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

Differential Resistance Reaction of Maize Genotypes to Maize Stem Borer (Chilo Partellus Swinhoe) at Chitwan, Nepal

Maize stem borer (MSB), Chilo partellus Swinhoe, Lepidoptera: Pyralidae is one of the most important insect pest of maize in Nepal. Host plant resistance is the cost-effective, ecologically sound and stable approach to reduce damage by stem borers. Forty four maize genotypes were screened for resistance to maize stem borer at the research field of National Maize Research Program, Rampur during spring seasons (March to June) of two consecutive years 2013 and 2014. The maize genotypes were evaluated in randomized complete block design with three replications and data were collected on foliar damage rating, tunnel length and number of exit holes made by the borer. The foliar damage and tunnel length damage were significant for genotypes for both the years. The exit holes were not significant in 2013 but significant in 2014 ranging from 2-6 scale. The foliar rating ranged from 2 to 5.5 in 2013 and 1.1 to 4.5 in 2014 on a 1-9 rating scale. The highly resistant genotypes (<2.0 score) were R-POP-2 and RML-5/RML-8. The tunnel length ranged from 3.2 to 22.5 cm in 2013 and 4.2 to 20.4 cm in 2014 on 0- >10 cm scale. The least susceptible genotypes (<5 cm) were RampurSO3F8, RampurSO3FQ02 and RampurS10F18. The genotypes having least exit holes (2.0) in 2014 were RampurSO3F8, RampurSO3FQ02, RampurS10F18. Thus less damage parameters were observed in R-POP-2, RML-5/RML-8, RampurSO3F8, RampurSO3FQ02 and RampurS10F18 and therefore they can be used as parents or as sources of resistance in breeding program

Screening of Maize Genotypes Against Maize Leaf Aphid [Rhopalosiphum Maidis (Fitch)] Under Field Condition at Chitwan, Nepal

Thirty maize genotypes including five hybrids, eight quality protein (QPM) and seventeen full season open pollinated (OP) were screened for their resistance against maize leaf aphid (Rhopalosiphum maidis Fitch) at the research field of National Maize Research Program, Rampur, Chitwan, Nepal during the year 2019 and 2020. The design of the experiment was randomized incomplete block with three replications. The plot size was 2 rows of 5 m long with the spacing of 60 cm × 25 cm. The recommended dose of fertilizer for full season OP and QPM were 120:60:40 and for hybrid maize 180:60:40 N: P2O5:K2O kg/ha with farmyard manure 10 t/ha and seed rate was 20 kg/ha. Data on aphid incidence, severity, yield and yield components were recorded. Maize hybrids RML-95/RML-96 (18%) and Rampur Hybrid-10 (22%), two quality protein maize (QPM) S00TLYQ-AB (22%) and S99TLYQ-A (23%) and two full season OP genotypes TLBRS07F16 (24%) and ZM 627 (26%) were less susceptible to aphid infestation and resulted in higher grain yield. The findings could aid in the selection of maize genotypes for the development of aphid resistant and high-yielding maize varieties

Evaluation of Maize Genotypes Against Post Flowering Stalk Rot Under Terai Region of Nepal

The inadequate source of resistance materials in maize against major biotic stresses is one of the main reasons for considerable loss of grain yield in Nepal. Post flowering stalk rot disease caused by Fusarium moniliforme is a serious disease that exposes high incidence at grain filling stage of maize in terai region of Nepal during summer season. This study was done to evaluate level of resistance, or tolerance in selected genotypes against the post flowering stalk rot disease of maize. Accordingly, thirty maize genotypes were tested for maize stalk rot resistance during summer season of 2016 and 2017 at National Maize Research Program, Rampur (NMRP), Chitwan. The experiment was done under natural epiphytotic condition at hot spot of the disease by using Randomized Complete Block design with 2 replications for each treatment. The package of practices was followed as per national recommendation. The summer season of 2016 and 2017 were affable for post flowering stalk rot of maize at NMRP, Rampur. Out of 30 genotypes, most of the tested entries showed susceptible reaction during both the years; however, RML-95/RML-96, Across-9942/Across-9944, ZM-401, Rampur 34, RamS03F08 and TLBRS07F16 showed resistant reaction against the disease and might be useful for the development of post flowering stalk rot resistant maize varieties for terai region of Nepal