Leaf Infestation Research Articles

Effect of Micronutrients on Incidence, Damage Severity of Sucking Insect Pests of Sunflower and its Impact on Yield and other Arthropods

An experiment was conducted in a field on 23074/N latitude and 90035/E longitude at the central farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh from November 2021 to April 2022. The experiment of eight treatments as follows: T1 = Urea @ 210 gm/plot + TSP @ 84gm/plot + MoP @ 98gm/plot [recommended doses (RD) of Urea, TSP and MoP] +Boron @ 7.0 gm/ Plot+ ZnSo4 @ 8.4 gm/ Plot ;T2 = RD of Urea, TSP and MoP +Spraying 0.2% Borax @ 2gm/ L of water; T3= RD of Urea, TSP and MoP +Spraying 0.2% ZnSo4 @ 2gm/ L of water; T4= RD of Urea, TSP and MoP +Spraying 0.5% Borax @ 5gm/ L of water; T5 RD of Urea, TSP and MoP +Spraying 0.2% Borax + 0.2% ZnSo4 @ 2gm/ L of water; T6 = Urea @ 210 gm/plot+ TSP @ 180 gm/plot+ MoP @ 150gm/plot + Spraying 0.5% ZnSo4 @ 5gm/ L of water; T7 = Urea @ 210 gm/plot+ TSP @ 180gm/plot+ MoP @ 150gm/plot+ MgSo4 @ 12 gm/ Plot and T 8= control. The experiment was laid out in a Randomized Complete Block Design (RCBD) with 8 treatments and 3 replications. The overall result indicates that the combination of different micronutrients decreased the incidence of sucking insect pests of sunflower and increased the abundance of beneficial arthropods compared to T8 treatment. In T1 treatment, the lowest leaf infestation percentage caused by aphid 17.49 and 19.50 %; Jassid 14.19 and 14.89 % and White fly 26.18 and 30.83 % at the vegetative and reproductive stages respectively. The highest number of beneficial arthropods per plot of lady bird beetle both adults and grubs ((3.63 and 5.53 respectively); honey bee (22.36), ant (3.55), spider (1.42) was also recorded in T1 treatment. The highest yield contributing characters of sunflower, the highest of head/ capitulam diameter (9.75cm), height of plant per plot (179.73 cm), leaf width (14.24 cm), leaf length (21.05 cm), area of leaves per plant (62.29 cm) and number of leaf per plant (21.93), number of total head per plot (29.83), number of seed per head (725.56), weight of single seed (1.03 mg), and weight of seed per head (54.96 gm) of sunflower were observed in T1 treatment which was statistically different from among all other treatments. The highest sunflower yield (1.92 kg /plot) and oil content (0.93 liter/2kg and 46.5%) were also observed from T1 treatment. Among the different micronutrient treatment combinations, different micronutrients using in T1 treatment were more effective for the reducing the incidence of sucking insect pests on sunflower. In the term of effect of micronutrients, T1= Recommended doses of Urea, TSP and MoP + Boron @ 7.0 gm/ Plot+ ZnSo4 @ 8.4 gm/ Plot; was an eco-friendly pest management practice for sunflower by which one can significantly reduce pest infestation without use of any chemical insecticides.

Efficacy evaluation of some bio-insecticides against green leaf hopper (<em>Amrasca biguttula biguttula Ishida</em>) infesting brinjal

In Bangladesh, brinjal (Solanum melongena L.) is an important vegetable crop due to its year-round cultivation, high demand for consumption, and nutritional value. The main obstacle to the successful cultivation and production of brinjal is insect pests. The current study was carried out in the winter, when green leafhoppers (Amrasca biguttula biguttula), one type of sucking insect pest, are most prevalent. Early in the vegetative stage, an infestation of green leaf hoppers (GLH) was noted; as the canopy size increased, so did their numbers. The consumption of brinjal with its peel poses a health risk due to possible contamination with toxic chemical insecticides. We assess a few non-toxic or minimally toxic bio-insecticides against GLH in order to tackle this crucial problem. Fizimite, one of the bio-insecticides, was found to be effective against GLH in a sodium lauryl ether sulfate preparation. Fizimite decreased the amount of GLH in the plant by 85.8%, the amount of leaf infestation by 77.84%, and the amount of GLH-infected brinjal leaf abundance by 54.34%. But Voliam Flexi, a chemical control, was also discovered to be successful against GLH. Fizimite may therefore be a non-toxic, bio-rational substitute for Voliam Flexi, a synthetic, toxic medication used to control GLH.

Induction of volatile organic compounds in chrysanthemum plants following infection by Rhizoctonia solani.

This study investigated the effects of Rhizoctonia solani J.G. Kühn infestation on the volatile organic compound (VOC) emissions and biochemical composition of ten cultivars of chrysanthemum (Chrysanthemum × morifolium /Ramat./ Hemsl.) to bring new insights for future disease management strategies and the development of resistant chrysanthemum cultivars. The chrysanthemum plants were propagated vegetatively and cultivated in a greenhouse under semi-controlled conditions. VOCs emitted by the plants were collected using a specialized system and analyzed by gas chromatography/mass spectrometry. Biochemical analyses of the leaves were performed, including the extraction and quantification of chlorophylls, carotenoids, and phenolic compounds. The emission of VOCs varied among the cultivars, with some cultivars producing a wider range of VOCs compared to others. The analysis of the VOC emissions from control plants revealed differences in both their quality and quantity among the tested cultivars. R. solani infection influenced the VOC emissions, with different cultivars exhibiting varying responses to the infection. Statistical analyses confirmed the significant effects of cultivar, collection time, and their interaction on the VOCs. Correlation analyses revealed positive relationships between certain pairs of VOCs. The results show significant differences in the biochemical composition among the cultivars, with variations in chlorophyll, carotenoids, and phenolic compounds content. Interestingly, R. solani soil and leaf infestation decreased the content of carotenoids in chrysanthemums. Plants subjected to soil infestation were characterized with the highest content of phenolics. This study unveils alterations in the volatile and biochemical responses of chrysanthemum plants to R. solani infestation, which can contribute to the development of strategies for disease management and the improvement of chrysanthemum cultivars with enhanced resistance to R. solani.

FALL ARMYWORM INFESTATION ON THE PERFORMANCE OF SWEET CORN VARIETIES

The study was conducted from November 2021 to April 2022 in the field and laboratory of Department of Entomology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh to compare the morphological, developmental, yield contributing characteristics and leaf infestation status by fall armyworm of four different maize varieties viz. BU Misti Vutta 1, BARI Hybrid Vutta 1, Mohona and Dola. Among the varieties, Dola was the tallest plant having height of 156.9±6.1 cm with the highest internode length (16.0±0.2 cm), and the highest number of internodes (12.8±0.2), number of leaves per plant (11.9±0.3), leaf length (82.0±2.7 cm), and leaf width (10.5±0.2 cm). The maximum base diameter (1.9±0.1 cm) was observed in BU Misti Vutta 1. The lowest duration for seedling emergence was observed in BARI Hybrid Vutta 1 (17.6±0.3 DAS) while the lowest durations for tassel initiation (75.2±0.4 DAS), silk emergence (87.1±0.4 DAS) and earliest harvesting maturity (111.9±0.3 DAS) was observed in BU Misti Vutta 1. There was no leaf infestation (0.0±0.0%) in BU Misti Vutta 1 at 100 DAS. The highest cob length (16.4±0.5 cm), cob diameter (4.0±0.1 cm), cob weight (196.6±22.1 g), number of kernel/ cob (537.2±32.1) and yield (12.6±0.1 t/ha) were also recorded in BU Misti Vutta 1.

The First Recording of Blue Pea Butterfly, Lampides boeticus L. on Ziziphus Spina-christi Trees in Nineveh Governorate

The larvae of the blue pea butterfly, Lampedies boeticus L., were observed for the first time feeding on Ziziphus spina-christi leaves in 2020 in the gardens of Mosul University / Nineveh Governorate. The larvae feed on the lower surface layer of the leaves, leaving the feeding places in the form of transparent linear spots. The leaf may be stripped of its green area when the infection intensifies and eventually leads to its fall. The rate and severity of leaf injury varied during the months of the year and reached its peak in November with an average of 61.42% and 20.06 linear/leaf spots, respectively, while the injury rate of leaf and severity were the lowest in May with an average of 2.47%, 0, 61 linear spots/leaf. The results also showed that the southern and eastern directions of the tree were the most preferred for the insect, as the average rates of leaf infestation were 22,84, 22.12%, respectively. The mid-site leaves on the stem were the most affected by the feeding of butterfly larvae, with a severity of 7.08 linear spot/leaf.

Efficacy of Trichoderma harzianum, as a biological fungicide against fungal diseases of potato, late blight and early blight

This study was conducted at Rangpur area of Bangladesh to evaluate the performance of Trichoderma harzianum based bio-fungicide against late blight and early blight of potato. A commercial fungicide, Agrizeb (Mancozeb) 80 WP was applied for comparison. These fungicides were applied in potato filed already infected by late and early blight. Lycomax found most effective for controlling both late blight and early blight while Agrizeb found potent for early blight. After applying Lycomax, late blight infection in plant has not increased rather decreased to 20.0% from the existing 22.67% and leaf infestation reduced to 10.67% from the existing 13.33%. In contrast for Agrizeb, plant infection increased to 71.67% from the prevailing 22.0% and leaf infection increased to 73% from the existing 14.67%. Thus, Lycomax confirmed 79.09% reduction of plant infection and 89.04% reduction of leaf infection compared to control which was 25.09% and 25%, respectively for Agrizeb. For early blight, same dose of Lycomax also reduce plant infection to 1.67% from existing 14.67% and leaf infection to 8.0% from prevailing 13.33%. Plant infection decreased to 5.0% from existing 15.0% and leaf infection 13.33% from 14.67% for Agrizeb. Therefore, Lycomax provided 98.19% control of plant infection and 90.16% control of leaf infection while Agrizeb provided 94.58% plant infection and 83.61% leaf infection over control. Moreover, Lycomax confirmed 21.66 ton/ha and 22.0 ton/ha of potato yield recovering the late blight and early blight diseases, respectively. These results conclude that Lycomax can effectively be applied to control late blight and early blight diseases.

Using Some Promising Insecticides as A Management Tool Against The Major Sucking Pests of Country Bean

An experiment has been conducted to know the efficiency of some promising pyrethroids and bio-rational insecticides for controlling the major sucking pests of country beans under field conditions during the winter season September 2020 – March 2021. The different treatments were Cypermethrin 10 EC (T1), Lambda-Cyhalothrin 2.5 EC (T2), Emamectin benzoate 5 SG (T3), Abamectin 1.8 EC (T4), Spinosad 45 SC (T5), and untreated control (T6). The rate of leaf infestation at the lower, middle, and top stages of country bean ranged from 8.82–17.78, 13.89–36.39, and 13.72–33.33% in T5treated and untreated control plots, respectively. The rate of shoot infestation at the middle and top stages of country bean ranged from 18.67–34.33 and 17.00–39.27% in T5 treated and untreated control plots, individually. The lowest and highest inflorescence infestation of 29.15% and 46.67% was recorded in T5 treated and untreated control plots, separately.The lowest fruit infestation of 8.84% by number and 8.32% by weight was recorded in the treated plot T5. The rate of reduction of pod infestation over control was 48.58, 24.02, 23.39, 21.81, and 19.92% by number and 73.53, 61.76, 58.82, 52.94, and 41.18% by weight in the treated plot T5, T4, T1, T3, and T2, respectively. The yield in different treatments ranged from 1.35-2.50 t ha-1. The highest adjusted net return and BCR of Tk. 52220.00 and 2.42, respectively were obtained from T2 treated plots. The second highest BCR of 2.16 was calculated from T4 treated plot. The lowest BCR of 1.05 was found in T2 treated plot. The treatments T5, T4, and T3 were effective to suppress the major sucking pests of the country bean.

Effect of Fungicide Protection of Sugar Beet Leaves (Beta vulgaris L.): Results of Many Years Experiments

The rosette is the above-ground morphological part of sugar beet in the first year of its ontogenesis. The size and health of the leaves determine photosynthesis and the production of sugars and their redistribution throughout the plant and thus the yields and quality of individual organs. One means of protecting leaves is to apply fungicides. Their efficacy and effects of use depend on, among other things, the active ingredient and number of sprayings, as well as environmental conditions. The aim of the 11-year study was to evaluate the effect that the foliar application of fungicides in sugar beet cultivation had on leaf infestation and damage, the Leaf Area Index (LAI), leaf yield, and a plant foliage index (FI) expressed as the ratio of leaf mass to root mass. In field experiments, six treatments were compared: a control without fungicides; three sprayings with triazoles, benzimidazoles, and strobilurins as the active ingredients; and a single application of tebuconazole, epoxiconazole, strobilurin, and an epoxiconazole + thiophanate-methyl mixture. The efficacy and effects of the fungicide protection depended on its method of application and environmental conditions. Applying fungicides weakened the positive correlation of sugar beet leaf infestation and leaf damage to the sum of precipitation relative to the unprotected plants. In ten of the eleven years of the study, fungicide protection significantly increased leaf yields of plants and decreased their FI. In only three years did three sprayings increase leaf yield more than single sprayings, and, in six years, at least one of the active ingredients or the epoxiconazole + thiophanate-methyl mixture was as effective as triple sprayings. It is therefore warranted to permanently monitor the condition of plants and to select the fungicide application method depending on conditions.

Succession and population dynamics of major insect pest of tomato in relation to weather parameters in Jabalpur region

The study was carried out at Vegetable Research Farm, Maharajpur, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur during Rabi season 2020-21. The tomato crop in Jabalpur has been found to be affected by whitefly (Bemisia tabaci), fruit borer (Helicoverpa armigera) and leaf miner (Liriomyza trifolii). The whitefly infestation began in the first SMW (vegetative stage) until the crop was harvested. While percent leaf infection of the leaf miner was documented in the 3rd SMW (vegetative stage). The per cent fruit damage of the fruit borer was reported in the 6th SMW (Fruiting stage) and persisted till the harvest of the crop. Relationship between the population of whiteflies and the weather factors showed that the number of white flies and the maximum temperature had a significant positive connection (r=0.560). The percent leaf infested by the leaf miner and maximum temperature had a substantial positive connection (r= 0.571). Percent leaf infestation was shown to have a substantial negative connection with morning relative humidity (r=-0.520) and evening relative humidity (r= -0.693). A significant positive correlation was observed between per cent fruit damage and temperature (maximum temperature (r=0.797) and minimum temperature (r=0.699)). A significant negative correlation was observed between per cent fruit damage of fruit borer with morning relative humidity (r= -0.560) and evening relative humidity (r= -0.697).

EFFICACY OF BOTANICAL PLANT EXTRACTS AGAINST LEAF HOPPER (Amrasca spp.) ON OKRA Abelmoschus esculentus CROP

Okra is a vegetable crop belonging to Malvaceae family which is widely cultivated in tropical and subtropical regions around the globe. Many insect pests cause losses in the yield of okra crop, however; the leaf hopper (Amrasca specie) is considered as the most damaging sucking insect pest of okra crop. Jassid can reduce yield up to 50% leading to significant economic losses. A field experiment was conducted at the Faculty of Agricultural Sciences, University of the Punjab Lahore during rabi season 2021-2022. This study was carried to figure out the insecticidal properties of five different plants extracts viz., Botanicals used in the form of extracts, that includes Garlic (Allium sativum L.), Parthenium (Parthenium hysterophorus L.), Turmeric (Curcuma longa L.), Red chilli (capsicum annum L.), and Red chilli + Garlic (capsicum annum + Allium sativum).. The experiment was laid out following RCBD having three replications of each treatment. Each treatment was used at 20% v/v concentration. The data was recorded on the per leaf infestation of jassids after 24, 48, 72, 168, 240 hours of exposure period. Among the trialed botanical extracts, the extracts of Garlic + red chilli extract were found the most effective against leaf hopper while red chilli was found least effective. Among the tested plant products, the extracts of Garlic and Garlic + red chilli extract were found most effective against plant hopper at seven days after treatment and resulted into minimum per leaf population of the tested insect. It is recommended that the extracts of Garlic + red chilli should be used as an effective control measure against the leaf hopper

Resistance of winter wheat varieties to pathogens in the conditions of the steppe zone of the Kabardino-Balkar Republic

Results of the studies (2019-2021) of species composition of the disease complex under conditions of steppe arid zone of Kabardino-Balkaria are presented, which have scientific and practical significance for determining the degree of resistance of winter wheat varieties under study to phytopathogens. Phytosanitary monitoring was conducted on 10 released varieties of winter wheat. The following diseases and their pathogens were identified: pyrenophorosis (Pyrenophora tritici-repentis (Died.)), septoriosis (Septoria tritici Rob. et Desm.), powdery mildew (Erysiphe graminis DC. f. sp.tritici Em. Marchal), brown and yellow rusts (Puccinia recondite Rob. et Desm.f.sp.tritici; P. striiformis West), head smut (Tilletia tritici (Bjerk) Wint), fusarium blight (Fusarium graminearum Schw.) and glume mold (Alternaria tenuis Ness et Fr.; Cladosporium herbarum Fris.). According to the results of the analysis of digital lesion data, no potentially tolerant winter wheat varieties to the pathogens of these diseases were identified due to the aggressiveness of the existing strains of P. tritici-repentis (Died.), A. tenuis Ness et Fr., C. herbarum Fris. All tested varieties of winter wheat are resistant to the causative agents of septoriosis, rusts, head smut, but are susceptible to the causative agents of pyrenophorosis and glume mold. The average weighted percentage of leaf infestation with pyrenophorosis ranged from 20.5 to 59.6%. The most resistant to this disease were the varieties Memory of Shatilov and Cheget, and the susceptible varieties were Laureate, Korona, Graf, Moskvich and Tanya, in which the weighted average percentage of the disease was above 46.7%. The malignant disease glume mold, which manifests itself in the period of milky-wax ripeness of grain, was studied. The average weighted percentage of lesions from this disease was higher than 50% in varieties Alievich, Taulan, Tanya, Moskvich, Graf. The maximum percentage of grain infestation in the variety Cheget was 60.2%. Fusarium head blight was noted to be depressed as dry and hot weather set in during the period of grain formation. Rainy weather is a favorable condition for the development of this disease.

A study on solomon 300 OD (Betacyfluthrin 90 + Imidacloprid 210 OD) against leaf minors (Phyllocnistis citrella Stainton) on kinnow plants

The study trial was conducted on kinnow 2 trees per treatment/ replicationat Agricultural Research Station, Sriganganagar during 2016-2017. Eight treatments including control were evaluated and each treatment was replicated three times and using RBD. Observations were also taken on number of leaves and infested leaves per twigs from 5 randomly selected twigs. The first application of each treatment was made at according to need based using a water volume of 10 liters per treatment and second application was imposed on a need basis at an interval. The population of leaf infested with leaf minors per 20 leaves were made from a tree before as well as 3, 7, 10 and 15 days after each spray and one day before spray to work out leaf infestation using formula and observed the combination of both @ 7.0 ml / 10 lit was best for the control of leaf minor of kinnow and on at par in comparision to other treatments. The yield of fruit was recorded after harvesting the kinnow.

Effectiveness of Some Bio-pesticides in Managing Major Lepidopteran Insect Pests of Cabbage (Brassica oleracea var. capitata L.)

Aims: The study aimed to evaluate the efficacy of some bio-pesticides applied against major insect pests of cabbage.
 Study Design: With three replications, the experiment was set up in a Randomized Complete Block Design (RCBD).
 Place and Duration of Study: The experiment took place in the Sher-e-Bangla Agricultural University's experimental field in Dhaka, Bangladesh, from October 2019 to January 2020.
 Methodology: Seven treatments, viz. T1 (Abamectin 1.2EC @ 1 ml/L of water); T2 (Azadirachtin 1EC @ 1 ml/L of water); T3 (Potassium salt of fatty acid @ 1 ml/L of water); T4 (Spinosad 45SC @ 1 ml/L of water); T5 (Bacillus thuringiensis @ 1 ml/L of water); T6 (Abamectin + Bacillus thuringiensis @ 1 ml/L of water) and T7 (untreated control) were used. All the treatments were applied at ten days interval.
 Results: Among the management practices, the lowest mean leaf infestation by cabbage caterpillar (6.00 leaves/5 plants) and diamondback moth larvae (4.48 leaves/5 plants) was found in Spinosad treated plot that reduced the highest leaf infestation over control (62.02% and 49.85 % respectively); whereas the highest infestation by cabbage caterpillar (15.80 leaves/5 plants) and diamondback moth larvae (8.93 leaves/5 plants) was found in un-treated plot. The lowest cabbage head infestation (21.37%) was recorded in Spinosad treatment, that gave the highest yield of cabbage (36.40 t/ha) followed by Abamectin (34.07 t/ha).
 Conclusion: From the above study it was found that, the treatment T4 comprised of Spinosad 45SC @ 1 ml/L of water at 10 days interval produced the highest performance compared to all other treatments used under the present study.

Efficacy of Some Biorational Approaches against Two-Spotted Spider Mite (Tetranychus urticae Koch) in Bitter Gourd (Momordica charantia L.)

Aims: The aim of the study was to test the effectiveness of several biorational techniques against two-spotted spider mite, Tetranychus urticae Koch. in bitter gourd.
 Study Design: The study used a single component Randomized Complete Block Design (RCBD) with three replications.
 Place and Duration of Study: The experiment was conducted at Sher-e-Bangla Agricultural University's central farm in Dhaka, Bangladesh from March 2021 to July 2021.
 Methodology: The study included seven treatments. T1= Spinomax (0.4ml/L water); T2= Neem Oil (5ml/L water); T3= Biomax (1.2ml/L water); T4= Ripcord (1ml/L water); T5= Trichoderma spp (200mg/L water); T6= Mehogany Leaf Extract (200mg/L water); T7= Absolute (Control). All the treatments were applied at 15 days interval.
 Results: Treatments for mite infestations showed varying responses in experiments with various biorational control techniques. Trichoderma spp. had the highest results, followed by neem oil, which was effective against mite pests infesting bitter gourd. The results showed that when Trichoderma spp. was used to treat leaf infestation, the total number of fruit set, % healthy fruit, and % infested fruit were all greater. Ripcord had the lowest outcomes against mite pests in most circumstances, with the exception of control treatment.
 Conclusion: It can be concluded that Trichoderma spp. @200mg/L of water can be used to treat two spotted spider mites in an environmentally acceptable manner.

Volatiles from Cotton Plants Infested by Agrotis segetum (Lep.: Noctuidae) Attract the Larval Parasitoid Microplitis mediator (Hym.: Braconidae).

Herbivore-induced plant volatiles (HIPVs), chemicals produced by plants infested by herbivorous insects, can act as kairomones that recruit natural enemies of the pest herbivore. Agrotis segetum (Denis and Schiffermüller) is a common, important pest of seedling cotton in Xinjiang Province, China, and the braconid Microplitis mediator (Haliday) is an important mortality factor of this pest’s larvae. In olfactometer tests, which included healthy foliage, infested foliage, or infested roots, M. mediator preferred A. segetum-infested cotton plants to healthy cotton plants. In GC-MS analyses of plant-emitted volatiles, we found that compounds emitted increased 14.9- and 13.3- fold after leaf infestation and root infestation, respectively, compared to healthy control plants. The volatiles were mainly p-xylene, nonanal, tetradecane, decanal, benzaldehyde, β-caryophyllene, and humulene, while linalool was only present in the leaf-infestation treatment. In addition, principal component analysis indicated that all 18 compounds were associated with the infested plants, especially β-caryophyllene, p-xylene, and decanal. Based on the above studies and previous functional evaluations of the volatile compounds, it can be demonstrated that these compounds play a crucial role in modulating the interactions between A. segetum and M. mediator and regulating parasitoid behavior. It may be possible to enhance the biological control of A. segetum by M. mediator through the application of HIPVs.

Arthropod Pests of Chilli and Associated Natural Enemies in Kymore Plateau and Satpura Hill Zone of Madhya Pradesh (India)

The survey was conducted in selected districts of Kymore Plateau and Satpura Hills zone of Madhya Pradesh (India) to assess the pest status of chilli during 2017-18 and 2018-19 rabi season. Crop was monitored at vegetative, flowering, and fruiting stages in four selected locations (pesticide-free fields) of seven districts viz., Seoni, Jabalpur, Katni, Rewa, Satna, Panna, and Sidhi. The pest spectra included four insect pests and a mite species namely, whitefly, Bemisia tabaci (Gennadius), thrips, Scirtothrips dorsalis Hood, leafhoppers, Amrasca biguttula biguttula (Ishida), fruit-borer, Helicoverpa armigera Hubner, and a mite species, Polyphagotarsonemus latus (Banks); one species of predator, transverse ladybird beetle, Coccinella transversalis Fabricius. The incidence of Leaf curl disease was also observed. The pooled mean population of B. tabaci in Seoni, Jabalpur, Katni, Rewa, Satna, Panna, and Sidhi was 2.86, 2.45, 2.67, 2.79, 2.90, 2.86, and 2.70 individuals/ 10 cm twig, respectively at the flowering stage. Mean population of S. dorsalis was 1.65, 1.48 and 1.34 individuals/ 10 cm twig at flowering stage in Jabalpur, Katni and Panna, while, in Seoni, Rewa, Satna and Sidhi, it was 1.37, 1.35, 1.34 and 1.48 individuals/ 10 cm twig, respectively at fruiting stage. Population of A. biguttula biguttula was 3.14, 3.80, 3.49, 3.14, 3.18, 3.40, and 2.98 individuals/ 10 cm twig at fruiting stage. P. latus population was 0.86, 1.01, 0.92, 0.99, 0.95, 1.13 and 0.96 mites/ leaf at fruiting stage. H. armigera population was 1.13, 0.43, 0.53, 0.62, 1.28, 0.86 and 1.19 larvae/ plant at fruiting stage. Populations of C. transversalis were 1.80, 2.25, 2.32, 1.85, 1.88, 2.36, and 1.67 beetles/ plant at the fruiting stage. The leaf curl (% leaf infestation) incidence was 27.28, 32.43, 33.33, 28.45, 36.03, 25.53, and 36.19 % at the fruiting stage in the mentioned districts of the zone.

Effects of grape phylloxera leaf infestation on grapevine growth and yield parameters in commercial vineyards: a pilot study

Grape phylloxera (Daktulosphaira vitifoliae) can infest both roots and leaves of Vitis species. In commercial vineyards planted with Vitis vinifera scions grafted on rootstocks, grape phylloxera infestation is generally limited to root feeding. Vineyards are, however, increasingly subjected to vineyard-wide foliar infestations that last throughout the growing season. While some vineyards are affected by the infestation pressure of external leaf-feeding populations, other annually affected V. vinifera vineyards do not have these in their vicinity. Much is known about the damage potential of grape phylloxera root feeding; however, data on how phylloxera leaf infestation affects V. vinifera grapevines in commercial vineyards are lacking. This study, therefore, aimed to assess whether grapevine growth and yield are affected due to leaf infestation as it occurred in three commercial vineyards in the study area. Treatments were based on phylloxera leaf infestation and additional defoliation. Single-leaf carbon acquisition was measured with gas exchange analyses on healthy and galled leaves. Pruning weight and internode length were measured to assess the effect of leaf infestation and the effect of plant growth and vigour on leaf gall outbreaks. Yield quantity and quality were measured, and grapes were vinified for sensory analyses. Furthermore, using enzymatic analyses, non-structural carbohydrates were analysed in perennial wood. A significant decrease in sugar content in grapes (10 %) and starch reserves in perennial wood (11 %) was found in the most heavily infested vineyard. Grape must of infested plants in another vineyard furthermore showed a significantly higher level of titratable acid (7.5 %). Significant infestation effects seen in one vineyard were not significant in the other two vineyards. No significant differences were seen for carbon acquisition, harvest quantity, wine sensory analysis, pruning weight or internode length. The overall effect of phylloxera leaf infestation in the studied vineyards was, therefore, marginal. Grapevine vigour did not differ between infested vines, insecticide-sprayed vines, and vines on which no leaf infestation outbreaks took place. By analysing phylloxera leaf infestation under field conditions, these preliminary results form a basis for future long-term field studies about phylloxera leaf feeding on Vitis vinifera within the context of other biotic and abiotic plant stresses.

Sustainable pest management approach against the hog plum leaf beetle, Podontia 14-punctata Linn. (Coleoptera: Chrysomelidae)

BackgroundThe hog-plum, locally known as “amra”, is a deciduous perennial tree with thick succulent leaves and it grows all over the country, but the quality fruits are produced only in the southern districts of Bangladesh. Its cultivation is seriously hampered by hog-plum leaf beetle or 14 spotted leaf beetle, Podontia 14-punctata Linn. (Coleoptera: Chrysomelidae). In most of the cases, insecticidal spray is not effective for controlling this pest as pupation completed in the soil. Therefore, the present study was carried out under both laboratory and field conditions to develop environment friendly sustainable management approaches against the hog-plum beetle.ResultsLaboratory test revealed that spraying with green pesticide spinosad (Success® 2.5% SC) at hog-plum leaflet and drenching with microbial pesticide Metarhizium anisopliae + Trichoderma harzianum + Beauveria bassiana + Trichoderma viride (Lycomax, Russell IPM) causes 75.00% larvae, 72.22% adults and 51.85% pupal mortality,, respectively. Some pest management approaches were developed based on the laboratory results, they were verified in field, during the two successive fruiting seasons 2018 and 2019. Field study indicated that approach 1: Hand picking + trunk banding with packaging tape + soil drenching with lycomax, Russell IPM + spraying of spinosad treated trees offered lowest leaf and fruit infestation; even though trunk banding with packaging tape did not show any effect to control this pest. Fruit yield was also increased 39.04–39.66% in approach 1 imposing hog-plum trees compared to control.ConclusionThe study showed that without banding of the hog-plum trunk, hand picking + soil drenching with microbial pesticides, lycomax, Russell IPM + spraying of spinosad might be sustainable and environment friendly pest management approach against P. 14-punctata.

Physico-chemical leaf attributes of sweet gourd influence the infestation of red pumpkin beetle

The study was conducted to explore the effects of leaf morphological and biochemical properties of twelve sweet gourd genotypes viz., BD 264, BD 265, BD 266, BD 268, BD 269, BD 274, BD 275, BD 277, BARI Mistikumra 1, BARI Mistikumra 2, Gazipur local line, and China line, on the abundance and infestation of red pumpkin beetle. The abundance of red pumpkin beetle with its different leaf infestation levels on the genotypes was observed and then correlated with leaf physico-chemical characteristics of each genotype. The genotypes of sweet gourd showed statistically significant variations in their morphological and biochemical characteristics of leaves. The genotypes having the higher leaf area, adaxial and abaxial leaf trichomes tended to be less infested by red pumpkin beetle. On the other hand, the abundance of the insect showed positive correlation with the number of leaf per plant. All the biochemical properties of sweet gourd leaf except reducing sugar had positive impact on the abundance of red pumpkin beetle.

Study the seasonal activity of insect pests in pea crop

Population of Aphis craccivora was first observed in SMW # 1 (1.37 aphids per plant). Peak population of Aphis craccivora was recorded during SMW # 4 (62.30 aphids per plant) and there after its population decline gradually. Its population remained high till the maturity of the crop in SMW # 8 (21.4 aphids per plant). Acyrthosiphon pisum appeared at a low level for the first time in SMW # 1 (0.47 aphids per plant) and the population remained low throughout the crop season (below 4.07 aphids per plant). The peaks population of Acyrthosiphon pisum was observed in SMW # 4 (4.02 aphids per plant) and in SMW # 6 (4.07 aphids per plant). Leaf infestation by Liriomyza trifolii was recorded to be 10% during SMW # 1. Its incidence increased gradually with peak infestation of 39.34% infested leaves in SMW #5. Thysanoplusia orichalcea was observed in pea crop at a very low level (below 1.0 individual per plant). Its mean population was 0.15, 0.32, 0.45, 0.30, 0.12 and 0.10 individuals per plant observed between SMW # 51 (2016) and SMW # 4 (2017). Helicoverpa armigera was recorded in pea crop at very low level between SMW # 50 and SMW # 4 with peak population of 0.65 larvae per plant in SMW # 1.