Effect of Biostimulants on Emergence and Growth of Watermelon (Citrullus lanatus) Transplants. - Evan Christensen Evaluation of Specialty Cucumber Cultivars in a High Tunnel Production System - Jacob Arthur Are Locally Sourced Biochar and Poultry Litter the Solution to Improving Soil Health and Sustainably Producing Tomatoes? - Emilio Suarez Romero Is Trellising Beneficial to High Tunnel Melon Yield? - Lewis Jett Interseeded Clover Does Not Impact Pumpkin Yield - Charlie Rohwer Protecting New Mexico’s Chile Crops from Curly Top Virus through Agrivoltaics - Mariela Estrada Integrating High-resolution Satellite Imagery to Monitor Crop Growth and Yield: A Case Study of Japanese Squash and Onion in Hollister, California - Elia Scudiero A New Tool to Manage Water and Nutrients in High Tunnel Tomato Production - Rebecca Brown Physiology of Heat Tolerant Tomatoes: Transplanting Through Harvest - Courtney DeKalb-Myers
The impacts of climate change and drought threatens water supplies that are necessary for watermelon production. Most production in the U.S. is seedless watermelon, typically grown in greenhouses and transplanted due to poor seed establishment in the field. Given the significance of high-quality transplants for the industry, we conducted a study to evaluate whether biostimulant products would improve transplant quality. In this study seven biostimulant products were tested on greenhouse-grown watermelon seedlings to measure seedling emergence and growth. Three bacterial (Continuum, Spectrum Ds, and Tribus Original), two mycorrhizal (MycoApply Endo, and Mighty Mycorrhizae), one humic (Huma Pro 16), and one seaweed extract product (Kelpak) were used. All products, except Kelpak, were incorporated into the growing media before sowing. Kelpak was applied at the first true leaf stage as a soil drench. Leaf area and root/shoot fresh and dry weight were measured over a 30-day period after stand establishment and data underwent analysis of variance (ANOVA) using SAS statistical software. Though some biostimulant products tended to have higher shoot and root weight they were not always significantly different, and the results were variable from trial to trial and analysis is ongoing.
Cucumbers are popular and high-value vegetable crops mainly marketed through local food markets for fresh consumption. Vegetable growers in Mississippi mainly operate on small to medium size farms. High value crops including tomatoes, peppers and cucumbers could be grown to increase competitiveness. Specialty cucumber cultivars including the parthenocarpic and mini types are in high demand due to their superior eating quality, these are often produced in protected environments like high tunnels or greenhouses. The objective of this study is to evaluate specialty cucumber cultivars and identify cultivars for superior yield and quality in the local climate under protected culture. This study was conducted in a high tunnel production system located at Mississippi State University through two growing seasons in 2022 and 2023. Twenty cucumber cultivars were evaluated including ten long Dutch/English slicer types: ‘Asteroid Long’, ‘Bologna Long’, ‘Boncanale Long’, ‘Davida Long’, ‘Durance Long’, ‘Georgia’, ‘Kasja Long’, ‘Tyria Long’, ‘Verdon Bio Long’, ‘Verdon Long’; five mini types: ‘Jawell Mini’, ‘Katrina’, ‘Manar Mini’, ‘Picolino’, ‘Socrates’; and four Asian types: ‘Itachi’, ‘Nokya’, ‘Unagi’, ‘Wokue’. The last cultivar ‘Striped Armenian’ is not a true cucumber and is actually part of the melon family. Plants were grown in 6-gallon containers using a modified drop line trellis system. Plant vegetative growth that was measured included plant height, stem diameter as well as soil plant analysis of development (SPAD). Cucumber fruits were harvested twice weekly, weighed for individual fruit weight, counted, and separated into marketable yield and unmarketable yield. Various fruit quality characteristics including: fruit diameter, fruit length, skin color, soluble solids content and fruit firmness were collected twice in each growing season. Cultivars varied in marketable and unmarketable yields in both growing seasons. In 2022, the cultivar ‘Picolino’ produced the highest marketable yield of 4.79 kg per plant with a majority of the other cultivars having statistically similar marketable fruit yields ranging from 2.87 kg in ‘Unagi’ to 4.75 kg in ‘Katrina’. The lowest marketable yield was produced by ‘Striped Armenian’ with 2.05 kg of marketable fruit for the entire growing season. Fruit quality parameters including soluble solids content, firmness, and fruit length had significant differences between cultivars. The cultivar ‘Kasja Long’ produced fruits with the highest soluble solids content of 4.18 °Brix, the other cultivars in this study had values ranging from 2.47 °Brix to 4.12 °Brix. The cultivars ‘Itachi’ and ‘Socrate’ produced the firmest fruit with values of 6.75 N and 6.70 N, respectively.
Agriculture is challenged by nutrient runoff, declining soil health, and high costs of inorganic fertilizers. This study investigates the potential of locally sourced biochar and poultry litter to address these issues by enhancing soil health and tomato production. Conducted in Spring 2023, the field trial assessed biochar application rates of 0, 10, 15, and 20 (tons/acre), combined with either organic (poultry litter) or inorganic fertilizer providing (225 N lbs/acre) for the growing period of the tomatoes. Utilizing a randomized complete block design, the experiment had four replications across ten treatments. The findings from this study revealed no significant differences in tomato yield between plants fertilized organically or inorganically across the various biochar application rates. Notably, the use of poultry litter as an organic fertilizer showcased promising results, particularly evident in the increased production of extra-large tomatoes. However, it also led to a higher count of culls. Biochar application significantly enhanced several key soil chemical properties, including pH levels, cation exchange capacity (CEC), and nutrient retention, especially at higher application rates. The incorporation of biochar was observed to substantially elevate soil pH by the season's end, attributed mainly to its considerable calcium content. A biochar application rate of (20 tons/acre) notably increased the pH to 6.8 in the inorganic treatment and even higher to 7.2 in the organic treatment when combined with calcium-rich poultry litter. In scenarios without biochar, the sandy loam soils exhibited a decrease in pH levels by the end of the season, indicating biochar's crucial role in counteracting soil acidification. The study also highlighted that a high biochar application rate significantly improved CEC in both inorganic and organic production systems by the season's end, facilitating better nutrient retention in sandy loam soils. Furthermore, higher biochar applications were associated with lower nitrate concentrations, while the absence of biochar in both treatments led to increased nitrate levels. This pattern was similarly observed with ammonium levels, where higher biochar applications resulted in reduced concentrations, suggesting that biochar effectively prevents the volatilization of ammonia. The research supports the hypothesis that biochar functions like a sponge, retaining essential nutrients within the soil matrix. This study provides evidence that biochar presents a viable strategy for organic and inorganic farmers to enhance soil chemical properties over the long term, offering a sustainable solution to improve agricultural practices and tomato production.
Cantaloupes (Cucumis melo var. reticulatis) are a fruiting vegetable which grow best in warm environments. Cantaloupes also are infected by many foliar diseases which are triggered or exacerbated by rainfall and high relative humidity which is common during the growing season in Central Appalachia. One potential option for growing cantaloupes in West Virginia is high tunnel production. High tunnels significantly increase the air and soil temperature. In addition, the crop can be drip irrigated so there is no wet foliage for disease infection. Trellising may be necessary to facilitate harvest. Vertical trellising with pruning may be necessary for high tunnel production. Trellising can potentially increase marketable yield. However, trellis and pruning labor can be as high as $150/1000 ft2. Cantaloupes (cv. ‘Sugar Cube’) were transplanted within a high tunnel in 2023 and 2024. Vertical trellising and pruning were compared with non-trellised and non-pruned plants. Inputs such as labor and trellising supplies were recorded. In 2023, trellising did not significantly increase marketable yield of cantaloupes, but did significantly improve harvest efficiency.
Pumpkins are usually grown using wide row spacing, and in Minnesota, the canopy does not close until mid-summer and the canopy senesces in early- to mid-autumn. This provides opportunity for establishing frost-tolerant or winter-hardy cover crops between rows before the canopy closes, which will continue to grow after pumpkin foliage is gone. To understand more about competition between interseeded cover crops and pumpkins, four species of clover (berseem, crimson, Persian, and red) were sown between pumpkin rows (10-ft spacing) in late June, and pumpkin yield and clover growth and N content were measured in the fall. Both ‘Cotton Candy’ and ‘Kratos’ pumpkins were studied. ‘Kratos’ yield (68.4 Mg / ha; 1185 fruit / ha), fruit size (9.7 kg), and fruit size variability (28%) were 1.8 times, 0.55 times, 3.2 times, and 1.1 times as much as ‘Cotton Candy’, but none of these responses were impacted by clover. Above-ground biomass of berseem, Persian, and red clovers averaged 0.41 Mg / ha in late fall (16 kg N / ha), but crimson clover yielded 1.2 Mg / ha (33.3 kg N / ha). Clover grown with ‘Kratos’ yielded 69% of the dry matter and 73% of the aboveground nitrogen (per ha) compared to clover grown with ‘Cotton Candy’. The average C:N ratio of all treatments was 18.3. These results show that clover interseeded into pumpkins, especially crimson clover, can grow successfully without impact on pumpkins. High-vigor pumpkins can reduce clover yield, however.
Chile (Capsicum annuum) consumption and production have been integral to New Mexican culture for over four centuries, and the state is the leading producer of chile (non-bell peppers) in the United States. Chile farmers face adverse conditions due to climate change, water scarcity and disease control. One of the most prevalent chile diseases in NM is Beet Curly Top Virus (BCTV; Curtovirus). BCTV causes chlorotic curled leaves, stunted growth, abnormal or minimal fruit production, and a potentially substantial yield reduction. BCTV is transmitted by beet leafhoppers (Circulifer tenellus), insects that prefer feeding in areas exposed to full sun. Agrivoltaic systems (AVS), the co-location of solar panels in agricultural fields, increases field shade. Advantages of AVS have been examined, but its potential role as a deterrent for pests remains unknown. The aim of this study was to determine the impact of AVS shade on chile yields, beat leafhopper abundance, and BCTV incidence. On 16 May 2023 ‘NuMex Odyssey’, a New Mexico pod-type green chile was transplanted into four solar panel plots and a full sun control at the New Mexico State University Leyendecker Plant Science Research Center, Las Cruces, NM. Plots shaded by solar panels had an average of 15% less light radiation compared to the full sun control. Fruit was harvested on 21 Aug 2023 and sorted into marketable green, blossom end-rot affected, and curly top affected fruit. Preliminary results show that marketable green and blossom end-rot affected fruit yields did not differ between solar panel shaded and the full sun control plots. BCTV affected fruit yield was significantly greater in the full sun control, which also had 55% more trapped beet leafhoppers than the solar panel plots. Initial results show potential for AVS as a method to mitigate the adverse effects on chile yield caused by BCTV. In addition to alleviating crop stress, AVS has the potential to deter beet leaf hoppers while generating electricity, a potential extra revenue for the farmer.
Accurate monitoring of crop growth and estimations of yield are essential for optimizing agricultural practices and ensuring food security. Traditional approaches to monitor crop and map yield in vegetable crops often rely on ground-based observations, which can be time-consuming and labor-intensive. Remote sensing techniques offer a promising alternative by providing frequent and spatially extensive information on crop health and vigor. In this study, we aimed to assess the feasibility of using high-resolution satellite imagery to monitor crop growth and predict yield in Japanese squash (Cucurbita maxima) and onion varieties (Allium cepa) in Hollister, California, over the growing seasons of 2022 and 2023. Daily imagery from PlanetScope with a resolution of 3 m and on-demand 0.5 m imagery from Planet SkySat were utilized. Vegetation indices including the Normalized Difference Vegetation Index (NDVI) and the Soil Adjusted Vegetation Index (SAVI) were calculated at various times during the growing season. Statistical analyses were performed to explore the correlations between these indices and crop yield. The results indicate significant correlations between vegetation indices such as NDVI and SAVI and crop yield in Japanese squash and onion varieties. Higher vegetation index values were associated with increased crop yield, suggesting that these indices can serve as reliable indicators of crop health and vigor. The use of high-resolution satellite imagery allowed for timely and accurate monitoring of crop growth dynamics, facilitating informed decision-making for growers. This study describes the potential of high-resolution satellite imagery and vegetation indices for monitoring crop growth and predicting yield in Japanese squash and onion varieties. The importance of integrating remote sensing techniques into agricultural practices to improve crop management strategies and enhance productivity will be discussed in the presentation.
Much of the tomato production on market farms in the northeastern United States utilizes high tunnels. Tunnels protect soils from rainfall, reducing leaching of nutrients. However, if nutrients are accumulating below the root zone in tunnel soils lateral flow could be moving the nutrients beyond the covered area, resulting in leaching. From July 2020 to October 2022 we monitored soil moisture, soil temperature, and mineralization and movement of nitrate and phosphate in high tunnel tomato production on five commercial market farms (2 in Connecticut and 3 in Rhode Island). We also tracked irrigation water and fertilizer applications. Activated mixed-bed resin capsules were buried at 30 cm depth in transects running across the width of each high tunnel and extending 1 m past the tunnel perimeter on each side. Resin capsules were exchanged in March, July and October of each year and analyzed for captured nitrate, ammonium and phosphate. Soil P in the tunnels ranged from 16 to 363 kg/ha and soil K from 207 to
Consumers are motivated to purchase locally grown tomatoes for a maximum flavor experience. With this demand, tomatoes are highly valuable in the local food system and one of the most profitable crops for small, diversified farms. Tomato production in Oklahoma, and other warm climates, can be difficult with the fruit’s temperature requirements for fruit set. Optimum conditions are available for a short period in Oklahoma. The additional threat of climate change could present even more challenging growing conditions in the future. There are heat tolerant tomatoes available, but these cultivars still have an upper limit for stress exposure. Previous research shows that there are distinct physiological differences between heat tolerant and heat sensitive cultivars, but these evaluations focus primarily on the early stages of the plant’s development. We aim to investigate the differences in cultivars throughout the entire plant life cycle. A field experiment will include six cultivars at different planting dates, showing a range of responses. The three planting dates will impose different temperature regimes throughout plant development. Physiological measurements will be recorded at regular intervals from transplanting through harvest. These parameters will include chlorophyll fluorescence, stomatal conductance, and electrolyte leakage. The results will assist with development of a model that enhances Oklahoma tomato production capacity through optimizing cultivar selection.
Nutsedge Management Through Soil Steaming - Shaun Broderick Early Season Soil Tarping Impacts on Weed Pressure and Onion Production in Eastern South Dakota - Hannah Voye Associations Among Crop/Weed Management Practices and Environmental Factors Highlight Challenges Facing U.S. Snap Bean Production - Martin Williams Impact of Early Season Tarping on Soil Conditions and Weed Populations in North Central United States Vegetable Production Systems - Carly Strauser Applying Advanced Lighting Practices for Vegetable Propagation - Rose Seguin Evaluating the Effect of Three Algae Extracts Application on Three Crops Growth and Yield in Hawaii - Amjad Ahmad Using the Feekes Growth Stage Scale to Predict the Carbon to Nitrogen Ratio of Cereal Cover Crops - Eric Brennan Evaluating the effect of fertilization and controlled-water deficit on growth and yield of compact vegetable plants - Michael Fidler
Soils host weeds, pathogens, and insects that can cause crop damage and reduce yield. Many methods have been developed to reduce these pressures within the soil, including soil solarization, chemigation, anaerobic soil disinfestation, and soil steaming. We have utilized soil steaming to reduce weed seeds and soil infestation in high tunnel and field tomato (Solanum lycopersicum) production. While it successfully reduces most weed species and southern blight (caused by Athelia rolfsii) in tomatoes, the emergence of nutsedge (Cyperus spp.) in soils with established populations can increase after steaming. Our research goal was to evaluate the efficacy of various soil preparation methods prior to steaming to allow the steam to penetrate the soil and target nutsedge directly. Except where noted, the field was first chisel plowed, disced, and then shaped into 2-foot-wide by 6-inch-tall beds. We compared 8 preparation methods for controlling nutsedge: a no-till control, herbicide control using S-metolachlor and halosulfuron-methyl, 6-inch-tall bed size, 12-inch-tall bed size, chisel plowed row, black plastic mulch, 4-inch-deep trenches on no-till, and 6-inch-deep trenches on no-till. Four trenches were cut into the soil with a soil trencher for each plot. Four replicates were included in a completely randomized design. Half of each bed was steamed until temperatures reached 160 °F, 4 inches deep, except for the herbicide beds and mulched beds, which were left unsteamed. Four sets of temperature probes were placed 12, 8, 6, and 4 inches deep in the soil and temperatures and used to monitor temperature changes in steam soils over time. Nutsedge coverage was visually estimated by placing a 1 by 6-foot rectangular PVC frame in each row over a representative section. 12-inch-tall beds had nearly 100% nutsedge coverage, while 6-inch-tall beds had nearly 50%. Herbicides reduced nutsedge coverage to 29%, and the plastic mulch reduced coverage to 8%. The steamed no-till, 4-inch trench, 6-inch trench, and chisel-plowed beds had no nutsedge emergence through the trial. The 6-inch-tall beds had lower temperatures at 6 and 8 inches deep than the other methods, which could account for the observed increases in nutsedge emergence post steaming. The time-consuming nature of soil trenching would make it impractical for most horticultural production settings; however, the chisel plow and no-till could be readily adopted. Determining effective methods to prepare the fields for soil steaming to reduce or eliminate nutsedge will make soil steaming a more viable method for organic farmers facing nutsedge pressures.
Cereals and other non-legume cover crops can help vegetable farms to reduce nitrogen leaching to ground water during rainy winter periods. A cover crop’s carbon to nitrogen ratio is an important metric that can help farmers better understand the nitrogen release dynamics from soil-incorporated cover crops. Cover crops with a lower C:N ratio (15:1) typically mineralize nitrogen when they are incorporated into the soil, whereas those with a higher C:N (25:1) usually immobilize nitrogen. But farmers need simple, reliable, field-based methods to predict a cover crop’s C:N ratio. Therefore, we evaluated the relationship between the Feekes growth stage scale and the C:N ratio of rye (Secale cereale L., ‘cv. Merced’) and triticale (X Triticosecale Wittmack, cv. ‘Pacheco’) cover crops in the Central Coast region of California. Over a hundred field samples of rye and triticale shoots were collected at various developmental growth stages from organic and conventional vegetable farms and planting date trials, across multiple soil types, planting times, row spacings, and plant densities. The Feekes scale was correlated with the C:N ratio of cover crop shoots of rye (r2=0.63) and triticale (r2=0.76). The transition from Feekes 9 (when the ligule of the flag leaf is visible) to Feekes 10 (‘boot’ stage) is roughly when the C:N ratio went from below to above 20:1. Regression plots were developed that illustrate the relationship between the Feekes scale and the C:N ratio. These results have practical implications for a new ground water protection regulation (Ag. Order 4.0) in California’s central coast region that incentivizes winter cover crops that are grown until the C:N ratio is 20:1 or more.
Snap bean production has decreased by ~30% recently due to an increase in imports and changing consumer preferences towards more fresh and frozen products. A major production concern is weed species that escape control, since they cause yield losses and can contaminate harvest loads. Coupled with changing weather patterns, snap bean processors and growers will have to adjust to these and future challenges. Field surveys were conducted to identify associations among crop/weed management practices and environmental factors on snap bean yield and weed density. From 2019-2023, snap bean fields throughout the major U.S. production regions were surveyed for weeds at harvest. Management records for each field were obtained from growers. Information on soil and weather conditions of each surveyed field also was obtained. In total 358 production fields were surveyed in the Midwest (Illinois, Iowa, Minnesota, Wisconsin), Northeast (Delaware, Maryland, New York. Pennsylvania), and Northwest (Oregon, Washington) regions. To determine associations among management and environmental variables on crop yield and weed density, the machine learning algorithm random forest was utilized. The models had 24 and 22 predictor variables for crop yield and weed density, respectively, and both were trained on 80% of the data with the remainder used as a test set to determine model accuracy. Partial dependence plots were used to visualize the change in response variables based on the most important predictors. The crop yield model had pseudo-R2 values of 0.56 and an accuracy of 74%. Higher average temperatures during early season growth, higher soil organic matter content, and planting midseason (June-July) predicted an increase in average crop yield. Meanwhile, excessive precipitation early in the season, high sand content of the soil, high temperatures at crop flowering and row cultivation predicted a decrease in crop yield. The weed density model had pseudo-R2 values of 0.55 and an accuracy of 81%. While row cultivation was associated with lower snap bean yield, it corresponded to a decrease in weed density, suggesting row cultivation had less-than-ideal selectivity between the crop and weed. Moreover, multiple spring tillage operations prior to planting predicted an increase in average weed density, implying that excessive tillage may favor emergence of weeds in snap bean. Over the coming decades, climate change-driven weather variability is likely to influence snap bean production, both directly through crop growth and indirectly through weeds that escape control practices that also are influenced by the weather.
Weed management is one of the biggest challenges vegetable growers face. Plastic mulch, herbicides, tillage, and hand-weeding are common ways vegetable growers manage weeds. These methods can be labor intensive, require specialized equipment, and cause environmental harm. Tarping is an alternative weed management method. Silage tarps or high-tunnel plastics are commonly used tarping materials; these are multi-functional tools that can be used for several years. Tarping facilitates stale seedbed weed management techniques by modifying the soil microclimate and promoting weed germination. After weed germination, opaque tarps can terminate weeds via occultation (lack of sunlight), whereas clear tarps terminate weeds by creating extreme temperatures. More information is needed for the type and timing of early-season tarp application for optimal weed control. The research was conducted at the Iowa State University Horticulture Research Stations in Ames, IA. This study examined three types of tarps: black, white, and clear, at three different durations: two, four, and six weeks prior to planting compared to a non-tarped control. Clear tarp and control treatments were cultivated at the time of tarp removal prior to planting. Soil temperature was recorded at 5 centimeters depth for 6-week tarp treatments. Early-season clear tarping did not elevate temperatures enough to terminate the majority of weeds. However, black and white tarps created a weed-free planting bed. Average soil temperatures underneath the clear tarp were the warmest (21.8ºC), followed by black tarp (15.1ºC). White tarp treatments (11.7ºC) had a lower average soil temperature than treatments with no tarp (14.8ºC). Two weeks following tarp removal, six-week clear tarp treatments had a higher percent weed cover than black and white tarp treatments measured using Turf Analyzer, a digital photo analysis software. Differing soil temperatures did not significantly impact soil microbial biomass carbon. The two-week white tarp had significantly higher soil microbial biomass nitrogen than all other treatments except four-week clear tarp. There was no effect of tarp type or duration on onion crop yield. These results indicate that the use of white and black tarps can be a feasible alternative weed management method in North Central vegetable production systems.
Propagation greenhouses produce a wide range of crops, each presenting unique responses to light quality and quantity. With dynamic LED lighting solutions now available and proven to be viable over large acreages, propagators can tailor their lighting protocols to each crop with regards to zone management, photoperiod, spectrum and intensity. The effects of light quality and quantity on plant morphology and growth are well documented and while the exact impact is not generalizable across all crops and varieties, certain themes hold true. For example, high levels of blue light are generally associated with compact plants and thick, waxy leaves. In contrast, high levels of far-red light can cause etiolation in multiple species through the shade avoidance response but enhances photosynthesis and growth when combined with red light. Given the high importance of crop morphology in propagation, dynamic Dynamic LED lighting has been used to develop advanced lighting protocols in the propagation of fruit, vegetable and ornamental crops. In the production of cucumber transplants, applying high levels of blue light and a long photoperiod effectively slows the growth of cucumber transplants at the end of the propagation cycle, a strategy which proved useful to a propagator looking to delay transplant delivery per the client’s request. Concretely, the combination of high blue levels and a long photoperiod slowed crop growth, prevented tendril development and restricted plant stretching. Further, the use of high-blue treatments over young leafy greens effectively reduced plant height by 2-3 cm and produced stronger plants. Another trial focused on the production of strawberry tray plants found that a balanced light spectrum produced more stolons (i.e., daughter plants) while a blue-enriched spectrum produced significantly more leaves. In the production of ornamentals, dynamic lighting can be used to reduce the greenhouse’s reliance on plant growth regulators (PGRs), enhance leaf or petal coloration and trigger bud formation. In red-leafed varieties, controlled light-induced plant stress through spectral and/intensity adjustments have proven effective at stimulating the production of red pigments and enriching the leaves’ hue. Results from various commercial and research trials demonstrate benefits of dynamic LED lighting in the propagation of horticultural and ornamental crops alike. This presentation presents data from the aforementioned case studies among others.
Rose Séguin is an agronomist specializing in controlled environment agriculture, with previous experience in indoor agriculture, agricultural innovation systems, and agricultural development in remote areas of Canada. She holds a bachelor's degree in agro-environmental sciences and... Read More →
Tuesday September 24, 2024 2:45pm - 3:00pm HST
Kahili
Food- and nutritional-security are among the highest concerns for Hawaii residents. The state imports about 85% of the consumed food and there’s roughly two-week worth of food locally at any given time. Local food production is costly due to high inputs cost. Algae extracts are known to supports plants' flowering and fruiting, increasing plant nutrient uptake, enhancing resistance and recovery from plant stress events, and increasing nutrient use efficiency and fertilizer assimilation. Three different algae extracts (Afrikelp, Acadian, and Kelpak) were evaluated for their effect on growth and yield of bush bean, bell pepper, and tomato in a randomized complete block design (RCBD) with 5 blocks. The algae extracts were applied 5 times during each growing season. The algae extracts were applied at dilution rate of 1:100 with a week between applications for the bush bean crop and two-week intervals for bell pepper and tomato crops. The results showed a highly significant (p < 0.01) increase in the three crops yield under all algae extracts compared to control (water only) treatment. The results also showed there was a significant (p < 0.05) difference between the algae extracts with highest yield recorded under Afrikelp extract compared to Acadian and Kelpak. The yield increase reached between 150-300% compared to control treatment.
Onions are a globally popular kitchen staple, not only for their flavor, but also their nutritional value. According to the Agricultural Marketing Research Center, onions are the fourth most consumed fresh vegetable in the United States. To bring this valued crop to our kitchen tables, quality onions must be produced in high quantities to meet consumer demands. Since they are especially susceptible to weed competition due to their minimal canopy cover, weed management is an important consideration for onion production. One weed management tool is soil tarping. This study evaluated the impact of two types of tarping (solarization and occultation) and duration of tarping (6-, 4- and 2-weeks) on weed control in Patterson and Candy onion production. Field experiments were conducted during the 2023 growing season in Brookings, South Dakota. Solarization was conducted using clear tarps secured with sandbags and buried edges. Tarps were placed in April and May at respective weeks before removal on May 30. Immediately following tarp removal, each plot was tilled, and rows of onion transplants were planted. Occultation was evaluated using white side up and black side up silage tarps, both applied at respective weeks before removal and onion planting. Each treatment plot filled a twenty-four by ten-foot area. A randomized complete block design with four blocks and ten treatment plots per block including a control with no tarp was established. Response variables for data collection included weed type, height, and biomass as well as onion yield. All tarping treatment plots resulted in less weed pressure than the control at tarp removal. Broadleaf weed count collected during the growing season was different among tarp treatments (p=0.03). Data collected June 12 showed 6-week clear tarp to have 67% less broadleaf weed count per acre than the control, and 74% less than the 4-week black tarp. There was no difference in onion yield due to tarping treatment. This may have been due to biweekly weeding events that evened out treatment effect on weeds over the growing season. There was, however, a difference in yield between Candy and Patterson onion cultivars (p=0.02). Candy averaged a marketable count of 19 of 48 planted onions while Patterson averaged a marketable count of 36 of 48 onions planted. Soil tarping may be an effective option for farmers to reduce early season weeds in onion production, however, it should be used alongside other management strategies to obtain a viable yield.
Sales of compact vegetable bedding plants for the home-gardening market segment are increasing. However, production guidelines for these new crops are limited. Our objective was to assess the effect of fertilizer use and controlled-water deficit (CWD) on plant growth during production, and after-production effects on fruit yield. ‘Siam’ tomato and ‘Basket of Fire’ pepper plants were grown in a greenhouse for 4 and 6 weeks, respectively, using 10-cm containers. Half of the plants received a water-soluble fertilizer once a week, and the other half were irrigated with tap water only, relying on the starter fertilizer charge in the substrate (EC = 0.9 mS·cm−1). Plants were irrigated when the substrate volumetric water content (VWC) reached 0.15, 0.30, 0.45, or 0.60 m3·m–3. After the experiment, plants were transplanted into 20-cm containers, top-dressed with controlled-release fertilizer (CRF), and grown for another 10 weeks to evaluate carryover treatment effects. Plants that did not receive fertilizer were shorter and had a lower shoot dry mass (SDM) than those that were fertilized, regardless of species. Shoot height of tomato followed a quadratic trend in response to CWD, which peaked at 0.45 m3·m–3, whereas SDM linearly increased with increasing VWC. No growth responses to CWD were measured for pepper. However, plants of both species that did not receive fertilizer looked chlorotic and had a lower chlorophyll concentration than those that were fertilized (15 and 32 µmol·m–2 for tomato and 15 and 27 µmol·m–2 for pepper, respectively). Plant greenness increased after applying CRF, suggesting that applying fertilizer right before shipping could increase quality of these plants when grown with limited or no fertilizer to control growth. After the carryover phase, differences in plant growth were maintained, and differences in yield was measured between fertilized and non-fertilized plants (56 and 48 fruits for tomato and 153 and 112 fruits for pepper, respectively). Our results show that growth and yield of compact tomato and pepper plants are affected to a larger extent by fertilizer use than by substrate VWC.
