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The okra crop, cultivated all over the globe, is a source of oil and protein. Despite the economic significance of okra in the livelihoods of millions of small-scale farmers, studies on the nutritional traits of okra are meager. Creating novel hybrid lines with desirable characteristics could be employed to maximize the nutritional quality of the okra plant, precisely the amount of anthocyanin content, phenols, and total antioxidants. We crossed an Egyptian variety, preferably in the market but with low production, with a highly productive Japanese variety with less nutritional value for consumers. The two okra genotypes with their hybrids and 16 segregating populations were arranged in a randomized complete block design. Approximate chemical analyses for primary and secondary metabolites were quantified for each genotype. The analysis of variances indicated a significant variation among okra genotypes in all the physiological and nutritional traits except for ascorbic acid content. Various traits revealed by Principal Component Analysis contributed distinctively to the total variation. Correlation analysis indicated some significant correlations between the nutritional characteristics. Protein contents had a positive and significant correlation with total antioxidant (0.521), 2,2-diphenyl-1-picrylhydrazyl (0.488), proline (0.498), flavonoids (0.474), and saponin (0.536). [ABSTRACT FROM AUTHOR]

Method of harvest strategy in dual-purpose okra, Abelmoschus esculentus (L.) Moench (syn. Hibiscus esculentus L.) may affect harvest frequency, diversify crop use, and improve grower income. In a 2-year field study, the influence of harvest strategy on yield, yield components, and potential economic benefits of dual-purpose okra was evaluated. Genotypes, cv. Clemson spineless and the landrace Ahwaz, and harvest strategies: harvesting all fruit fresh; harvesting upper fruit fresh and leaving lower pods for seed; harvesting lower fruit fresh and leaving upper pods for seed, and leaving all pods for seed were used. The umber of harvests during the growing seasons were 41 and 18 times in full fresh fruit harvest and lower part harvest, respectively. The number of fruit and the number of fruit per harvest in the upper part were twice that of the lower section of plants. Seed yield of the upper part, 27.3 g/plant, was almost half of the lower part, 52.4 g/plant, due to heavier seed set in the lower part and seed immaturity in the upper part. The calculated Monetary Equivalent Ratio (MER) for dual-purpose strategies was >1 in both genotypes, indicating higher financial benefit over-cultivation of single-purpose okra. The highest MER for 'Clemson spineless' was 1.22 (22% increase in revenue) when lower pods were left for seed; the MER for landrace Ahwaz was 1.23 when upper pods were harvested for seed. Understanding the responses of fruit to harvest strategy and the number of harvests may help farmers make a decision to maximize net income. [ABSTRACT FROM AUTHOR]

Light interception by okra [Abelmoschus esculentus (L.) Moench] can be altered by changing row and plant spacing and plant/row orientation. In okra, reduction in yield can occur due to improper planting arrangement, use of inappropriate cultivar, weed interference, and ineffective weed control. A field experiment was conducted at the Federal University of Agriculture, Abeokuta, Nigeria, to assess the effects of planting arrangement on okra and on its ability to control weeds. Cultivars NHAe 47–4 and LD 88 were established at a population of 40,000 plants∙ha−1 as a result of spatial arrangement using 100 cm inter-row distance and respective intra-row distances of: 25 cm with 1 plant/stand; 50 cm with 2 plants/stand, and 75 cm with 3 plants/stand. Data were collected on number of leaves, plant height, stem diameter, leaf area, days to first flowering, days to 50% flowering; total fruit yield, weed density, weed fresh weight, and weed dry matter content. Cultivar and planting arrangement affected growth, yield, and weed interference. More and wider, leaves with taller plants were produced by cv. NHAe 47–4 planted at 1 plant/stand. Cultivar LD 88 planted at 1 plant/stand produced wider stems, higher yields and best weed suppression (7 weeds.m2) while earlier flowering was observed at 2 plants/stand. The days to 50% flowering was similar for cv. NHAe 47–4 planted at 1 or 2 plants/stand and 'LD 88ʹ planted at 2 plants/stand. Cultivar LD 88 planted at 1 plant/stand had higher yield and suppressed weeds best, 7 weeds∙m2. Plant spatial arrangement can affect growth and yield. The best planting arrangement for a crop could have impact on productivity and cost of production. The late-maturing cv. LD 88 planted at 100 × 25 cm at 1 plant/stand produced optimum okra growth, yield, and efficient weed control in a traditional cropping system in the tropics. [ABSTRACT FROM AUTHOR]

Wide variability does not exist in okra [Abelmoschus esculentus (L.) Moench], requiring induction of genetic variability. Mutagenesis creates desired variability among genotypes without altering the agronomic base which is sometimes difficult to induce using other breeding methods. Seed germination/seedling emergence and seedling growth were evaluated under laboratory and field conditions by imposing 300 to 1000 Gy (Gray, the SI unit of radiation) gamma radiation to determine median lethal (LD50) and median growth reduction (GR50) doses with Co60gamma rays. The LD50 and GR50 doses varied for both growing conditions. More than 80% of seed exposed to the LD50 dose of gamma radiation in the laboratory did not emerge under field condition. The LD50 and GR50 doses of gamma radiation determined under field condition exhibited close correspondence and presented a reliable picture regarding lethality and injury in the M1 generation (the first generation from the irradiated seed). The R2 for the linear model for seedling emergence, shoot and root length, fresh and dry weight of seedlings under field condition were 0.908, 0.902, 0.911, 0.983 and 0.972, respectively. Determination of the LD50/GR50 is important to optimize the radiation dose to isolate desired utilizable mutants. Dose optimization should be determined through use of LD50 and GR50 under field condition. The gamma radiation dose between 350 Gy and 450 Gy was optimum to create desirable mutants in okra. The optimal dose could induce a higher rate of mutation with little biological damage in succeeding generations of okra. [ABSTRACT FROM AUTHOR]

Planting density affects the level of competition for resources needed for the growth and production of okra (Abelmoschus esculentus [L.] Moench). Competition from weeds can affect yield. Field experiments were conducted at the Federal University of Agriculture, Abeokuta, Nigeria, to study the effects of planting density on growth and pod yield of okra cvs. NHAe 47-4 and LD 88 and weed suppression, in 2012 and 2013. Plants were established at 100 × 50 cm at densities of one, two, or three plants/stand (25,000; 50,000; and 75,000 plants∙ha−1). Okra plants were generally shorter in 2012 than in 2013, but height was not affected by planting density or cultivar in both years. The number of leaves/plant was similar for cultivars but were reduced with increasing plant density. Leaf area was higher for one plant/stand in 2012 but similar for the higher densities in 2013. Plant height and number of leaves per plant were generally higher for 'NHAe 47-4ʹ. The cv. LD 88 had a higher cumulative pod yield than 'NHAe 47-4ʹ. Cultivar LD 88 had higher yields with three plants/stand; yield of cv. NHAe 47-4 was higher with one or two plants/stand. Okra growth and yield were reduced with increasing planting density. There were no differences between cultivars or planting density on weed growth. The planting density for optimum yield of an okra should be determined for each cultivar. [ABSTRACT FROM AUTHOR]

Increasing demand for fresh okra (Abelmoschus esculentus L.) has necessitated that shelf-life be extended. Natural edible coatings do not have human safety issues associated with chemical preservatives. Extension of shelf-life due to delay of chlorophyll degradation in okra was assessed using guar gum coating alone or mixed with sodium chloride. All coatings preserved chlorophyll content over 21 days of storage in a range of 1.30- to 2.35-fold higher compared with the distilled water treated control. A modified second polynomial equation indicated a good fit model with coefficients of determination of 0.99406–0.99952, low root means standard error of 0.6746–2.3843, and Chi-square of 0.45521–5.68504. Gum coating has potential to preserve nutrients in pods while reducing the microbial load in okra. Senescence could be delayed when gums are used as coating material in okra. [ABSTRACT FROM AUTHOR]

Micronutrient malnourishment is a problem in developing countries, most especially among women and preschool children. Breeding okra [Abelmoschus esculentus (L) Moench] for high seed contents of micronutrients in a high pod yielding background may contribute to correcting this problem. This requires evaluating micronutrients association with agro-morphological and seed elemental traits. Field evaluations were conducted with 20 okra landraces during 2016 and 2017 at Abeokuta, Nigeria. Genotypic correlation, regression and path analyses were performed to determine key driving traits of high pod yield, and seed iron and zinc contents. There were significant differences in landraces in the agronomic and nutritional traits. Correlation analysis indicated a positive, significant, relationship between plant height at flowering and maturity, and number of seed per pod with pod yield. Regression analysis indicated number of pods per plant was the most important trait for pod yield improvement as it retained the highest coefficient of determination. Path analysis identified tall plants with more pods be used for improvement of pod yield. Heavier seed should be used for improvement of seed iron content, seed magnesium and potassium contents should be targeted to achieve seed zinc content improvement. Plant height and number of pods per plant should be focused on in improvement of pod yield in okra. The 100-seed weight could serve as a major selection criterion to achieve increased seed iron content. Determination of other yield-related, and nutritional, traits might provide additional insight into improving pod yield and seed elemental minerals in okra. [ABSTRACT FROM AUTHOR]

Any increase in okra [Abelmoschus esculentus (L.) Moench] production depends on effective use and application, of appropriate management practices. This will likely require changes in knowledge, and skills, of okra growers that can be accomplished by training. The study was conducted to identify the training needs of okra growers. Slightly more than half (54.6%) of okra growers required a medium level of training. Weed management, disease and pest control, and availability of quality seed and planting were topmost aspects requiring training. Educational level and area of land cultivated with okra were positively, and significantly, associated with okra growers training needs. Planning and execution of training programs for okra growers are necessary to improve yield. [ABSTRACT FROM AUTHOR]

Okra [Abelmoschus esculentus (L.) Moench] landraces found in Nigeria are being examined as sources of genetic variation offering potential to improve agro-morpho-nutritional traits and broaden the gene pool. Objectives of this investigation were to: (1) assess variability of agro-morpho-nutritional traits in okra landraces sourced from five agroecological zones in Nigeria, and (2) estimate divergence among the germplasm. The landraces were evaluated in field experiments over a period of 2 years at the research farm of the Federal University of Agriculture, Abeokuta, Nigeria. Principal component analysis, cluster analysis, and Mahalanobis D 2 statistics were employed to study the diversity pattern. Differences existed for all evaluated traits among landraces. Genotypes NGB00378b, NGB00297, NGB00347, NGB00293, and NGB00350 combined high seed mineral concentrations with high yield potential. A genotype × year interaction was present, as reflected by relatively low broad-sense heritability (<30%) and genetic advance (GA) (<10%) for pod yield and pod width (PDW), which limits potential for improvement. Heterosis breeding could be effectively used to improve K and Mg, as these traits expressed high variation and broad-sense heritability coupled with moderate GA. Using D2 divergence analysis, landraces were separated into seven distinct clusters, with no phylo–agroecological pattern of diversity. Based on the present study, selection for a trait in 1 year may not provide the same benefit in other years due to year-to-year fluctuations in environmental conditions, evaluation in more than 1 year is required. [ABSTRACT FROM AUTHOR]

Okra enation leaf curl virus (ELCV) disease is an emerging threat to okra (Abelmoschus esculentus L. Moench.) cultivation in the tropics. Identifying and utilizing tolerant germplasm, and understanding the genetic control of ELCV disease tolerance, is necessary to develop an effective breeding strategy. Six generations of the crosses: Tolerant × Tolerant and Tolerant × Susceptible, were utilized to study the genetic basis of ELCV disease tolerance. The pattern of segregation of 2 tolerant parents indicated a single dominant gene, along with some minor factors, governed ELCV disease susceptibility in tolerant parents. The segregation pattern for ELCV disease in the F2 generation of 2 Tolerant × Susceptible crosses indicated existence of 2 genes with duplicate recessive epistasis. Non-additive gene action and duplicate epistasis were the most predominant types of gene effects controlling days to 1st appearance of ELCV disease and percent disease index of ELCV traits. For improvement of these traits, selection should be in later segregating generations, and intermating among selected segregates be followed by 1 or 2 generations of selfing to break the undesirable linkage and allow accumulation of favorable alleles. [ABSTRACT FROM AUTHOR]

Okra (Abelmoschus esculentus L. Moench) production in the tropics is threatened by heavy incidence of enation leaf curl virus (ELCV) causing crop loss when infection is at the early growth stages. A high yielding okra hybrid with acceptable tolerance to ELCV disease is needed. In this investigation, six diverse cultivated genotypes were crossed in half diallel fashion to study the extent of heterosis, mode of gene action, combining ability effects, and dominance effects of 14 yield component traits including disease severity of ELCV. Predominance of nonadditive gene action occurred in the control for all characters studied except for percent disease index of ELCV which was conditioned by both additive and nonadditive gene action. Partial, to overdominance, effects were involved in inheritance of fruit yield and most of horticultural traits studied. Two parents '2014/OKYV RES-5ʹ and '2014/OKYV RES-10ʹ were identified as most promising donors for future breeding. Heterosis for fruit yield per plant was manifested through node at first flowering, plant height, fruit length, number of fruit per plant, nodes on the main stem, and seed per fruit. Two promising hybrids '2014/OKYV RES-5 × 2014/OKYV RES-10ʹ and '2014/OKYV RES-5 × BCO-1ʹ were identified based on average values, heterosis manifested, and relevance of specific combining ability effects, and these hybrids could be commercialized in okra growing zones in the tropics after critical testing. [ABSTRACT FROM AUTHOR]

Okra [Abelmoschus esculentus (L.) Moench] production is threatened by yellow vein mosaic virus (YVMV) and enation leaf curl virus (ELCV) diseases, of which ELCV has become prevalent and serious in the tropics. Identification of tolerance to ELCV among cultivated species of okra for utilization in breeding is lacking. The study was conducted to identify okra genotypes that can be utilized in hybridization to retrieve potential line(s) having degrees of tolerance against ELCV and YVMV, and which also exhibit high yield. Thirty-five okra genotypes, collected from different sources, were screened for tolerance to YVMV and ELCV and other quantitative traits. A wide range of variability occurred for the traits. No coincidence of YVMV and ELCV diseases occurred at the same time in any genotype. Genotypes were grouped into six distinct clusters emphasizing the relative contribution of various quantitative characters to total variability. The clusters do not represent place of origin indicating genotypes in a cluster were geographically diverse; genotypes obtained from the same region were genetically different. The principal components, Percent disease index (PDI) of YVMV, PDI of ELCV and plant height, had eigen values >1 and together accounted for 100% of total variation. Based on multivariate analysis and average values, genotypes '285-1-3A-1-17-1,' 'VRO-178,' '285-1-3-1-15-2-1,' and '12/OKYV RES-1' were identified as potential donors that could be passed on to breeders for ELCV and YVMV disease resistant breeding, respectively. [ABSTRACT FROM AUTHOR]

Water deficit in semi-arid areas is a limiting factor affecting crop production and quality. The Middle East suffers from low rainfall and high temperatures. Foliar fertilization with Tecamin max®, compensates for nutrient deficiency by roots due to water deficit. The water soluble fertilizer Tecamin max® was applied to foliage to determine effects on morphological traits of the okra [Abelmoschus esculentus (L.) Moench], cvs. Samara and Ptira, under water deficit. There were irrigation levels of 50 and 100% based on field capacity, and concentrations of Tecamin max® (0, 2.5 and 5.0 mL∙L−1). 'Samara' had the tallest plants (115.50 cm), most leaves/plant (~ 31), longest time to flowering (30.44 days), most fruit/plant (51.38) and highest total yield (1.120 kg∙m−2). The 100% irrigation level produced values for plant height (107.66 cm), number of branches/plant (12.72), number of leaves/plant (29.77), total leaf area (492.00 dm2/plant), number of fruit/plant (46.27), and total yield (0.982 kg∙m−2) that were higher than for the 50% level. The 2.5 mL∙L−1 application of Tecamin max® produced plants that were 110.75 cm tall, having 14.25 branches/plant, a total leaf area of 529.33 dm2/plant, ~ 48 fruit/plant and total yield of 1.056 kg∙m−2 that were greater than for the other treatments. Foliar application of Tecamin max®, regardless of cultivar, improves vegetative growth under normal, and water deficit, conditions. [ABSTRACT FROM AUTHOR]

Drought causes severe reduction in okra [Abelmoschus esculentus (L.) Moench] yield. However, the impact of drought on okra physiology has been impeding breeding where relative degrees of tolerance need to be quantified. The okra, cv. NHAe 47-4, was exposed to 25, 50, 75, or 100% field capacity (FC) to impose water deficit for 5 or 10 days, at the vegetative (V), vegetative and reproductive (VR), or reproductive (R) stages, and effects on growth and yield, leaf relative water content (LRWC), leaf photosynthetic pigments, proline, and cysteine accumulation assessed. Simulated drought reduced LRWC, leaf chlorophyll content, biomass accumulation, and okra growth compared to the control (100% FC). The effect was more severe on plants subjected to water deficit of 10 days duration at vegetative and reproductive stages at 25% FC. Plants treated at the vegetative stage alone recovered faster than those treated at the reproductive stage alone and treatment at the two stages together. After recovery, plants exposed to water deficit at the vegetative stage alone produced more chlorophyll than the control. Okra plants exposed to water deficit produced more proline, cysteine, and carotenoids than untreated plants, with the least recorded in control, and the response varied based on duration and different FC at every growth stage. The highest values for proline and carotenoids were at 25% FC for 10 days duration at every growth stage. Plants exposed to water deficit produced more fruit than the control, especially those exposed at the vegetative stage only. Under prolonged water deficit for 10 days at the vegetative stage, there was 90.95, 70.80, and 131.18% increase in fruit yield at 25, 50, and 75% FC, respectively, compared to the control. Soil water maintained at 75% FC throughout the growing period enhanced fruit production compared to other field capacities including control. Okra response depends on water deficit severity, duration, and growth stage. Production of proline and carotenoid could be a strategy employed by okra plants for tolerance under water deficit. [ABSTRACT FROM AUTHOR]

Knowledge of productive and nonproductive water loss of okra [Abelmoschus esculentus (L.) Moench] is essential during water scarcity, and for assessing links between yield and water use. The study was conducted using subsurface drip irrigation to evaluate okra transpiration and evaporation using the SIMDualKc Model. The model computed soil evaporation was 132.89 and 157.84 mm, respectively, whereas transpiration was 381.22 and 340.36 mm in 2016 and 2017, respectively. Pod yield of okra was 12.1 and 12.5 t∙ha−1; dry biomass above ground was 5.7 and 4.9 t∙ha−1 in 2016 and 2017. Biomass above ground and fresh pod yield of okra indicates that high water deficit before harvesting pods causes a depression in fresh fruit yield and decreases total pod yield. Several water deficit occurrences during the growing period lowers total transpiration and adversely impacts okra dry biomass above ground. The SIMDualKc Model is capable of quantifying evaporation, transpiration and other water balance components. It is an effective tool for assessing and predicting the impact of water deficit on plant development and yield and can be used to identify the correct irrigation strategy for maximizing crop production. [ABSTRACT FROM AUTHOR]

The most effective means of combating reduced productivity in Okra [Abelmoschus esculentus (L.) Moench] is development of genotypes with potential for high yield. Selection for crop yield improvement can only be effective when information is available on yield association with component characters. A study was conducted to identify indirect selection criteria for yield in okra. Sixteen hybrid genotypes obtained through North Carolina Design II mating between four genotypes as males and four as females were established in single-row plots in Oct. and May of 2013 and 2014, respectively. Beginning at flowering, data were recorded on number of days to 50% flowering, stem diameter, plant height, number of leaves per plant, number of branches per plant, number of pods per plant, pod width, number of ridges per pod, number of seed per ridge, number of seed per pod, 100-seed weight, and seed yield·per hectare. Analysis of variance was performed on separate and combined data and analysis of covariance was performed on data from individual planting dates. Genotypic and phenotypic correlation coefficients were estimated from variance and covariance analyses. Genotypic correlation coefficients of characters were partitioned into direct and indirect effects for early planting. Correlation and path coefficient analyses identified characters having useful association with seed yield/plant. Sufficient strength of the relationship existed for indirect selection of characters with seed yield. Number of pods/plant appears to be the most reliable indicator of yield in okra. [ABSTRACT FROM AUTHOR]

In the tropics, Okra (Abelmoschus esculentusL. Moench) is an important vegetable crop and its production is a means of income; however, there are challenges in its marketing. Fresh okra marketing in the Ibadan metropolitan area of Oyo State, Nigeria, was examined. Responses were obtained from 96 fresh okra marketers (33 wholesalers, 63 retailers). Data from questionnaires were analyzed with descriptive statistics, marketing margin, and the Herfindahl index. Almost all wholesalers and retailers were women. The majority of wholesalers were 41–50 years old and retailers were 31–40 years old. About a third of wholesalers and slightly more than half of retailers had been in okra marketing for 11–20 years. An average of 40 baskets (each weighs 10 kg) were sold by wholesalers and six baskets were sold by retailers weekly. The farmers’ share of the recovered price was 36.09%, which is considered to be low. Marketing efficiency for wholesalers and retailers were greater than unity (ME>1). The Herfindahl indices for wholesalers and retailers were 0.044 and 0.017, respectively, indicating that the market tends toward perfect competition because no single marketer could influence price or supply of okra. Retail markets were more perfectly competitive and efficient. Major marketing constraints identified by marketers were transportation and finances. Improved credit to marketers could improve market efficiency. [ABSTRACT FROM AUTHOR]

Increased okra [Abelmoschus esculentus(L.) Moench] production cannot be achieved without application of improved cultural practices. Okra growers’ use of these practices depends on their knowledge of the practices. The study was conducted with 125 okra growers selected through random sampling. A structured questionnaire and face-to-face interviews were used to collect data. The majority of respondents (49.6%) had a medium level of knowledge of okra cultivation practices followed by low (29.6%) and high (20.8%) levels of knowledge. Okra production will likely be increased if grower knowledge of cultivation practices is improved. [ABSTRACT FROM AUTHOR]

The root knot nematode,Meloidogyne incognita(Kofoid and White) Chitwood, is an important pest of okra [Abelmoschus esculentus(L) Moench], causing root galling and yield losses in commercial and local consumption cultivars. Use of expensive, toxic nematicides needs to be replaced with genetic improvement of plants for resistance to nematodes. A study was conducted to determine pathogenicity of root knot nematode on okra accessions and their degree of resistance to the nematode. Okra accessions obtained form the National Centre for Genetic Resources and Biotechnology, Ibadan, Oyo State, Nigeria, were exposed to 0 or 5000 eggs ofM. incognitaper plant. Two seeds from each accession were sown in pots containing a sterilized sandy loam soil and thinned to one plant per pot before inoculation with nematodes. Data were collected on plant height, shoot weight, fruit weight, numbers of galls, and nematode population in roots and soil. Reductions in plant height due toM. incognitainfection ranged from 13.69% to 75.64%, shoot weight from 13.69% and 67.24%, and fruit weight from 12.96% to 53.29%. Accessions NG/TO/JUN/09/007, NHGB/10/048, NG/AA/SEP/09/040, NHGB/09/057, and NG/SA/DEC/07/0528 were tolerant toM. incognita. Accessions CEN/009, NG/AA/SEP/09/038, NG/SA/DEC/07/498, and NHGB/09/055 were susceptible toM. incognitainfection. Resistance to root knot nematode may be able to be achieved through breeding. [ABSTRACT FROM PUBLISHER]

Productivity of okra [Abelmoschus esculentus(L) Moench] can be affected by sowing date and/or cultivar. Field experiments were conducted in the tropical rain forest zone of Nigeria to investigate effects of sowing date on leaf growth, pod yield, and fruiting duration of okra cvs. NHae47-4, LD88, and Jokoso. Early sowing supported development of more leaves/plant than normal or late sowing. Highest leaf area (LA) was from regular and late-sown plants in the first year. In the second year, highest LA was from early sown plants. The dwarf cv. Jokoso had the highest leaf area index (LAI) with early sowing in the second year. The cv. NHae47-4 attained first flowering 6 and 7 days earlier than ‘LD 88’ and ‘Jokoso’. Days to 50% flowering was not affected by cultivar or sowing date. With early sowing, cv. NHae47-4 attained first pod harvests in 59 days; cvs. LD 88 and Jokoso attained first pod harvests in 67 and 70 days, respectively. Harvesting lasted for 43 days with early sowing and 37 and 26 days for regular and late sowing, respectively. Number of pods/plant and pod yield were highest with early sowing. Okra leaf growth and pod yield may be improved with early sowing. [ABSTRACT FROM PUBLISHER]

Productivity of okra [Abelmoschus esculentus(L.) Moench] can be affected by variety and/or planting density. Field experiments were conducted in the tropical rainforest zone of Nigeria to investigate the effects of planting density on growth, pod yield, and fruiting duration of okra cvs. NHae 47-4, LD 88, and Jokoso. Plants were established at densities of 1, 2, and 3 plants/site (33,333, 66,667, and 99,999 plants·ha−1). Leaf area was decreased and leaf area index (LAI) increased as planting density increased. Cultivar NHae 47-4 had the highest LAI, fewest days to 50% flowering and first fruiting, longer harvest duration, and higher yield than ‘LD 88’ and ‘Jokoso’. Pod yield·per hectare increased as planting density increased. Number of leaves per plant, number of pods, and pod weight per plant decreased as planting density increased. Peak fruit yield was achieved at 12 weeks. Early maturing okra can be established at 3 plants/site (99,999 plants·ha−1) for early and high yield. [ABSTRACT FROM PUBLISHER]

There is little work on the bioefficacy of mineral oil on management of whitefly in vegetable crops. The bioefficacy of mineral oil, a safer material than synthetic chemical pesticides, was determined against whiteflyBemisia tabaci(Gennadius) on okra [Abelmoschus esculentus(L.) Moench]. Laboratory and pot culture studies were conducted to test the bioefficacy of mineral oil alone or in combination with other materials against whitefly on okra. A 2% concentration of mineral oil + neem oil and mineral oil +Pongamia glabraseed oil produced 95% and 93.33% mortality at 48 h after treatment under laboratory conditions. In pot culture, 2% concentrations of mineral oil + neem oil and mineral oil +Pongamia glabraseed oil were effective againstB. tabaciwith a mean population reduction of 81.83% and 81.52%, respectively. Foliar application of up to 5% mineral oil on okra produced no phytotoxicity on 30- and 45-day-old plants. However, mineral oil at 7%, 10%, 15%, and 20% produced injury to tips and surfaces of leaves with a rating of 2.0, 2.0, 3.33, and 6.33 on 30-day-old plants and 2.0, 2.0, 3.0, 5.0 on 45-day-old plants, respectively. Mineral oil at 3% and 5% concentrations did not cause phytotoxicity. Laboratory experiments conducted on the safety of mineral oil and its combinations for the predatorChrysoperla carnea(Stephens) eggs and grubs indicated that all mineral oil–based treatments were safe with negligible negative effects on hatching of eggs 89%–93.5% hatching and minimum grub mortality of 3.33%–16.67%. Mineral oil in combination with either neem oil orPongamia glabraseed oil is efficacious in checking the whitefly population; furthermore, it is not phytotoxic and is safer for its common predatorChrysoperla carnea(Stephens). [ABSTRACT FROM AUTHOR]

Competition between plants affects fruit and seed yield of okra (Abelmoschus esculentusL. Moench). An experiment was conducted in a tropical rainforest zone with plant populations from 33,333 to 111,111 plants·ha−1to assess plant development, fruit size, and okra seed yields. Plant stem height and diameter were not affected. The 33,333 plants·ha−1population had more leaves/plant and higher average leaf area. Leaf area index (LAI) was highest (1.7) at the 55,555 plants·ha−1population. Okra fresh fruit yields (6.4 to 7.6 Mt·ha−1) were similar at all populations. The lowest population had a comparable yield due to greater fruit size; the high population had more small-sized fruit. Average seed yield was linearly related to plant population. There was 3.4 to 5.9 Mt·ha−1of seed produced. An income return of 7 to 12 times can be made from cultivating okra for seed. [ABSTRACT FROM PUBLISHER]

Conservation of okra [Abelmoschus esculentus(L.)Moench] germplasm is mainly by seed storage in gene banks. Efficient management of seed collections, especially under tropical conditions, requires the ability to quantify and predict seed viability during storage. To quantify longevity of okra seed for purposes of viability prediction, two controlled deterioration (CD) experiments were conducted. In the first experiment, seed of six accessions of okra were stored at 45°C and 60% relative humidity (RH), and germination determined at 0, 3, 5, 10, 20 35, 50, 70, and 100 days to estimate probit seed longevity parameters. Mean probit seed longevity (P50) was 102.59 ± 38.21 days, indicating that okra seed are long-lived compared to a longevity marker species,Brassica napus(L.). In the second experiment, constants of a model for predicting viability were determined for okra seed stored for 300 days at 45°C and 2.19 to 12.9% seed moisture content (MC). The fit of log σ and log MC wasR2= 0.90 when log σ data for okra seed dried below 4.09% MC were not included in the fit. Estimates of derived viability constants wereKE= 6.659 andCW= 2.448. Estimated viability constants should be used for viability predictions under typical tropical ambient storage and practical gene bank storage conditions. [ABSTRACT FROM AUTHOR]

Continuous use of previous generation acaricides in okra [Abelmoschus esculentus(L.) Moench] has increased resistance to pesticides and pest resurgence. The project was undertaken to evaluate a new acaricide, fenazaquin 10 EC, for effective control of two-spotted spider mites [Tetranychus urticaeKoch (Acari: Tetranychidae)] in pot culture and under field conditions. Fenazaquin was used at 75, 100, 125, or 150 g·ha−1a.i. and compared with the standard acaricide dicofol 18.5 EC at 250 g·ha−1a.i. and an untreated control. The adulticide bioassay, ovicidal action toT. urticaeand safety of Dwarf honey bees (Apis floreaFabricius), was performed under laboratory conditions. Pot culture and two field trials were conducted to evaluate efficacy. Impact on okra yield and phytotoxicity were determined. The LC50was 1.440 mg·L−1and LT50at 1.50 mg·L−1was ˜8 hours. Fenazaquin produced more than 70% egg mortality in all doses forT. urticae. Fenazaquin at 125 and 150 g·ha−1a.i. caused the highest reduction in numbers of mites in pot culture and field experiments. Fruit yields (9.89 Mt·ha−1, 10.59 Mt·ha−1) and cost–benefit ratio (1:3.25, 1:3.48) were higher in fenazaquin-treated plants at 150 g·ha−1a.i in field experiments. No test doses were phytotoxic and all doses were relatively safe to Dwarf honey bees. [ABSTRACT FROM PUBLISHER]

The absence of market integration has important implications for market efficiency. An integrated vegetable market will permit low spatial and intertemporal variation in prices, implying that commodity market prices will be functionally related. Vegetables are important sources of nutrients and income. The study assessed market integration between urban and rural markets ofAmaranthus cruentusL,Corchorus olitoriusL, and okra [Abelmoschus esculentus(L.) Moench] in South-western Nigeria. Data on monthly prices from 2004 to 2009 was collected from the Oyo State, Nigeria, Agricultural Development Project. Data were analyzed using augmented Dicker-Fuller and Granger causality tests and the index of market connection (IMC). Prices ofA.cruentusandC.olitoriuswere stationary at its level, and the price of okra was stationary by the first difference. Johansen co-integration analysis indicated that rural and urban vegetable market prices are co-integrated and form part of the same market, indicating a flow of market price information. The Granger causality test suggested that urban and rural prices ofCorchorushave a causal relationship. Rural okra andC.olitoriusexhibited a bidirectional causal relationship. The IMCs forAmaranthus,Corchorus, and okra were 0.64, 0.26, and 3.32, respectively, indicating thatAmaranthusandCorchorusmarkets exhibit high short-run market integration, whereas okra exhibited low short-run market integration. There is quick transmission of prices between urban and rural markets forAmaranthusandCorchorus, whereas there is slow transmission of prices between urban and rural markets for okra because the flow of information regarding okra prices is not efficient. The policy implication of the study is that market price information should be made available to farmers through various agricultural programs and a market infrastructure including transportation and communication facilities should be developed. [ABSTRACT FROM AUTHOR]

Improving yield and ensuring its sustainability under adverse conditions through resistant hybrids is the major objective of heterosis breeding in okra (Abelmoschus esculentusL. Moench). A study was undertaken to determine gene action, heterobeltiosis, and combining ability for 15 characters through a Line × Tester mating design in okra. Nonadditive gene action controlled all characters studied. Crosses showing high specific combining ability (sca) and yield involved parents showing high general combining ability for plant height, number of nodes on the main stem, number of leaves per plant, fruit diameter, fruit weight, and number of fruits per plant. Parental lines and hybrids were categorized according to disease reaction. The hybrids ‘VNR Green’ × ‘Shagun’ and ‘Barsha Laxmi’ × ‘Parbhani Kranti’ were selected on the basis of their mean (per se) performance, heterosis manifested in them, and sca effects. These hybrids could be used commercially due to high yield and low percentage disease index values for yellow vein mosaic virus (YVMV) disease. [ABSTRACT FROM PUBLISHER]

Monocropping of okra and eggplant reduces the net return of small-scale farmers in Upper Egypt due to price fluctuation. The effects of row configurations on the yield and economics of intercropping okra cv. Balady and eggplant cvs. Balady Black (BB) and Balady White (BW) were investigated. The row configurations of okra and eggplant were 1:1:1:1 (okra : BB or BW : okra : BB or BW), 1:2:1 (okra : BB or BW : okra), and 1:3 (okra : BB or BW) were tested. Monocropped okra produced the tallest plants at flowering and end of season, highest number and weight of pods/plant, and early and total yields of fresh pods. Among the row configurations the 1:2:1 (okra : eggplant : okra) produced the tallest plants at flowering and at the end of season, highest number and weight of pods/plant, and early and total yields of marketable pods. The row configuration 1:3 (okra : eggplant) had the shortest plants at season end, lowest number and weight of pods/plant, and early and total yields of marketable pods. Monocropped eggplant BB had the tallest plants at flowering and end of season, highest number and weight of fruit/plant, and early and total yields. The row configuration of 1:3 (okra : eggplant) had the greatest number and weight of fruit/plant and early and total yields, whereas the 1:2:1 (okra : eggplant : okra) configuration had the lowest number and weight of fruit/plant and the 1:1:1:1 (okra : eggplant : okra : eggplant) configuration had the highest early and total yields. The land equivalent configuration (LER) was greater than one for all row configurations except for 1:1:1:1 (okra : BB : okra : BB) and 1:2:1 (okra : BB : okra). Aggressiveness values indicated that okra was the dominant crop. The highest net return (30,761.06 Le·ha−1) was obtained when okra was intercropped with eggplant in the 1:3 (okra : BB) configuration; the lowest net return (13,849.70 Le·ha−1) was for monocropped okra; Le is the Egyptian pound where 1 Le = $US0.168. Intercropping offers insurance against single crop failure. [ABSTRACT FROM AUTHOR]

Okra, Abelmoschus esculentus (L.) Moench, is attacked by the adult chrysomelid flea beetles, Podagrica spp. Information on physiological disruptions that occur due to flea beetle infestation affecting okra yield loss is incomplete. Screenhouse and field experiments were established to examine the effects of insect populations on leaf abscission, chlorophyll concentration, and biomass partitioning. Okra plants were grown in wire mesh screen cages and artificially infested with flea beetles, P. uniforma Jac., at population densities of 0, 5, 10, 20, 30, and 40 pairs per plant at 3 weeks after sowing (1 pair = 1 male and 1 female). In both experiments, okra plants had increased leaf abscission up to 100% at the 40-pair level in response to P. uniforma–induced injury. There were no significant differences in chlorophyll concentrations of plants at 0-, 5-, and 10-pair levels of infestation, suggesting the use of a compensatory mechanism by plants; at the 20-pair level a significant reduction occurred. Number of leaves per plant, shoots, roots, and dry fruit and total dry matter yield were reduced with infestation above the 20-pair level. More biomass was partitioned into roots at the 5- and 10-pair levels, but insect damage at populations beyond these levels completely suppressed the plant's ability to partition biomass. Dry fruit yields were reduced more than 50% when beetle populations increased beyond 20 pairs in both experiments. There was a correlation between insect density and number of leaves per plant and shoot, root, dry fruit, and total dry matter yield. The reduction in okra leaf production and chlorophyll content and increase in leaf abscission as a result of flea beetle infestation apparently resulted in a reduction in dry matter yield. The 20-pair level appeared to be the damage threshold of the insects. Physiological disruptions induced by the flea beetle at this level overcame the plants' ability to compensate for damage and caused significant reductions in leaf production, chlorophyll content, and dry matter yield and an increase in leaf abscission. [ABSTRACT FROM AUTHOR]

There is continuing need to develop improved cultivars with traits that can be determined in various generations. To identify traits that can facilitate selection of productive progenies in late-segregating generations, elite F5 progenies of okra [Abelmoschus esculentus (L.) Moench] along with the open-pollinated variety Varsha Uphar were investigated for the extent of genetic variability and correlation among various characters related to fruit and seed yield. Number of fruit, average fruit weight, fruit length, and internodal distance were important for developing genotypes for higher fresh fruit yield. For high seed yield, genotype-pertinent characters were average fruit weight, fruit length, seed number/fruit, seed weight/fruit, 100 seed weight, and shelling percentage. Most characters exhibited moderate heritability, indicating that high fresh fruit and seed yields can be selected through simple selection but not with high reliability in okra. Number of branches/plant, internodal distance, numbers of seed/fruit, stalk length, and fresh fruit yield confer the preponderance of variation that needs to be considered in late-generation selection in okra. Yield characters, number of fruits/plant, fruit length, and average fruit weight were major contributors to fresh fruit yield. For seed yield increase, fruit number, dry fruit weight, number of seed/fruit, and 100 seed weight were associated and need to be considered in developing genotypes for higher seed yield. [ABSTRACT FROM PUBLISHER]

Okra [Abelmoschus esculentus (L.) Moench] is susceptible to at least 19 plant viruses with Okra mosaic virus (OkMV) being reported to be the most severe. Alternative host plants have been suspected to harbor OkMV which have contributed in its transmission. A study was carried out to determine the incidence of OkMV in weed species found near cultivated okra. Weed species growing around okra field, and exhibiting virus, or virus-like disease, symptoms were sampled and serologically analyzed to determine whether they harbored OkMV. Vector transmission tests were carried out with Aphis craccivora, A. spiraecola, Podagrica unifoma, P. sjostedti and Syagrus spp. to determine if the virus was insect-transmitted from the weeds to healthy okra and indicator plants. In the second experiment, healthy okra plants were inoculated with OkMV, at 14, 21, and 28 days after emergence and the effect of OkMV on yield components was estimated. Presence of OkMV in some weed samples was confirmed by symptom expression, host range, and serology. Leaf extract from the weeds produced symptoms on at least two common indicator hosts upon mechanical inoculation. Datura spp. exhibited the greatest ability to harbor OkMV. Cucumber mosaic virus (CMV; genus Cucumovirus), a non-persistently transmitted virus was isolated as a result of differential transmission tests with candidate vectors of CMV from Datura sp. The effect of OkMV infection on okra growth and yield varied with time of inoculation. There was a positive correlation between fruit weight and numbers of fruit for all inoculation times. There was reduction in yield components due to infection with OkMV in all time of inoculation. [ABSTRACT FROM AUTHOR]

Application of compost in horticultural crops has the potential to provide many benefits and yet there are concerns regarding accumulation of heavy metals in the crop and on human health. Effects of amending soil with compost made from mixed municipal solid waste (MSW) on yield of okra (Abelmoschus esculentus L.) and watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] and on heavy metal concentrations (Cd, Cu, Cr, Ni, Pb, and Zn) in pods of okra and pulp and juice of watermelon were investigated. Four MSW compost rates were applied, 25, 50, 75, and 100 Mg·ha-1, and compared to a non-amended control with no compost application. Addition of MSWC increased yield of okra and weight of watermelons over the control. There were no differences among treatments in heavy metal concentrations in okra pods, watermelon pulp, or juice. [ABSTRACT FROM AUTHOR]

Okra (Abelmoschus esculentus L.) cv. 'Balady,' that is monocropped over 5-6 months in Upper Egypt usually grows slowly in the first 5-7 weeks. There is no information available on whether a secondary summer vegetable can be produced within main crop okra rows. In the present study, okra was planted on April 1, 2004 and April 7, 2005 at 40 cm within-row spaces on 70-cm wide rows. Cowpea or cucumber was planted at mid-distance between okra hills either simultaneously with okra (April 1, 2004 and April 7, 2005) or later after growing okra (April 27, 2004 and April 28, 2005). Sole crop treatments were also involved. Data indicated that okra-cowpea intercropping did not affect okra pod yield. Cowpea, on average, produced 257 kg·ha,sup>-1>/sup> dry seed yield when planted simultaneously or 3 weeks after planting okra. Calculated “aggressiveness” indicated that okra was the dominant crop. Land equivalent ratio (LER) of okra-cowpea intercropping was, on average, 1.2 for both years. With regard to cucumber, fruit yield was produced only when it was planted simultaneously with okra. Okra-cucumber intercropping based on simultaneous planting of both crops depressed okra pod yield to 90% of its monocropped yield. Intercropped cucumber yield as percent of sole culture was 60%. “Aggressiveness” showed that cucumber was the dominant crop. LER of okra-cucumber intercropping, on average, was 1.5 when both crops were simultaneously planted. doi:10.1300/ J512v13n02_04 [ABSTRACT FROM PUBLISHER]