Field Screening of Lentil Genotypes Against Aphid Infestation in Inner Tarai of Nepal

Twenty lentil (Lens culinaris Medik) genotypes received from Grain Legumes Research Program, Khajura, Banke were screened for relative tolerance against aphid (Aphis craccivora Koch.) at the research field of National Maize Research Program, Rampur, Chitwan during winter seasons of two consecutive years 2016 and 2017. The design of the experiment was Randomized Complete Block having three replications. The unit plot size was 4m × 1 m with 25cm row to row spacing and continue plant to plant spacing was maintained and net harvested plot was 4 square meters. The recommended dose of fertilizer was 20:40:20 N:P2O5:K2O kg/ha and seed rate 30 kg/ha. Insect data were collected based on aphid population found at apical twigs (10 cm) per plant and scoring was done during flowering and pod formation stage. The grain yield was recorded. All screened genotypes differed significantly (p<0.05) on aphid population and grain yield.  Genotypes, ILL 9924, RL 83, ILL 10856, ILL 6458 and RL 67 were less susceptible with higher grain yield. These results have important implications for the development of aphid tolerant high yielding lentil variety in inner Tarai of Nepal

Evaluation of Barley Genotypes Against Spot Blotch Disease in Inner Tarai Region of Nepal

Spot blotch caused by Bipolaris sorokiniana (Sacc. in Sorok.) Shoem. is an important disease of barley (Hordeum vulgare L.). A total of 126 barley genotypes received from Hill Crops Research Program, Kabre, Dolakha having SoluUwa as a susceptible check and Bonus as a resistant check were evaluated as barley disease screening nursery (BDSN) under natural epiphytotic condition at National Maize Research Program, Rampur, Chitwan during winter seasons of 2017 and 2018. The nursery was planted in augmented design. The resistant and susceptible checks were repeated and planted after each 10 tested entries. The unit plot size was 2 rows of one meter length for each genotype planted continuously with 25cm row to row spacing. The seed rate was 100 kg/ha. The recommended fertilizer dose of 23:30:0 N:P2O5:K2O kg/ha was applied. The double digit scale (00 to 99) was used to measure overall foliar infection on the whole plant during flowering, soft dough and hard dough stages. Other agronomic practices were followed as per recommendation. Genotypes B86019-1K-3K-0K3, ACC 2087, ACC 2441, ACC GHv-06816, ACC 1597, ACC 1612, ACC 2059 and ACC 2032 were resistant against spot blotch disease. Similarly, 32 barley genotypes were moderately resistant and rest of the tested genotypes were susceptible to the disease. The selected resistant barley genotypes can be used in crossing program and/or promoted for further testing to develop spot blotch resistant varieties for inner Tarai region of Nepal

In-vitro Evaluation of Botanicals, Fungi-toxic Chemicals and Bio-control Agent for Efficacy Against Turcicum Leaf Blight of Maize

Maize is the second most important cereal crop of Nepal. Its growth and production is severely affected by Turcicum leaf blight caused by Exserohilum turcicum at pre-harvest stage. A total of 6 botanicals, 4 chemical fungicides and 1 bio-control agent were evaluated for efficacy against Exserohilum turcicum under in vitro conditions following poisoned food technique at National Maize Research Program, Rampur, Nepal. The experiment was carried out in a completely randomized design with 5 replications. All the tested botanicals, fungicides and bio-control agent exhibited fungicidal action and significantly inhibited mycelial growth of the test pathogen over untreated control. Among botanicals, extract of Acorus calamus L. at 1% W/V checked the pathogen growth completely in-vitro. The mycelial growth inhibition percent of Artimisia indica Willd, Lantana camera L., Allium sativum L., Xanthoxylum armatum DC., and Azadirachta indica A. Juss. at the concentration of 2.5% W/V on PDA was 75.18%, 74.00%, 44.68%, 44.21% and 37.59% respectively. Among fungicides, the mycelial growth inhibition percent of E. turcicum due to ACME-COP (Copper oxychloride 50% WP), SAAF (Carbendazim 12% + Mancozeb 63% WP), Dithane M-45 (Mancozeb 75% WP) and Bavistin (Carbendazim 50% WP) at the concentration of 1000 ppm on PDA was 70.69%, 68.44%, 61.23%, and 60.52% respectively. Antagonist Trichoderma viride developed more rapidly than E. turcium in single as well as in dual cultures. T. viride caused significantly inhibition of 35% of the pathogen E. turcicum on the 5th day of incubation. These results have important implications for the management of turcicum leaf blight disease in maize

Evaluation of insecticidal efficacy against maize leaf aphid [Rhopalosiphum maidis (Fitch)] under inner terai condition of Nepal

Field experiments were carried out at the National Maize Research Program in Rampur, Chitwan, with the objective of comparing the effectiveness of insecticides in the field for controlling maize leaf aphid (Rhopalosiphum maidis Fitch) during the winter season of 2019 and 2020. The design of the experiment was randomized complete block with four replications. The plot size was 6 rows of 5 m long with the spacing of 60cm × 25cm. Maize hybrid Rampur Hybrid-14 (RML-86/RML-96) was used as experimental variety. The efficacies of five insecticides viz., thiomethoxam 25% w/w 0.2g/L (T1), acetamiprid 20%WP 2g/L (T2), flonicamid 50% WG 0.5g/L (T3), neemix 3ml/L(T4), imidacloprid 0.5ml/L(T5) and untreated control (T6) were used as experimental treatments. The recommended dose of fertilizer was 180: 60: 40 N: P2O5: K2O kg/ ha with farm yard manure 10 t/ha and seed rate was 20kg/ha. Data on aphid incidence, severity, yield and yield components were recorded. All the tested insecticides significantly (P≤0.05) reduced the plant infestation caused by maize aphid, and thereafter increased the grain yield of maize compared to control. However, newer insecticide flonicamid 50% WG 0.5g/L was found as the most effective insecticide with lower aphid colony per plant (2.85), aphid score (2.63), aphid infested plant (7.33%) and higher crop yield (7904.79kg/ha). The application of insecticides prior to their severe infestations is necessary for the efficient control of the maize leaf aphid. The research findings will assist maize farmers in choosing and applying the best insecticide to ensure efficient management of maize leaf aphid with high yield

Management of Anthracnose in Soybean Using Fungicide

Experiments on soybean (Glycine max L. Meril) were carried out aiming to control anthracnose (pod blight) caused by fungus, Colletotrichum truncatum with five treatments represented by different fungicidal sprays against control receiving no spray with three replicates of each under field conditions during two consecutive years from 2012 to 2013. In 2012, the higher Percent Disease Control (PDC) and Percent Yield Increase (PYI) were estimated in plot treated with SAAF (Carbendazim 12% + Mancozeb 63%) followed by Mancozeb fungicides. The mean Pod Infection (PI) was low in plots treated with SAAF followed by Mancozeb. Almost similar trends of disease control were observed in 2013. The lower Percent Disease Index (PDI) was 46.25% and mean PI was 29.67% with higher yield value of 2431.25 kg/ha obtained from the plots sprayed with SAAF then by Mancozeb. The results showed that, the combined treatment with fungicides, SAAF followed by Mancozeb were effective to control anthracnose or pod blight disease of soybean to increase the yield.Journal of Nepal Agricultural Research Council Vol.1 2015 pp.29-3

Life cycle study of maize stem borer (Chilo partellus Swinhoe) under laboratory condition at National Maize Research Program, Rampur, Chitwan, Nepal

Maize stem borer (Chilo partellus swinhoe) is one of the major threatening global pests of maize and considered as the national top priority entomological research problem in Nepal. The Life cycle of maize stem borer was studied under laboratory condition at National Maize Research Program (NMRP), Rampur, Chitwan, Nepal during 2018. Development of stem borer undergoes following stages like egg, larvae, pupa and adult. Eggs and different instars of maize stem borer larvae were collected from maize fields were put with host materials (maize leaf and stem) to become different instars of larva, pupae and finally turned to adults. Eggs were harvested from adults and kept on blotting paper which was kept inside petriplates and reared for adults. Their life span in each stage (egg, larva and pupa) and the fecundity of adults recorded. Daily room temperature and relative humidity (RH) in laboratory conditions were recorded. The Egg incubation period ranged from 4-7 days and hatched generally in the early morning (6-8 AM). The complete larvae period ranged from 29 to 36 days while pupal period was ranged from 7 to 12 days. The average male pupal length was found 13 mm and female was 16 mm long. The fecundity of C. partellus Swinhoe was recorded 150-160 eggs per female. The Oviposition period was  4 days and adult male survived for 4-7 days while female for 4-9 days. The average life cycle of C. partellus completed in (44-48) days during summer whereas (60-64) days during winter at average room temperature of (26-27° C) and RH of (70-80%). These results have important implications to know the survival and development of pest including effective pest management strategy

Verification of disease management technology on lentil against Stemphylium blight at farmer’s field in Nepal

Technologies generated from lentil (Lens culinaris Medik) stemphylium blight (Stemphylium botryosum Walr) management experiments were verified at farmers field of 5 districts viz., Chitawan, Rautahat, Dang, Parsa and Banke during two winter seasons of 2013-2014 and 2014- 2015. The experiment was laid out in randomized complete block design with factorial arrangement of treatments and replicated 4 times. The plot size was 340 m2 (1 Kattha) with 25 cm row to row spacing. There were altogether 3 factors of the experiment i.e. year (2013-2014 and 2014-2015), location (5 districts) and package of practice (improved and farmers practice). The higher crop yield (1142.50 kg/ha) with lower disease index (34.95%) and higher benefit cost ratio of 2.42 were recorded in the farmers field of Banke district following seed rate (30 kg/ha), 8 hour primed improved variety (Black lentil), fertilizer doze of (20:40:20 NPK kg/ha+ 1 kg/ha B basal doze) and subsequent 3 sprays of Dithane M-45 @ 2.5 g/l of water at 10 days interval

Antifungal assessment of plant extracts, biocontrol agents and fungicides against Fusarium verticillioides (Sacc.) causing ear rot of maize

Saabunud / Received 28.03.2021 ; Aktsepteeritud / Accepted 13.06.2021 ; Avaldatud veebis / Published online 13.06.2021 ; Vastutav autor / Corresponding author: Subash Subedi [email protected] rot is a prominent biotic threat of maize causing significant yield loss and poor quality of grains. The antifungal activity of aqueous extract of Acorus calamus L., Xanthoxylum armatum DC., Azadirachta indica A. Juss., Lantana camera L. and Artemisia indica Willd at three different concentrations (1, 2 and 3% W/V), four chemical fungicides viz., Dithane M-45 (Mancozeb 75% WP), SAAF (Carbendazim 12% + Mancozeb 63% WP), ACME-COP (Copper oxychloride 50% WP) and Bavistin (Carbendazim 50% WP) at (500, 1000 and 1500 ppm) and three biocontrol agents (BCA) namely Trichoderma viride, Trichoderma harzianum and Trichoderma koningii were investigated against Fusarium verticilliodes (Sacc.) causing ear rot of maize. The experiment was carried out by poisoned food and dual culture techniques in a completely randomized design with five replications under laboratory conditions at National Maize Research Program, Rampur, Chitwan during the summer season of 2019. F. verticillioides showed significant growth inhibition in all the treatments compared to control. The A. calamus even at a lower dose (1% W/V on PDA) was able to check completely the growth of pathogen (4.00 mm). The mycelial growth inhibition per cent of A. calamus, L. camera, X. armatum, A. indica, and Artemisia indica at 3% W/V was 95.50, 51.13, 45.50, 42.12 and 35.36% respectively. In the case of fungicides, at 1500 ppm, the maximum antifungal potential was observed with SAAF (86.32%) followed by Dithane M-45 (80.27%), Bavistin (64.80%) and ACME-COP (59.42%). Antagonist Trichoderma viride completely overgrows F. verticillioides and covers the entire medium surface and exhibit more than 60% inhibition on the 7th day of incubation. The antifungal components from these plant extracts, fungicides and antagonists explored in this study need to be tested further in field experiments to control the ear rot of maize

A review on important maize diseases and their management in Nepal

ABSTRACT In Nepal, maize ranks second after rice both in area and production. In recent years, maize area and production has shown a steady increase, but productivity has been low (2.46 t/ha). The major maize producing regions in Nepal are mid hill (72.85%), terai (17.36%) and high hill (9.79%) respectively. A literature review was carried out to explore major maize diseases and their management in Nepal. The omnipresent incidence of diseases at the pre harvest stage has been an important bottleneck in increasing production. Till now, a total of 78 (75 fungal and 3 bacterial) species are pathogenic to maize crop in Nepal. The major and economically important maize diseases reported are Gray leaf spot, Northern leaf blight, Southern leaf Blight, Banded leaf and sheath blight, Ear rot, Stalk rot, Head smut, Common rust, Downy mildew and Brown spot. Information on bacterial and virus diseases, nematodes and yield loss assessment is also given. Description of the major maize diseases, their causal organisms, distribution, time and intensity of disease incidence, symptoms, survival, spreads, environmental factors for disease development, yield losses and various disease management strategies corresponded to important maize diseases of Nepal are gathered and compiled thoroughly from the available publications. Concerted efforts of NARC commodity programs, divisions, ARS and RARS involving research on maize pathology and their important outcomes are mentioned. The use of disease management methods focused on host resistance has also been highlighted