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Butternut, acorn, and buttercup/kabocha winter squash (Cucurbita sp.) cultivars were evaluated in a conventional system in central, southeastern, and southwestern Pennsylvania in 2010–11. Results from individual locations were used to create statewide recommendations, which are also relevant for the mid-Atlantic U.S. region. Additionally, butternut and acorn cultivars were evaluated in an organic system in central Pennsylvania. In a conventional system, butternut cultivars JWS6823, Betternut 401, Quantum, and Metro are recommended based on equal or higher marketable yield than the standard Waltham Butternut. Acorn squash cultivars that performed equally to or better than the standard, Tay Belle, were Table Star, Harlequin, and Autumn Delight. In the kabocha/buttercup category, ‘Sweet Mama’ and ‘Red Kuri’ had marketable yields not different from the standard ‘Sunshine’ in central and southeastern Pennsylvania. In the organic system, butternut cultivars JWS6823, Betternut 401, and Metro all had marketable yields not different from the standard Waltham Butternut. For acorn cultivars, Celebration yield did not differ from the standard Table Queen.

Sixteen cultivars of green bell peppers (Capsicum annuum) were evaluated on the basis of yield in three locations across Pennsylvania during the growing seasons of 2008–09. Cultivars were evaluated in comparison with the cultivar Paladin. In central Pennsylvania, all the cultivars trialed had marketable yields (based on weight) not different than ‘Paladin’ except ‘Lynx’, ‘Socrates’, and ‘Escape’. In terms of fruit number, all cultivars were not different than ‘Paladin’ except ‘Socrates’. For large-sized fruit, all the cultivars trialed are recommended. In southeastern Pennsylvania, all the cultivars trialed except SP-05–47 had marketable yields not different than ‘Paladin’. For large-sized fruit, ‘Revolution’ outperformed all other cultivars, including ‘Paladin’. In southwestern Pennsylvania, all the cultivars trialed except Lynx and SP-05–47 produced comparable marketable yields to ‘Paladin’. None of the cultivars evaluated, including Paladin, consistently outperformed Revolution in terms of large fruit. Statewide, all the cultivars, except Lynx and SP-05–47, are recommended on the basis of marketable yields. For growers looking for large-sized fruit to meet market demand the cultivar Revolution is recommended over ‘Paladin’.

High tunnels are becoming an increasingly important production tool for vegetable, small fruit, and cut flower growers in many parts of the United States. They provide a protected environment relative to the open field, allowing for earlier or later production of many crops, and they typically improve yield and quality as well as disease and pest management. Producers, ranging from small-scale market gardens to larger scale farms, are using high tunnels of various forms to produce for early markets, schedule production through extended seasons, grow specialty crops that require some environmental modification, and capture premium prices. The rapid ongoing adoption of high tunnels has resulted in numerous grower innovations and increased university research and extension programming to serve grower needs. An informal survey of extension specialists was conducted in 2007 to estimate numbers (area) of high tunnels and crops being grown in them by state, and to identify current research and extension efforts. Results of this survey provide an indication of the increasing importance of these structures for horticultural crop production across the country.

Mulches usable in organic production were evaluated in high tunnels for their ability to suppress weeds. Mulch treatments were shredded newspaper, sheets of newspaper, straw, and a no-mulch control that was weeded once. Four cucumber (Cucumis sativus) cultivars were also evaluated. Yields were highest and fruit largest from ‘Sweet Marketmore’ and lowest from ‘Lemon’. Yields were unaffected by mulch treatments. Weed populations were highest in control plots and lowest in those with shredded newspaper. Cultivars did not affect weed populations. Sheets of newspaper degraded the most, followed by shredded newspaper and straw. Yields were not influenced by any mulch treatment, indicating weed populations remained below yield-depressing levels regardless of treatment.

The utility of alumina-buffered phosphorus (Al-P) fertilizers for supplying phosphorus (P) to bell pepper (Capsicum annuum L.) in soils with low-P availability was evaluated. Plants were grown at low-P fertility (about 100 kg·ha–1, low-P control; LPC), with conventional P fertilization (205-300 kg·ha–1 annually, fertilizer control; FC), or with one of two Al-P sources (Martenswerke or Alcoa) in 2001–03. The two Al-P fertilizers were applied in 2001; no additional material was applied in 2002-03. Plants grown with Martenswerke Al-P had similar shoot dry weight, root dry weight, root length, leaf P concentration, and fruit yield compared with plants grown with conventional P fertilizer in both 2002 and 2003 seasons. Bell pepper grown with Alcoa Al-P had similar shoot dry weight, root dry weight, root length, leaf P concentration, and fruit yield compared with plants grown without P fertilizer in both seasons. Alcoa Al-P continuously released bioavailable P for 2 years between 2001 and 2002, while Martenswerke Al-P continuously released bioavailable P at least 3 years between 2001 and 2003. These results indicate that some formulations of Al-P can serve as long-term P sources for field vegetable production.

At the Pennsylvania State University (Penn State) High Tunnel Research and Education Facility, a system of production of high-value horticultural crops in high tunnels has been developed that uses plastic mulch and drip irrigation. The Penn State system involves small-scale, plastic-application equipment that prepares and applies plastic mulch and drip-irrigation tape to individual raised beds. It differs from the production system developed by researchers at the University of New Hampshire in which drip-irrigation tape is manually applied to the soil surface and then the entire soil surface in the high tunnel is covered with a black plastic sheet. An overview of the production system used in the Penn State high tunnels is presented in this report.

Butternut squash (Cucurbita moschata) plants are susceptible to defoliation and plant population (stand) reduction by insect, disease, temperature extremes, water, hail, or other mechanical damage. The timing of such losses may have variable effects on final fruit quality and yield. The objectives of these studies were 1) to determine the influence of the degree and timing of defoliation and stand reduction on the marketable yield of winter squash; 2) to determine yield compensation after stand reduction and defoliation; and 3) to explore effects of defoliation on fruit total carotenoid content. Experiments were conducted over 2 years in New York and Pennsylvania to explore these objectives. Marketable yields consistently improved with increasing plant population. If population losses occurred while plants were in the rapid vegetative growth phase, the remaining plants responded by increasing fruit number and weight per plant. Plant losses later in the season during fruit enlargement, however, did not elicit the same magnitude of response. Defoliation of 66% leaf area reduced marketable yields, and effects were most severe under high plant populations. Competition among plants restricted compensation. Moderate defoliation (33%) reduced yield in only one of three studies. This level of defoliation also increased the percentage of medium [1.0 to 1.5 kg (2.20 to 3.31 lb)] and large [1.5 to 2.0 kg (4.41 lb)] fruit and decreased the number of jumbo fruit (>2.0 kg). Total carotenoid concentration in mature fruit was unaffected by the defoliation or population treatments. Thus, butternut squash compensated for up to 33% leaf area loss at any time during the season. While the crop could compensate, under some conditions, for up to 50% plant losses, final plant population was more important than the growth stage of damage or defoliation for effects on crop yield.

Twenty-two ornamen tal corn (Zea mays) cultivars were evaluated in the summer of 1998. The cultivars were evaluated for marketable yield, percent cull, stalk characteristics, and ear characteristics. In addition, three ears of each cultivar were photographed to show size and variability in kernel color. The marketable yield of each cultivar was generally related to percent germination, established plant population, and ear size. Highest marketable yields (dozen/acre) were generally harvested from small-eared cultivars [ear size 2.0 to 4.5 inches (5.1 to 11.4 cm)]. Data from this trial suggest that multiple cultivars should be grown in Pennsylvania based on market requirements and extremes in weather patterns throughout the state.

The Center for Plasticulture's High Tunnel Research and Education Facility was established at Pennsylvania State University in 1999. Since its inception, applied research has been conducted at this facility by a team of researchers and extension specialists on the development of a new high tunnel design. The development of crop production recommendations for vegetables, small fruits, tree fruits and cut flowers grown in high tunnels has been a priority. To complement the applied research program, an aggressive extension education program was developed to extend information on the technology of high tunnels to county extension personnel, growers, industry representatives, students, master gardeners and the general public. The extension programming effort consisting of demonstration high tunnels, field days, tours, in-service training, publications and presentations made at winter meetings will be discussed in the report below.

Plasticulture technology, especially high tunnels for extending the production period of a wide variety of horticultural crops, is an accepted production practice worldwide. In particular, high tunnels offer a production system that minimizes the effect of the environment on crop production and allows growers to continue to farm in densely populated areas. Only recently has the use of high tunnels in the U.S. been investigated and this research has been centered in the northeastern U.S. In 1999 the High Tunnel Research and Education Facility was established at Pennsylvania State University that resulted in the development of a unique high tunnel design. A detailed description of the new design and construction is presented in this report.

An experiment examining the effect of burcucumber emergence date and corn competition on burcucumber fecundity was conducted in 1997 and 1998 in central Pennsylvania. Burcucumber seedlings were transplanted in the field in approximately 10-d intervals starting in late May through mid-August with or without competition from corn. Burcucumber plants grown without competition from corn produced 716 g dry matter and 4,500 seeds plant−1 in 1997 and 607 g dry matter and 1,800 seeds plant−1 in 1998. Biomass was greatest for plants established in late May, whereas seed production was greatest for plants established in mid-June. Although seed numbers were reduced in comparison to the May and June establishment periods, plants established as late as August still produced seed. Burcucumber established in corn produced 96% less dry matter and seed than the plants in a noncompetitive environment in both years of the study. Although the growth and seed production of burcucumber grown in corn was drastically re...

Experiments examining burcucumber management in glufosinate-resistant (GR) and imidazolinone-resistant (IMI) corn were conducted in 1997 and 1998 in southeastern Pennsylvania. GR corn was planted in 38- and 76-cm rows, and postemergence (POST) treatments of glufosinate and glufosinate plus atrazine were applied to corn at the V4 or V5 growth stage. In a second study, IMI corn was planted in 76-cm rows, and 15 preemergence (PRE) and POST herbicide programs were evaluated. Herbicide treatments included RPA-201772, CGA 152005, simazine, imazethapyr plus imazapyr, imazamox, chlorimuron plus thifensulfuron, nicosulfuron plus rimsulfuron plus atrazine, CGA 152005 plus primisulfuron, and combinations with atrazine. Burcucumber germinated throughout the growing season, with greatest emergence occurring in early June, gradually decreasing to minimal emergence by mid-July. Glufosinate alone controlled burcucumber 79 to 90% 7 weeks after planting (WAP) regardless of application timing or row spacing. By 10...

An experiment was conducted in 1998 and 1999 in southeastern Pennsylvania to examine the effect of tillage and soybean row spacing on burcucumber emergence and growth. A second experiment evaluated postemergence (POST) soybean herbicides on burcucumber control. In the tillage and row spacing study, a glyphosate-resistant soybean variety was planted in no-till and reduced-tillage systems in 38- and 76-cm row spacings. In the POST herbicide experiment, chlorimuron, glyphosate, CGA-277476, thifensulfuron, and several combinations of these herbicides were applied at two different POST application timings in 38-cm row soybean planted in a reduced-tillage system. In the tillage and row spacing study, burcucumber emergence was greatest starting in late May through mid-June and mostly ceased by early July, regardless of tillage system or row spacing. Although there was no difference in germination period in either tillage system, preplant tillage increased the number of emerged plants by 110% in 1997 an...

Twenty-two cabbage cultivars were evaluated in the spring and 26 cabbage cultivars evaluated in the fall of 1997. The cultivars were evaluated for uniformity of maturity, marketable yield, percent cull, stem core length, and head firmness. In addition, three heads of each cultivar were tasted at harvest by the summer farm crew and responses noted on the data collection forms. The highest yielding cultivars were not necessarily the best performing ones evaluated in the trial. Average head weight was significantly different between spring and fall plantings. Data from this trial suggests that multiple cultivars should be grown in Pennsylvania based on whether it is a spring or fall cabbage crop. Cabbage, Brassica oleraceae var. capitata L., has been a very important vegetable crop in Pennsylvania for the last 50 years. Cabbage has been primarily grown for the fresh wholesale and retail market with very little being used in the preprocessing or processing market. In the last 10 years, the acreage of cabbage has dropped ≈40% in the state with most growers now growing cabbage for markets demanding very specific head size and quality. In addition, there has been a larger array of cabbage maturities developed by seed companies to fit these various market segments (Howell, 1999; Scaife et al., 1998). From previous experience, cabbage cultivars maturing in less than 105 d will consistently produce uniform, tight heads in most of Pennsylvania (Orzolek et al., 1999).

Muskmelons were grown on raised beds and imidacloprid was applied to control cumber beetles. The imidacloprid was applied as a band on bare soil, a single chemigation under plastic mulch, and as split chemigation under plastic mulch at three levels: label rate, reduced rate, and zero rate (control). Muskmelon yield increased ten-fold when imidacloprid was drip chemigated under black plastic mulch as compared to no chemigation and no plastic mulch. A four-fold yield increase resulted from plastic mulch alone while a 2.5 times yield increase resulted from imidacloprid alone. The reduced rate of imidacloprid produced the same weight of marketable melons as the label rate when a single dose of the pesticide was applied after transplanting. During a heavy rainfall period, drip chemigation of imidacloprid under plastic mulch prevented pesticide leaching through the root zone and pesticide transport via soil erosion off the beds.

and burying the seeds of large-seeded species can increase germination due to better seed-to-soil contact The effect of tillage and herbicide application timing was examined (Clements et al., 1996). In no-till systems, the majority on established populations of burcucumber (Sicyos angulatus L.) in corn (Zea mays L.). The field study consisted of three tillage regimes of weed seeds are found near the soil surface (Buhler (moldboard plow/disk, chisel plow/disk, and no-tillage) and three her- and Mester, 1991; Yenish et al., 1992). bicide treatments: atrazine (6-chloro-N-ethyl-N9-(1-methylethyl)- Field studies demonstrate that burcucumber seeds 1,3,5-triazine-2,4-diamine) plus the dimethylamine salt of dicamba; can germinate from depths of 15 cm (Mann et al., 1981). 3,6-dichloro-2-methoxybenzoic acid applied preemergence (PRE) or This suggests that vigorous tillage, such as moldboard postemergence (POST); and no atrazine plus dicamba (no broadleaf plowing, may not prevent seedling emergence. Dor- herbicide). Postemergence treatments were applied to 3- to 6-leaf mancy of burcucumber seed is common and caused pri- corn and cotyledon to 8-leaf burcucumber. In two of three field loca- marily by an impermeable seed coat (Mann et al., 1981). tions, late-season burcucumber dry weight was approximately 65% Research with velvetleaf (Abutilon theophrasti Med- less in no-tillage than in the moldboard plow treatment, while no icus), which has a similar dormancy mechanism, has difference in burcucumber dry weight was observed between chisel plow and no-tillage treatments. Regardless of tillage system, atrazine shown that germination does not readily occur on the plus dicamba applied POST was more effective than PRE applica- soil surface (Buhler and Oplinger, 1990). Under no-till tions. Corn grain yield was not affected by tillage treatment, but was conditions, burcucumber seeds could experience higher higher in both the PRE and POST treatments than in the no broadleaf mortality rates on the soil surface due to poor seed-to- herbicide treatment. Depth of burcucumber seedling emergence was soil contact, germination and subsequent desiccation, examined in the greenhouse. Pre-germinated burcucumber seeds were predators, and parasites (Fround-Williams et al., 1981; placed in the soil at 0, 1, 3, 5, 10, 15, and 20 cm deep. Percent emergence Reader, 1991; Roberts and Feast, 1972; Zorner et al., was highest in the 1 to 5 cm depth. Less burcucumber emerged from 1984). depths of 10 cm or greater or when burcucumber was placed on the Herbicides are an important component of weed man- soil surface. These data suggest that tillage and herbicide timing can agement programs. Atrazine applied PRE has been the influence burcucumber control.

A postemergence (POST) timing study was conducted on established populations of bur- cucumber (Sicyos angulatus) in corn (Zea mays), and a second study examined the residual activity of several herbicides for burcucumber control under greenhouse conditions. In the field study, flum- iclorac, halosulfuron, primisulfuron, CGA 152005, and CGA 152005 + primisulfuron (45, 71, 40, 40, and 20 + 20 g ai/ha, respectively) were applied at two POST timings. CGA 152005, primisul- furon, and the combination provided greater than 85% control of burcucumber 14 wk after planting (WAP). Flumiclorac and halosulfuron provided 60% control or less by 8 WAP. Timing of the POST applications did not influence burcucumber control by 11 WAP with any herbicide. In the greenhouse, germinated burcucumber seeds were placed in soil treated with atrazine, chlorimuron, primisulfuron, or CGA 152005 at normal field use rates. All treatments provided similar residual control early; however by 4 wk after treatment (WAT), control from atrazine was less than 10% compared to 69% for chlorimuron and about 50% for primisulfuron and CGA 152005. This research suggests that CGA 152005 and primisulfuron can both be effective for managing burcucumber in corn, whereas flum- iclorac and halosulfuron proved ineffective. Nomenclature: Atrazine, 6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine; chlorimu- ron, ethyl 2-(((((4-chloro-6-methoxy-2-pyrimidinyl)amino)carbonyl)amino)sulfonyl)benzoate; flumi- clorac, (2-chloro-4-fluoro-5-(1,3,4,5,6,7-hexahydro-1,3-dioxo-2H-isoindol-2-yl)phenoxy)acetic acid; halosulfuron, methyl 5-(((4-,6-dimethoxy-2-pyrimidinyl)amino)carbonylaminosulfonyl)-3-chloro- 1- methyl-1-H-pyrazol-4-carboxylate; primisulfuron, methyl 2-(((((4,6-bis(difluoromethoxy)-2-pyrimi- dinyl)amino)carbonyl)amino)sulfonyl)benzoate; CGA 152005 (proposed name, prosulfuron), 1-(4- methoxy-6-methyl-triazin-2-yl)-3-(2-(3,3,3-trifluoropropyl)-phenylsulfonyl)-urea; burcucumber, Sicy- os angulatus L. #3 SYCAN; corn, Zea mays L. Additional index words: Herbicide application timing, residual control. Abbreviations: EPOST, early postemergence; POST, postemergence; PRE, preemergence; WAP, weeks after planting; WAT, weeks after treatment.

The systemic nitroguanidine insecticide imidacloprid was investigated in cantaloupes, Cucumis melo L. variety reticulatus, for management of Acalymma vittata (F.) and bacterial wilt caused by Erwinia tracheiphila (E. F. Smith) Holland that is vectored by this beetle. The influence of management strategies using imidacloprid upon plant growth and development, beetle population dynamics, and bacterial wilt disease incidence and severity was evaluated. Application of imidacloprid to seedlings at higher doses caused short-term marginal leaf necrosis, and biomass of seedlings was reduced in an approximately linear pattern with increasing dose on a log scale up to 0.01 g (AI) per plant. Application to seedlings at doses low enough to avoid any phytoxicity resulted in adult A. vittata mortality rates that declined exponentially with time. Exponential decay models of bioassay data suggested ≍11d of 100%adult mortality was achieved with low rates applied to seedlings before transplanting. Applications to seedlings delayed adult immigration, and the combination of seedling application and limited foliar sprays resulted in significant increases in yield. Addition of imidacloprid at low rates to seedlings combined with 2 foliar sprays, or application to seedlings combined with an application through drip irrigation and 2 foliar sprays, was not effective in reducing the proportion of cantaloupe plants that showed bacterial wilt symptoms but did significantly reduce severity of the disease. The results suggest that low rates of imidacloprid applied before or near the time of transplanting, at times combined with few foliar sprays, could dramatically improve crop productivity via influence upon both a herbivore and a plant pathogen vectored by the herbivore.

Exposure to chilling temperatures (0-10°C) increases ethylene synthesis in several species, but it is not clear whether this increase in ethylene synthesis is involved in the development of chilling tolerance. To determine this relationship, chilling tolerance development of the ethylene-insensitive Never-ripe (Nr) tomato (Lycopersicon esculentum Mill. cv. Pearson) mutant was compared to that of a normal isogenic line. Plants were grown for 3 weeks at 25/20°C day/night, and then half the plants of each genotype were chill-hardened at 25/5°C day/night for 10 days, while the other half remained at 25/20°C. All plants were then exposed to a severe chill (5/5°C day/night) for 7 days, and a recovery period (25/20°C day/night) of 4 days. Chill hardening increased ethylene synthesis in both genotypes, but increased the rate of leaf development and dry weight accumulation during the recovery period only for the normal plants. Hardening also caused a greater decrease in lesion development in the normal plants following the severe chill. Therefore, chill hardening was more effective in the ethylene-sensitive normal plants than in the ethylene-insensitive mutants, indicating that a response to ethylene is involved in chilling tolerance development. However, chill hardening was effective for both genotypes in maintaining chlorophyll a fluorescence levels (F v /F m ), suggesting that ethylene does not control all aspects of chilling tolerance. In a separate experiment, application of a 500 ppm ethephon solution to normal 'Pearson' plants led to higher rates of ethylene synthesis and a higher rate of leaf development following a 6 day severe chill (5/5°C day/night). These results further indicate that ethylene is involved in the development of chilling tolerance.

Zandstra, B.H. and D.D. Warncke. 1993. Interplanted barley and rye in carrots and onions. HortTechnology 3:214–218. Summary. Plasticulture enables growers to optimize establishment of vegetable and fruit crops under nonoptimum conditions and in locations with short growing seasons. Generally, warm-season crops such as muskmelon, pepper, and tomato, are established from transplants to decrease the time to maturity in the field. Directly seeding vegetables such as sweet corn, cucumber, and snap bean through plastic allows for optimum soil temperature and moisture to ensure maximum seed germination and subsequent seedling emergence. Mechanized transplanting or seeding of vegetables in plasticulture is available and successful if a firm, flat bed with plastic firmly stretched over the bed is formed and specific crop requirements are followed during establishment. Common mistakes made with plant establishment in plasticulture are discussed.

Baby corn, the young flowering ear of any Zea mays genotype, has become a familiar part of the American diet, but production of the crop occurs almost exclusively in Asia. Cultivar, planting date, and seed spacing trials were conducted in 1988 and 1989 to assess yield of baby corn. Cultivars were also evaluated for organoleptic qualities-specifically color, taste and appearance. Cultivar was the single most important factor determining the yield of baby corn in both years. Planting date and plant spacing also sign& cantly affected yield. The cultivars from 1988 that were high in yield and attributes as baby corn were re-evaluated in 1989. No single variety met all the requirements for ideal baby corn, but several cultivars met most of the characteristics. The cultivar best meeting the criteria was 'Robust 41-10', a popcorn type.

As early as 1929, university scientists began the quest to determine the ideal age at which to transplant tomatoes (Lycopersicon esculentum Mill.). Investigations have included seedlings of 2 to 15 weeks of age produced in wood, peat, plastic, or Styrofoam containers. Early researchers often omitted descriptions of soil mixes and nutrient regimes, and used a wide variety of container types. Later investigators were inclined to use commercial soilless mixes, well-defined nutrient regimes, and polystyrene trays. Pioneers of transplant age research tended to use plants of 7 weeks and older, whereas work within the past 30 years has concentrated on younger plants. Many researchers drew conclusions after only 1 year of experimentation, while others found that results varied across years. Prior to the 1980s, virtually all studies were initiated and conducted in areas far from the thriving transplant industry established in the southeastern United States. Southern-grown transplants often were not in cluded for comparison, and few studies were implemented using plants grown under commercial conditions. After more than 60 years of transplant age research, it appears that transplants of 2 to 13 weeks can produce comparable yields, depending on the many factors involved in commercial production.

The effects of higher density plantings on tomatoes (Lycopersicon esculentum Mill.) at three nutritional levels were evaluated over two years. At each of two commercial sites, four in‐row spacings were combined with three fertilizer treatments in a split‐block design with six replications. Increasing plant density of the processing cultivar, ‘U.S. 68’, by changing spacing from 23 cm in single rows to 30 cm in double rows (46 cm apart) increased total and vine yields substantially, lowered yield/plant and decreased fruit weight slightly. Decreasing spacing to 23 cm in double rows did not further increase total yield but yield/plant was reduced. At all spacings, fertilizer banded at 56N‐56P‐56K kg/ha increased total fruit and vine yields and increased yield/plant but reduced mean fruit weight. The higher banded rate, 112N‐112P‐112K kg/ha, showed few trends towards further effects. Reducing spacing of the fresh market cultivar, ‘Count II’, from 76 to 30 cm in single rows substantially increased tota...

Flower formation in the Cucurbitaceae family is compromised at high temperatures; both male and female flowers and therefore fruit productivity are greatly reduced as the growing temperatures for these vegetable crops are increased above 26C. This intractable phenomenon has been documented both with outdoor field experiments at various latitudes on the eastern seaboard in the USA and in a laboratory, temperature-regulated setting. We now report that an agricultural product, FP, which has been, and is used globally on many commercial crops to increase flower number and strength during blossom formation and development, overcomes the apparent refractory floral initiation and development at high temperatures. This is a new and unexpected finding. Additionally, in another facet of the experiments reported here, the parthenocarpic fruit development potential of FP was tested by eliminating bee pollination. This aspect of the study was addressed in part because of the recent concerns with bee colony collapse disorder. Flower formation, flower development and fruit yield were increased by FP over the bee-pollinated, untreated controls at high temperatures. FP was developed over a number of years of outdoor field trials as an approach to crop productivity that included hormonal regulation of floral strength and supported by mineral supplements through to the fruit production process.

Optimization of crop production can be accomplished only if successful stand establishment is achieved first, since each plant contributes to the total crop yield. Reduction of plant populations after planting will reduce yield and/or quality, even though plants compensate to some degree for stand losses. Successful stand establishment is achieved if factors that affect establishment are known, evaluated, and modified appropriately at the time of field planting. The factors that affect stand establishment are biotic and/or abiotic. Biotic factors are generally pathogens that attack plants as parasites, while abiotic factors are the environmental and physical conditions to which the plant or seed is exposed at the time of planting. Abiotic factors can be classified under three headings: soil, planting requirements, and environmental stress.

After being interviewed by a newspaper reporter on high tunnels and explaining in great detail what a high tunnel is and how it is different from a greenhouse, you can guess my shock to read the headline “High Tunnels—A Poor Man's Greenhouse.” High tunnels do not offer the precision of conventional greenhouses for environmental control, but they do sufficiently modify the environment to enhance crop growth, yield, and quality and provide some frost protection, but their primary function is to elevate temperatures a few degrees each day over a period of several weeks. In addition to temperature control, there are benefits of wind and rain protection, soil warming, aid in control of insects, diseases, varmints, and birds. They are relatively inexpensive, about $1.30/sq. ft., excluding labor. This system is particularly appealing to new-entry growers with limited capital who utilize retail-marketing channels. High tunnels like plastic-covered greenhouses are generally quonset-shaped with a peak, constructed of metal bows that are attached to metal posts, which have been driven into the ground about 2 feet deep. They are covered with one layer of 6-mil greenhouse-grade polyethylene, and are ventilated by manually rolling up the sides each morning and rolling them down in early evening. There is no permanent heating system, although it is advisable to have a standby portable propane unit to protect against unexpected below-freezing temperatures. There are no electrical connections. The only external connection is a water supply for trickle irrigation.

High tunnels offer growers in temperate regions the ability to extend the production season. Past research has shown that these low-input structures also reduce disease and pest pressure. These characteristics make high tunnels extremely attractive to organic growers. Tomatoes (Lycopersiconesculentum Mill.) are the crop most often produced in high tunnels in Pennsylvania and many producers are interested in combining both high tunnel and organic production methods. Growers may be hesitant to transition to organic production due to conceptions concerning reduced yields specifically during the 3-year transition period to USDA certified organic status. A field trial investigating tomato production in high tunnels during the first year of organic transitioning was conducted in 2004 at The Penn State Center for Plasticulture, Russell E. Larson Agricultural Research Center, Rock Springs, Pa. The objective of this research was to evaluate yield of the four cultivars Big Beef, Mountain Fresh, Plum Crimson, and Pink Beauty in an organic system relative to a scheduled fertilization/irrigation regime and a fertilization/irrigation regime employed using T-Systems International's Integrated Agronomic Technology. Data collected included total weight, total fruit number, weight by grade, fruit number by grade, total marketable yield, and fertilizer and water usage. Yield across cultivars ranged from 4.96 kg/plant to 6.83 kg/plant. `Pink Beauty' exhibited the lowest yields in both treatments, while `Plum Crimson' and `Mountain Fresh' exhibited the highest yields in the IAT and scheduled treatments, respectively. This experiment will be repeated in 2005 to further evaluate the performance of these cultivars.

Acreage of white potato production in Pennsylvania has steadily declined in the past 20 years, from ≈25,000 acres in 1976 to 18,000 acres in 1996. This decline in acreage has occurred mainly with potatoes used for chips, with a much smaller acreage loss for tablestock potatoes. The most common tablestock varieties on the market are round white or long russet varieties, which have been around for 30 to 50 years. However, the 90's consumer is more perceptive and creative with food choices, such that color, texture, and taste have become important characteristics in choosing new food items. Specialty new potatoes represent a relatively unexplored market with excellent potential for sales expansion in the fresh market and tablestock industry. Today's consumers are demanding more variety with respect to virtually all produce commodities and potatoes are no exception. Consumers demand different size, color, and taste of fresh vegetables, including potatoes. New specialty potato varieties (Yukon Gold is an example) are currently in demand by restaurants and some retail markets, and it appears that relatively high returns are possible with these specialty potatoes. Twenty-nine red, buff, or blue-skinned and white-, yellow-, purple-, or red-fl eshed potato varieties were planted in a replicated study at the Hort Research Farm, Rock Springs, Pa., in 1996. Yield and quality characteristics of these varieties will be presented along with some consumer acceptance/evaluation data collected from a local supermarket.

Early weed infestation in vegetable crops reduces both early and total marketable yield and quality. Even if escape weeds (12 inches tall or larger) are later killed by a postemergence herbicide application, their skeletons can cause yield loss due to competition for light, temperature modification within the plant canopy, and interference with fungicide and insecticide applications. In addition, weeds can also serve as a reservoir for insect and disease organisms, especially viruses. Experiments in nonchemical weed control in cabbage were conducted at the Horticulture Research Farm, Russell E. Larson Research Center, Rock Springs, Pa., from 1993 to 1995. In addition to weedy and hoed check plots, flaming weeds at 2- to 4-leaf stage of growth with propane gas burners and planting annual ryegrass (Lolium multiflorum) between the rows of cabbage, living mulch, were evaluated during 3 years. The cabbage cultivar Rio Verde was transplanted generally between 15 June and July during each year. Both flaming and living mulch treatments produced yield and head quality similar to the hoed check. Management and timing of ryegrass planting in relation to cabbage establishment is very critical for success with living mulch. Flaming requires straight rows of cabbage or other crop, tractor with driver that can maintain a straight line, and burners that are aligned to burn weeds and not the crop. Results will be discussed.

The dramatic reduction in available greenhouse insecticides and the potential for increased insect resistance has necessitated a change in insect control techniques. Because of the large acreage of greenhouse production in Pennsylvania and the need for a more environmentally effective method of controlling insects in greenhouses, an aggressive Integrated Pest Management research program was initiated and has been on-going since 1989. Our objectives were to develop a bibliography of major insect pests; to determine effectiveness of parasitoids on greenhouse and silverleaf whitefly, western flower thrip, and aphids; to reduce pesticide usage; and to comply with worker protection standards. The program was implemented by a joint venture among the Pennsylvania State Univ. faculty and technical staff, grower cooperators, the Pennsylvania Dept. of Agriculture, and the Pennsylvania Vegetable Growers Association. The IPM program was started with an active scouting and monitoring program in commercial houses to determine threshold levels. Control measures were implemented with biological controls, cultural management, and lastly chemical. In addition, the implementation of the results of this research to commercial growers has resulted in the formation of a Greenhouse Crop Management Association. Results of the 5-year research program are discussed.

A long term study was initiated in 1993 to evaluate the effect of composted sewage sludge on growth, yield, and quality of different vegetables. The composted sewage sludge consisting of 40% hardwood sawdust and 60% clean municipal wastewater sludge was obtained from the University Area Joint Authority (UAJA) in State College, PA. The composted sewage sludge is currently sold by UAJA as a fertilizer amendment under the name CornposT. Two rates of the ComposT product (11 and 22 dry T/A) were compared to a granular fertilizer application of 800 lbs/A of 10-10-10. The low rate of ComposT also received half of the fertilizer rate. After incorporation of the amendments into a Hagerstown clay loam soil, lettuce, tomato, muskmelon, cabbage and pepper were transplanted in the field in a Randomized Block Design with 3 replications. ComposT application did not reduce yield or quality of cabbage, lettuce tomato,and muskmelon; in fact, yields were generally higher with the application of composted sewage sludge. The application of ComposT did not reduce the macro or micro nutrient concentration of leaf tissue below optimum levels nor did it result in any phytotoxic effects in plant growth. In addition, the application of ComposT did not increase the heavy metal (Cd, Ni, Pb) concentration in leaf tissue or increase the risk of microbial contamination in the edible portion of the vegetables.

The concept of using Foam in agriculture is not new. Researchcrs at LSU in 1972 recommended Foam be used for; a carrier for insecticides and pesticides, frost protection agent, short-life mulch, evaporation suppressant and soil cover for fumigation. In 1974, Johnson Manufacturing Co., Pendleton, ND tested a light weight, low solids Foam as a frost protectant material on strawberries at the University of Maryland Research Farm, Salisbury, MD. Unfortunately, the Foam dissipated within 8 hours and was difficult to apply when winds were greater than 5 mph. In addition, equipment had not been developed to utilize the Foam technology in a field situation. In 1986, anew generation of Foam technology had been developed by Aqualon, Inc. and was initially tested in the spring of 1987 on several vegetable crops at the Horticulture Research Farm, Rock Springs, PA. The Foam was applied with a modified high pressure sprayer and banded over the seeded rows at a width of 10 cm and height of either 5 or 10 cm. Compared to bare-ground checks, there was no soil capping when the Foam was applied to carrots, beets, snap bean, broccoli, cucumber, lettuce and spinach. Generally, seeds emerged earlier and more uniform with the Foam treatments than the bare-ground checks. In addition, higher soil temperatures and moisture levels were observed under the Foam treatment. In the last 2 years, a prototype Foam Applicator was developed by Smucker Manufacturing, Harrisburg, Oregon.

“Majestic” cauliflower plants were transplanted into furrows with either a polymer alone or in combination with ammonium nitrate. The polymers were banded in the furrow at planting time at 16.9, 33.7 or 67,4 kg/ha with or without a concurrent application of nitrogen at 44.9 kg/ha. The cauliflower received at least 1.2 cm water from an overhead irrigation system immediately after transplanting. Checks were both watering as plants were set in the field and water with a 12-48-8 starter fertilizer. Highest total yields were recorded when polymers were applied alone in the furrows. The addition of 44.9 kg/ha of the nitrogen generally decreased total marketable yields, head weight and plant weight. Soil samples were taken in the treatment rows after crop harvest. One of the polymer materials reduced soil pH by an average of 0.4 units and decreased the percent saturation of calcium from 90% to 70%.