Carrot Rows Research Articles

Sustainability of carrot-cowpea intercropping systems through optimization of green manuring and spatial arrangements

ABSTRACT: One of the biggest challenges in intercropping of two or more crops is to maintain their productivity as that of their sole counterparts. In order to obtain sustainable intercropping systems in a semi-arid environment, this study evaluated the agro-economic advantage and sustainability of intercropped systems of carrot and cowpea, optimizing the green manuring and spatial arrangements. Experiments were conducted in the period from July to October 2017 and 2018, using a randomized complete block design with the treatments arranged in a 4 x 3 factorial scheme, with four replications. Treatments included four amounts of M. aegyptia incorporated into the soil (20, 35, 50, and 65 t ha-1 on dry basis) with three spatial arrangements (2:2, 3:3, and 4:4) between the components cultures formed from cowpea rows alternated with carrot rows. The agro-economic advantage indices evaluated in the intercropping systems were: land equivalent ratio (LER), area-time equivalent ratio (ATER), score of the canonical variable (Z), actual yield loss (AYL), intercropping advantage (IA), gross income (GI), net income (NI), rate of return (RR), and profit margin (PM). The highest agro-economic advantages of the carrot and cowpea intercropping were obtained for LER, ATER, NI, and RR of 2.60, 4.16, US$ 8,720.99 ha-1, and US$ 2.21, respectively, for M. aegyptia biomass amounts of 46.42, 47.82, 32.60 and 31.51t ha-1 added to the soil. The 2: 2 spatial arrangement was the one with the best productive performance, with higher net income and rate of return in the intercropping of carrot-cowpea.

A holistic carrot production system for season-long weed management

AbstractWeed management in carrot is challenging, given slow and inconsistent crop emergence and early-season growth and the lack of practical season-long management tools such as herbicides. We investigated holistic carrot production systems with a focus on minimizing inputs while optimizing resource use. In an overall sense, results of this work were consistent between years, and stark. The choice of carrot variety had a moderate influence on carrot foliar canopy development and, subsequently, weed density. For example, ‘Cupar’ carrot formed a complete crop canopy sooner than the other dicer-type ‘Canada’ variety. Likely as a result, density of weed species such as spotted ladysthumb and common lambsquarters was less where ‘Cupar’ was grown compared with where ‘Canada’ was grown. Gibberellic acid as a foliar application was not successful in these studies and, in a few cases, may have even increased weed-seed germination and establishment. Adding two carrot rows to the current regional industry-standard three-row bed system not only enhanced competitiveness with weeds but also improved carrot yield without additional fertilizer, water, or pest management inputs. By far, though, the most successful strategy to reduce weed density while maintaining or improving carrot yield was to delay seeding by 17 to 19 d. We anticipate more holistic production system research that integrates low-input alternatives in other crops as herbicide-resistant weeds proliferate while few new herbicides are developed. As was demonstrated in this research, such novel approaches can be successful without adding significant economic burden to the farmer or increasing risk of crop failure.

Efikasnost združivanja mrkve i crnog luka na njihova morfološka i nutritivna svojstva

A trial involving intercropped and pure stands of carrots 'Nantes' and onions 'Kupusinski jabucar' was conducted on a certified organic farm in Futog. The yield, morphological and nutritional properties of the crops analyzed were determined in the study. Furthermore, the biological efficiency of intercropping was assessed using the relative yield (RYT) and the land use efficiency index (LER). The mixture of crops had influenced the morphological properties examined. In both experimental plant species, the nutritional properties of onions and carrots exhibited a higher content of dry matter (DM) in the double-row growing system without maize gluten meal (onions - 11.42 %, carrots - 10.45 %) compared to single crops. The highest content of β-carotene was determined by alternating single rows of onions and carrots in a plot without the use of gluten (68.94 μg/g DM). The relative yield and the land use efficiency index have shown that there is a biological efficiency of combining carrots and onion as the values obtained are higher than 1. Carrots and black onions are favorable for intercropping because they are complementary, thus interactively contribute to increasing the yield per unit area and improving the nutritional properties.

Real‐time variable‐rate herbicide application for weed control in carrots

SummaryA camera sensor for precision weed control in arable fields has been developed at the Leibniz Institute for Agricultural Engineering. For herbicide spraying in carrots, the sensor was positioned at the front three‐point linkage of a tractor and was operated between carrot rows. In field trials in 2 years, real‐time (online) technology in which sensing and spraying were performed in one step was evaluated in comparison with a conventional uniform spraying application. The spray volume was linearly adjusted to the camera‐detected weed coverage level from a minimum of 200 L ha−1if no weeds were present to a maximum of 400 L ha−1. The herbicide savings were 30% in 2007 and 34%, 43% and 36% for each of three applications in 2010. There were no significant differences between the camera‐based and conventional spraying approaches with regard to yield parameters, total carrot weight and weight of marketable carrots. Regarding the weed control efficiency of the camera‐based spraying procedure in the 2010 experiment, no trend was observed between the weed coverage and the application rate of the previous spraying.

Desempenho agroeconômico da cenoura adubada com jitirana (Merremia aegyptia)

O uso de plantas espontâneas do bioma Caatinga como adubo verde vem se constituindo numa opção viável de produção de hortaliças na região do Nordeste brasileiro. Entre essas plantas, está a jitirana, planta espontânea adaptada às condições edafoclimáticas da região, com alta produção de fitomassa, rápido crescimento e estreita relação C:N. O objetivo desse trabalho foi avaliar o desempenho agroeconômico da cenoura (cv. Brasília) em função de quantidades de jitirana adicionadas sob o solo e de seus tempos de incorporação. O estudo foi conduzido em área rural, localizada em Mossoró (RN), de setembro a dezembro de 2009. O delineamento experimental usado foi em blocos completos casualizados com os tratamentos arranjados em esquema fatorial (4x4) + 1, com 3 repetições. O primeiro fator foi constituído pelas quantidades de jitirana colocadas entre as linhas de cenoura até a profundidade de 15 cm (5,4; 8,8; 12,2 e 15,6 t ha-1 em base seca) e o segundo fator pelos tempos de incorporação desse material (0, 15, 30 e 45 dias depois da semeadura da cenoura). O tratamento adicional (testemunha) foi de 40 t ha-1 de esterco bovino aplicado 10 dias antes da semeadura. Foram avaliados a produtividade comercial e total de raízes, percentagens das diversas classes de raízes e os indicadores econômicos, renda bruta, renda líquida, taxa de retorno e índice de lucratividade. Não houve interação significativa entre os fatores quantidades de jitirana sob o solo e seus tempos de incorporação em nenhuma das características avaliadas na cenoura. O melhor desempenho agroeconômico do cultivo da cenoura foi obtido com a adição ao solo de 15,6 t ha-1 de jitirana. A otimização desse desempenho foi alcançada no tempo de incorporação de 26 dias.

Selection of the most efficient wavelength bands for discriminating weeds from crop

The aim of this study was to select the best combination of filters for detecting various weed species located within carrot rows. In-field images were taken under artificial lighting with a multispectral device consisting of a black and white camera coupled with a rotating wheel holding 22 interference filters in the VIS-NIR domain. Measurements were performed over a period of 19 days, starting 1 week after crop emergence (early weeding can increase yields) and seven different weeds species were considered. The selection of the best filter combination was based on a quadratic discriminant analysis. The best combination of filters included three interference filters, respectively centred on 450, 550 and 700 nm. With this combination, the overall classification accuracy (CA) was 72%. When using only two filters, a slight degradation of the CA was noticed. When the classification results were reported on field images, a systematic misclassification of carrot cotyledons appears. Better results were obtained with a more advanced growth stage.

Produtividade biológica em sistemas consorciados de cenoura e alface avaliada através de indicadores agroeconômicos e métodos multicritério

O experimento foi conduzido de maio a setembro de 2002, na UFERSA, Mossoró-RN, para avaliar consórcios de cenoura e alface, através de critérios agronômicos, econômicos (rendimentos financeiros) e de eficiência produtiva (avaliada segundo modelos de Análise de Envoltória de Dados - DEA). Para agregar a informação de todos os critérios e identificar os melhores tratamentos, foram utilizados os métodos multicritério ordinais de Borda, Condorcet e Copeland. O delineamento experimental foi blocos casualizados, em fatorial 3 (cultivo solteiro e consorciado, em faixas, com três fileiras de cenoura e três de alface (3F) e quatro de cenoura e quatro de alface (4F)) x 4 (cultivares de alface americana: Lucy Brown, Tainá, Laurel e Mesa 659), com quatro repetições. Em cada bloco foi plantada a cenoura solteira. Avaliou-se o índice de uso eficiente da terra (UET), o índice de lucratividade (IL) e a eficiência produtiva DEA. Uma análise de variância univariada foi usada para avaliar estes indicadores, no esquema fatorial 2 x 4 + 1 (dois sistemas consorciados em faixas, quatro cultivares de alface e cenoura solteira). Os UETs dos sistemas consorciados foram significativamente superiores ao UET do cultivo solteiro, com a vantagem dos sistemas consorciados variando de 90 (cenoura + cultivar Tainá 4F) a 133% (cenoura + cultivar Mesa 659 4F). Não se observou diferença significativa no índice de lucratividade entre os cultivos solteiro e consorciado. Na eficiência produtiva DEA foi observada interação significativa entre sistemas de cultivo e cultivares de alface. Os métodos multicritério indicaram Cenoura + Mesa 659 (4F), Cenoura + Laurel (3F) e Cenoura + Mesa 659 (3F) como os melhores sistemas de cultivo. A eficiência produtiva DEA e a ordenação dos métodos multicritério foram mais eficientes na discriminação do desempenho dos sistemas de cultivo consorciados que os indicadores agroeconômicos.

(217) An Evaluation of Sulfur Status and the Effects of S on Uptake, Distribution, and Yield of Processing Carrots (Daucus carota L.)

A reduction in the atmospheric deposition of sulfur (S) and S-containing fertilizers has greatly reduced S inputs to the soil in recent years. At the same time, S removal from the soil has increased as a result of increased crop production and higher yields. Sulfur deficiency has been found to reduce yields in several crops. A study was conducted to gain an understanding of the S status of Nova Scotia soils that support carrot production, as well as to examine the effects of rate of S application, method of S application, and type of S fertilizer on carrot uptake, distribution, yield, and recovery. Initial S concentrations in carrot-producing fields ranged from 52–440 kg·ha-1 of S. In general, King's County soils were lower in S than Colchester County soils. In the S trial, banding and broadcasting S on the side of carrot rows improved yield, and recovery compared to placing the S in the seed row. Banding S also significantly increased undersize carrots, leaf fresh weight, leaf dry weight, and root fresh weight. Rate of S application did not affect yield, recovery, or growth of carrots. At this time, S supplies from the atmosphere and soil are sufficient to meet the demands of carrots produced for processing in Nova Scotia. Growers do not need to apply S as fertilizer at this time to improve carrot yields. Monitoring of the S status of soils should be periodically conducted to assess S concentration as SO2 emissions and crop production continue to change.

Desempenho agroeconômico do bicultivo de alface em sistema solteiro e consorciado com cenoura

Dois experimentos foram implantados de setembro a dezembro/2002, na ESAM (RN), para avaliar o desempenho agroeconômico do bicultivo de dois grupos de alface em sistema solteiro e consorciado com duas cultivares de cenoura em faixas. O delineamento experimental foi de blocos balanceados em grupos, com quatro repetições. Foram avaliadas as cultivares pertencentes aos grupos crespa (Lucy Brown, Tainá, Laurel e Verônica) e lisa (Babá de Verão, Maravilha das Quatro Estações, Elisa e Carolina). No experimento consorciado foi utilizado o esquema de parcelas sub-divididas, onde os tratamentos designados às parcelas foram as cvs. de cenoura Alvorada e Brasília e os designados às sub-parcelas foram as cvs. de alface do grupo crespa e as do grupo lisa. Na alface foi avaliado o rendimento de folhas e na cenoura o rendimento total, comercial e a classe das raízes. Foram usados índices agroeconômicos para medir a eficiência do sistema consorciado: Índice de Uso Eficiente da Terra, Renda Bruta, Renda Líquida, Vantagem Monetária, Vantagem Monetária Corrigida, Taxa de Retorno e Índice de Lucratividade. Não houve interação significativa entre os fatores cvs. de cenoura e cvs. de alface sobre os rendimentos das culturas. As cvs. de cenoura não influenciaram os rendimentos das culturas. As cvs. de alface não afetaram os rendimentos da cenoura. No bicultivo da alface consorciada com cenoura, recomenda-se o emprego das cvs Lucy Brown e Tainá do grupo crespa ou da 'Babá de Verão' e 'Maravilha das Quatro Estações' do grupo lisa no primeiro plantio. No segundo plantio, apenas a cv. do grupo lisa Maravilha das Quatro Estações se sobressaiu das demais no desempenho produtivo em cultivo consorciado.As cultivares de alface do grupo crespa consorciadas com cenoura se sobressaíram daquelas do grupo lisa no desempenho produtivo. Os consórcios cenoura 'Alvorada' x alface 'Lucy Brown'; e cenoura 'Brasília' x alface 'Maravilha das Quatro Estações', tiveram os melhores indicadores agroeconômicos, com índices de uso eficiente da terra de 2,16 e 2,15, taxas de retorno de 2,05 e 2,33, e índices de lucratividade de 53,92% e 59,83%, respectivamente.

Carrot Cultivar Trials in Oklahoma

The objectives of this trial were to collect yield and quality data on a fall planted carrot trial. Fifteen different carrot varieties were included in the trial. Plots were 20 feet by 2.5 feet and consisted of two rows of carrots with 15-inch row centers. Plots were replicated 4 times in a RBD. Carrots were direct seeded on 8 Aug. 2003 at 20 seeds per foot. Plots were fertilized with 90 lbs/acre of nitrogen and received overhead water as needed. Yield and quality data were recorded on 5 Dec. 2003. Data included exterior root color, interior root color, percentage of split and forked roots, overall yield, average root length and weight. Exterior root color did not vary significantly for any of the cultivars in the trial, but interior root color varied significantly for several cultivars. `First Class', `Bolero', and `C 7105' had the most distinct differences between the pith and out ring colors as indicated by the interior root color ratings and `Ingot' had the lowest. Interior root color ratings for these four cultivars were 3.8, 3.6, 3.1, and 1.4, respectively. Crispness did not vary for either the initial or second ratings that were recorded. Of potential defects only the percentage of forked roots varied significantly and of these four cultivars had less than 10% forked roots. `Florida', `Kamaran', `Pipeline', and `C 7105' had 5%, 7%, 9%, and 9% forked roots, respectively. `Samantha' had 31% forked roots, the highest percentage recorded in the trial. No differences were recorded for root weight, diameter or length. The three highest yielding cultivars in the trial were `Ingot', `Heritage', and `Neptune' that had overall yields of 24.9, 20.6, and 20.6 tons/acre. `Bremen' recorded the lowest yield in the trial with 13.7 tons/acre.

Desempenho agroeconômico do consórcio cenoura x alface lisa em dois sistemas de cultivo em faixa

O desempenho de quatro cultivares de alface lisa, em cultivo solteiro e consorciado com cenoura, em dois sistemas de cultivo em faixas, foi avaliado em experimento, de outubro a dezembro de 2000, na ESAM em Mossoró. O delineamento experimental utilizado foi de blocos casualizados completos em esquema fatorial 3 x 4 + 1, com quatro repetições. Os tratamentos do fatorial resultaram da combinação dos sistemas de cultivos (solteiro, consorciado em faixas com três fileiras de cenoura alternadas com três fileiras de alface e consorciado em faixas com quatro fileiras de cenoura alternadas com quatro fileiras de alface) com quatro cultivares de alface lisa (Babá de Verão, Karla, Verdinha e Elisabeth), mais um tratamento adicional (cenoura 'Brasília' solteira). Avaliou-se para a cultura da alface: altura e diâmetro de plantas, número de folhas por planta, matéria seca da parte aérea e produtividade; para a cultura da cenoura avaliou-se: altura de plantas, matéria fresca da parte aérea, produtividade total, comercial e classificação de raízes. Alguns indicadores agroeconômicos foram usados para medir a eficiência dos sistemas consorciados. Não houve interação significativa entre sistemas de cultivos e cultivares de alface para nenhuma das características avaliadas. Os sistemas de cultivo afetaram todas as características avaliadas tanto na cultura da alface como na da cenoura, e as cultivares de alfaces testadas influenciaram apenas o número de folhas/planta, com a cultivar 'Karla' registrando maior número. A produtividade média da alface nos sistemas consorciados, embora inferior à do sistema solteiro, representou uma fonte adicional de renda. O consórcio cenoura 'Brasília' x alface cv. 'Verdinha' em faixas com quatro fileiras foi o que apresentou maior viabilidade agroeconômica, com índice de uso da terra em torno de 19% e taxa de retorno ao redor de 3,0.

Potential for Carrot Production on Georgia Mountain Soils

Carrots (Daucus carota L.) have become an economically important vegetable crop for Georgia. Currently the harvest season extends from December through May. One possibility for extending the harvest season would be to produce carrots in the cooler mountain area of Georgia during the summer months. This study was undertaken to examine the potential for fresh-market carrot production on Georgia mountain soils and to evaluate which varieties of carrots might be most suitable for this area. Ten commercially available carrot varieties were direct seeded into a Transylvania clay loam soil on 28 May 1999 in Blairsville, Ga. Plots consisted of three twin rows of carrots each 20 feet in length. The twin rows were each three inches apart and there were 20 inches between each set of twin rows. Each plot was replicated four times. Base fertilizer of 20 pounds of nitrogen, potassium, and phosphorous were incorporated into the plots prior to seeding. Sidedress applications of 15 pounds each of N, P, and K were applied at 3-week intervals throughout the season. Recommended pest control practices were applied. A three-foot section of the center twin row was harvested on 23 Sept. 1999. The varieties `Pacific Gold' and `Topnotch' produced the highest marketable yield; however, all yields were below acceptable levels. Percent marketability was <60% for all varieties. Percent stand was extremely variable due to variability in seed size. All carrots had severe nematode damage although a nematicide was used preplant. The length of season for spring-planted carrots was too long for the life of the nematicide at the rate and method applied. Late summer–planted carrots would likely be a more viable option for this area.

Use of conifer volatiles to reduce injury caused by carrot psyllid,Trioza apicalis, Förster (Homoptera, Psylloidea)

The feeding and oviposition of the carrot psyllid,Trioza apicalis, were reduced by the application of fresh spruce and pine sawdust along the seedling rows in carrot fields. Turpentine and separate monoterpene hydrocarbons, mixed into old sawdust and/or placed in polyethylene tubes, were also effective. At a dose of 0.5 liter/m, fresh sawdust reduced the damage to 18% of the plants, compared to 100% damage in untreated plants. The sawdust materials were spread on the soil surface at four- or seven-day intervals during the oviposition period. The tubes were placed along the carrot rows before the oviposition started. Turpentine and separate monoterpene hydrocarbons afforded a protective effect of the same order of magnitude as that obtained from fresh sawdust. The volatile profiles of the spruce and pine sawdust as well as of the turpentine used were determined.

Effect of intercropping carrots and onions on damage caused by the carrot fly, Psila rosae (F.) (Dipt., Psilidae)

In small-scale field experiments carried out in southern Finland in seven successive years, rows of carrots were grown a) between carrot rows, b) between a carrot and an onion row, and c) between onion rows. The damage caused by the carrot fly, Psila rosae (F.) was slightly less in carrot rows adjacent to onion rows than in those adjacent to carrot rows. The infestation by the carrot fly was generally very low.

Intercropping carrot and sweetcorn in a multiple cropping system

Intercropping of carrots ( Daucus carota L.) and sweetcorn ( Zea mays L.) in a multiple cropping system effectively increased the combined yield of these vegetable crops. The best planting sequence was seeding sweetcorn first, followed by drilling of carrots 20 days later. Sweetcorn seeded on 26 May, followed by 3, 2 or 1 rows of carrots produced the highest yield and value per unit of land as evaluated by land equivalent ratio and gross monetary return. Intercropping did not significantly reduce soluble solids and dry foliage weight of the carrots, but the root fresh weight of some of the carrot intercrop treatments was reduced.

Early Warning System for the Carrot Weevil (Coleoptera: Curculionidae) and Its Evaluation in Commercial Carrots in Ontario

The carrot weevil (CW), Listronotus oregonensts (LeConte), was monitored during the active period of overwintered adults (early May–early July) in commercial carrot fields and experimental plots in the Holland Marsh, Ontario from 1980 to 1983. Carrot root sections were placed in soil between carrot rows and examined at 3- to 4-day intervals, to detect oviposition cavities. The method provided a seasonal record of CW activity that was more precise than traps for adults. It also provided an early warning of the need for insecticide application, since peak activity in carrot root sections generally occurred before new crop carrots were susceptible to attack. A tentative action threshold of 0.3 cavities per section per day, or 0.5 cavities per section per day if <50% of carrot root sections are infested, is suggested. Satisfactory control of CW was achieved in commercial fields where insecticide application was recommended based on monitoring, and where two sprays of phosmet (1.1 kg [AI]/ha) were applied.

Dispersive movement of carrot fly (Psila rosae) larvae and factors affecting it

SUMMARYThe movements of Psila rosae larvae were studied under field and laboratory conditions. In the field, larvae moved up to 60 cm along and between carrot rows, although more larvae moved during the first generation than the second. Sudden increases in soil moisture, and not its prevailing level, stimulated the larvae to move from carrots into the soil surrounding the roots. Up to 50% of the larvae that left their mines in carrots following a sudden increase in soil moisture did not return to the same mine. Evacuation of mines by larvae appears to be a reflex response to the flooding of their mine and might be connected with the production of toxic conditions within the mine following flooding.

Uptake of chlorfenvinphos and phorate from soil by carrots as influenced by mode of application and cultivar

AbstractGranular formulations of chlorfenvinphos and phorate were applied to sandyloam soil at 2 kg a.i./ha either broadcast and incorporated to 2.5 cm, broadcast and incorporated at 10 cm or by the bow‐wave method along the carrot rows. Depth of incorporation did not influence the rates of residue decline in the soil. Bow‐wave applications produced the highest residues in root and foliage and also reduced the rate of oxidation of phorate. 30 weeks after sowing the carrots, all treatments gave the highest residue concentrations in the uppermost 6 cm of carrot root. The peel of carrots grown in the soil treated to a depth of 10 cm contained 88 % and 23 % of the total chlorfenvinphos and phorate residues respectively.Significant differences were found in the residue concentrations in five carrot cultivars treated with chlorfenvinphos and phorate by the bow‐wave method at 1.5 kg a.i./ha. The concentrations were inversely correlated with root size so that amounts of insecticide (μg/carrot) were similar in all cultivars. Prolonged growth of cv. Norfolk Giant slightly extended the period of uptake of chlorfenvinphos, but the uptake of phorate was ultimately less than its rate of dissipation.Neither the method of application nor the selection of carrot cultivar extended the period of uptake very greatly but differences which were obtained in residue concentrations in the carrot may become significant in the event of regulatory control of residue levels.

Effects of placement and distribution on the performance of granular formulations of insecticides for carrot fly control

AbstractEffects of granule distribution relative to carrot rows are discussed and further results described. Placing insecticides 5 to 10 cm deep 7.5 cm away from the centre line of the carrot row usually, but not always, improved their performance compared with bow‐wave applications. Both sides of the row need to be protected. The efficiency of chlorfenvinphos in a sandy loam, and phorate in a peaty‐loam, decreased with increasing distance from the row but they were slightly effective even 19 cm away. The optimum depth for side‐placing granules at sowing time varied from 5 to 10 cm, and combining side‐placement with a bow‐wave application did not greatly enhance efficiency. The most effective combination on a peaty‐loam was a bow‐wave application of 3 kg phorate/ha at sowing time followed 6 to 9 weeks later by a similar amount side‐placed 7.5 cm deep 7.5 cm from the row centre. Comparison of the performance of phorate broadcast, applied by the bow‐wave method or deep side‐placed indicated that efficiency was improved by restricting the granule distribution but that higher concentrations of granules were then needed in the treated zones to be equitoxic with more uniformly broadcast granules. Uptake by the carrot root system is an important factor in the action of insecticides against carrot fly larvae.

Spacing and 'Bolting' of Vegetables

LANDAU1 has pointed out that the incidence of bolting in onions is affected by the spacing of the plants. He found that more bolting occurred on the outside rows of experimental plots than in the centre, and suggested that competition for light constituted one of the determining factors. That this effect of spacing on bolting is not an isolated phenomenon is shown by results which our experiments over a period of two years have yielded. In these experiments on beet, carrots and shallots the plant spacings have been deliberately altered by varying either the thinning or planting distance, and some of the results obtained are tabulated below. The rows of beet and carrots were in all cases 18 in. distant.