer and Helen C. Harrison

Using Native Plants is a 120-min videotape that was developed as a result of a Cooperative Extension Partnership Programming Grant between the Univ. of Minnesota, Minnesota Extension Service and the Cooperative Extension–Univ. of Wisconsin-Extension. The content covers woodland wildflowers, prairie establishment and maintenance, landscaping lakeshores, and using native plants in traditional gardens settings.Video segments include: Eloise Butler Wildflower garden, Minneapolis, Minn.; Curtis Prairie, Madison, Wis.; Big Sandy Lake, Minn.; and the Minnesota Landscape Arboretum, Chanhassen. Developed originally as advanced Master Gardener training, the program was a national satellite broadcast on 29 Feb. 1996. It was viewed by at least nine states and more than 500 participants. Video production costs, including a 20-page participant's handout with extensive references and plant lists, were just under $13,000. A cost analysis, evaluation, sample of the participant's packet, pictures from the videotape and an order form will be presented. Copies of the tape and print packet may be obtained for $50 from Minnesota Extension Service, 1.800.876.8636, or Univ. of Wisconsin-Extension, at 1.608.262.3346.

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Michelle Hadawi-Broeske and Helen C. Harrison

Renewed interest in soil conservation over the past decade has led to greater research efforts in the area of living mulch cropping systems. However, crop/mulch competition continues to present challenges. The objective of this study was to determine what effect two types of chemical growth suppressants (Mycogen 6121—an herbicidal soap, and Royal Slo-grow—a soil plant growth regulator) had on the water-use efficiency, nutrient use, and soil-shading ability of two annual living mulches, ryegrass (Lolium multiflorum) and crimson clover (Trifolium incarnatum). Two greenhouse experiments were performed in sand culture using a modified Hoagland's soap, one rate of growth regulator, and a mechanical treatment of mowing. Significant differences in nutrient use and soil-shading ability were obtained. The second experiment (69 days) replicated the ryegrass treatments less one rate of soap and included the legume crimson clover with one rate of soap and one rate of growth regulator. Results from both experiments will be discussed.

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Juan M. Quintana, Helen C. Harrison, James Nienhuis and Jiwan Palta

Pod stomatal density and Ca concentration levels were analyzed for six commercial snap bean cultivars harvested at four planting dates in an attempt to find morphological traits that are related to cultivar differences in pod Ca concentration. The experimental layout was a randomized complete-block design with two replications per planting date, all grown in one location. Snap beans were planted at 1 week intervals beginning 9 June 9 1995 and were harvested in August. Sampling consisted of five pod sizes (1, 2, 3, 4, and 5 according to commercial standards) from each genotype. Stomatal countings were performed using a microscope linked to a television camera. Determinations for pod Ca concentration were made using an atomic absorption spectrophotometer. No differences were detected for pod Ca concentration among planting dates, although there were differences for pod Ca concentration and stomata density among cultivars. Pod stomatal density was positively correlated to pod Ca concentration (R 2 = 0.60), while pod maturity appeared to be negatively correlated to pod Ca concentration (R 2 = 0.37) and pod stomatal density (R 2 = 0.49).

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Juan M. Quintana, Helen C. Harrison and James Nienhuis

Calcium is an essential element for human nutrition. The lack of it causes various problems, such as osteoporosis. Snap beans rank as good sources of calcium among vegetables and are well-liked by most teenagers. In this study, pod yield and Ca concentration were analyzed for 64 genotypes of snap beans, plus four checks. The experimental design was a 8 x 8 double lattice, repeated at two locations (Arlington and Hancock, Wis.). Snap beans were planted in June 1993 and machine-harvested 67 days later, in Aug. 1993. Calcium analyses were made using an Atomic Absorption Spectometer. Results indicated significant differences for pod Ca concentration and yield. Pod size and Ca concentration showed a strong negative correlation (R = 89.5). Clear differences among the locations were also observed. Results were consistent—high-Ca genotypes remained high regardless of location or pod size. Selected genotypes appeared to have the ability to absorb Ca easier than others, but this factor was not related to yield.

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Juan M. Quintana, Helen C. Harrison, James Nienhuis and Jiwan P. Palta

Flow rate, Ca content, and Ca concentration of sieve sap were measured at four developmental stages (flowering and 1, 2, and 3 weeks after flowering) in six commercial snap bean cultivars to better understand physiological factors associated with genetic differences for pod Ca concentration. Sampling began 5 weeks after greenhouse planting and consisted of 1) decapitation of the plant at the first node; 2) covering the stem with preweighed dry cotton; and 3) removing the cotton, reweighing it, and saving it for Ca determination. Flow rate was defined as the difference in cotton weight (expressed as milliliter) per 12 hours. Ca determinations were made using an atomic absorption spectrophotometer. Calcium content was defined as milligram of Ca per total volume of sieve sap after 12 hours. Concentration of Ca was the quotient of Ca content by flow rate (expressed as milligrams Ca per milliliter sap). A positive correlation between flow rate and total Ca content of sieve sap (R 2 = 0.83), flow rate and Ca concentration of sieve sap (R 2 = 0.36), and Ca content and Ca concentration (R 2 = 0.80) were found. Maturity appeared to be an important factor affecting flow rate and Ca influx in snap bean plants. Significant differences between genotypes for Ca content and flow rate were observed. High Ca genotypes reflected a high flow rate regardless developmental stage.

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Juan M. Quintana, Helen C. Harrison, Jiwan P. Palta and James Nienhuis

To understand physiological factors associated with genetic differences for pod Ca concentration between snap bean genotypes, flow rate and Ca uptake of sieve sap were measured, as well as pod Ca concentration. Measurements for flow rate and Ca uptake were done at three developmental stages (fl owering and 1 and 3 weeks after) in two commercial snap bean cultivars (Hystyle and Labrador) grown aeroponically. Pods were collected 2 weeks after flowering only. Flow rate and Ca uptake sampling began 4 weeks after transplanting and consisted of: 1) decapitation of the plant at the first node; 2) covering the stem with pre-weighed dry cotton; and 3) removing the cotton, reweighing it, and saving it for Ca determination. Flow rate was defined as the difference in cotton weight (expressed as ml) per 17 hr divided by foliage mass. Ca uptake was defined as mg of Ca per total volume of sieve sap after 17 hr divided by foliage mass. Ca determinations were made using an atomic absorption spectrophotometer. A positive correlation between flow rate and total Ca uptake of sieve sap (R 2 = 0.90), flow rate and pod Ca concentration (R 2 = 0.47), and Ca uptake and pod Ca concentration (R 2 = 0.42) were found. Hystyle reflected 1.5 times more flow rate and pod Ca concentration than Labrador. Significant differences between genotypes for pod Ca concentration, Ca uptake, and flow rate were observed. Results were consistent across developmental stages.

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Juan M. Quintana, Helen C. Harrison, James Nienhuis and Jiwan P. Palta

We have previously observed significant variation for pod Ca concentration among snap bean genotypes. In the present experiment, we compare pod Ca concentration between snap bean and dry bean genotypes. Eight snap bean cultivars and eight dry bean cultivars were chosen to be evaluated for pod Ca concentration in summers of 1995 and 1996 at Hancock, Wis. The experimental design consisted in randomized complete blocks with three replications in 1995 and six in 1996. Snap and dry beans were planted in June and hand-harvested in August for both experiments. Soil analysis showed 430 ppm of Ca in soil at time of planting. No additional Ca was applied. Plots consisted of 10 plants each. Harvesting was made by collecting a pooled sample of medium size pods from the 10 plants. Ca determinations were made using an atomic absorption spectrophotometer. Data was presented as mg of Ca per gram of dry weight, pooled from both years, and analyzed using SAS. Results reflected significant differences between genotypes. Checkmate (5.5) showed the highest pod calcium concentrations and Labrador (3.9) the lowest among snap beans. G0122 (5.1) resulted in the highest and Porrillo (3.6) the lowest within dry beans Results were consistent across years. Snap beans (4.6) presented significantly higher pod calcium concentration than dry beans (4.2). Apparently, snap bean genotypes have the ability to absorb calcium from the soil more efficiently than dry bean genotypes, and this phenomenon is not significantly influenced by environmental factors.