Total Marketable Yield Research Articles

Impact of Foliar Application with Calcium under different Kaolin Rates on Growth and Yield of Tomato Grown in High Temperature Condition

Two experiments were carried out at a private farm located in Dimiana village, Belqas District, Dakahlia Governorate, Egypt during the two consecutive summer seasons of 2018 and 2019 to study the effect of different rates of kaolin (0.0, 20, 40 and 60 g /l) in combined with calcium (0.0, 400 and 800 mg/l) on vegetative growth, water relations, leaf chemical composition as well as fruits yield and its quality of tomato.. The obtained results revealed that the highest values of plant height, leaf area per plant, leaf dry matter percentage, relative water content percentage, leaf pigments, fruit yield per plant as well as total marketable yield per feddan, vitamin C and lycopene content of tomato plant were achieved with kaolin at 40 g/l with significant difference comparing the other rates under study. While, increasing kaolin to 60 g/l decreased the above mentioned parameters during both seasons. Furthermore, increasing calcium rate from 400 to 800 mg/l increased tomato growth and productivity compared to control (untreated plants). In general, it could be concluded that spraying tomato plants with 40 g/l of kaolin combined with 800 mg/l of calcium, showed improvement in vegetative growth parameters, water relations, leaf pigments, fruits yield and its components as well as fruits chemical constituents under Dakahlia Governorate conditions.

Estimation of fruit quality parameters in different genotypes of bitter gourd (<em>Momordica charantia</em> L.)

Study of 40 genotypes of Bitter gourd was carried out during Kharif season 2014 and 2015 in central Uttar Pradesh, India to study the association among fruit quality and their direct and indirect influence on total marketable fruit yield and income. Observations were recorded on Total Soluble Solid (TSS) and vitamin C content and data analyzed statistically. Comparatively higher total soluble solid was recorded in IC-085626 (4.96 & 5.58) and maximum Vitamin ‘C’ was recorded in IC-085612 (81.05 & 81.57) followed by IC-085616 (80.49 & 81.04) and IC-085622 (76.67 & 79.88) which were statistically at par with each other and significantly higher from the check germplasms. Minimum Vitamin ‘C’ was recorded in PBIG-5 (70.47 & 71.20) during both the years of investigation. It was possibly due to genotypic and phenotypic characters of the germplasms respectively during both the years of investigation suggesting most efficient as well as highly profitable.

Yield and quality of three potato cultivars under series of nitrogen rates

AbstractUndesirable growth of potato (Solanum tuberosum L.) crop under an excessive N fertilizer application is the main obstacle presently. This research was conducted to investigate the response of different potato cultivars; Russet Burbank, Shepody, and Superior, and its qualitative characteristics under a series of N rates. Six rates of N fertilization (0–280 kg ha−1) were applied on 11 sites in a randomized complete block design, with four replications. Sites with ≥30 g kg−1 of soil organic matter (OM) produced total tuber yield, marketable yield, and tuber weight per plant 39.5, 45.2, and 54.9%, respectively, higher than sites with ≤30 g kg−1 of OM. Tubers specific gravity increased by 0.18% in the sites with ≥30 g kg−1 of OM. The total tuber yield for the three cultivars was maximized at 168 kg N ha−1. Marketable specific gravity, starch, and dry matter content were achieved by applying 168 and 112 kg N ha−1 at ≤30 and ≥30 g kg−1 of OM sites, respectively. Russet Burbank produced a higher yield than Shepody and Superior cultivars significantly, but there was no significant difference among them regarding specific gravity. Excessive N application (>168 kg ha−1) decreased potato tuber production and quality.

The effect of novel biodegradable films on agronomic performance of zucchini squash grown under open-field and greenhouse conditions

The soil mulching is an important agricultural practice for increasing crop productivity and earliness. Mulching can be made with natural or synthetic materials. The common films being used these days are usually made of low density polyethylene (LDPE), but its disposal can represent a serious environmental and economic problem. The biodegradable mulching can overcome these problems. Two experiments were carried out comparing the effects of biodegradable and LDPE mulching films on yield and quality of zucchini (Cucurbita pepo L.) grown in two environments (open-field vs. greenhouse). In both the environments a randomized complete block design was adopted. The treatments composed of no-mulched crop (control), soil covered by 15 microns black biodegradable film (MB15) and soil covered by 50 microns black LDPE film. The results showed that MB15 was able to maintain discrete technical proprieties until the end of cycle, especially in greenhouse, assuring a sufficient heating of soil, similar to LDPE. The soil heating promoted crop development. Furthermore, earliness was increased (84 in greenhouse vs. 99 days in open air) in greenhouse. The early production of zucchini grown on MB15 was similar to the one in LDPE production in greenhouse. The total marketable yield of plants grown on both films was not different but it was lower in open air. The biodegradable film significantly improved fruits quality, with higher values of firmness and total soluble solid than fruits grown on LDPE.

Determination of optimum nitrogen concentrations in hydroponics for tomato grown in coir medium in tropical greenhouse

Protected culture is a production technology for growing high-value horticultural crops. Fertigation in soilless culture is a major determinant of the quality and quantity of the greenhouse crop yields. Nitrogen is the widely used plant nutrient in fertigation and also the major potential environmental contaminant. Mismanagement of nitrogen in different growth stages has been reported in literature. Therefore, increasing of nitrogen use efficiency is vitally important for ensuring economic and environmental sustainability of protected culture. This study was conducted to determine optimum rates of nitrogen application for tomato addressing the plant nutrient status and total marketable yield. Tomato plants were fertigated with a progressive array of ten N treatments covering vegetative and reproductive stages. Plant analysis, growth parameters and total harvest were measured to find out the optimum nitrogen requirement. The treatment, supplied with N rates of 50, 60, 90 and 140 mg/plant/day at vegetative, early, middle and late reproductive stages, respectively showed the highest plant response. Thus it was selected as the most appropriate fertigation schedule for tomato grown soilless culture which comparatively increases tomato yield while reducing the cost of fertilizer and environmental hazards associated with excessive use of N fertilizer.

Performance of Potato (Solanum tuberosum L.) varieties Using True Potato Seed (TPS) at Gerado, Northeastern Ethiopia

Potato is one of economically important crop in Ethiopia. However, the average yield is far below the potential due to many challenges like lack of improved variety and quality seed potatoes. True potato seed is alternative seed source for potato production with many advantages, particularly where seed tubers is hampered by diseases. TPS used in Ethiopia, is negligible but it is likely to gain thrust in future particularly where quality seed tubers are either not available or expensive. Therefore, this study was conducted to evaluate the performance of potato varieties established by open-pollinated TPS seedling for yield and yield components. Eight potato varieties (Local, Bulle, Challa, Dagim, Gudanie, Jalenie, Shonkolla and Zengena) were established by open-pollinated TPS seedling for yield and yield components. The experiment laid in Randomized Complete Block Design with three replications. The results revealed that a significant variation in most traits was observed. The highest plant height (118.87cm) was recorded from Zengena. Bulle scored the highest marketable, unmarketable, total tuber number and marketable tuber yield per hill was 25.31, 26.03, 51.34 and 1.1117kg respectively. Local scored the highest tuber weight (1.2949 kg hill -1 ) and tuber yield (54.44 ton ha -1 ) but not significant different with Bulle, Gudanie, Dagim and Challa varieties due to its highest unmarketable tuber yield (0.3296 kg hill -1 ). The result of the study reviled that the open-pollinated potato varieties established through TPS have a great influence on yield and yield components of potato. Bulle variety has been recommended in all yield and yield components than others. Keywords : Potato, variety, Tuber number, Tuber yield, Tuber weight, True Potato Seed (TPS) DOI : 10.7176/JNSR/9-22-02 Publication date: November 30 th 2019

Genetic mapping of tuber size distribution and marketable tuber yield under drought stress in potatoes

Drought sensitivity of potato leads to a reduction in total tuber yield and marketable yield. An investigation of drought effects on tuber yield attributes will facilitate our understanding of how to reduce such huge yield losses. We have evaluated tuber yield, tuber size distribution and marketable yield of a set of 103 European commercial potato cultivars under irrigated and non-irrigated conditions in the field. The multi-year results from two locations, Connantre, France (2013–2015) and Nieuw-Namen in Zeeland, The Netherlands (2013–2014), were analysed. We used Normal and Gamma Distribution models to describe the tuber size distribution of tuber fresh weight and tuber number, respectively. The interactions among parameters of tuber size distribution and total/marketable tuber yield traits were analysed using correlation matrices and biplots. Finally, we used a 14K Infinium SNP marker array to find associations between the parameters or traits and genetic loci on the potato genome. Late foliage maturity facilitated a wider spread of tuber size distribution in favour of larger-sized tubers. Drought effects on total yield were representative of their impact on marketable yield, however, absolute values of total tuber number may not be indicative of marketable number of tubers. We found significant marker-trait associations between a region on chromosome 3 and the spread of tuber number distribution, size class with maximum tuber number and marketable fractions of tuber number and tuber weight. These findings will contribute to improvement and selection for drought tolerance in potato.

ABSCISIC ACID AND IRRIGATION LEVELS EFFECTS ON MORPHOLOGICAL CHARACTERISTICS OF STRAWBERRY

The high value of strawberries creates potential for high rates of employment and farm income in Turkey. Optimizing water application and effective cultivation practices are of considerable importance in improving strawberry yield. In this study, the effects of four different irrigation regimes and Abscisic Acid application (ABA use and control) effects on the leaf area, plant dry matter and crown number of strawberry (Fragaria × ananassa cv. Rubygem) were evaluated under Spanish type high tunnels conditions. ABA was applied three times starting from March to May via foliar application as 20 μmol L-1. From the initiation of the treatment to the end of the trial, a total of 552, 447, 342 and 237 mm of water were applied to treatments IR125, IR100, IR75 and IR50 respectively. The IR50 treatment caused a significant decline in morphological parameters, indicating that the amount of irrigation water did not meet the plant water requirement. The increased amount of irrigation water increased the leaf area, dry matter and the crown number significantly. Furthermore, the ABA application increased the leaf area by 15%, the plant dry matter 12% and crown number by 8%. Under water stress conditions (IR50), ABA significantly increased growth rate as well as increasing leaf area, plant dry matter and the crown number by 13%, 12% and 11%, respectively, when compared to the control plot. Consequently, in the protected cultivation, the IR125 irrigation level and the ABA application enhanced vegetative growth and in turn the total marketable fruit yield and its components.

The Effect of The Density of Cucumber Nested with The Potato Crop to Reduce The Damage of The White Fly And Its Effect on 2 - The Population Density of The Insect and Some Characteristics of The Quantitative Yield of The Potato Crop

أجريت التجربة في أحد الحقول الزراعية في محافظة كركوك في الموسم الخريفي 2017 لدراسة تأثير كثافة نبات الخيار المزروع متداخلا مع محصول البطاطا على الكثافة السكانية للذبابة البيضاء وبعض صفات الحاصل الكمية للبطاطا، تضمنت الدراسة عاملين الأول ثلاثة أصناف من البطاطا وهيActrice وAlaska وOxyania وأربعة مستويات من كثافة نبات الخيار المزروع متداخلا مع محصول البطاطا وهي 0 و1 و2 و3 نبات خيار لكل وحدة تجريبية والتي تبلغ مساحتها 3 م2، احتوت التجربة اثنتا عشرة معاملة ناتجة عن التوافيق بين العاملين أعلاه، طبق نظام الالواح المنشقة بتصميم القطاعات العشوائية الكامل (RCBD) وبثلاثة مكررات واختبرت معنوية الفروق بين المتوسطات وفق اختبار دنكن متعدد الحدود عند مستوى احتمال 0.05 وأظهرت النتائج ما يلي: تفوق الصنف Actrice بأقل عدد من حشرات الذبابة البيضاء المتواجدة على أوراقه بلغت 12.90 حشرة لكل عشرة أوراق، كما أن زراعة الخيار متدخلا مع البطاطا وبكثافة نباتين لكل وحدة تجريبية (3 م2) أدى إلى تواجد أقل عدد من الحشرات بلغت 6.03حشرة لكل عشرة أوراق من محصول البطاطا. وتفوق الصنف Actrice معنويا بصفات الحاصل الكلي للنبات الواحد815.00) غم نبات-1(والحاصل القابل للتسويق للنبات الواحد 676.9) غم نبات-1) والحاصل الكلي القابل للتسويق 36.10) طن هـ-1(، بينما تفوق الصنفAlaska في عدد الدرنات الكلية للنبات 10.724) درنة نبات-1) وعدد الدرنات القابلة للتسويق 7.973) درنة نبات-1)، في حين تفوق الصنف Oxyania في متوسط وزن الدرنة للحاصل القابل للتسويق 93.85) غم درنة-1). كما بينت النتائج أن زراعة نبات الخيار متداخلا مع نبات البطاطا وبكثافة نباتين للوحدة التجريبية أدى إلى الحصول على أفضل القيم في صفات عدد الدرنات الكلي 11.838) درنة نبات-1 (وعدد الدرنات القابلة للتسـويق 9.946) درنة نبات-1) والحاصل القابل للتسويق للنبات (724.1غم نبات-1) والحاصل الكلي للنبات 852.778) غم نبات (1-والحاصل الكلي القابل للتسويق (38.62طن هـ1-) .

Assessing Heat Management Practices in High Tunnels to Improve the Production of Romaine Lettuce

A three-year experiment evaluated the beneficial effects of independent and combined practices on thermal conditions inside high tunnels (HTs), and further investigated the temperature impacts on lettuce production. Specific practices included mulching (polyethylene and biodegradable plastic films, and vegetative), row covers, cover crops, and irrigation with collected rainwater or city water. The study conducted in eastern Tennessee was a randomized complete block split-split plot design (RCBD) with three HTs used as replicates to determine fall lettuce weight (g/plant) and lettuce survival (#/plot), and the changes in soil and air temperature. The black and clear plastic mulches worked best for increasing plant weight, but when compared to the bare ground, the higher soil temperature from the plastics may have caused a significant reduction in lettuce plants per plot. Moreover, the biodegradable mulch did not generate as much soil warming as black polyethylene, yet total lettuce marketable yield was statistically similar to that for the latter mulch treatment; while the white spunbond reduced plant weight when compared with black plastic. Also, row covers provided an increased nighttime air temperature that increased soil temperature, hence significantly increased lettuce production. Cover crops reduced lettuce yield, but increased soil temperatures. Additionally, irrigation using city water warmed the soil and provided more nutrients for increased lettuce production over rainwater irrigation.

Soil Solarization and Calcium Cyanamide Affect Plant Vigor, Yield, Nutritional Traits, and Nutraceutical Compounds of Strawberry Grown in a Protected Cultivation System

Soil solarization is a hydrothermal procedure of disinfesting soil of soilborne diseases and pests. Solarization can be combined with many other chemical or non-chemical alternatives to afford integrated pest and diseases management or improve plant yield. Calcium cyanamide (CaCN2) is a fertilizer used in agriculture sector and is also effective in suppressing soilborne pathogens. The present study assessed the influences of different pre-plant CaCN2 dosages on strawberry grown on solarized or non-solarized soil. Soil solarization and 500 kg ha−1 CaCN2 significantly increased early marketable yield by 105.3%, total marketable yield by 53.0% and firmness by 3.0%, respectively compared with the control (no solarization × 0 kg ha−1 of CaCN2). Exposing solarized plots to CaCN2 at 1000 kg ha−1 significantly increased fruit ascorbic acid content by 77.5% and phenolic content by 13.3% compared with fruits from control plants. Overall, plants grown on solarized soil performed better than those cultivated on no-solarized plots. Plants grown on soil treated with a dosage of 500 or 1000 kg ha−1 CaCN2 increased plant height, number of shoots plant−1, number of leaves plant−1, root collar diameter, plant visual quality, anthocyanins, and antioxidant capacity compared to control plants. Fruits from plants grown on soil exposed to CaCN2 with a dosage of 500 and 1000 kg ha−1 showed a lower N fruit content (5.4 and 19.5%, respectively) than control plants (non-treated control).

Evaluation of Tomato (Solanum lycopersicum L.mill) Varieties for Yield and Fruit Quality in Ethiopia. A Review

Tomato is one the most important vegetable crop in Ethiopia. Different variety evaluation experiments were conducted in regions and across regions of Ethiopia by research, higher learning institutions and non-governmental institutions. Among tomato varieties evaluated under open field and greenhouse condition at JUCAVM, variety Marglobe and Moneymaker showed the highest total fruit yield per plant in greenhouse. From ten improved tomato varieties with one local check evaluated at Agaro and Jimma for their yield, Varieties ARP tomato D2, showed superior and scored a marketable fruit yield of 22.18 ton ha -1 at Jimma and variety Fetan showed highest yield 10.67 ton ha -1 at Agaro. In Borena YPDARC, there were variations among the varieties evaluated in fruit yield ton ha -1 . In Erer valley of Babile, Melkashola scored 30.86 ton ha -1 and Bishola 28.69 ton ha -1 . Under irrigation deficit experiment both shoot and fruit weight loss was decreased with increase in stress level while the fruit dry matter weight increased. The total yield and marketable yields were decreasing as the deficit level was increased. Fruit soluble solid content increased with increase in water stress. Among the Hybrid varieties evaluated at Melkassa, Debreziet, Koka, Wonji and Ziway districts in Central Rift Valley of Ethiopia during off-season under irrigation, variety Venis was the highest yielding with preferable quality tomato. In the response to tested locations, Koka site show the highest total yield of 93.45 ton ha -1 which is all most all double of Melkassa area. From the nine Evaluated tomato varieties at Humera agricultural research center (HARC), the highest marketable yield was obtained by Melkasalsa (56.07ton ha -1 ) and the least yield was recorded by Bishola (17.89 tonha -1 ). Keywords: fruit quality, fruit yield, improved variety and hybrid variety. DOI : 10.7176/JNSR/9-17-02 Publication date :September 30 th 2019

Evaluation of Tomato (Solanum lycopersicum L.mill) Varieties for Yield and Fruit Quality in Ethiopia. A Review

Tomato is one the most important vegetable crop in Ethiopia. Different variety evaluation experiments were conducted in regions and across regions of Ethiopia by research, higher learning institutions and non-governmental institutions. Among tomato varieties evaluated under open field and greenhouse condition at JUCAVM, variety Marglobe and Moneymaker showed the highest total fruit yield per plant in greenhouse. From ten improved tomato varieties with one local check evaluated at Agaro and Jimma for their yield, Varieties ARP tomato D2, showed superior and scored a marketable fruit yield of 22.18 ton ha -1 at Jimma and variety Fetan showed highest yield 10.67 ton ha -1 at Agaro. In Borena YPDARC, there were variations among the varieties evaluated in fruit yield ton ha -1 . In Erer valley of Babile, Melka shola scored 30.86 ton ha -1 and Bishola 28.69 ton ha -1 . Under irrigation deficit experiment both shoot and fruit weight loss was decreased with increase in stress level while the fruit dry matter weight increased. The total yield and marketable yields were decreasing as the deficit level was increased. Fruit soluble solid content increased with increase in water stress. Among the Hybrid varieties evaluated at Melkassa, Debreziet, Koka, Wonji and Ziway districts in Central Rift Valley of Ethiopia during off-season under irrigation, variety Venis was the highest yielding with preferable quality tomato. In the response to tested locations, Koka site show the highest total yield of 93.45 ton ha -1 which is all most all double of Melkassa area. From the nine Evaluated tomato varieties at Humera agricultural research center (HARC), the highest marketable yield was obtained by Melkasalsa (56.07ton ha -1 ) and the least yield was recorded by Bishola (17.89 tonha -1 ). Keywords: fruit quality, fruit yield, improved and hybrid variety. DOI : 10.7176/FSQM/89-03 Publication date : August 31st 2019

Efficacy of different management practices against tomato fruit borer, helicoverpa armigera hubner

The study was conducted to evaluate the efficacy of different management practices to control tomato fruit borer (TFB) under field condition. The field experiment was carried out with eight treatments, namely Neem oil, Mahogany oil, Fish and Fermented Gur (brown sugar), Netting, Chlorpyriphos, Emamectin Benzoate and Cartap along with untreated control in Randomized Complete Block Design (RCBD) and each treatment was replicated thrice. The study was under taken during the period from 25 October, 2017 to 06 April 2018. Data were collected on number and weight of total fruits plot-1, number and weight of total healthy fruits plot-1, number and weight of total infested fruits plot-1, fruits infestation (%) in number and weight, infestation reduction over control for number and weight, number of holes, and larvae plot-1, total yield plot-1 and marketable yield plot-1. Among the different management practices, netting provided the highest infestation reduction over control. The percent fruit infestation reduction over control (number basis) was the highest in Netting treated plot resulting 61.87%, 73.27%, 84.68% and 92.70% at four different harvests, respectively. The percent fruit infestation reduction over control (weight basis) was the highest with the same treatment resulting 61.38%, 74.26%, 88.41% and 91.71% at four different harvests, respectively. The number of holes plot-1 was also the lowest in Netting treated plot resulting 5.00, 8.00, 15.33 and 8.67 at four different harvests, respectively. The number of larvae plot-1 was the lowest with the same treatment resulting 2.00, 2.33, 3.67 and 3.00 at four different harvests, respectively. The maximum marketable yield (33.95 t ha-1) was achieved in the Emamectin Benzoate treated plot with the highest (1.46) benefit cost ratio.
 Bangladesh J. Agril. Res. 44(2): 339-353, June 2019

Jatropha – Potential of biomass steam processing to convert crop residues to bio-coal and thus triple the marketable energy output per unit plantation area

Jatropha curcas cultivation is being undertaken mainly for fuel oil production, but it also results in biomass residues such as fruit husks, seed shell, seed cake or kernel meal, together making up >80% of the dry fruit weight. Additionally, plant biomass from crop management is also generated. The various biomass residue fractions have gross energy contents ranging from 13 MJ/kg to over 18 MJ/kg. The conversion of these residues into marketable products would contribute to broadening the circumstances under which the jatropha crop is profitable. Biomass Steam Processing (BSP) is a steam assisted thermochemical conversion process, which aims to increase the energy density of lignocellulosic feedstock. Basically, during this process biomass is heated to a temperature of 250–400 °C in a steam atmosphere at atmospheric pressure. It converts biomass residues efficiently into bio-coal in a relatively short time period of about 1 h. In the current investigation, BSP was deployed to transform different potential jatropha crop and seed processing residues into marketable high quality bio-coal. The energy density of jatropha residues could be raised considerably, resulting in an estimated total marketable energy yield of 90 GJ per year per hectare of a 5-year-old jatropha plantation compared to a total yield of 30 GJ per year when jatropha oil alone is marketed, as currently practiced.

Effect of Municipal Solid Waste Compost, Farm Yard Manure, Inorganic Fertilizers and Their Combinations on Potato Yield in Wolmera District, Ethiopia

The study was conducted in Wolmera district of Oromia Regional State, Ethiopia. The main research objective was to evaluate the effect of municipal solid waste compost on potato yield in comparison to inorganic fertilizers and farm yard manure and combined applications. The experimental design was a factorial in randomized complete block design (RCBD) with three replications. The treatments were: i) combination of diammonium phosphate (97.5 kg/ha), urea (82.5 kg/ha) and municipal solid waste compost (10,000 kg/ha), ii) combination of diammonium phosphate (97.5 kg/ha), urea (82.5 kg/ha) and farm yard manure (10,000 kg/ha), iii) diammonium phosphate (195k g/ha) and urea (165 kg/ha), iv) farm yard manure (20,000 kg/ha), v) municipal solid waste compost (20,000 kg/ha), and vi) control. The findings of the research indicated that the combination of municipal solid waste compost and inorganic fertilizers resulted in the highest total tuber yield and total marketable yield, 18.2±0.7 ton/ha and 17.8±0.7 ton/ha, respectively, with 149% relative marketable yield advantage over control. Sole application of municipal solid waste compost was also resulted in significant (P=.05) potato yield increment compared to the control. It resulted in an increase of marketable potato tuber yield advantage of 52% over the control with total marketable yield of 10.9±0.9 ton/ha. Hence, combined use of municipal solid waste compost and inorganic fertilizers may be a promising option for poor potato farmers around the City of Addis Ababa.

Fertilizer Program Impacts Yield and Blossom End Rot in Bell Pepper

High-value vegetable crops such as bell pepper (Capsicum annuum) are heavily fertilized by growers who seek to maximize yields. Field experiments were conducted in Spring 2016 and 2017 evaluating two liquid fertilizers with and without calcium (Ca), applied at three nitrogen (N) and potassium (K) levels in two varieties of bell pepper to determine whether current fertilizer recommendations were adequate and whether fertilizer source impacted fruit yield and quality. Plants were grown using plastic mulch and drip irrigation following standard production practices for the region. Two liquid fertilizer programs [7N–0P–5.8 (7–0–7) and 4N–0P–6.6K/9N–0P–0K–11Ca (4–0–8/CN9)] were applied twice weekly at three N rates (175, 200, and 225 lb/acre N). Yield, cull rate, and foliar nutrient concentrations were measured. In 2016, total marketable yields were greatest [910 boxes/acre (28 lb/box)] and blossom end rot (BER) incidence (14.4%) lowest in plants grown with the supplemental Ca (4–0–8/C9 fertilizer) at 175 lb/acre N. Cull rates increased in plants grown without supplemental Ca during the season (7–0–7 fertilizer), with BER incidence ranging from 22.9% to 27.2%. Yields ranged from 590 to 740 boxes/acre in plants grown without supplemental Ca in 2016. In 2017, yields ranged from 530 to 790 boxes/acre in plants grown with supplemental Ca at 200 and 175 lb/acre N, respectively. Culls due to BER were lower in 2017 than in 2016. In 2016, BER incidence was greater in ‘PSO9979325’ compared with ‘Antebellum’, despite no differences in total yield. Foliar nutrient levels were largely unaffected by fertilizer program; however, foliar N and K concentrations increased with the rate of N and K fertilization. The results of this study suggest that using liquid fertilizer program containing some Ca may benefit bell pepper growers in some, but not all, growing seasons.

Yield, Quality, and Performance of Organic Sweetpotato Slips Grown in High Tunnel Compared with Open Field

Sweetpotatoes (Ipomoea batatas) are nutritious, easily stored, and well adapted to a variety of organic farming operations. This widely consumed root crop is propagated through the use of cuttings, known as slips. Slips are commercially grown primarily in the southeastern United States, and growers in the central United States still have limited access to sweetpotato planting material. Production of organic slips in high tunnels (HTs) could be a profitable enterprise for growers in the central United States given the season extension afforded by controlled-environment agriculture, which could allow growers to diversify their operations and facilitate crop rotation. In trials conducted in 2016 and 2017 at two research stations in northeast and south central Kansas, a systems comparison was used to evaluate the yield and performance of organic sweetpotato slips grown in HT as compared with the open field (OF), with four to six replications at each location. Propagation beds planted with ‘Beauregard’ seed roots in 2016 and ‘Orleans’ in 2017 were established in HT and OF under similar cultural methods and planting schedules. Slips were harvested from both treatment groups and transplanted to field plots to investigate the impact of production system on transplant establishment and storage root production. Slip yield from HT was greater than OF at both locations in 2016 (P ≤ 0.001), but this trend was inconsistent in 2017. Slips grown in HT were on average 12% less compact (slip dry weight per centimeter length) with fewer nodes than their OF counterparts in 2016. Nonetheless, mean comparisons for vine length, stem diameter, and total marketable storage root yield were not significant between HT and OF treatments (1.7 and 2.1 lb/plant, respectively). Similarly, the number of marketable storage roots for HT and OF groups was comparable (3.4 and 3.8 storage roots/plant, respectively). Although more research is needed to evaluate the feasibility of slips grown in HT and to determine recommendations for seed root planting densities, results from this study suggest that HT organic sweetpotato slip production could be a viable alternative to OF production as it relates to slip performance. According to this study, HT production could be a useful mechanism for growing sweetpotato slips, which could provide regional growers more control over planting material. Furthermore, HT slip production could promote the adoption of an underused vegetable crop that can be grown throughout many parts of the United States.

The dual-purpose use of orange-fleshed sweet potato (Ipomoea batatas var. Bophelo) for improved nutritional food security

Orange-fleshed sweet potato (OFSP) leaves can be utilised as a fresh green leafy vegetable, in addition to the traditional use of storage root; therefore, OFSP can be seen as a “dual-purpose’’ crop. We hypothesized that no vine harvesting combined with fertiliser application and irrigation will improve the storage root yield and selected plant parameters (water productivity, leaf and storage root nutrient concentrations, nutritional yield, and nutritional water productivity). The objectives of the study were to (i) evaluate the effect of vine harvesting on the selected plant parameters, and, (ii) assess the effect of irrigation regimes and soil fertilisation on these selected parameters. Field experiments were conducted at ARC-VOP, Pretoria, South Africa, during the 2013/14 and 2014/15 seasons. Treatments included irrigation regimes [well-watered (W1) and supplemental irrigation (W2)], soil fertilisation [well-fertilised (F1) and no fertiliser application (F2)], and vine harvesting [no vine harvesting (H1) and vine harvesting (H2)]. For the 2014/15 season, the well-watered regime improved total storage root yield (W1 = 13.0 t DM ha−1; W2 = 7.5 t DM ha−1). Under the practice of vine harvesting, soil fertility treatments did not affect (total dry storage root yield and dry marketable storage root yield) storage root production. Our results further revealed that vine harvesting reduced storage root nutrient concentrations (23% for iron; 14% for zinc; 12% for β-carotene). Nevertheless, total nutritional yields increased; the highest total nutritional yields for iron, zinc, and β-carotene were found under the water and nutrient input regime (W1F1). Assessments showed that boiled orange-fleshed sweet potato aboveground edible biomass could potentially contribute to the daily-recommended nutritional requirement of iron and vitamin A for a family of six people. More water was needed to meet the daily-recommended nutrient intake (iron, zinc, and vitamin A) with OFSP grown as a storage root crop only than when grown as a dual-purpose crop. Our results indicated that there is an opportunity to utilise OFSP as a dual-purpose crop for rural resource-poor households because total nutritional yields (iron, zinc, and β-carotene) and total nutritional water productivities (iron, zinc, and β-carotene) were improved. More research is needed to assess the effect of vine harvesting on a range of OFSP varieties and should be conducted on the farm. Rural resource-poor households are encouraged to produce OFSP for their own consumption and the surplus could be sold at the local market.

Onion growth, yield and quality as influenced by different drip lateral depths and irrigation levels

This research aimed to evaluate the different lateral depths and irrigation water applied with subsurface drip irrigation on onion production traits during the spring growing seasons of 2009 and 2010 in Tekirdag conditions. Three different lateral depths as 0 (surface drip), 10 and 20 cm (subsurface drip) and four different irrigation (50, 75, 100 and 125% of Class A pan evaporation). The seasonal evapotranspiration ranged from 337.1 and 715.4 mm depending on irrigation water applied. The highest onion yield obtained in the treatment which lateral was buried in 20 cm depth and the amount of irrigation water was applied based on 125% of Class A pan evaporation. It can be said that the total marketable onion yield increases as the amount of lateral depth and applied irrigation water increases. The irrigation water use efficiency (IWUE) changed from 4.03 to 18.30 kg m−3 while the water use efficiency (WUE) changed from 2.61 to 6.86 kg m−3. The highest IWUE and WUE obtained in the treatment which lateral was buried in 20 cm depth and the amount of irrigation water was applied based on 50% of Class A pan evaporation.