Non-marketable Yield Research Articles

Evaluation of Intercropping and Tobacco Leaf Extract for Management of Fruit Borer (Helicoverpa armigera) and Some Associated Beneficial Insects on Tomato in Eastern Hararghe, Ethiopia

Tomato production is challenged by different insect pests among these, fruit borer is the most destructing pests of tomato. To tackle these problems, the study was initiated with the objective to evaluate intercropping and tobacco extract on fruit borer and some associated beneficial insects on tomato in Eastern Hararghe. Head cabbage, common bean, onion, tobacco leaf extract and karate were used as treatments. The experiment was laid out in RCBD with four replications. From these results, significant differences were observed between treatments on larval population per plant and infestation per plant for all insect pests tested and also in population reduction. Tobacco leaf extract highly reduced the population occurrence and infestation level of fruit borer next to karate and followed by onion intercropping. The number of branches, number of fruits, and number of damaged fruits, marketable yield, non-marketable yield, and total yield also showed a significant difference (P < 0.05) among the treatments. The number of fruits per plant, marketable yield, and Total yield were the highest on onion intercrops followed by karate and tobacco extracts whereas the lowest number was observed from head cabbage intercrops. Maximum yield and yield traits were recorded on tomato onion intercropping compared to the rests of intercrops while the botanical extract comparably maximized the yields with Karate. Therefore, tomato-onion intercropping and tobacco leaf extract were used as the best alternatives to karate, the synthetic insecticides in the management of tomato fruit borer.

Integrating Metarhizium anisopliae entomopathogenic fungi with border cropping reduces black bean aphids (Aphis fabae) damage and enhances yield and quality of French bean

French bean growers, rely mainly on pesticides for pest management. The acceptable tolerance for pesticides residue in French beans is a major concern and has led to several tonnes of the crop continuously rejected and listed as unsafe for human consumption. There is growing demand for alternative approaches and products that are effective at managing pests without the side-effects associated with reliance on pesticides. A field study to determine the combined effects of Metarhizium anisopliae, (Metarril WP E9 and Biomagic) biopesticides and border crops (Sunflower and wheat) on aphid population, damage severity, growth, yield and quality of French bean. A two-factor experiment was conducted at the Egerton University, Kenya. First factor included two border crops (sunflower and wheat) and no border crop (control). Second factor included spraying Metarril WPE9 (2 × 108 cfu/g), Biomagic (2 × 108 cfu/ml) biopesticides, alpha-cypermethrin (synthetic insecticide) and water. Data on growth, yield and quality parameters were collected and analyzed using the SAS version 9.4M8. Results showed that M. anisopliae and border crop significantly (p < 0.0005) enhanced growth, yield and quality of French bean in both seasons. French bean grown with wheat or sunflower borders showed a significant reduction in aphid population (p < 0.0001) and damage severity (p < 0.0001) when sprayed with various treatments compared to the control. Plots with wheat border caused an increase in collar diameter of French bean. The plots (Metarril and wheat border) caused a 4 % and 5 % increase in marketable yield, a 2 % and 12 % reduction in non-marketable yield. To exploit the benefits of biopesticides, the study recommends their integration with and border crops. Thus, French bean growers could benefit more from fungal-based biopesticides in aphid-IPM approach, as it reduces pre-harvest intervals and residues compared to synthetic insecticides.

GROWTH AND YIELD OF BRAZILIAN SPINACH UNDER DIFFERENT SHADING INTENSITIES AND HARVESTING PERIODS IN A TROPICAL LOWLAND URBAN ECOSYSTEM

Brazilian spinach (Alternanthera sissoo) is a less prominent perennial leafy vegetable growing in the tropical ecosystem. Therefore, this research aimed to investigate the effects of different shading intensities and harvesting periods on the growth and yield of Brazilian spinach in a tropical lowland urban ecosystem. The investigation used a split-plot design, with different shading intensities (no-shading, 45%, 55%, and 80% shading) as the main plot and harvesting periods (every 2, 3, and 4 weeks) as the subplot. The results showed that Brazilian spinach growth was significantly enhanced under no-shading conditions compared to shading treatments. Furthermore, 80% shading negatively impacted plant growth during early stages, as evidenced by alterations in parameters including canopy area (26.47 cm2), diameter (7.98 cm), and index (0.52), as well as Soil Plant Analysis Development (SPAD) values. This led to reduced branch elongation, marketable yield (14.76 g), and non-marketable yield (4.68), along with a decreased dry weight of stems (0.25 g), branches (0.40 g), leaves (0.85 g), and roots (0.44 g). However, marketable leaves from unshaded plants had higher carbon content (34.64%) and lower nitrogen content (2.83%). More frequent harvesting every 2 weeks elevated marketable yield (67.22 g) but suppressed the growth of stems (1.05 g), branches (4.39 g), and roots (1.73 g). Based on these observations, the cultivation of Brazilian spinach in unshaded areas with a biweekly harvesting routine was recommended

RESPONSE OF SNAKE TOMATO (Tricosanthes cucumerina) TO DIFFERENT FERTILIZER SOURCES IN SOUTHERN GUINEA SAVANNA ZONE OF NIGERIA

Snake tomato is gaining popularity due to its nutritional, medicinal and health benefits. Its production is constrained by depleting soil fertility. Recently, there is increased interest in organic food owing to health and environmental benefits. Thus, an experiment on growth and yield of snake tomato as affected by fertilizer sources was conducted at Ponyan and Kabba during the 2019 cropping season. The experiment was laid out in a randomized complete block design with three replications. The treatments consisted of the control, residues from maize, guinea corn and spear grass, residues from soybean, cowpea and black bean, residues from cocoa and kola, pig manure, goat manure, cow dung manure and NPK plus B fertilizer. Data were taken on vine length, number of leaves, vine girth, days to 50% flowering, fruit length, fruit girth, number of seeds/fruit, fresh fruit weight, marketable fruits, non-marketable fruits and fruit yield (t/ha). Analysis of variance results indicated that plants treated with NPK plus B fertilizer significantly (P&lt;0.05) recorded the longest vine, more number of leaves and branches. It also produced more fruits, longest fruit and heaviest fruits. Number of seeds/plant and marketable fruits were more in animal base manure. It is pertinent to know that non-marketable yield was highest in NPK plus B fertilizer. Contrarily, NPK plus B fertilizer increased yield, although statistically similar to animal base manure. Therefore, considering the benefits of organic manure on health and the environment, animal manure applied at 10 t/ha is recommended for snake tomato production in the study area

Effects of soil amendments on bacterial wilt incidences and potato tuber yield across different environments in Malawi

This study investigated the effects of soil amendment on potato yield and incidences of bacterial wilt caused by Ralstonia solanacearum that can cause up to 80% yield loss in potato. The research was conducted at four research stations in Malawi during the 2020/21 and 2021/22 growing seasons, using a randomized complete block design (RCBD) with six treatments: lime, four Calciprill rates (CALC25%, CALC50%, CALC100%, and CALC150%), and NPK fertilizer (control). Data on soil properties, bacterial wilt incidence, and potato tuber yield were collected and analyzed using R programming. Soil fertility was found to be low, with a pH range of 4.4–6.05. Control resulted to significantly higher incidences of bacterial wilt at Kandiyani during 2020/21 (63.6%) and 2021/22 (34.6%) and at Lunyangwa during 2021/22 (20.4%) while lime and all levels of Calciprill led to relative incidence reduction (4%–89%) across sites and season, except CALC25% at Bembeke. Marketable yield showed interaction between amendments and season at Bvumbwe (p = 0.04), highest being 10.02 tha−1 in CALC150% during 2020/21 while non-marketable yield showed interaction at Lunyangwa (p = 0.02) highest being 3.9 tha−1 recorded in CALC150% during 2021/22. A significant negative correlation between bacterial wilt incidences and yield at all sites except Bembeke highlighted the importance of controlling bacterial wilt for yield improvement. The findings suggest that soil amendment through liming is an effective and sustainable approach for managing bacterial wilt and increasing potato yields. Further research on-farm conditions required to ensure the applicability of the findings for different sites.

Phytostimulatory Potential of Turan Biostimulant on the Growth and Yield of Brassica rapa subsp. chinensis (Pechay)

The growth and yield of pechay affected by Turan Biostimulant under field conditions were studied in Oogong, Sta. Cruz, Laguna Philippines to evaluate its effects and determine its best level for the optimum growth and yield of pechay. Turan is a patented high-analysis formulation with plant nutrients complexed by bioactive polyphenols that enhances nutrient availability to plants and provides a biostimulant effect to improve plant vitality and activate natural bio-defenses to protect the plant from stresses. There is a need for a plant food supplement that can promote quick nutrient absorption in the organic pechay production process, thus a randomized complete block design with four replications experiment was conducted. Parameters such as total fresh yield, marketable yield, non-marketable yield, plant height, number of leaves, leaf width, and root length/biomass were gathered from a sample of 40 plants per treatment (10/rep) and analyzed using statistical methods. The study showed that the test product was able to slightly enhance pechay production in terms of total fresh yield, plant height, leaf length, leaf width, root length, and root biomass with an estimated increase of more than 1.18%, 1.06%, 1.04%, 1.03%, 1.13%, and 1.12%, respectively, compared to inorganic fertilizer application alone. In general, pechay is very responsive to granular fertilization and the application of Turan biostimulant. The findings also showed that the addition of a biostimulant would further enhance the amount and quality of harvested pechay. One and a half doses of Turan biostimulant, or even more, is strongly recommended in terms of its viability in pechay cultivation to maximize profits.

Effects of Ca Sprays on Fruit Ca Content and Yield of Tomato Variety Susceptible to Blossom-End Rot.

Several factors are involved in the incidence of blossom-end rot (BER) in tomato fruit, but the main one is insufficient Ca uptake and transport through the plant, resulting in Ca deficiency in the fruit. Sprays of Ca-containing products are considered to be a possible measure to overcome the local Ca deficiency in tomato fruit. Therefore, the main objective was to evaluate the effectiveness of additional Ca supply to tomato fruits for increasing Ca content and reducing fruit damage. Sprays of five different commercial preparations containing (Brexil Duo, Calmax Zero N, Ca(NO3)2, CaCl2) or promoting (Greenstim) Ca uptake were tested using BER-sensitive large-fruit variety 'Beorange'. The experiment was conducted in the commercial greenhouse 'Getlini EKO', Latvia, during the autumn-spring season of 2020/2021 under controlled conditions, eliminating the adverse impact of external factors. The results revealed that none of the preparations were effective in increasing Ca content, preventing BER, and did not promote the tomato yield. As good agricultural practices were followed in the greenhouse to manage BER, we concluded that a non-marketable yield of around 15% should be expected for 'Beorange' when grown under artificial light, possibly due to the impact of abiotic stresses and genetically determined susceptibility.

Producing Cherry Tomatoes in Urban Agriculture

Agriculture in urban and urbanizing areas will be increasingly critical to enhancing food security and food sovereignty, creating income, strengthening social interactions, and improving health outcomes in cities. We used three roofs, a hydroponic system, an aquaponic system, and field rows in an urban environment to grow six dwarf tomato cultivars: ‘Micro Tom’, ‘Red Robin’, ‘Sweet ‘n’ Neat’, ‘Terenzo’, ‘Tiny Tim’, and ‘Tumbler.’ We measured the marketable yield and non-marketable yield, mass of non-marketable tomatoes exhibiting defects, and the content of 12 mineral nutrients in fruits. We found the productivity often varied among cultivars within a cropping system. ‘Terenzo’ and ‘Tumbler’ were always some of the most productive cultivars, whereas ‘Micro Tom’ was normally among the least productive cultivars. The production from ‘Red Robin’, ‘Tiny Tim’, and ‘Sweat ‘n’ Neat’ was more variable, sometimes producing high, moderate, or low mass. The mineral content was especially variable across the cultivars and we did not identify cultivars that were consistently high or low in mineral content across systems, indicating that the mineral content was highly influenced by a genotype x environment interaction. The amount of 5 minerals differed across cultivars in aquaponics, 9 differed in hydroponics, and 6–12 differed in the roof systems. A high-yielding cultivar should be selected first and production methods can then be modified to maximize the nutrient content.

Effect of integrated nutrient management on growth, yield and economics of potato (Solanum tuberosum L.) in Jalandhar (Punjab)

The field experiment laid out in randomized block design with three replications of ten different combinations of organic and chemical fertilizer i.e., (FYM, poultry manure, vermicompost) and the chemical fertilizers at different levels, using kufri Pukhraj variety of potato, showed that the growth parameters like percentage of plant emergence, percent tubers emerged, plant height at 30 and 75 DAP, number of haulms plant-1 (75 DAP), number of compound leaves plant-1 at 75 DAP as well as the yield attributing characters (ie., number of tubers plant-1, tuber weight plant-1, marketable yield plot-1, and non-marketable yield plot-1 and total yield plot-1) were significantly influenced by different treatment combination of FYM, NPK, poultry manure and vermicompost. However, the combination of poultry manure and the RDF applied @10t h-1 + 50 per cent R.D.F exhibited maximum weight of tuber plant-1, marketable yield plot-1, non marketable yield plot-1, total yield plot-1, gross income (Rs. 2,79.666), net income (Rs 163914) and B: C ratio (141), minimum weight of tubers plant-1, marketable yield plant-1, the total yield gross income, net income and the Benefit: Cost and the lowest was recorded in T4 (vermi compost @ 20 t ha-1).

Tomato Yield and Quality Response to Water Application Technique and Management

Tomato (Lycopersicon esculentum Mill) is one of the most important and has the highest acreage of any vegetable crop in the world. Such quantitative analysis is based on the assessment of data from sequential collections of plant traits linked to environmental conditions, as well as yield potential under optimal growth conditions. The objective in this study was to evaluate the performance of tomato crop under furrow, basin and hosepipe irrigation techniques in Kabos, Serere District of Eastern Uganda. The materials and methods used in this study included tools like water pump (model DCX2-50D), Tomato variety Rionex, weighting scale, CROPWAT 8.0 software, CANOPEO software among others. Generally, quantitative techniques through several experiment designs were used. Daily and monthly weather variables, in-situ primary datasets of plant height, canopy cover percentages and fruit characteristics, and weight of harvested tomatoes were measured at three growth stages and analyzed using RCBD experiment with six treatments and four replications.&#x0D; Findings showed that overhead treatments had lowest rate of rotten yield compared to basin and furrow but had highest rate of discolored fruits attributed to sunshine and impact of water pressure during irrigation. Rotting of yield was highest in basin treatments. The rotting was attributed to water logging, poor drainage that accelerated fungal infection in the tomatoes. Furrow treatments had better drainage which reduced quantity of nonmarketable yield. There was no significant difference on the weight of tomatoes below 65g. This meant that fruit weight was independent of irrigation method. Treatments under hosepipe irrigation-overhead. Conclusively, water management practices have big impact on the crop yield giving a relationship that yield is directly proportional to water management practices, which however, should be followed by detailed soil and water analysis through such studies. The Safe-Water-for Food (SWFF) target can be reached and eventually reduce on the global hunger syndrome.

Tomato Yield and Quality Response to Water Application Technique and Management

Tomato (Lycopersicon esculentum Mill) is one of the most important and has the highest acreage of any vegetable crop in the world. Such quantitative analysis is based on the assessment of data from sequential collections of plant traits linked to environmental conditions, as well as yield potential under optimal growth conditions. The objective in this study was to evaluate the performance of tomato crop under furrow, basin and hosepipe irrigation techniques in Kabos, Serere District of Eastern Uganda. The materials and methods used in this study included tools like water pump (model DCX2-50D), Tomato variety Rionex, weighting scale, CROPWAT 8.0 software, CANOPEO software among others. Generally, quantitative techniques through several experiment designs were used. Daily and monthly weather variables, in-situ primary datasets of plant height, canopy cover percentages and fruit characteristics, and weight of harvested tomatoes were measured at three growth stages and analyzed using RCBD experiment with six treatments and four replications.&#x0D; Findings showed that overhead treatments had lowest rate of rotten yield compared to basin and furrow but had highest rate of discolored fruits attributed to sunshine and impact of water pressure during irrigation. Rotting of yield was highest in basin treatments. The rotting was attributed to water logging, poor drainage that accelerated fungal infection in the tomatoes. Furrow treatments had better drainage which reduced quantity of nonmarketable yield. There was no significant difference on the weight of tomatoes below 65g. This meant that fruit weight was independent of irrigation method. Treatments under hosepipe irrigation-overhead. Conclusively, water management practices have big impact on the crop yield giving a relationship that yield is directly proportional to water management practices, which however, should be followed by detailed soil and water analysis through such studies. The Safe-Water-for Food (SWFF) target can be reached and eventually reduce on the global hunger syndrome.

Influence of period of weed interference and age of pepper (Capsicum annuum L. cv. Cayenne pepper) seedlings on pepper fruit quality and marketability

The field trials were conducted in the early and late wet seasons of 2012 at the Federal University of Agriculture, Abeokuta, Ogun State, Nigeria. The objective of the study was to evaluate influence of period of weed interference on fruit quality and marketability of pepper fruit under different seedling ages. Split-plot arrangement in a randomized complete block design with three replicates was adopted in the trials. The main plot treatments were ages of pepper seedlings at transplant, four and six weeks after sowing (WAS). Sub-plot treatments consisted of 10 periods of weed interference. Data collected on weed cover score, cumulative dry weed weight, dry plant biomass, number of leaves, fruit girth, fruit length, marketable fruit count and yield as well as non-marketable fruit count and yield were subjected to analysis of variance and treatment means were separated using least significant difference at p ≤ 0.05. The results showed that six week old pepper seedling had higher plant biomass, number of leaves and marketable fruit yield than the four week old. Also, pepper growth parameters, pepper fruit quality and marketability increased with weed free period and decreased with weed infestation period. Uncontrolled weed infestation for whole season caused 98.4% and 91.8% reduction in pepper marketability in the early wet and late wet season, respectively.

Effect of Biochar and Inorganic Fertilizer on the Soil Properties and Growth and Yield of Onion (Allium cepa) in Tropical Ethiopia.

Biochar is a carbon-rich product, which is processed by pyrolyzing biomass to improve soil properties and maintain environmental sustainability. This study aim was to investigate the effect of biochar and inorganic fertilizer on soil properties, growth, and yield. Four treatments and four replications have been used for the experimental plots using Randomized Complete Block Design (RCBD). Soil physiochemical properties have been investigated based on soil samples within 0–30 cm depth in each plot. The two types of biochar (grass and chat waste) have been used for the treatments. The pyrolyzing temperature required for grass and chat waste is 250°C and 1100°C, respectively. The plant height, total yield, and the marketable and nonmarketable yield of onion have been examined. The analysis showed that treatment with grass biochar and inorganic fertilizer had a similar effect on soil properties but chat (Catha edulis) biochar had a lower effect on soil properties. The total yield and days to 70% maturity have been increased due to the cumulative treatment of grass biochar and inorganic fertilizer. The biochar of grass and inorganic fertilizer have been significantly increased in marketable bulb yield, but unmarketable yield becomes decreased. The chat waste and controlled treatments shown an increased unmarketable yield and declined marketable bulb yield. Overall, biochar can substitute the inorganic fertilizer, which can help to improve the w soil fertility and environmental sustainability. Therefore, biochar has a win-win solution.

Pre-harvest field application of enhanced freshness formulation reduces yield loss in orange

BackgroundOrange (Citrus sinensis L.) production in Tanzania is constrained by several pre-harvest factors that include pests. Hexanal, sprayed as Enhanced Freshness Formulation (EFF) is a relatively new technology that has been reported to reduce pre-harvest loss in fruits. However, the effects of hexanal on pre-harvest yield loss of orange are not known. We studied the effects of hexanal as EFF on yield losses of three sweet orange cultivars namely, Early Valencia, Jaffa, and Late Valencia. Factorial experiments tested the effects of EFF concentration, variety, and time of EFF application on number of dropped fruit, percentage of non-marketable fruit and incidence of pest damage.ResultsResults showed significant negative correlation (p < 0.001) between EFF and the percentage of dropped fruit, non-marketable yield, and incidence of pest damage. An increase in hexanal concentration by 1%, is expected to reduce number of dropped fruit by 50, percentage of non-marketable by 35.6, and incidences of pest damage by 36.5% keeping other factors constant. Results also show significant association (p < 0.001) between time of hexanal application and non-marketable yield. Percentage of dropped fruit is expected to increase by 1 for each day away from harvest, keeping other factors constant.ConclusionPre-harvest application of hexanal as EFF can significantly reduce number of dropped fruits, percentage of non-marketable fruit and incidence of pest damage.

Evaluation of yield and nitrogen utilisation with urease and nitrification inhibitors in sweet potato crop (Ipomoea batatas L.)

Abstract Sweet potato (Ipomoea batatas L.) is a new tuber crop grown in Greece. It constitutes an innovative dietary component for both humans and animals, due to its nutritional properties. The cultivation of sweet potato focuses on the growth of both tubers and plants. Nitrogen is considered an essential element for almost all crops. This study set out to compare the effect of nitrogen inhibitors on yield components of sweet potato. In the literature, it is stated that in sweet potato cultivation nitrogen mainly affects the plants’ growth such as the tuber's yield and some quality characteristics such as dry matter and protein content. To furthermore explore this particular area, field experiments took place in West Greece, during the years 2018 and 2019. Several urea combination treatments were used in the experimental process. The treatments were urea (46-0-0), urea with urease inhibitor (UI), urea with nitrification inhibitor (NI), urea with double inhibitors (UI + NI) and control (without fertilizer) in a randomised complete block design. Leaf area index (LAI) was significantly affected by the fertilizer marking the highest value of 5.35 under urea + UI + NI treatment. Marketable yield was profoundly affected by the fertilizer in the experimental years and ranged from 18,180 to 23,230 Kg · ha−1 whereas non-marketable yield was not affected by the fertilizer. A considerable impact of fertilizers was noticed on yield where the highest value was 30,923 Kg · ha−1 under urea + NI + UI treatment. The percentage of nitrogen on tubers and upper parts was significantly affected by the fertilizers. Nitrogen markers, such as nitrogen use efficiency (NUE), nitrogen harvest index and nitrogen agronomic efficiency (NAE), were used to evaluate nitrogen release. A significant positive correlation was noticed between marketable yield and NUE (0.774). Also, the significant increase in yield showed a positive correlation with NAE (0.727). For yield components of sweet potato, the highest values were observed in urea with double inhibitors treatment in both experimental years.

Pre-harvest field application effects of hexanal formulation on fruit losses in mango grown in eastern Tanzania

ABSTRACTMango (Mangifera indica L.) production is constrained by several pre-harvest factors. This study determined the effects of enhanced freshness formulation (EFF) on yield losses in “Apple,” “Palmer” and “Keitt” varieties. Factorial experiments tested the effects of EFF concentrations, seasons, varieties, and times of EFF application on percentage of dropped fruit, non-marketable yield and incidences of pest defects. Percentage of dropped mango was significantly (p < 0.001) affected by EFF concentration, time of application and season, EFF × season, EFF × variety, time × season, time × variety, and time × variety × season interactions. Non-marketable mango fruits were significantly (p < 0.001) affected by EFF concentration, variety, EFF concentration × season, variety × season and variety × time of application. Incidences of pest defects were significantly (p < 0.001) affected by EFF concentration and EFF concentration × season and variety × season. EFF concentration of 0.01% is recommended to reduce yield losses.

EFFECTIVENESS OF UREA WITH UREASE INHIBITOR – UTEC TO THE POTATO

In the he article are presented the research result on effectiveness of application new form of urea on potato. New urea form is urea with urease inhibitors. This fertilities type allow to reduce losses of nitrogen in ammonium form. Field experiment was carried out in 2017 on solonetc light chestnut soils with heavy granulometric compound in the conditions of the Volgograd region in the experimental polygon of the lower Volga agricultural research Institute – branch of Federal state budgetary scientific institution "Federal scientific center for agro-ecology, integrated land reclamation and protective afforestation wounds". As an object of research used potatoes mid-early table varieties Nevsky. The advantage of a new fertilizer form is the yield increase and improvement of tubers quality. Urea UTEC application leads to formation bigger and uniform tuber size. The use of urea UTEC provide the potato yield of 56.4 t/ha, with marketable tubers fraction up to 54.82 t/ha, the total yield increase to the control – 35.6%, in monetary terms this amounted to 245887.0 RUB/ha additional profit. Under these conditions, was obtained lowest amount of non-marketable yield – 0.16 t/ha, which is 2.65 times less than in the control variant. The advantage of urea UTEC application in comparison with ammonium nitrate was the increase in the yield of marketable potatoes by 5.1 t/ha and an additional profit up to 76.8 thousand rubles/ha. The Assessment of the potato quality showed that the best treatment was also the treatment with UTEC urea, the starch content in tubers was 9.22%. Note that almost the same value of the indicator in the variant with the use of urea (option 2), and the lowest starch content was noted when using ammonium nitrate – 9.05%.

Potato cultivar BRS F63 Camila has higher yield at lower plant spacing

ABSTRACT The plant management used in potato crop is usually similar across the main producing regions in Brazil. Same plant spacing are commonly used, despite the differences in climate and soil of the various potato planting areas. The objective of this work was to evaluate the yield of potato cultivars in response to different plant spacing. Experiments were conducted in the field, and the treatments consisted of three cultivars (Agata, BRS Clara and BRS F63 Camila) and three plant spacing (20, 25 and 30 cm) in randomized blocks with three repetitions in two years. The total, marketable and non-marketable tuber yield, total and marketable number of tubers per area and size class, mean total and marketable tuber weight and percentage of tuber dry weight of the tubers were evaluated. Camila was the cultivar with highest yield when spaced 20 cm due to the greater number of tubers in the marketable class 100-200 g. In the 25 and 30 cm plant spacing, there was no difference in yield among cultivars. Depending on the cultivar and the destination of the harvested tubers, producers can choose the most appropriated plant spacing.

Fruit Cluster Pruning of Tomato in an Organic High-Tunnel System

This research assessed fruit load management and production techniques for cultivating indeterminate tomatoes in a high tunnel under intensive organic management. The successful production of high-quality, high-yielding crops is important for fruit and vegetable producers, especially growers using high tunnels. High tunnels are well-suited to organic farming and can be used to grow many valuable specialty crops. Fruit load management is practiced in fruit production (e.g., apples, peaches, and grapes), but there is lack of consensus concerning the effectiveness of fruit cluster pruning on tomato (Solanum lycopersicum) and its impact on fruit yield, quality, and marketability. In addition, there is no published research on tomato cluster pruning in certified organic systems or intensively managed high tunnels (e.g., densely planted, trellised, vegetatively pruned plants) for the Front Range of Colorado. In 2016 and 2017, a randomized complete block design was used to test the effects of cluster pruning within a high tunnel on certified organic land at Colorado State University’s (CSU’s) Agricultural Research, Development, and Education Center, South. Two treatments and three tomato cultivars were selected for the study; the treatment–cultivar combinations were replicated six times within a high tunnel. The treatments involved reducing fruit loads to three fruit and six fruit per cluster, whereas plants with unpruned clusters, which naturally developed as many as 10 fruit, served as the control. Tomato cultivars evaluated were ‘Cherokee Purple’, a widely studied heirloom, and two hybrids: ‘Jet Star’ and ‘Lola’. Parameters measured included total yield, individual fresh fruit weight, soluble solids content (SSC), marketable yield, and nonmarketable yield. Individual fresh fruit weight increased for both hybrids in the three-fruit treatment, averaged over two growing seasons. ‘Cherokee Purple’ did not respond to the cluster pruning treatments. There was no decrease in total yield, across all cultivars, between treatments and the unpruned control. However, ‘Jet Star’ yielded more than the other two cultivars. In addition, SSC and marketability measurements were more influenced by cultivar than cluster pruning treatments. ‘Lola’ had a significantly greater SSC than the other two cultivars. ‘Jet Star’ had the greatest marketable yields of all cultivars tested whereas ‘Cherokee Purple’ produced greater nonmarketable (cull) yields. Cluster pruning produced larger organic tomatoes without reducing yield or quality for two of the three cultivars used in the study. Cultivar selection remains one of the greatest factors in determining yield, quality, and marketability of a crop.

Modeling the impact of sweetpotato weevils on storage root yield

Abstract This study estimated the amount of loss in storage roots caused by various levels of damage caused by sweetpotato weevils (Cylas spp). Seven varieties of sweetpotato (Ipomoea batatas L. (Lam)) were evaluated in three production sites in northern Ghana for two years (2014 and 2015). Yield data for each experimental plot were collected. A regression analysis was carried out using the generalized linear model approach. In the study, nonmarketable roots were classified as all undersized roots (&lt;100g) and spoilt roots due to weevil, millipede, and soft rot. The results indicated weevil damage as the only significant predictor of nonmarketable yield at 5% level of significance. From the study, the average values for total root yield, marketable root yield, and nonmarketable root yield were 9.39, 6.71, and 2.67 ton/ha respectively. The minimum weevil damage (score 2) resulted in a yield loss of 2 ton/ha which represents 8.3% while severe damage at score 9 could cause a loss of 7.43 ton/ha of storage roots representing 31% of the attainable yield of sweetpotato. Weevil susceptibility needs to be treated as a serious trait when evaluating sweetpotato genotypes to be released as varieties.