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Horticulture Facilities- Research Projects

[Ecology of Roots | Organic | Plant Nutrition | Potato | Small Fruit | Tomato Genetics &Breeding | Tree Fruit | Vegetable Crops ]  
 
Faculty Member: Ricky M. Bates

Canaan Fir Improvement Surveys indicate that needle loss or “messiness” is a major reason why consumers choose artificial over real Christmas trees.  We need to strengthen our efforts to improve several Christmas tree traits, especially needle retention.  The objective of this research project is to locate and develop sources of Canaan fir with superior postharvest characteristics. 

During October 2003, 2004 and 2005, Canaan fir branches were removed from selected trees and evaluated at the P.S.U. post harvest display room at the Russell E. Larsen Research Center, Rock Springs, PA.  Needle loss data was compared and correlated each year of the 3-yr. test period to verify individual tree performance.  Of the fifty-five trees tested, eight received an excellent needle retention rating.  These eight trees were grafted during spring of 2005 and 2006 (Figure 1).  After the grafts successfully healed, the trees were transplanted into larger containers and moved into the P.S.U. Pot-in-Pot nursery (Figure 2).  This production system optimizes the root growth environment resulting in a large plant in a relatively short period of time.  After the 2006 season in the Pot-in-Pot nursery the first group of grafted trees were large enough to move to the seed orchard.  In 2005 a four acre site was secured at the P.S.U. Horticulture Farm at Rock Springs, PA for the establishment of the Canaan fir seed orchard.  The site was cleared and prepared for planting during 2005-2006.  The first grafted Canaan fir trees were planted in October, 2006 (Figure3). 
pot in pot
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Faculty Member: Mike Orzolek
I have two focused areas of applied field research; 1)environmental modification for the production of horticultural crops and 2) evaluation of specialty crops and germplasm improvement.  I have conducted field studies and high tunnel research for the last 20 years.  Penn State has the largest High Tunnel Research Facility in North America.  This facility enables us to evaluate high tunnel structures and their components including plastic covers for efficacy and durability.  I also conduct annual field studies with biodegradable plastic mulches, colored mulches and row covers.  In many cases, the plastic technology is integrated into our high tunnel production programs to increase soil temperatures, air temperatures, increased available soil moisture and photosynthetic active radiation (PAR) within the high tunnel environment.   Hand in hand with the high tunnel program is my specialty crop evaluation program.   The goal of this program is to find out what new crops may be profitably grown and marketed by Pennsylvania growers.   Through selection and new grafting techniques,characteristics of specific crop germplasm may be improved to increase the marketable yield, quality and economic return to high tunnel growers in PA and the east coast.  Currently, I will be evaluating papaya germplasm for potential production in high tunnels and the adaptation of Goji plants for high tunnel production in northern climates. [top]
 
Faculty Member: Dr. Bill Lamont
Specialty Potato Evaluation
We have been evaluating specialty potato varieties that are simply potatoes that are distinctive from the standard or mainline potato varieties commonly found in the marketplace.  They may have an unique skin color such as deep blue, purple or apricot or the inside flesh color may be white, blue, shades of red or varying degrees of yellow.  A yellow-fleshed potato such as Yukon Gold, which in the United States is considered a specialty potato, is the standard fare in Europe.  Specialty potatoes can also be a red potato that is unique because of its size such as, one that produces all B size potatoes (i.e. Red Pearl) that are becoming popular in the marketplace.  We are evaluating not only the yields and quality attributes but are evaluating various uses for such specialty varieties.  We have recently partnered with a potato chip company to looked at using the red, blue and yellow fleshed potatoes as potato chips, which is certainly a promising avenue of investigation. We have also used them in potato salads, boiled, mashed, baked and even as French fries. The aim of this research is to increase the opportunities for these potatoes to be grown in Pennsylvania.

Production of Potatoes Using Plasticulture
Potato growers in Pennsylvania are located within a 500-mile radius of a large portion of the consuming public in the United States and southern Canada.  This should provide a competitive advantage to Pennsylvania growers but it hasn’t, as evidenced by the continuing decline in both the number of growers and acreage in production.  This decline is not unique to Pennsylvania alone but is being felt throughout the Northeast and Mid-Atlantic region.  The decline has been do to a number of factors, some of which have nothing to do with production or lack of profitability in potatoes. 
The question is what do we need to do to be competitive in today’s marketplace.  This is a complex question because it involves not only production but also marketing.  Both will have to be addressed if we are indeed to be competitive in marketing fresh market and specialty potatoes. We are addressing the production side by incorporating some of the intensive production technology (plastic mulch, drip irrigation, fertigation, soil sanitation, high tunnels, and row covers), which are currently being used extensively in other selected vegetable crops in Pennsylvania.  By using this technology we have been able to provide for earlier production, increase marketable yields and improve quality of the product especially for the small acreage growers growing for their own markets and for the early “new potato” market in the spring.  In Pennsylvania we can have not only unpredictable growing conditions in the spring both in terms of temperatures and amount of precipitation, but during the growing season, which can cause a delay in the maturity of the potato crop.  The quality of the potatoes can be affected by too much or too little water during the growing season.  Couple this with the move toward marketing fresh market potatoes by count and size in clear poly bags and it is evident that the market is going to require high quality potatoes that are free from defects and blemishes.  We currently grow two acres of research potatoes at Rock Springs each year utilizing plasticulture. We have evaluated different colored mulches, drip irrigation watering regimes, use of row covers, and the use of fertigation.  In recent research we evaluated   an Auto-Dibbling machine for punching the holes through the plastic mulch for planting the potato seed pieces. A Master’s Degree student in the Department of Agriculture and Biological Engineering developed this machine.  It is hope that this machine will be available for growers in the near future. [top]
 
Faculty Member: Dr. Dave Eissenstat The Ecology of Root Lifespan in Temperate Trees
 August 1, 2006 - July 31, 2009. Funded by NSF IOB-Environmental and Structural Systems Cluster Despite its importance, variation in root lifespan among species and in response to changes in the environment is poorly understood.  Relatively few species have been examined and rarely have multiple species been compared in a common environment.  The work proposed will examine the root lifespan of 12 tree species that vary widely in root diameter, root tissue density and potential growth rate using state-of-the-art approaches. Variation in root lifespan will be related to plant potential growth rate, root structure (specific root length, diameter, tissue density) and root N concentration.  Do roots and leaves share parallel suites of traits commonly associated with their lifespan?  Three hypotheses are proposed that attempt to explain what controls and constrains root lifespan: the “Starchdepletion hypothesis” (SDH) of Marshall and Waring, the “Resource optimization hypothesis” (ROH) and a new hypothesis proposed here, which is referred to as the “Metabolic activity hypothesis” (MAH).  The Starch depletion hypothesis assumes that a finite amount of stored carbohydrates (starch) is deposited at root formation and that the rate the carbohydrates are depleted by root respiration determines the lifespan of the root.  The Resource optimization hypothesis assumes that root lifespan is optimized to provide the greatest benefit in terms of water and nutrients for the least cost (usually measured in carbon) over the lifespan of the root or cluster of roots.  The Metabolic activity hypothesis suggests that root lifespan is mainly governed by metabolic rate; roots with higher respiratory activity live shorter lives than those with lower respiratory activity.  This study will have several broader impacts.  A better understanding of root lifespan will be valuable to those attempting to model ecosystem carbon cycles because of the important link root turnover has in this process.  Many of the trees proposed to be examined in this study are forest dominants in much of eastern hardwood forests.  Better understanding of their root lifespan will be useful to forest managers as well as investigators of climate change. This study will provide strong support for the training of graduate and undergraduate students in research. [top]

Faculty Member: Dr. David Eissenstat Graduate Student: Luis Valenzuela, PhD Candidate
Root and leaf responses to different levels of reproduction in Vaccinium corymbosum. Collaborators: Kathy Demchak, Elsa Sanchez
Luis has been supported by Consejo Nacional de Ciencia y Tecnologia (CONCYT) fellowship and the National Science Foundation. Optimizing carbon (C) allocation is key to maximizing fruit production without diminishing long-term plant vigor. Fruit production constitutes a large C sink, which competes with the production, maintenance, and storage pools of shoots and roots. The level that a crop affects root and shoot processes depends on the photosynthetic capacity of the plant. Thus, a whole-plant C budgeting approach is necessary to fully understand the effects of crop load on plant vigor. Fine root carbon costs are the least understood, but can have high construction and maintenance costs. Roots that turnover more quickly have higher production costs. Similarly, leaf costs are governed by the number of leaves produced, how frequently they need to be replaced to maintain a given canopy size, and the costs (dark respiration) required for their maintenance. In addition, leaf C assimilation may increase somewhat with increases in crop.  Therefore, I will determine how blueberry root and leaf production, turnover and maintenance as well as whole-canopy C assimilation, are affected by different levels of reproduction. Blueberry plants may be particularly unique in this regard. Blueberries and other members of the Ericales are very distinct from other plant orders because of the unique root architecture. Blueberry roots are extremely fine, extensively branched, lack root hairs and are colonized by ericoid mycorrhizal fungi.  This may cause the carbon costs of blueberry roots to differ markedly from other plants.

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Faculty Member: Dr. Jonathan Lynch
Graduate Student: Eric Nord, PhD candidate in Ecology
Crop breeding over the last half century has focused on improving plant responses to fertilizer and reducing the length of the crop cycle, but some crop breeders are now beginning to address the demands of low-input systems, which are common in subsistence farming in developing nations.  One common response of plants encountering low phosphorus (P) availability is delays in flowering and maturity. In this project we are investigating the utility of this response. Specifically, we would like to know if crop varieties with longer cycles are better adapted to low Penvironments.  We have been growing varieties of soybean and common bean which vary in their time to maturity under both sufficient and deficient P conditions, to see whether the later maturing plants have any advantages for deficient P conditions.  Preliminary analysis of data from common bean supports this hypothesis. The photo shows plantings of 4 genotypes of soybean, in varying stages of maturity. These were all planted at the same time, but mature at different times.

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Faculty Member: Jonathan Lynch
We have several projects at Rock Springs oriented to developing crops andcropping systems with reduced fertilizer requirements. Over several years we have created differences in phosphorus fertility in replicated plots in a formerly fallow field just outside the farm (Field 300). Using these plots we conduct studies to discover crop germplasm with better adaptation to low fertility soil. In the image below several such studies are shown. In one study, the effect of crop phenology (ie time to flowering and maturity) on growth under low P conditions is being studied in bean and soybean. In another, we are studying the effect of root architecture in differing bean genotypes on growth and yield in bean/maize intercrops. [top]
 
Faculty Member: Dr. Rob Crassweller
Tree Fruit Research

Rootstock Evaluation Trials are being conducted as part of the international NC-140 Research project. The purpose of these trials is to evaluate new dwarfing rootstocks that are more efficient and productive for their performance in Pennsylvania. Penn State has been a founding member and a leader in the national apple cultivar trials that started with the NE-183 regional research project. Currently we have over 60 different cultivars under testing. Some are advanced selections from breeding programs, some are chance sports from commercial orchards and some are new cultivars from European countries. Many have resistance to one or more common orchard diseases.

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Tree Training and Production Systems.
We have been evaluating different tree training systems for the past 10 years for both fresh market and processing apple cultivars. The processing cultivar plantings are located in grower orchards in Adams County and the fresh market system plantings are located at Rock Springs. The cultivars at Rock Springs are Ginger Gold, Gala and Fuji. Training systems utilized are Vertical Axe, Slender Spindle, V-Axe, and Penn State 4-Wire Low Trellis. Besides yield and fruit size data is also collected on labor inputs by timing different operations performed in the orchard. In the spring of 2008 we will be establishing a new training system planting to build on what we have learned from the previous years.

Rootstock-Dependent Gene Expression in Apple Tree Systems.
This is a large cooperative project that is looking at how rootstocks modify the genetic expression of the scion. Previous work had shown that rootstock can modify the susceptibility of the scion to certain pathogens. From this initial work several gene sequences have been identified that seem to be preferentially amplified by the rootstock. A replicated planting is located and maintained at the Horticulture farm where the physical parameters of growth are measured and tissue samples are periodically collected to map the differential expression of genes. The scion cultivar is ‘Crimson Gala’ and the rootstocks are Budagovsky 9, M.9Fleuren 56, Geneva 30, M.7EMLA, MM.111EMLA, Supporter 4, M.27, and M.27/MM.111.
The orchards at Rock Springs serve as the teaching laboratory for Horticulture 432, Deciduous Tree Fruit Production. Older larger apple trees are utilized to teach the basic pruning principles and as the students master new and better techniques they move to more current modern systems such as trellis and vertical axes to hone their skill. A small peach planting is utilized to let students to practice learning how to prune peaches and to see different pruning/training techniques being used by the industry. [top]

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Faculty Member: Dr. Majid Foolad
Tomato Genetics and Breeding Research in the Horticulture Farm In 2006, tomato genetics and breeding research was conducted in approximately 12 acres of land at Rock Springs, PA. This research included projects related to fresh market and processing tomato breeding as well as basic genetic research. The overall goal of the Penn State Tomato Genetics and Research Program is to develop tomato cultivars with strong disease resistance (in particular early blight and late blight), improved fruit quality (in particular high lycopene content), and adaptation to PA conditions (e.g. high yield). Additional goals include characterization of genetic basis of several agriculturally important traits in tomato. Specifically, we are identifying and mapping new genes and/or QTLs controlling early blight and late blight resistance as well as those contributing to high fruit lycopene content in tomato. The information is used in our breeding program to develop breeding lines and cultivars of tomato with improved characteristics. For example, we have already developed inbred lines of cherry, grape and plum tomatoes, which are currently being used in crosses to develop experimental hybrids. The hybrids will be tested for commercial use. Large-fruited fresh market as well as processing tomatoes with improved disease resistance and high fruit lycopene content are also in the pipeline. [top]
 
Faculty Member: Kathy Demchak Small Fruit Research Small Fruits in High Tunnels 2006 Cooperators: Dr. Fumi Takeda (USDA-ARS, Kearneysville,WV), Bill Lamont and Mike Orzolek (PSU Dept. of Horticulture)     Research on small fruit crops in high tunnels was continued in 2006 at the Horticulture Research Farm at Rock Springs, PA.  Most of the work this year was on strawberries.
  Strawberry plants were planted in the fall of 2005 in a raised-bed plasticulture system within a 14’ x 96’ tunnel, and were harvested in the spring and early summer of 2006. Cultivars tested were the spring-bearers ‘Chandler’, ‘Ventana’, ‘Araza’ and ‘Carmine’, and day-neutrals ‘Seascape’, NCL 03-05 and NCL 03-08. 
  ‘Chandler’ was the best performer among June-bearers, producing about 0.8 lb per plant.  This was a relatively low yield for ‘Chandler’ on this site, but the plants at first suffered from high soluble salt levels at about 3.9 mmhos/cm. Salts were eventually flushed from the soil in the raised beds. ‘Ventana’ produced about half as much yield as ‘Chandler’, though berries were slightly larger.  ‘Ventana’s harvest season ran about 5 days earlier than for ‘Chandler’.  ‘Araza’ and ‘Carmine’ had very low yields at 1/3 pound per plant or less, and both also produced smaller berries than either ‘Chandler’ or ‘Ventana’. The day-neutrals were harvested only for the spring crop.  All performed very well. The day-neutral selections NCL 03-05 and NCL 03-08 (Fig. 1) from North Carolina State University both produced nearly 1.5 pounds of fruit per plant, and produced about a month longer into the summer than the June-bearing cultivars did before hot temperatures caused them to stop fruiting. Yield of ‘Seascape’ was lower at 0.8 lb/plant.  Fruit size, color, and flavor were excellent for all three of these day-neutrals. ‘Autumn Britten’ and ‘Heritage’ red raspberries, and ‘Triple Crown’ blackberries planted in 2000 continued to produce fruit, though yield data was not collected in 2006.

Day-Neutral Strawberry Production Practices
Coperators: W. Lantz and H.J. Swartz (University of Maryland) This project is part of a project funded by NE SARE, and is being done together with Willie Lantz and Harry Swartz from the University of Maryland.   During the first year of this project, the cultivar Seascape is being grown on a reflective plastic mulch (Fig. 2). Fertilization practices are being evaluated through the use of three levels of compost as a source of nitrogen (0, 400, and 800 lbs/acre of total nitrogen, assumed to supply 0, 40, and 80 lbs/acre of nitrogen in year 1), and three levels of nitrogen applied weekly through trickle irrigation (0, 1, or 2 lb/acre/week of nitrogen).  Identical experiments were carried out both at the Horticulture Research Farm at Rock Springs, PA, and at Garrett College in western Maryland.   Year 1 environmental data at Rock Springs showed that soil temperatures at a 4” depth were typically 8-10 degrees cooler under reflective mulch relative to black mulch, and that reflected light levels from the mulch (at planting) were at about 50% in addition to that received from the sky.   First year yield data from Rock Springs showed no significant difference in marketable, unmarketable, or total yields, or percentage marketable fruit or mean berry weight among treatments.   Total yields overall were relatively high, ranging from 12,300 lb/a for the 0 compost 0 N treatment to 16,200 lb/a for the high compost rate with no nitrogen fertigated.  Mean berry weight ranged from 11.0 g/berry to 12.0 g/berry.  Percentage marketable fruit ranged from 58.5% to 60.1%.

Evaluation of New Blackberry Cultivars for PA
Cooperators: Timothy Elkner (PSU Coop. Ext., Lancaster Co.) and David Johnson (Southeast Agricultural Research and ExtensionCenter, Landisville)
A study comparing blackberry cultivars was established at Southeast Agricultural Research and ExtensionCenter at Landisville (Lancaster Co.) in 2005. Cultivars being tested are thorny floricane-bearers ‘Chickasaw’, ‘Fort Kent King’, ‘Illini Hardy’, ‘Kiowa’, and ‘Shawnee’; thornless floricane-bearers ‘Apache’, ‘Cacanska’, ‘Doyle’s Thornless’, ‘Navaho’, ‘Ouachita’, and ‘Triple Crown’; and primocane-bearers ‘Prime-Jim’ and ‘Prime-Jan’.  Primocane-bearers are a new development in blackberry cultivars from the University of Arkansas breeding program.  These plants can be pruned by mowing them to the ground late in the winter, after which they produce new canes and a fall crop.
All cultivars established very well except for the cultivar Chickasaw.  In 2006, the first bearing year for this study, a light crop was harvested.  Many of the cultivars, with the exception of ‘Fort Kent King’, appear to have potential, though results are still preliminary.  ‘Fort Kent King’ was vigorous, but fruit qualities (size and flavor) were substandard. [top]

 
Faculty Member: Dr. Jim Sellmer
Understanding the Impact of pH on Landscape Plant Growth Investigators: Jim Sellmer, Tracey Harpster, and Larry Kuhns This long-term study initiated in 1999 was designed to address the question “How does pH impact plant growth of pH sensitive woody ornamentals?” Several pH sensitive plants including Tsuga canadensis (Eastern hemlock), Picea pungens (Colorado spruce), Abies fraseri (Fraser fir), Pseudotsuga menziessi (Douglas fir), Nyssa sylvatica (Black gum), Liquidambar styraciflua (Sweet gum), Acer rubrum (red maple), and  Quercus palustris (Pin Oak) along with several indicator plants were planted in three replicate pH plots of 5.5, 6.5 and greater than 7.0. In order to determine the impact of pH on growth overall growth measurements have been collected along with quality ratings on an annual basis. This project will be destructively harvested in 2009 after 10 years in the field with root development and overall growth, fresh weight and dry weight measurements being recorded.

 
Hemlock Evaluation Project   Investigators: Rick Bates, Greg Hoover, Benjamin Hoover, and Jim Sellmer Established in 2003 this plant adaptability evaluation project has grown into a pest challenge and plant/pest interaction project. Recognizing the importance of Tsuga canadensis (Eastern Hemlock) to the nursery and landscape industry of Pennsylvania and the eastern U.S. and the significant challenge this species of hemlock is facing from attack by several pests including hemlock woolly adelgid (HWA) and elongate hemlock scale (EHS).  The objectives of this project were established to: 1) evaluate the insect susceptibility of western US and Asian hemlocks for these and other common hemlock pests with interest in finding resistant or tolerant hemlock germplasm; 2) develop a method for screening and characterizing infestation responses of the species to HWA and EHS; and 3) evaluate non-native hemlocks for introduction into the Pennsylvania landscape. This project was designed as a university-grower cooperative project and include sites across the state of Pennsylvania along with the site here at the research center. The species under evaluation include: Tsuga canadensis (Canada hemlock), T. caroliniana (Carolina), T. chinensis (Chinese), T. diversifolia (North Japanese), T. heterophylla (Western American), T. mertensiana (Mountain, Black), T. sieboldii (Southern Japanese), and T. yunnanensis.
Evaluation of the Invasive Potential of Norway Maple Cultivars Investigators: Jim Sellmer and Janine Conklin In 2003, research was initiated to characterize the invasive potential of Norway maple (Acer platanoides) cultivars and the species. The Russell Larson Center is being used as an exterior germination testing site. Seeds are collected from the test cultivars and are planted in a shaded woodlot on the center to determine the germination potential under understory conditions in a woodlot.
Evaluation of the Establishment and Rooting Characteristics of Landscape Trees Grown for Extended Time in Pot-in-Pot Container Production Systems Investigators: Jim Sellmer, Dave Despot, Jim Savage, and Tracey Harpster
This research and education project established in 2006 was initiated to explore the growth dynamics and structural development of pot bound landscape trees after planting in the landscape. Pot bound trees from the Penn State Horticulture Department Pot-in-Pot (PIP) System at the Landscape Management Research Center were planted with and without remediation of the circling root system which developed from too long within the same 20 gallon container. These trees will be allowed to establish in the landscape and selected trees will be excavated using an air spade to evaluate root development, structure, and overall growth after various lengths of time in the ground: 2, 4, 8, 16 years. The information from this project will be used to educate the industry and undergraduate students within the department on the effect of overextended container production and plant survival and establishment.

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Recently concluded research activities at the center include:
Developing Nutrient Management Guidelines for Container Grown Woody Ornamentals Investigators: Mary Conklin, Montogomery Co. Extension, Christina Mullen, and Jim Sellmer
 This research was designed to define the sensitivity of foliar analysis over a range of fertilizer rates and to develop a method for producing guidelines for fertilization of container grown woody ornamentals using foliar nutrient analysis. The above system was initiated to developed to determine the feasibility of create a series of standards for fertilizer recommendations for the nursery industry. The intent being that such standards would assure proper fertilization while reducing over-fertilization and loss of valuable nutrients to the environment. Experiments were conducted to compare the growth rate and foliar nutrient levels among plants treated at 0, ½, 1,  2 and 3 times the standard rate of a 17-6-10 fertilizer applied as a single application and two split applications over the growth cycle. In addition, this work was designed to determine the rate and level of nutrient loss from fertilized pots under standard irrigation conditions.
 
Evaluating the Soil Building and Growth Benefits of Composted Organic Products on Field Grown Nursery Stock   Investigators: Jim Sellmer and Tracey Harpster
     High quality soils are essential for the production and marketing of high quality field grown nursery stock.  Field production results in the loss of topsoil and the depletion of organic matter in the soil.  To maintain high quality soils, organic matter must be built up sometime during the production cycle.  Traditionally, nursery fields are allowed to lie fallow every three to seven years.  During this time, cover or green manure crops are grown and tilled under to rebuild the organic matter content of the soil. Removing acreage from production is financially costly.  Continuous cropping of a field is costly to the soils leading to long-term loss of organic matter and depletion of soil quality.  One method for managing soil organic matter without removing fields from production is the application of compost.  However, only limited research has been conducted comparing the benefits of readily available urban and agricultural compost products in the growth of field grown liner stock.  This project was initiated to: 1) Compare the physical and chemical properties of the composted products (i.e., manure, yard waste, biosolids, and spend mushroom substrate); 2) Evaluate the long-term affect of single applications of compost to water retention and the soil pH, fertility, and bulk density; 3) Compare the growth (size, nutrient content, water stress levels, and general quality) of the deciduous and evergreen landscape plants on soils amended with the various composts and 4) Evaluate the cost effectiveness of compost additions to nursery soils Finally, the hoop house facilities at the Russell Larson Agricultural Research Center, Horticulture Farm are annually used for the production of seedlings, culture and maintenance of nursery stock for other research projects, and as an over-wintering facility for nursery stock.  [top]
 
Faculty Member: Elsa Sanchez Composts for Organic Bell Pepper Production
Elsa Sanchez & Emily Cook, M.S. graduate student (this project is being funded by The Pennsylvania Vegetable Research and Marketing Board)

Organic growers in Pennsylvania have expressed the need for better information for managing nutrients with compost. The objective of this experiment was to evaluate three composts applied at various rates on a field crop of green bell peppers. The study was conducted at the Russell E. Larson Research and Education Center, Rock Springs, PA in 2006. Treatments were: 1) Dairy manure/food scrap compost (DMC) and 2) mushroom compost, each applied to meet 100% of crop N needs assuming 20% mineralization, 3) DMC applied to meet 100% of crop P needs assuming 10% nutrient availability, 4) DMC applied at a commonly used rate of 20 tons/acre, 5) leaf compost applied to meet 100% of crop N needs assuming 10% mineralization, and 6) an unamended control. Data collected included compost analysis, yield, pre and post- season soil chemical properties and plant nutrient levels. Compost composition varied greatly in nitrate, ammonium, calcium and salt levels. Yields were typical for bell peppers regardless of treatment. However, only plots amended with mushroom compost had higher yields than control plots or plots amended with DMC applied to meet N needs. Soil chemical properties changed as a result of compost application. Notably, salinity levels increased 30%, to slightly toxic levels for bell peppers, when plots were amended with mushroom compost. Based on leaf tissue analysis at early fruiting, nitrogen levels were in ranges considered adequate regardless of treatment. Compost composition underscored the importance of analysis. This trial suggests that less compost than the commonly used 20 tons/acre is needed. This trial will be repeated in 2007.
 

Evaluation of Alternative Chemicals and a Cultural Strategy for Managing Gray Mold on Raspberries
Elsa Sanchez, Kathy Demchak, and Graham Sanders, M.S. graduate student (this project is funded by NE-SARE LNE05-227, IR-4, State Hort. Assoc. of PA and North American Bramble Growers Assoc.)
Gray mold, caused by Botrytis cinerea, is an important disease impeding raspberry production. In 2005 and 2006, seven treatments for managing gray mold on ‘Prelude’ and ‘Nova’ red raspberries were evaluated at the Russell E. Larson Research and Education Center, Rock Springs, PA. Treatments were: 1) Water spray (control 1), 468 l/ha; 2) Captan 50WP, 4.5 kg/ha and Elevate 50WDG, 1.7 kg/ha in rotation (control 2); 3) Milstop, 4.2 kg/ha; 4) Endorse, 2 kg/ha; 5) Lime Sulfur Solution, 1% spray solution volume; 6) Phostrol, 4.4 l/ha; 7) Milstop, 4.2 kg/ha + Oxidate, 1% spray solution volume; 8) Oxidate, 1% spray solution volume + Vigor-Cal-Phos, 9.4 l/ha; and 9) Cane thinning to four to five canes/lin. 0.3 m in August 2005. Phytotoxicity ratings, yields and postharvest disease incidence were recorded. ‘Nova’ was more susceptible to phytotoxicity than ‘Prelude’ in both years. Using Phostrol resulted in higher phytotoxicity ratings than all other treatments. Marketable and unmarketable yields were not affected by the treatments in both years. In 2005, berry size was not affected by treatments; however in 2006, the use of control 2 resulted in larger berries than all other treatments. In 2005 ‘Prelude’ and ‘Nova’ yielded similarly. However, in 2006, yields were higher and berries larger from ‘Nova’ than ‘Prelude’. For berries harvested on 17 July 2006 disease incidence was similar one and three days after harvest. Two days after harvest, while some significant differences were calculated, none of the gray mold treatments resulted in disease incidence different than control 1 for ‘Prelude’ berries. ‘Nova’ berries had higher disease incidence when treated with Oxidate + Milstop. All other treatments resulted in similar disease incidence to the water control.
Weed Suppression with Mulches for High Tunnel Organic Cucumbers Elsa Sanchez, Bill Lamont and Mike Orzolek (this project is funded by departmental funds)
Weeds are frequently cited as the top pest problem by organic growers. Three mulches useable in organic production were evaluated for their ability to suppress weeds in a high tunnel cucumber crop. This study was conducted in 2005 and 2006 at the Russell E. Larson Research and Education Center, Rock Springs, PA in four high tunnels under organic management. A split-plot design was used with mulches (wheat straw, shredded newspaper, sheets of newspaper and no a mulch-control which was hand weeded once during the growing season) applied to whole plots. Subplots consisted of four cucumber cultivars (‘Sweet Marketmore’, ‘Lemon’, ‘Diva’ and ‘Prolific’). Yields, mulch degradation and weed populations were recorded. In both years marketable yields were highest and fruit largest from ‘Sweet Marketmore’ and lowest from ‘Lemon’ plants. In 2005, the number of cucumbers did not differ by cultivar. In 2006, the most cucumbers were harvested from ‘Sweet Marketmore’ and the least from ‘Diva’ plants. All yield parameters were not affected by mulch treatments. Cultivar grown did not effect weed populations in either year. Weed populations were highest in control plots and lowest when shredded newspaper was used. By the end of the growing season in each year, sheets of newspaper degraded the most followed by shredded newspaper and straw. While the shredded newspaper was the most effective for suppressing weeds, yields were not influenced by any mulch treatment indicating weed populations were below thresholds regardless of mulch treatment.

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