Okra Crop Research Articles

Foliar use of TiO2-nanoparticles for okra (Abelmoschus esculentus L. Moench) cultivation on sewage sludge-amended soils: biochemical response and heavy metal accumulation.

Considering its richness in organic and inorganic mineral nutrients, the recycling of sewage sludge (SS) is highly considered as a soil supplement in agriculture. However, the fate of hazardous heavy metal accumulation in the crops cultivated in SS amended soils is always a source of concern. Since nanoparticles are widely recognized to reduce heavy metal uptake by crop plants; thus, the present experiment deals with okra (Abelmoschus esculentus L. Moench) cultivation under the combined application of SS and TiO2-nanoparticles (NPs). Triplicated pot experiments were conducted using different doses of SS and TiO2-NPs such as 0g/kg SS (control), 50g/kg SS, 50g/kg SS + TiO2, 100g/kg SS, and 100g/kg SS + TiO2, respectively. The findings of this study indicated that among the doses of treatment combinations investigated, 100g/kg SS + TiO2 showed a significant (p < 0.05) increase in the okra plant yield (287.87 ± 4.06g/plant) and other biochemical parameters such as fruit length (13.97 ± 0.54cm), plant height (75.05 ± 3.18cm), superoxide dismutase (SOD: 110.68 ± 3.11 μ/mg), catalase (CAT: 81.32 ± 3.52 μ/mg), and chlorophyll content (3.12 ± 0.05mg/g fwt.). Also, the maximum contents of six heavy metals in the soil and cultivated okra plant tissues (fruit, stem, and root regions) followed the order of Fe > Mn > Cu > Zn > Cr > Cd using the same treatment. Bioaccumulation and health risk assessment indicated that foliar application of TiO2-NPs significantly reduced the fate of heavy metal accumulation under higher doses of SS application. Therefore, the findings of this study suggested that the combined use of SS and TiO2-NPs may be useful in ameliorating the negative consequences of heavy metal accumulation in cultivated okra crops.

Dr IMPACT OF VARIOUS ORGANIC AND CULTURAL PRACTICES ON YIELD AND WEED MANAGEMENT IN OKRA (Abelmoschus esculanta L.)

Weed management in okra field is one of the most challenging and expensive steps that ultimately reducing the productivity. A field experiment was conducted to evaluate impact of various organic and cultural practices on yield and weed management in okra crop at Agronomy Research Farm, The University of Agriculture, Peshawar, Pakistan during spring season 2021 in a Randomized Complete Block Design (RCBD) having three replications. The following treatments were applied to the experimental trail. T1=Parthenium Parthenium hysterophorus) weed extraction (120g/L), T2= Coco grass (Cyperus rotundus) weed extraction (120g/L), T3= Field bind weed (Convolvulus arvensis) weed extraction (120g/L), T4= Mulching (Eucalyptus leaves), T5= Mulching (News Paper), T6= Hand weeding (Once) 20 days, T7= Hand weeding (Twice) 20 &amp;40 days, T8= Weedy check. Results shows that all the studied parameters of okra crop were significantly affected by all the applied treatments except number of flowers plant-1. Maximum weed fresh biomass (143.3g), weed dry biomass (42.2g), plant height (64.2cm), number of branches plant-1, (11), fruit length (11.73 cm), fruit diameter (1.8 cm) and yield (3246.6kg/ha) were noted in a Hand weeding (Twice) 20- &amp; 40-days treatment followed by Hand weeding (Once) after 20 days, however the minimum values was noted in weedy check treatment except weed density which was found maximum in weedy check treatment. Hand weeding twice after 20 &amp; 40 days of crop sowing was recommended to get in okra crop better yield.

Effect of Different Levels of Pusa Hydrogel on Soil Moisture Retention in Different Soil of Ranchi Region under Polyhouse Condition

The pot experiment was conducted under polyhouse conditions during 2019 in Kharif season (August- December) in the Department of Agrometeorology and Environmental Science, Birsa Agricultural University, Ranchi, Jharkhand, India using Factorial Complete Randomized Design. The treatments consists three levels of Pusa hydrogel (5 g, 10 g, and 20 g) with three replications in upland, upper medium land and lower medium land soil. This study was carried out with specific objectives of the influence of Pusa hydrogel-induced varying soil moistures on the performance of the okra crop. Results revealed that the treatment T3 (20 g of Pusa hydrogel) recorded significantly high soil moisture content compared to all other treatments. It recorded the highest average soil moisture content (25.1% in upland,26.8% in upper midland, and 27.5% in lower midland soil) while the control i.e. without hydrogel (T7) recorded the least soil moisture content as 14.96% in upland, 15.55%. in upper midland and 15.57% in lower midland soil.

Genotypic, phenotypic variability and evaluation of okra [Abelmoschus esculentus (L.) Moench] genotypes for yield components

Okra [Abelmoschus esculentus (L.) Moench] is India's major vegetable crop, accounting for 60% of exports. Comparatively, Tamil Nadu has a small area of cultivation and production. Hence, the present study involves the utilizatization of simple measure of variability and genetic variance to develop new varieties. The experiment was conducted with 60 genotypes of okra crop using 20 quantitative traits. The analysis of variance found that genotypes were significant (P 0.05 and P 0.01) for all of the traits tested. The fruit yield plant-1 ranged from 176.40 to 438.40 g, with 347.42 g being the average. In all the traits studied, the phenotypic coefficient of variation (PCV) was higher than genotypic coefficient of variation (GCV). The closeness of PCV and GCV values suggested that the environment had little influence on manifestation of the characters under examination. GCV (1.89-13.98) and PCV (4.06-16.61) levels were found to be moderate (10-20) and low (&lt;10), respectively, in the study. Heritability ranged from 21.73 (days to first fruit harvest) to 97.19 (plant height) percent. At 5% selection intensity, the genetic advance (GA)% mean ranged from 1.82 (days to first fruit harvest) to 27.38 (plant height). Plant height (13.68, 13.48), internodal length (16.61, 13.98), first fruiting node (13.00, 10.89), number of fruits plant-1 (13.19, 11.91), number of marketable fruits plant-1 (13.36, 11.97) and fruit yield plant-1 (13.75, 12.29) showed high heritability and high GA% mean. Thus, the above-mentioned characteristics are additive genetic control and direct selection in okra has good potential for improvement in fruit yield.

Studies on Correlation and Path Coefficient for Direct Selection between Pair of Traits Using Green Fruit Yield as Dependent Characters in Okra

The study was carried out at the Horticulture Research Centre, Sardar Vallabhbhai Patel University of Agriculture &amp; Technology, Modipuram, Meerut (U.P.). The fourteen quantitative traits, thirty genotypes of okra were tested in a Randomized Block Design (RBD) with three replications during the summer season of 2021. Fruit yield per plant showed highly significant and positive correlation with plant height, fruit diameter, number of branches per plant, fruit length, number of flowers per plant, test weight and number of fruits per plant at both genotypic and phenotypic level, indicating mutual association of these characters. Path coefficient analysis exhibits positive direct effect was observed towards fruit yield per plant for number of branches per plant followed by number of fruits per plant, days to first fruit harvesting, days to first flower initiation, fruit diameter, plant height, days to first fruit set and duration of crop at genotypic level. At the phenotypic level also the estimates of direct and indirect were generally less than genotypic level. The magnitudes of residual effects were found to be small at both the phenotypic and genotypic levels. These traits could be utilized in a selection procedure for okra crop enhancement in the future.

Salicylic-Acid-Regulated Antioxidant Capacity Contributes to Growth Improvement of Okra (Abelmoschus esculentus cv. Red Balady)

The improvement of crop yield and quality are currently of prime concern to achieve global food security and sustainability. Plant elicitation with salicylic acid (SA) has been shown to play a key role in regulating plant growth and productivity. Here, the effects of foliar SA application (1, 2, and 4 mM) on antioxidant capacity and phenolic metabolism, among other biochemical parameters, were studied in okra leaves. The results showed that SA treatments markedly increase the levels of endogenous free SA and trigger the accumulation of chlorophylls, soluble proteins, proline, antioxidant capacity, and phenolic compounds, alongside the stimulation of the enzymatic activities of phenylalanine ammonia-lyase and peroxidase, with these changes being paralleled by decreased levels of lipid peroxidation. The beneficial effects of SA treatments were also tested on field-grown okra plants. Results revealed that yield-associated agronomic attributes significantly increased upon SA treatments, especially at 2 mM SA. Altogether, these results point to a connection between SA-induced antioxidant system strengthening and crop growth and productivity. Therefore, foliar application of SA seems to be a potent and workable approach to enhance okra crop quality and yield.

Development and Stability Analysis of a Self-propelled High Clearance Multi-utility Vehicle

A self-propelled hydraulically actuated vehicle was developed for field crops of up to 2.0 m in height to carry out different operations like spraying, weeding, harvesting. The vehicle has provision for variable/adjustable ground clearance and track width to suit different spacing and heights of horticultural crops. Gradability, torque, and power required for the vehicle were calculated based on the dimensions of the selected bias ply traction tyre. The centre of gravity of the vehicle was calculated by the weight moment method. Microsoft Excel add-in was used to create a point manipulation programme, and the positions of the standard components were determined through an iterative process. The static load over the rear wheel and front wheel was kept at 60% and 40%, respectively, for design purposes. Analysis of chassis mechanics was done to find out weight transfer and impending stability on level ground as well as longitudinal and lateral slope. In longitudinal slope, the developed vehicle was found to be stable up to 45.19° and 20.68° under static and dynamic conditions, respectively; whereas in lateral slope, the vehicle was stable up to 39.08° and 22.10° under static and dynamic conditions, respectively. The developed vehicle was tested for weeding and spraying of okra and maize crops with an average height of 1.1 m to 1.5 m. The field capacity for the spraying and weeding operations was 1.9 ha.h-1 and 0.16 ha.h-1, respectively. The cost of operation for spraying and weeding was 400 ?.ha-1 and 1,500 ?.ha-1, respectively. Weeding efficiency and plant damage of the weeder were 92.58% and 1.55%, respectively.

Succession of insect Pests on Okra, Abelmoschus esculentus (L). moench

The present investigation on succession of insect pests on Okra, Abelmoschus esculentus was carried out in the Vegetable Research Farm, Maharajpur, Department of Horticulture, JNKVV, Jabalpur, Madhya Pradesh during Kharif season during the year 2018 (July to October). Results revealed the incidence of different insect pests at different stages of the okra crop, i.e., vegetative stage, flowering stage, fruiting stage, maturity stage and at harvest In all, five insect pests and a natural enemy were recorded on different stages of the crop i.e., jassid, Amrasca biguttula biguttula (Ishida), Whitefly, Bemisia tabaci (Genn.), Aphid, Aphis gossypii (Glover), Red cotton bug, Dysdercus cingulatus F., Shoot and fruit borer, Earias vittella (Fab.) and Ladybird beetle, Coccinellas eptempunctata (L.). The predator namely Lady bird beetle, Coccinella septempunctata, Coleoptera and Coccinellidae was also recorded.

Integration of Fish and Poultry Farming into Cropping Systems to Improve Production Yields

This study aims to evaluate and compare the fertilizing effects of fish-breeding water and river water combined or not with composted poultry manure on the growth and production of okra and lettuce crops. Thus, a sample of 2000 Nile tilapia Oreochromis niloticus fry and a sample of 100 Cobb 500 strain chicks were reared and monitored for six months and fifteen days. Poultry manure and fish-breeding water were then collected and used to fertilize and water okra and lettuce crops. Two systems were used for the crops (okra and lettuce) tested in an elementary plot design with replicates for each treatment (T1: fish-breeding water alone; T2: river water alone; T3: fish-breeding water combined with manure; T4: river water combined with manure). Morphometric parameters and phenological traits of okra and lettuce crops as well as the total harvest weight and production yield were evaluated and compared between treatments. The results reveal better growth and higher yields (0.67 kg/m2 vs. 0.45 kg/m2) of okra crops that received treatment T1 compared to T2. The best growth and yields of lettuce were obtained with treatments T3 (3.34 kg/m2) and T1 (1.89 kg/m2) compared to T4 (1.23 kg/m2) and T2 (1.20 kg/m2). These results show that fish-breeding water combined with poultry manure can boost okra and lettuce production and would be a real asset to stimulate local agricultural development. Thus, the adoption of such an agro-ecological approach integrating fish farming and animal husbandry could increase local production and provide food of good nutritional quality.

Response of Silica Enriched Nutrient Management on Pest Infestation and Disease Incidence of Okra

An investigation conducted at open field of Horticulture farm, Department of Horticulture, Rajasthan College of Agriculture, MPUAT, Udaipur during two consecutive seasons of 2019 and 2020. The factorial experiment was laid out in split plot design with three replications, assigning Seven levels of silica enriched nutrient management (Control, 25 tonnes FYM/ha + Silica Diatomaceous 2%, RDF + Silica diatomaceous 2%, RDF + 25 tonnes FYM/ha + Silica diatomaceous 2%, RDF + 25 tonnes FYM/ha + Silica diatomaceous 4%, RDF + 25 tonnes FYM/ha + Silica diatomaceous 6% and RDF + 25 tonnes FYM/ha + Silica diatomaceous 8%) and four levels of spray scheduling (Three weeks after sowing, Five weeks after sowing, Seven weeks after sowing and Nine weeks after sowing). The whole field was divided into three blocks each representing a replication and each replication consists of 28 treatments combination. The results showed that silica enriched nutrient management levels non-significantly improved insect pest and disease incidence percentage of okra crop during both the years of investigation. The maximum growth attributes was recorded with RDF + 25 t FYM/ha + silica diatomaceous 8% (F7) being at par with RDF + 25 t FYM/ha + silica diatomaceous 6% (F6) and RDF + 25 t FYM/ha + silica diatomaceous 4% (F5) during first and second year of investigation. Spray scheduling also significantly enhanced growth, yield attributes and yield of okra crop and recorded maximum values with S1(three weeks after sowing) being at par with S2(five weeks after sowing) during both the years of The investigation.

Method validation for determination of nine pesticides in okra and their mitigation using different solutions.

In this paper we optimized QuEChERS method for extraction of nine pesticides viz. acephate, acetamiprid, chlorpyrifos, cypermethrin, imidacloprid, thiamethoxam, profenofos (insecticides), carbendazim and tebuconazole (fungicides) and performed their quantitative estimation in okra crop by HPLC-UV and GC-ECD. Decontamination treatments namely washing with running tap water, soaking in lukewarm water (50–60°C), soaking in solutions of 1% NaCl, 5% NaHCO3, 2% CH3COOH, 0.01% KMnO4 and three commercial formulations were also done for ten minutes every time, to calculate the extent of pesticide removal from okra. Results revealed that the proposed extraction method was efficient, inexpensive, accurate, rapid and precise and can suitably be used for the simultaneous quantitative determination of the above pesticides. The standard curve was linear over the concentration range of 0.05–5μg g-1 with R2 close to one (0.999). Soaking of okra in 2% acetic acid and then washing proved as the best decontamination treatments for all the pesticides. It showed the highest relative decontaminating capacity in comparison to the other solutions tested. Since the pesticide residues are usually present in higher amount in vegetables being consumed, it is of utmost importance to keep an eye over the use of pesticides to protect the crops.

PERCEPTION AND ATTITUDE OF THE FARMERS TOWARDS IMPROVED OKRA CULTIVATION PRACTICES IN EAST GODAVARI DISTRICT OF ANDHRA PRADESH

Okra (Abelmoschus esculentusL.) also known as Lady’s Finger is an economically important summer vegetable crop that belongs to the family Malvaceae. It is known to have originated in tropical Africa. The crop is quite popular due to its easy cultivation, dependable yield and resistant to drought &amp; water logging adaptability to varying moisture conditions &amp; soil types. (Maurya et al., 2013). the major findings are 74.16 percent of the respondents have knowledge on soils that are Loose, loamy soils are required for Okra cultivation, followed by 64.16 percent of the respondents are saying that they cultivate Okra crop throughout the year. Okra plant produces fiber by 20.2 to 7.2 percent. (Chauhan 1972) East-godavari district of Andra pradesh state was selected purposively based on the maximum farmers’ availability. Descriptive research design was used for the present study. A total of 120 respondents were selected purposively as a sample for the present investigation. The data was collected by using pre-tested schedule and analyzed using appropriate statistical tools. Karl Pearson’s Co-efficient of Correlation test was applied to find out the association between farmers socio-economic profile with independent variables. It was concluded that the socio-economic status of the respondents constitute medium level. It was observed that majority of the respondents belonged to the high level of perception and towards improved okra cultivation practices. There was a positive and significant relationship between independent variables with dependent variables.

Pan evaporation and sensor based approaches of irrigation scheduling for crop water requirement, growth and yield of okra

The results of this study revealed that the pan evaporation and sensor based irrigation scheduling along with fertigation scheduling significantly affected the plant height, fruit weight, fruit length, crop water requirement, crop yield and water use efficiency of okra crop. The pan evaporation and crop evapotranspiration (ETc) values significantly vary over different stages of okra crop. The maximum and minimum average daily pan evaporation was recorded 8.4 mm day-1 and 4.5 mm day-1 at mid stage and late stage of okra crop respectively while, the maximum average daily ETc was recorded 7 mm day-1 at mid stage of okra crop. A approach of irrigation scheduling with 100 per cent field capacity, based on soil moisture sensor under automated drip irrigation system along with 100 per cent RDF through fertigation in equal splits at 4 day intervalor 80 % per cent of volume of crop water requirement based on pan evaporation under automated drip irrigation along with 100 per cent RDF through fertigation in equal splits at 2 day interval, can be used for irrigating okra crop with significant water saving, crop yield and water use efficiency under limited availability of daily weather datain climatic condition of Udaipur district of Rajasthan.

Effects of organic and inorganic fertilization with bio-inoculants on the sustainable management of plant-parasitic nematodes infesting okra (Abelmoschus esculentus)

Root-knot nematodes are believed to be amongst the biological constraints causing severe damage and a great reduction in the productivity of okra. The purpose of this study was to apply organic matter and non-symbiotic nitrogen-fixing bacteria to minimize the addition of chemical fertilizers that constantly pollute the environment. Experimental studies were conducted in the field for two summers to determine the effect of inoculations of non-symbiotic nitrogen-fixing bacteria, such as Azotobacter chroococcum and Azospirillum brasilense singly and in combinations, with different recommended doses of inorganic nitrogen as well as organic matter such as neem seed cake on the growth, yield, and organic parameters of the okra crop towards the management of plant-parasitic nematodes. The results show a significant reduction in nematode multiplication through soil application of nitrogen-fixing bacteria and neem seed cake along with different recommended doses of nitrogen inoculated plants. Azotobacter was found to be less effective than Azospirillum in agronomic parameters and nematode control. The most pronounced increases were observed in the yield and growth parameters such as plant height, fresh as well as dry weights, fruit weights/plant, number of total fruits/plant and primary branches, chlorophyll content, and ascorbic acid content when A. chroococcum and A. brasilense were added concomitantly in various combinations. Agronomic parameters such as NPK content in the plant as well as in residual soil increased considerably in almost all the combinations irrespective of these biofertilizers and neem seed cake. In conclusion, the combined application of a 100% recommended dose of nitrogen fertilizer along with Azospirillum and neem seed cake is recommended for better growth and yield of okra with better control of nematodal population.

EFFECT OF SALINE AND NON-SALINE WATER ON OKRA CROP PRODUCTION

Under the situation of acute water crises and the regular or occasional use of marginal to saline groundwater by the farming community to cultivate the crops, the research needs to be conducted on the use of marginal to saline groundwater based on the guidelines and strategies for the effective use be developed. In context of this, the experiment was conducted at the field research station of the laboratory of the Department of Land and Water Management (LWM) Faculty of Agricultural Engineering (FAE), Sindh Agriculture University (SAU) Tandojam during the year 2019. The experiment was arranged in a completely randomized design with three treatments of varying water qualities with three replications were deployed. The treatments were: W1 = non-Saline water (canal water) E.C= 1.0 dS m-1, W2 = Saline water (groundwater) EC= 4 dS/m-1and W3= Saline water (groundwater) EC= 6 dS/m-1. Okra crop was grown on ridges. The results showed that the soil EC decreased 0.76 dS/m-1 under T1, and increased 0.83 and 1.33 dS/m-1 under T2 and T3, respectively. The soil pH decreased by 0.29, 0.43, and 0.44 under T1, T2, and T3. The soil Mg increased 21.57, 22.11, and 27.03; soil SAR increased 6.15, 7.82, and 8.91; and soil ESP increased 6.51, 8.61, and 10.33 under T1, T2, and T3, respectively. The soil Ca decreased 1.34 under T1 treatment; and increased 0.30 and 10.28 under T2 and T3, respectively. The maximum yield of 18500 kg ha-1 was found with T1 followed by 17391 kg ha-1 with T2 and the lowest yield of 16836 kg ha-1 was found with T3. The highest water productivity of 1.91 kg m-3 was found with T1 treatment followed by 1.79 kg m-3 with T2 treatment and the lowest water productivity of 1.73 kg m-3 was found with T3 treatment.

Screening of wild okra (Abelmoschus moschatus) germplasm for okra yellow vein mosaic disease resistance in India

Okra yellow vein mosaic disease (OYVMD) is a major viral disease of okra crop caused by Okra yellow vein mosaic virus (OYVMV). The disease is responsible for direct yield loss in terms of both quantity and quality of capsules (fruits). Initially, DNA-A of coat protein, intergenic region and partial rep protein sequences were determined using OY2395F/OY680R specific primer and the amplified 1.2 Kb band product showed presence of OYVMV. Two years field screening of wild okra accessions (Abelmoschus moschatus ssp. moschatus) carried out during kharif 2017 and 2019 against OYVMD in agro-ecological conditions of New Delhi. Among seventy six (76) wild okra accessions 10 accessions, viz. EC360586, EC360794, EC360830, EC360900, EC359730, EC359836, EC359870, EC360351, EC361171 and EC361111 exhibited resistant (R) response in kharif 2017. While in 2019, out of these 10 promising accessions, four accessions, viz. EC360794, EC360586, EC360830 and EC361171 further showed R response. Rest of the tested lines showed either moderately resistant (MR) or susceptible (S) response. Average percent disease incidence (PDI) value was 19.51% and range value was 4.46 to 64.06% for the first year of field screening. Whereas the recorded average PDI were 21.77% with the range value of 4.36 to 67.33% in the second year. For both the years, out of 76 accessions, four accessions, viz. EC360794, EC360586, EC360830 and EC361171 were found promising and exhibited R response consistently. These promising lines could be utilized in breeding programmes for development of varieties resistant to OYVMV.

Comparative Toxicity of Nitenpyrem and Neem Oil Against Amrasca biguttula biguttula in Okra

The Jassid, Amarasca bigutulla bigutullaa is an important sucking pest of the okra crop. An experimental study was conducted during 2018 to check the comparative toxicity of nitenpyrem and neem oil against jassid under okra field conditions. The study revealed that 24 hours after treatment, nitenpyrem was found more toxic and effective with maximum reduction of jassid population (72.15%). Whereas, 120 hours after treatment with 4% neem oil, 15.05% jassid reduction was observed. The mortality rate of the jassid was increased with increasing in time after application of chemical insecticides. The study concluded that insecticide was most toxic and gives higher mortality of jassid as compared to neem oil. Keywords: Abelmoschus esculentus, Malvaceae, Amarasca bigutulla bigutullaa, botanicals, insecticides, Pakistan

Efficacy of Synthetic Pesticides Against Thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae) on Okra Abelmoschus esculentus (L.) Moench

Okra (Abelmoschus esculentus L.) is an essential vegetable crop with good nutritional significance. Insect pests are the major threat for poor production of the okra crop. Thrips of vegetable crops are known to be serious pests on a wide range of fruit, vegetable, flower, and agronomic crops. The present field study was carried out to know the efficacy of different insecticides (acetamiprid 19% weightable water (ww), lambda 25% ww, colarphipare 32% ww, lambda 2.5% ww and abamectin 1.3% ww) against Thrips, Thrips tabaci (Lindeman) on okra crop during the year 2019, and observations against T. tabaci (Lindeman) were recorded after 24 hrs, 48 hrs, 72 hrs and 07 days of each spray in all the treatments. The pre-treatment count of thrips on okra was non-significant (P &amp;gt; 0.05); while the evaluated efficacy of different insecticides against thrips was significant (P &amp;lt; 0.01). It was noted that all the insecticides showed their highest efficacy after 7 days of spray and acetamiprid 19% weightable water (ww) was more efficient to combat the T. tabaci as compared to other pesticides that produced field efficacy of 73.92 and 74.91% against thrips after 7 days of 1st and 2nd spray respectively. Abamectin, 1.3% ww, was reasonably successful, yielding 53.81 and 56.66% field efficacy against T. tabaci (Lindeman) after 7 days of first and second spray. Also, moderately effective was colarphipare 32% ww, which developed field effectiveness of 56.41 and 61.49% against T. tabaci (Lindeman) after 7 days of first and second spray, respectively.

Pathogenicity of Paecilomyces Lilicanus Fungus Toward Sucking Insects Pests of Okra Crops and Their Predators

The present work targeted to evaluate the role of entomopathogenic P. lilicanus fungus in overcoming the major okra sucking pests besides the side effect toward their predator.The targeted entomopathogenic fungus was cultured on Sabouraud dextrose yeast agar and prepared three Serial dilutions concentration suspensions to test their efficacy toward Aphids under laboratory and field conditions, while leafhopper was tested under field condition only. The obtained results were cleared that the high concentration 1x108 spore/ml, caused the best mortality percentage toward Aphis gossypii after 7 days of post-treatment. While under field conditions, the treatments were caused reduction ranged between 72.7% and 63.0 % toward A. gossypi population and 88.7%%, 86.7 % in leafhopper population, respectively. On the other side, the predators' population (F/coccinellidae) was also affected due to reducing the population of their prey.

Field Evolved Resistance in Earias vittella (Lepidoptera: Noctuidae) From Punjab, Pakistan Against Commercial Formulations of Bacillus thuringiensis kurstaki.

Transgenic commercial cotton expressing Bacillus thuringiensis (Bt) Cry endotoxins or vegetative Vip toxins provide protection to cotton against bollworm attack. Continuous exposure of these targeted pests to cry toxins and to Bt commercial spray formulations has resulted in the development of resistance through natural selection. Spotted bollworm Earias vittella (Noctuidae: Lepidoptera) is considered to be one of the most destructive pests of cotton and okra crops in South Asia including Pakistan and has developed resistance to various synthetic insecticides. In the present study, the level of resistance in field populations of the spotted bollworm E. vittella against Bt Cry toxins has been evaluated for the first time. We collected twelve populations of E. vittella from three districts of Punjab, Pakistan for testing against four commercial Bt formulations containing different strains of B. thuringiensis subspecies kurstaki (Btk) with a range of Cry toxins. Low to high levels of resistance were found in the field populations compared with a laboratory-reared susceptible population of E. vittella (resistance ratios 6 to 111-fold). These results suggest that E. vittella has developed resistance against different Cry toxins after continuous exposure to Bt cotton in field. In order to prevent field control failures, regular insecticide resistance monitoring programs are required together with the use of integrated management approaches, including the use of Bt cotton varieties expressing two or more toxins to delay the development of resistance against Bt toxins in E. vittella.