Matted Row Research Articles

Probiotic Bacteria, Anaerobic Soil Disinfestation, and Mustard Cover Crop Biofumigation Suppress Soilborne Disease and Increase Yield of Strawberry in a Perennial Organic Production System.

Black root rot complex and crown rot of strawberry caused by soilborne fungi limit sustainable strawberry production in the northeastern United States, especially in perennial systems, including matted row and plasticulture. As pathogen populations build up over time in the rhizosphere and infect the root system, feeder roots are pruned, which diminishes nutrient and water uptake and causes stunted plant growth or death. Alternative management options are needed for many organic and small growers who can't use chemical fumigants due to new regulations and potential health hazards. Strawberry plug plants were grown on beneficial microbe-inoculated or uninoculated planting mix followed by transplanting in fruiting field plots that either was biofumigated with mustard cover crop (MCC), anaerobically disinfested (ASD), or left untreated. Different combinations of plug plants and field plot treatments were used to determine the efficacy of individual treatments or synergistic effects from combination treatment. Plug plants were transplanted in pretreated plastic mulched raised beds and grown following a typical organically recommended production system. Plants grown on TerraGrow (TG)-inoculated planting mix showed enhanced plant vigor in the fruiting field compared with untreated plants. Weeds that grew through planting holes were significantly (P ≤ 0.045) suppressed in ASD plots compared with untreated plots in the first year. Plants treated with a combination treatment of TG and ASD had significantly higher fruit yield in both years (2019 and 2020), although the difference was greater in the second year. Plant vigor and survival in treated plots except MCC were also significantly higher in the second year compared with the untreated control. Suppression of pathogenic microbes and plant vigor improvement in treated plots appear to be the factors providing beneficial effects and higher net economic return. Taken together, our results suggest that a combination of beneficial microbes and ASD could be an alternative to synthetic fumigation in a perennial strawberry production system.

Strawberry Cultivar Susceptibility to Neopestalotiopsis Leaf Spot in Indiana

In June 2020, a leaf spot caused by Neopestalotiopsis sp. in Indiana strawberry production was confirmed to be the same disease recently found in Florida strawberry production. Differences in cultivar susceptibility were observed in the field. Greenhouse trials using either bare-root or plug plants were conducted to explore possible differences in host resistance to the foliar phase of the disease caused by Neopestalotiopsis sp. Clear differences in cultivar susceptibility were observed. Florida Brilliance, Florida Sensation, Camino Real, and Florida Radiance were among the most susceptible cultivars evaluated in these trials. Several short-day cultivars, including AC Valley Sunset, Darselect, Earliglow, Flavorfest, Galletta, Honeoye, Jewel, and Sonata, remained asymptomatic in the trials. Because many of the abovementioned asymptomatic short-day cultivars are commonly used in matted row systems typical of Indiana strawberry production, future field trials with the matted row system could demonstrate that the foliar phase of the disease caused by Neopestalotiopsis sp. may be less common in Indiana than in other areas of the United States.

Can hemp hurd or paper mulch and biochar application improve weed management in matted-row strawberry production systems?

AbstractDuring 2015 and 2016, studies were conducted at Absaraka and Dickinson, North Dakota to evaluate the impacts of hemp (applied at 1156 m3 ha−1) and commercial paper mulch, as well as soil-applied biochar (applied at 11.25 m3 ha−1), on weed suppression and strawberry growth during the establishment year, and on weed suppression and strawberry yield during the production year, in a matted row production (MRP) system. During 2015, biochar influenced dry weed biomass only within the hemp mulch, with slightly more weed biomass associated with biochar application compared to zero biochar (3.1 vs 0.4 g m−2), suggesting that biochar may have increased weed germination and/or emergence from beneath hemp mulch. Biochar application also slightly increased soil pH, from 6.9 in non-amended soil to 7.0 in amended soil. Strawberry runner number during 2015 was greater in association with hemp or paper mulch compared to zero mulch (4.5 and 4.9 vs 2.4 runners plant −1, respectively). This result mirrored a similar differential in per berry mass across sites (7.6 and 7.4 vs 6.2 g berry −1 for hemp mulch, paper mulch and zero mulch, respectively). These results may be related to hemp and paper mulch reducing maximum soil temperatures during summer 2015. During the establishment year, both hemp and paper mulch suppressed weeds well compared to zero mulch, although at Absaraka hemp mulch provided slightly better weed suppression than paper mulch. During the production year, both mulches continued to suppress weeds compared to zero mulch at Dickinson. However, at Absaraka, only hemp mulch provided weed suppression compared to zero mulch, possibly because of faster paper degradation caused by greater numbers of large precipitation events and greater relative humidity at Absaraka compared to Dickinson. Weeds were removed from plots during 2015 to allow separation of weed suppression from other possible mulch impacts; therefore, yield data do not reveal striking differences among mulch treatments. Because previous research has demonstrated the impact of weed management during the establishment of strawberries in a matted row system, we concluded that hemp mulch may provide more durable weed suppression compared to paper mulch, which would increase strawberry yield protection in an MRP system. Material cost may be an issue for implementing hemp mulch, as hemp hurd cost was 25 times paper mulch at the application rates used in this study. However, hemp mulch could still be a beneficial option, especially for organic strawberry growers desiring a renewable and environmentally sound replacement for plastic mulch who are able to find affordable local sources of this material.

Rotation with Cover Crops Suppresses Weeds and Increases Plant Density and Yield of Strawberry

Yield of strawberry grown continuously on the same site often declines over time as a result of proliferation of weed seeds and pathogenic organisms in the soil. Plots were established and maintained in seven different cover crops and as continuous strawberry or continuous tillage for 10 years (1996 to 2005) in a site that was previously in strawberry production for 10 years (1986 to 1995). Cover crops included blackeyed Susan (Rudbeckia hirta L.), sorghum Sudangrass [Sorghum bicolor (L.) Moench], marigold (Tagetes erecta L.), big bluestem (Andropogon gerardii Vitman), perennial ryegrass (Lolium perenne L.), switchgrass (Panicum virgatum L.), and Indiangrass [Sorghastrum nutans (L.) Nash]. Treatments were ended in 2005 and plots were planted with ‘Honeoye’ strawberry in a matted row. Effectiveness of soil pretreatments in reducing weed populations and enhancing strawberry production was evaluated for four growing seasons by quantifying weed growth by type and biomass and strawberry plant density and yield. The results indicate that matted-row strawberry production plots that were either in continuous tillage or established in S. bicolor, P. virgatum, or A. gerardii before planting strawberry had lower weed biomass and greater strawberry plant establishment and yield than plots established in L. perenne or R. hirta or that had supported continuous strawberry production.

Horticultural and Economic Considerations in the Sustainability of Three Cold-climate Strawberry Production Systems

Three cold-climate strawberry (Fragaria ×ananassa) production systems, conventional matted row (CMR), advanced matted row (AMR), and cold-climate plasticulture (CCP), were compared for horticultural and economic aspects of sustainability over a 3-year planting cycle. The systems were tested using a single cultivar, Allstar, to avoid treatment × cultivar interaction. System-specific management operations and materials affected the total production costs of each system. Both CMR and AMR had higher management costs than CCP as a result of labor costs for weed control, but CCP had much higher cost of materials. Overall expenses were lowest for CMR and highest for AMR. Yields in the first fruiting year were highest for CMR at 17.4 Mg·ha−1 followed by AMR and CCP at 13.2 Mg·ha−1 and 11.8 Mg·ha−1, respectively. In the 2004 harvest season, CMR and AMR were the highest yielding at 10.0 Mg·ha−1 and 9.0 Mg·ha−1, respectively, with CCP the lowest yielding at 6.0 Mg·ha−1. Low yield and fruit size in the second year and high material costs for establishment limit the economic viability for CCP when managed as a perennial system.

Effect of Different Cultural Systems on Antioxidant Capacity, Phenolic Content, and Fruit Quality of Strawberries (Fragaria×aranassaDuch.)

The effect of cultivation practices for controlling strawberry black root rot (BRR) on fruit quality, antioxidant capacity, and flavonoid content in two strawberry cultivars Allstar and Chandler (Fragaria x ananassa Duch.) was evaluated. Strawberry fruits used in this study were from plants grown in soils which had a prior history of BRR and red stele, and had not been fumigated during the seven years prior to the study. Results from this study showed that fruit from plants grown in compost socks had significantly higher oxygen radical absorbance capacity (ORAC), flavonoids, anthocyanins, soluble solids content (SSC), titratable acid (TA), fructose, glucose, sucrose, malic acid, and citric acid than fruit produced in the black plastic mulch or matted row systems. Cultivar Chandler surpassed cv. Allstar in sugar content, acid content, and flavonoid content regardless of preplanting vinegar drenching and various culture treatments. However, preplanting vinegar treatment increased cyanidin-based and pelargonidin-based anthocyanins but decreased sugar content in fruits of both cultivars.

A Comparison of Three Cold-climate Strawberry Production Systems: Environmental Effects

The environmental effects of the three strawberry (Fragaria ×ananassa) cold-climate production systems were compared: the traditional method of conventional matted row (CMR) and the two more recently developed practices of advanced matted row (AMR) and cold-climate plasticulture (CCP). Side-by-side field plots were instrumented with automated flow meters and samplers to measure and collect runoff, which was filtered and analyzed to determine soil, pesticide, and nitrogen losses. Although annual mean runoff volumes were similar for all three production systems, the soil losses from CMR plots were two to three times greater than the CCP plots throughout the study and two to three times greater than the AMR plots only in the first year of the 3-year study. In general, decreases in erosion and runoff volumes were observed in plots that were disturbed less by machine operations and had less foot traffic as a result of decreased need for hand weeding and in the plots that used straw mulch in the furrows between the beds. Timing and intensity of precipitation events also influenced the amount of soil erosion. Pesticide residues and nitrogen losses were also greatest in the runoff from the CMR plots. The two systems that used drip fertigation, AMR and CCP, also had higher nitrogen uptake efficiencies. Overall, the CCP and AMR systems performed similarly for most criteria; however, considering the nonrenewable nature of the plastic mulch and the need to dispose of the plastic mulch in a landfill, the AMR system was more environmentally sustainable than the CCP system.

RESEARCH CONCERNING THE INFLUENCE OF THE CULTURE SYSTEM ON THE STRAWBERRY FRUITS PRODUCTION

SUMMARY The raised costs of the plantation strawberry plant establishment, require the achievement of high production on small areas, using planting distances which should allow a maxim efficiency from the quantitative and qualitative point of view. (Diaconeasa M. and the col.-1995; Takeda F., and all - 2004). The main objectives of this experience refer to: the achievement of fruit production in conditions of practicing larger planting distances and the decrease of the investment, as well as the establishing of the most economic possibilities for maintaining the plants in multiannual culture of the strawberry plant. We estimated the two possibilities of maintaining the plants in multiannual culture (individual plant or matted row) in the conditions of planting at different distances (25cm, 75 cm, 125 cm).The experimental variants (V1 – individual plant x 25 cm; V2 - individual plant x 75 cm; V3 - individual plant x 125 cm; V4 (Mt) – matted row x 25 cm; V5 - matted row x 75 cm; V6 matted row x 125 cm), were put in randomized blocs, in 3 repetitions, on a uniform field. One elementar parcel’s surface had an area of 29 m². The variants in which we utilised plantation distances of 75 cm, respectively of 125 cm, there were made up all the rows till normality in the first year ( 25-30 cm between the plants on the row) with the first 2 or 3 runners formed on the mother-plants. Analyzing the dates of production in the six culture systems we have established that the best culture system was represented by the combination “25cm x individual plant” (V1 – 21,63 t/ha), and the lowest was at combination “125cm x matted row” (V6 – 15,91 t/ha). As compared to the control (V4 -17,78 t/ha), which represents the culture system practiced at present, there have been obtained superior productions in all variants where individual plants were maintained (V1 – 21,63 t/ha, V2 – 20,10 t/ha, V3 – 19,66 t/ha).

Resveratrol Content in Strawberry Fruit Is Affected by Preharvest Conditions

This study investigated the occurrence of resveratrol in Fragaria x ananassa Duchesne and the effect of preharvest conditions on resveratrol content. Both cis- and trans-resveratrol were detected in strawberry achenes (seeds) and pulp (receptacle tissue). Resveratrol was found to be higher in achenes than in fruit pulp. The levels of resveratrol were affected by genotype variations, fruit maturation, cultural practices, and environmental conditions. High growing temperature (25 and 30 degrees C) or enriched CO 2 in the atmosphere significantly enhanced resveratrol content of strawberries. Advancing maturation also increased resveratrol content. The mature pulp and achenes contained higher amounts of resveratrol than the immature fruit. Adding compost as a soil supplement or preharvest application of methyl jasmonate (MJ) also significantly enhanced the level of resveratrol in strawberry fruit. Among the plants grown in hill plasticulture, fruits of 'Ovation (B28)', 'Mohawwk', 'Earliglow', and 'B35' had higher amounts of resveratrol than fruits of other genotypes. 'Ovation' contained the highest amount of resveratrol among strawberries grown in matted row, whereas 'Latestar' contained the least. Ten of 14 tested genotypes (all except 'Allstar', 'Delmarvel', 'Northeaster', and 'MEUS 8') had higher amounts of resveratrol when grown in hill plasticulture compared to matted row.

A Comparison of Fruit Quality and Consumer Preferences Among Three Cold-climate Strawberry Production Systems

In consumer-harvested marketing, crop management practices and production systems directly affect the experience of the customer. An experiment was designed to compare overall consumer preference and fruit quality characteristics among three perennial cold-climate strawberry (Fragaria ×ananassa) production systems: conventional matted row (CMR), advanced matted row (AMR), and cold-climate plasticulture (CCP). Replicate plots of each system were maintained for two harvest seasons. Volunteers harvested subplots in each system and completed a survey to evaluate pick-your-own consumer preferences. The CCP system was preferred by a majority of consumers in the first year, whereas the AMR system was rated highest in the second year. Preferences were positively correlated with ease of harvest and fruit appearance and negatively correlated with the percentage of fruit unfit for harvest. Fruit quality measurements made on marketable fruit in the second harvest season indicated that there were no treatment differences in titratable acidity or soluble solids concentration, but significantly lower fruit firmness in the CCP treatment compared with CMR and AMR.

SUSTAINABILITY OF COLD-CLIMATE STRAWBERRY PRODUCTION SYSTEMS

An experiment was conducted to compare three cold-climate strawberry pro-duction systems. Replicated field plots of conventional matted row, advanced matted row and cold-climate plasticulture production systems were established in 2002 at Beltsville, MD, and managed according to commercial standard practices for the re-gion. The following components of sustainability were determined: economic viability and efficiency, environmental impacts, and public acceptance. Marketable yields for the first harvest season in the spring of 2003 were lower than normal due to above average rainfall and high disease incidence. The conventional matted row was the highest yielding at 17,400kg/ha, followed by the advanced matted row and plasticul-ture with 13,200 and 11,800 kg/ha, respectively. During the establishment year, soil loss from rain-induced surface runoff was more than 4-fold greater in conventional matted row, and 1.5-fold greater in plasticulture compared to advanced matted row. To identify preferences of pick-your-own customers, volunteers harvested fruit from subplots in each system and completed questionnaires. Overall, the volunteers indi-cated a preference for plasticulture, which was likely a result of larger fruit size, ease of harvest, and a higher percentage of marketable fruit.

Fruit Nitrogen Content of Sixteen Strawberry Genotypes Grown in an Advanced Matted Row Production System

In the perennial strawberry production system, removal of the harvested crop represents a loss of nitrogen (N) that may be influenced by cultivar. Eight strawberry (Fragaria ×ananassa Duch.) cultivars and eight numbered selections grown in advanced matted row culture were compared over three seasons for removal of N in the harvested crop. Replicated plots were established in 1999, 2000, and 2001 and fruited the following year. `Allstar', `Cavendish', `Earliglow', `Honeoye', `Jewel', `Northeaster', `Ovation', and `Latestar' and selections B37, B51, B244-89, B683, B753, B781, B793, and B817 were compared for yield and fruit N concentration. Harvest removal of N (HRN) was calculated from total season yield and fruit N concentration at peak harvest. There were significant differences in HRN among genotypes, ranging from 1.80 to 2.96 g N per meter of row for numbered selections B781 and B37, respectively. Among cultivars, HRN ranged from 2.01 to 3.56 g·m–1 for `Ovation' and `Jewel', respectively. The amount of HRN was largely determined by yield, however, there were also significant genotype differences in fruit N concentration, ranging from 0.608 to 0.938 mg N per gram fresh weight for B244-89 and `Jewel', respectively. These differences indicate that N losses in the harvested crop are genotype dependent.

Consumer Preference among Three Cold-climate Strawberry Production Systems

Three cold-climate strawberry production systems, conventional matted row, advanced matted row, and cold-climate annual hill plasticulture, were compared for consumer preference in a pick-your-own (PYO) setting. Replicated 6 × 15 m plots were established in 2002 in Maryland and cropped in 2003 and 2004. To simulate PYO marketing, volunteers were recruited to harvest 3.6-m plots in each of the three production systems and to complete a five-part questionnaire. The questionnaire collected demographic information and allowed volunteers to compare the three systems both prior to and after their harvesting experience. Harvests were carried out twice weekly, with 75 participants in 2003 and 45 participants in 2004. The 2003 season was cool and wet, with frequent rainfall and a high incidence of fruit rot. Spring 2004 was unseasonably hot, resulting in an unusually short harvest season. Consumer preference differed between years and among harvests within a season. The annual hill system was favored early in the 2003 season, with preference shifting to the other systems as the season progressed. The advanced matted row was favored early in the 2004 season. Many of the participants' comments, both positive and negative, were directed at the plastic mulch and raised beds. In several cases, participants indicated that their preferences after picking from each system did not match their initial impressions. Implications of this research to the social components of sustainability will be discussed.

Weed Competition in a Mature Matted Row Strawberry Planting

Various levels of weed competition were implemented in a second-year well-established strawberry (Fragaria ×ananassa `Jewel') planting by cultivating and hand weed removal for defined periods of time over 3 years. The impact of weeds on subsequent productivity was then determined. Sixteen treatments were established where weeds were allowed to grow for defined periods (0, 1, 2, 3, 4, or 5 months) throughout the growing season. Treatments were maintained in the plots for 3 consecutive years. Spring weed biomass in 1997 had no impact on yield that same year. Weed biomass in 1997 was negatively associated with yield in 1998, although the trend was nonsignificant. However, several individual contrasts were significant. For example, the weed-free control treatment had the highest average yield, while season-long weed competition reduced yield by 14%. The inverse relationship between weed biomass and fruit yield became significant in 1999. For every 100 g·m-2 increase in weed biomass in 1998, fruit yield was reduced by 6% in 1999. Season-long uncontrolled weed growth reduced productivity by 51%. However, several plots with a limited amount of weed competition had higher yields than the continuously weeded control. These data indicate that yields from a well-established strawberry planting may not be vulnerable to a limited amount of weed competition for at least 2 years. Furthermore, data suggest that hand weeding and cultivation on a monthly basis for multiple years may be damaging as well. Growers should direct a majority of their efforts and resources toward controlling weeds in the planting year. Once the planting is well-established, growers may limit the number of times they hand weed to two or three per season.

Influence of Rate, Timing, and Method of Nitrogen Fertilizer Application on Uptake and Use of Fertilizer Nitrogen, Growth, and Yield of June-bearing Strawberry

Fertilizer nitrogen (FN) recovery, and changes in nitrogen (N) and dry weight partitioning were studied over three fruiting seasons in June-bearing strawberry (Fragaria ×ananassa Duch. `Totem') grown in a matted row system. Fertilizer nitrogen treatments were initiated in 1999, the year after planting. The standard ammonium nitrate N application at renovation (55 kg·ha-1 of N) was compared to treatments where additional N was applied. Supplemental treatments included both ground-applied granular ammonium nitrate (28 kg·ha-1 of N) applied early in the season and foliar urea [5% (weight/volume); 16 kg·ha-1 of N] applied early in the season and after renovation. When labeled N was applied (eight of nine treatments) it was applied only once. The impact of no FN from the second through the third fruiting season was also evaluated. Fertilizer nitrogen treatment had no impact on total plant dry weight, total plant N, yield or fruit quality from the first through the third fruiting seasons. Net dry matter accumulation in the first fruiting season was 2 t·ha-1 not including the 4 t·ha-1 of dry matter removed when leaves were mowed during the renovation process. Seasonal plant dry weight and N accumulation decreased as the planting aged. Net nitrogen accumulation was estimated at 40 kg·ha-1 from spring growth to dormancy in the first fruiting season (including 30 kg·ha-1 in harvested fruit, but not including the 52 kg·ha-1 of N lost at renovation). Recovery of fertilizer N ranged from 42% to 63% for the broadcast granular applications and 15% to 52% for the foliar FN applications, depending on rate and timing. Fertilizer N from spring applications (granular or foliar) was predominantly partitioned to leaves and reproductive tissues. A large portion of the spring applied FN was lost when plants were mowed at renovation. Maximum fertilizer use efficiency was 42% for a granular 55 kg·ha-1 application at renovation, but declined to 42% just before plant growth the following spring, likely a result of FN loss in leaves that senesced. In June, ≈30% of the N in strawberry plants was derived from FN that was applied at renovation the previous season, depending on year. This stored FN was reallocated to reproductive tissues (22% to 35%) and leaves (43% to 53%), depending on year. Applying fertilizer after renovation increased the amount of remobilized N to new growth the following spring. The following June, 15% of plant nitrogen was derived from fertilizer applied at renovation 2 years prior.

VEGETATIVE AND FLORAL CHARACTERISTICS OF SIX STRAWBERRY CULTIVARS ASSOCIATED WITH FRUIT SIZE, YIELD AND SUSCEPTIBILITY TO TARNISHED PLANT BUG INJURY

Strawberry cultivars can differ in their susceptibility to tarnished plant bug injury, but the mechanisms for such differences have not been determined. Isolating such mechanisms could allow breeders to develop significant insect resistance in commercial strawberry cultivars. Selected vegetative and floral characteristics were measured in six strawberry cultivars grown in a perennial matted row system and compared to the yield data and levels of tarnished plant bug injury. 'Mira' and 'Mesabi' had the highest marketable yields, followed by 'Jewel' and 'Sable'. 'Cabot' and 'Northeaster' had the lowest yields. 'Cabot' had the largest fruit size, followed by 'Jewel', 'Mira', 'Northeaster', 'Sable' and 'Mesabi'. Naturally occurring levels of tarnished plant bug injury were lower than expected, but some significant differences were observed among the six cultivars. 'Mire', 'Northeaster' and 'Cabot' had the highest levels of tarnished plant bug injury. 'Jewel', 'Mesabi' and 'Sable' had lower levels of injury. There was no significant correlation between yield and levels of tarnished plant bug injury, reflecting the low levels of injury in this experiment. Of the parameters evaluated, only high pollen levels were significantly correlated with higher levels of tarnished plant bug injury. Flower size, flower number, pedicel length, peduncle length and petiole lengths were not significantly correlated with injury. Primary flower diameter and flower dry weight were positively correlated with average fruit weight.

Cultural system affects fruit quality and antioxidant capacity in strawberries.

Cultural system [hill plasticulture (HC) versus matted row (MR)] and genotype interactions affected strawberry fruit quality. In general, fruit soluble solids content, total sugar, fructose, glucose, ascorbic acid, titratable acid, and citric acid contents were increased in the HC system. Fruit from HC also had higher flavonoid contents and antioxidant capacities. Strawberry fruit contains flavonols as well as other phenolic compounds such as anthocyanins and phenolic acids. Pelargonidin-based anthocyanins such as pelargonidin 3-glucoside, pelargonidin 3-rutinoside, and pelargonidin 3-glucoside-succinate were the predominant anthocyanins in strawberry fruit. The content of cyanidin-based anthocyanins, cyanidin 3-glucoside and cyanidin 3-glucoside-succinate, was much lower than that of pelargonidin-based anthocyanins in either system. Strawberry fruit from the HC system had significantly higher amounts of p-coumaroylglucose, dihydroflavonol, quercetin 3-glucoside, quercetin 3-glucuronide, kaempferol 3-glucoside, kaempferol 3-glucuronide, cyanidin 3-glucoside, pelargonidin 3-glucoside, pelargonidin 3-rutinoside, cyanidin 3-glucoside-succinate, and pelargonidin 3-glucoside-succinate. Fruits from plants grown in the MR system generally had the lowest contents of phenolic acids, flavonols, and anthocyanins. Strawberry fruit grown under HC conditions had significantly higher peroxyl radicals (ROO*) absorbance capacity (ORAC).

A Comparison of Temperate-climate Strawberry Production Systems Using Eastern Genotypes

Anticipating the phaseout of methyl bromide, the USDA-ARS small fruit breeding program at Beltsville, Md., discontinued soil fumigation in strawberry breeding and selection trials in the mid 1990s. To address resulting weed and pathogen pests, a modified or advanced matted row system was developed. This system uses matted row-type culture, established on raised beds with subsurface drip irrigation and organic mulch. The mulch is the residue of a killed cover crop that fixes some nitrogen and provides an economical, biodegradable mulch for suppressing weeds and reducing erosion. Since 1996, the small fruit breeding program has conducted replicated performance trials on both advanced matted row and a regional adaptation of annual hill plasticulture. Both of these systems were managed without methyl bromide fumigation or fungicide application. Data from these trials were used to compare advanced matted row and plasticulture for yield, fruit quality and harvest season. Yield for the two systems was genotype dependent, and the advanced matted row system had later production and slightly lower fruit quality.

Early Season Weed Competition Reduces Yield of Newly Planted Matted Row Strawberries

Competition from weeds and an interplanted sudangrass [Sorghum bicolor (L.) Moensch, formerly S. sudanense (Piper) Stapf.] cover crop was allowed to occur in newly-planted strawberries (Fragaria ×ananassa Duch.) for varying lengths of time, and at different times during the growing season. Newly planted strawberries were most susceptible to weed and cover crop competition during the first 2 months after planting, as both runnering (stolon formation) and subsequent yield were impacted. In 1994-95, 1 month of weed competition in June reduced yield by 20%, whereas 2 months of weed competition reduced yield by 65%. However, 1 month of uncontrolled weed growth later in the growing season had little to no impact on yield, although weed biomass was much less then. Herbicide (napropamide) use alone was insufficient to prevent weed competition and yield reduction. In our study, yield was reduced 0.67 t·ha-1 or 5.5% for each 100 g·m-2 of weed biomass. The data suggest that it is critical for growers to minimize weed competition early in the planting year when weed growth is greatest. Since an interplanted sudangrass cover crop displaced a portion of the weeds, it could be seeded later in the year to provide some weed suppression without a negative impact on yield. Chemical names used: N, N, Diethyl-2-(1-naphthalenyloxy)-propionamide (napropamide); N-(phosphonomethyl)glycine (glyphosate).

Compensatory Ability of Strawberries to Bud and Flower Removal: Implications for Managing the Strawberry Bud Weevil (Coleoptera: Curculionidae)

The strawberry bud weevil, Anthonomus signatus Say, is considered a major pest of perennial matted row strawberry plantings in the eastern United States with an economic threshold of 2 clipped buds per meter row. No relationship was found between the number of naturally clipped buds per meter (range, 0–20) and subsequent yield over 2 field seasons for the strawberry cultivar ‘Earliglow’ indicating the potential for compensatory fruit production. In field experiments, flower buds or open flowers were removed by hand and the impact on yield for 3 strawberry cultivars measured. For the cultivar ‘Jewel’, removal of all primary or secondary buds did not result in a significant decrease in yield relative to control plots, although the removal of all tertiary plus higher order buds did result in a significant decrease. For ‘Seneca’ and ‘Kent’, removal of all primary, secondary, or tertiary buds did not significantly decrease yield compared with control plots. Compensation to bud removal was achieved by increasing fruit weight of remaining buds and increasing the number of higher order buds matured. When similar treatments were applied to flowers, we observed a negative impact on yield for all 3 cultivars. In 1996 we assessed the benefit of treating for strawberry bud weevil when injury reached the economic threshold at 7 commercial strawberry operations in upstate New York. Untreated plots had significantly more clipped buds per meter than treated plots (13 versus 4), however, there was no difference in yield.