The hybrid maize cultivars of multinational seed companies are gradually being popular among the farmers in Nepal. This paper reports on research finding of 117 maize hybrids of 20 seed companies assessed for grain yield and other traits at three sites in winter season of 2011 and 2012. The objective of the study was to identify superior maize hybrids suitable for winter time planting in eastern, central and inner Terai of Nepal. Across site analysis of variance revealed that highly significant effect of genotype and genotype × environment interaction (GEI) on grain yield of commercial hybrids. Overall, 47 genotypes of 16 seed companies identified as high yielding and stable based on superiority measures. The statistical analysis ranked topmost three genotypes among tested hybrids as P3856 (10515 kg ha^-1), Bisco prince (8763 kg ha^-1) as well as Shaktiman (8654 kg ha^-1) in the first year; and 3022 (8378 kg ha^-1), Kirtiman manik (8323 kg ha^-1) as well as Top class (7996 kg ha^-1) in the second year. It can be concluded that stable and good performing hybrids identified as potential commercial hybrids for general cultivation on similar environments in Nepal.

Keywords:Genotype grouping, G × E interaction (GEI), grain yield, hybrid maize, superiority measure

Management of stem borer (Chilo partellus  Swinhoe) in maize using conventional pesticides in Chitwan, Nepal

Saraswati Neupane, Ghanashyam Bhandari, Sheela Devi Sharma, Surendra Yadav and Subash Subedi

Abstract
The stem borer (Chilo partellus Swinhoe) is one of the most destructive pests of maize crop. Research experimentations were carried out on maize to control stem borer using conventional pesticides under field condition during summer season of two consecutive years from 2015 to 2016 at Rampur, Chitwan. All used pesticides had significant effect (P≤0.05) on percent damage and crop yield over control. In 2015, the lower percent damage (5.3%) with higher crop yield (4.52 t ha^-1) and lowest insect score (1.00) was observed in plot sprayed with spinosad 45% EC at 0.5 ml L^-1 of water followed by plot treated with chloropyriphos 50% EC+cypermethrin 5%EC @1.5ml L^-1 of water with percent damage of 6.60%, crop yield (4.23 t ha^-1) and insect score of 1.60. Almost similar trend of insect incidence along with damage percentage and yield data were observed in 2016. The higher percent damage control (79.06%) was observed at the plot sprayed after spinosad 45% EC at 0.5 ml L^-1 of water with higher crop yield (4.58 t ha^-1) and lowest insect score (1.00) followed by the plot treated with imidacloprid 17.8% @ 0.5 ml L^-1 of water with percent damage control of 73.10 %, crop yield (3.38 t/ha) and insect sore 1.50. The highest percent damage (20.63%) was observed in the control plot with lower yield (0.95 t ha^-1) and highest insect score (6.00). Over the years, spinosad 45% EC at 0.5 ml L^-1 of water was effective bio-pesticide to control maize stem borer damage and also increase the yield.

Keywords: Maize, pesticide, stem borer

This study was undertaken in 2016 to analyze the production and utilization of maize in Nepal. Sixty maize growers from Kavre and Lamjung districts were selected using purposive, cluster and simple random sampling techniques. Similarly, six feed industries and five maize experts from Chitwan district were also interviewed. Study shows 56% of the total areas were used for maize production and 50% of the maize areas were covered by hybrid maize. There was no practice of contract maize production. The results revealed that 60%, 25% and 3% of the grain were used for animal feed, food and seed respectively in hill districts. Whereas the remaining amount of the maize (12%) was sold to the different buyers. The proportion of maize feed supply to different animals in the study area was varying. Result shows that at least 1.5 million tons of maize is required only to the feed industries affiliated with national feed industry association in Nepal. Similarly, out of total maize used in feed production, 87% of the maize was imported from India each year by feed industries. Analysis shows negative correlation between scale of feed production and use of domestic maize due to unavailability of required quantity of maize in time. The major pre-condition of feed industries for maize buying was moisture content which must be equal or less than 14%. Very little or no inert materials and physical injury, free from fungal attack and bigger size were also the criteria for maize buying. However, some of the feed industries were also thinking about protein and amino acid contents. Result shows 13% and 8.5% increasing demand of poultry feed and animal feed, respectively over the last five year in Nepal.  Most likely, maize is known as a means of food security in Nepal, however, in the context of changing utilization patterns at the farm level and also tremendous increasing demand of maize at the industry level suggest to give more focus on development and dissemination of maize varieties that can contribute to the feed security issues as well.

Keywords: Maize, feed security, food security, utilization pattern, food habit

Maize stalk rot complex is becoming a serious threat for maize growing areas of Nepal. A field monitoring for maize stalk rot complex was done during crop season (August, 2016) covering 10 farmers field each of Surkhet, Banke, Dang, Chitwan and Nawalparasi districts. Maize crop showed highly susceptible reaction to the disease at western belts of Dang and susceptible reaction was marked in Chitwan and Nawalparasi districts while the disease effect was mild at Banke and Surkhet district. Most of the plant diseases managed successfully through the application of bio-control agents, host resistance, chemicals and other different cultural control methods. The result of field experiment conducted at Dang showed that all the treatments had significant (P≤0.05) effect on percent disease index (PDI) and crop yield over farmers practice to control maize stalk rot. The higher percent disease control (52.36%) and yield increase (40.29%) were recorded from the plot sprayed with streptocyclin @ 2 g L^-1 and insecticide (cypermethrin + chloropyrifos @ 2.5 ml L^-1 of water during knee height and subsequent spray after 15 days interval as compared to farmers practice. Out of 30 genotypes, Rampur composit, Arun 2, Rampur 34, RamS03F08, TLBRS07F16 and Rampur 24 were found resistant against stalk rot complex with higher yield at Rampur Chitwan.

Keywords: Disease management, stalk rot, maize

Assessment of soil fertility status of Agriculture Research Station, Belachapi, Dhanusha, Nepal

Dinesh Khadka, Sushil Lamichhane, Shahabuddin Khan_, Sushila Joshi and Buddhi Bahadur Pant

Soil test-based fertility management is important for sustainable soil management. This study was carried out to determine the soil fertility status of the Agriculture Research Station, Belachapi, Dhanusha, Nepal. Using soil sampling auger 25 soil samples were collected randomly from a depth of 0-20 cm. Soil sampling points were identified using GPS device. Following standard methods adopted by Soil Science Division laboratory, Khumaltar, the collected soil samples were analyzed to find out their texture, pH, N, P₂O₅, K₂O, Ca, Mg, S, B, Fe, Zn, Cu, Mn and organic matter status. The soil fertility status maps were made using Arc-GIS 10.1 software. The observed data revealed that soil was grayish brown in colour and sub-angular blocky in structure. The sand, silt and clay content were 36.03±3.66%, 50.32±2.52% and 25.42±2.25%, respectively and categorized as eight different classes of texture. The soil was acidic in pH (5.61±0.14). The available sulphur (0.73±0.09 ppm) status was very low, whereas organic matter (1.34±0.07%), available boron (0.56±0.10 ppm), available zinc (0.54±0.22 ppm) and available copper (0.30±0.01 ppm) were low in status. The extractable potassium (95.52±13.37 ppm) and extractable calcium (1264.8±92.80ppm) exhibited medium in status. In addition, available phosphorus (33.25±6.97 ppm), available magnesium (223.20±23.65 ppm) and available manganese (20.50±2.43 ppm) were high in status. Furthermore, available iron (55.80±8.89 ppm) status was very high. To improve the potentiality of crops (maize, rice, wheat etc.) for studied area, future research strategy should be made based on its soil fertility status.

Keywords:Nutrient management, research efficacy, soil fertility maps, and soil testing

Food preference by the maize weevil, Sitophilus zeamais Motschulsky was studied on seven different crops and varieties including maize, wheat and rice. They were maize cultivars namely Arun-2, Manakamana-4, Deuti, buckwheat local cultivar, wheat cultivar namely Annapurna-1, polished rice-Radha 4 and unshelled rice cultivar Mansuli under storage condition at  Institute of Agriculture and Animal Science, Rampur, Chitwan, Nepal from June 2013 to February 2014 . The hosts were tested using completely randomized design with three replications and were laid in free-choice and no-choice conditions. The maximum number of grain loss was recorded in wheat followed by polished rice respectively. Similarly, the highest weight loss was recorded in polished rice followed by Wheat in both conditions. F1 progeny emergence of weevil was highest in wheat followed by polished rice in free-choice and in no choice conditions, the highest progeny were emerged from polished rice followed by wheathe lowest numbers of weevils emerged from rice in both conditions. Maximum germination losses were recorded in wheat (24.33%) and lowest in Arun-2 (9.67). The rice showed a relatively higher preference to maize weevil under storage condition.

Keywords:  Food, maize, preference, weevil

Genotype × environment interaction of quality protein maize grain yield in Nepal

Jiban Shrestha, Chitra Bahadur Kunwar, Jharana Upadhyaya, Maiya Giri, Ram Bahadur Katuwal, Ramesh Acharya, Suk Bahadur Gurung, Bhim Nath Adhikari, Amrit Prasad Paudel and Ram Babu Paneru

Abstract

In order to determine G × E interaction of quality protein maize grain yield, six maize genotypes were evaluated under different environments of three Terai (Chitwan, Surkhet and Doti) and four mid hill (Dhankuta, Lalitpur, Dolakha and Kaski) districts of Nepal during summer seasons of 2014 and 2015. The experiments were conducted using randomized complete block design along with three replications. The  genotypes namely S99TLYQ-B, S99TLYQ-HG-AB and S03TLYQ-AB-01 were identified high yielding and better adapted genotypes for Terai environments with grain yield of  4199 kg ha^-1, 3715 kg ha^-1, and 3336 kg ha^-1 respectively and  S99TLYQ-B and S03TLYQ-AB-01 for mid hill environments with grain yield of  4547 kg ha^-1 and 4365 kg ha^-1 respectively. Therefore, these genotypes can be suggested for cultivation in their respective environments in the country.

Keywords: Evaluation, grain yield and quality protein maize

Ishwari Prasad Upadhyay, Shiva Kumar Jha, Tika Bahadur Karki, Jitendra Yadav and Balram Bhandari

Tillage methods and mulch influences the productivity and water requirement of spring maize hence a field experiment was conducted at the National Maize Research Program, Rampur in spring seasons of 2011 and 2012 with the objectives to evaluate different tillage methods with and without mulch on water requirement and grain yield of spring maize. The experiment was laid out in two factors factorial randomized complete design with three replications. The treatments consisted of tillage methods (Permanent bed, Zero tillage and Conventional tillage) and mulch (with and without). Irrigation timing was fixed as knee high stage, tasseling stage and milking/dough stage. Data on number of plants, number of ears, thousand grain weight and grain yield were recorded and analysed using GenStat. Two years combined result showed that the effect of tillage methods and mulch significant influenced grain yield and water requirement of spring maize. The maize grain yield was the highest in permanent beds with mulch (4626 kg ha^-1) followed by zero tillage with mulch (3838 kg ha^-1). Whereas total water applied calculated during the crop period were the highest in conventional tillage without mulch followed by conventional tillage with mulch. The permanent bed with mulch increased the yield and reduced the water requirement of spring maize in Chitwan.

Keywords: Conventional tillage, permanent beds, spring maize, water requirement, zero tillage

Maize response to time of nitrogen application and planting seasons

Parbati Adhikari, Bandhu Raj Baral and Jiban Shrestha

Abstract

Nitrogen (N) response by maize differs due to growing seasons, growth stages, duration and growing domain as N losses is higher due to leaching as well as volatilization. Objective of this study was to know the response of split applications of N and growing seasons on maize under Chitwan environments. Field experiments were conducted for two consecutive years at the research field of NMRP Rampur during the winter, spring, and summer seasons of 2012/013 and 2013/014. Experiments were laid out in factorial randomized complete block design with four replications for all the seasons. Early maturing maize genotype Arun-1 EV was used for the experiments. Five splits of recommended dose of N were tested. Grain yield, days to flowering, plant height, ear height, kernel rows per ear, no. of kernels per row, ear length and thousand grain weight significantly differed due to growing seasons and split applications of N. Significantly higher grain yield (3911 kg ha^-1) was obtained with the application of 30 kg N ha^-1 each at 30, 45, 60, and 75 days after sowing as compared to control (2801 kg ha^-1). Regarding the growing seasons, highest grain yield was obtained in winter (4393 kg ha^-1) followed by spring (3791 kg ha^-1) and summer (2468 kg ha^-1) season, respectively. Results of these studies  revealed that four splits of N viz. application of 30 kg N each at 30, 45, 60, and 75 days after sowing respectively, would be more economical to minimize N losses from the soil and efficient use of N at critical growth and development stages of maize.

Keywords: Leaching, maize, nitrogen, seasons

Grain yield stability of early maize genotypes

Chitra Bahadur Kunwar, Ram Bahadur Katuwal, Sailendra Thapa and Jiban Shrestha

The objective of this study was to estimate grain yield stability of early maize genotypes. Five early maize genotypes namely Pool-17, Arun1EV, Arun-4, Arun-2 and Farmer’s variety were evaluated using Randomized Complete Block Design along with three replications at four different locations namely Rampur, Rajahar, Pakhribas and Kabre districts of Nepal during summer seasons of three consecutive years from 2010 to 2012 under farmer’s fields. Genotype and genotype × environment (GGE) biplot was used to identify superior genotype for grain yield and stability pattern. The genotypes Arun-1 EV and Arun-4 were better adapted for Kabre and Pakhribas where as pool-17 for Rajahar environments. The overall findings showed that Arun-1EV was more stable followed by Arun-2 therefore these two varieties can be recommended to farmers for cultivation in both environments.

Keywords: Early maize genotypes, grain yield, stability

Phosphorous as the major yield limiting nutrient for maize in the river basin areas of western Nepal

Bhanu Bhakta Pokharel, Shashi Ram Sharma, Gam Bahadur Pun and Naina Singh Chhetri

Abstract

Maize is a heavy feeder crop but not always higher quantity of chemical fertilizers leads for higher grain yield. Objective of the study was to identify the major yield limiting macro nutrient for maize in the river basis areas. Field experiments were conducted at four locations viz. Dasharathpur, Ramghat, Mehelkuna, and Gumi VDCs of Surkhet district, under research command areas of Agriculture Research Station, Surkhet. Different doses of nitrogen, phosphorous and potassium fertilizers were applied. Planting was done in the summer season of 2010 and 2011. All field experiments were laid out in randomized complete block designs with three replications at each site and year. Deuti variety of maize was used in the experiment. Days to tasseling, silking, and physiological maturity due to fertilizer application were found significant. One week earlier silking, tasseling, and physiological maturity was observed due to use of 100:100 kg ha^-1 nitrogen and phosphorous as compared to the most late maturity with application of 100 kg nitrogen ha^-1. The highest grain yield (6802 kg ha^-1) was found with application of 100:100 kg nitrogen and phosphorous ha^-1 and the lowest grain yield (4174 kg ha^-1) was found with the normal recommended fertilizer dose. Phosphorous was observed as the major yield limiting factor in this study.

Keywords: Grain yield, maize, phosphorous, river basin, western Nepal

Evaluation of maize genotypes for Turcicum leaf blight (Exserohilum turcicum) in Terai and inner terai of Nepal

Tirtha Raj Rijal, Govind KC, Kesab Babu Koirala  and Jiban Shrestha

Thirty maize genotypes in 2014-2015 at Dumarwana, Nijgadh, Keureni and Rampur and ten genotypes in 2015-2016 at Anandpur, Shitalnagar, Dumarwana, Nijgadh and Rampur were evaluated for resistance to Turcicum leaf blight (Exserohilum turcicum) under farmers field conditions. The scale used for disease severity ranged from 1-5 scale based on the proportionate leaf area affected by the disease. The combined analysis over locations in 2014-2015 showed that among the 30 genotypes 25 genotypes were resistant (1.0-2.0 scale), and 5 genotypes were moderately resistant (2.1-3.0 scale). Similarly the pooled analysis over locations in 2015-2016 showed that 7 genotypes were resistant (1.0-2.0 scale) and 3 genotypes were moderately resistant (2.1-3.0 scale). The maize genotypes namely Z376-26, Z478-3, Z433-99, Z464-5, Z478-2, Z466-1, CAH1513, RML-95/RML-96, CAH1515, CAH1521, CAH1515, CAH151, CAH153, ZH114228 , Z376-9, Z466-3, Z376-5, RML-32/RML-17, RML-86/RML-96 and 900MGold were resistant with disease severity scale of 1.5 and with higher grain yield in both the years. Thus above genotypes were identified as promising sources of resistance against E. turcicum and they can be used to develop disease resistant and high yielding varieties to enhance maize productivity in terai and inner terai of Nepal.

Keywords:Resistant, susceptible, genotypes, severity

Assessing the effect of phosphorus application on early growth of maize at Sunderbazar, Lamjung, Nepal

Ram Kumar Shrestha, Lal Prasad Amgain and Sadikshya Aryal

Phosphorus (P) is an essential nutrient element for maize production. A pot experiment was conducted during May-June, 2015 to assess the effects of different rates of P on early growth of maize plant at Sundarbazar, Lamjung. Two maize varieties (Rato Makai and Poshilo Makai-1) were subjected to four P levels (0 kg ha^-1, 13 kg ha^-1, 18 kg ha^-1, and 23 kg ha^-1) in randomized complete block design with four replications. The effects of different P level on root elongation, root biomass, plant height, root shoot biomass ratio and total dry matter were investigated at 45 days after sowing. For all parameters, the maximum value was obtained when soil was added with 18 kg P ha^-1 & the minimum value under the control of 0 kg P ha^-1. Maize varieties differed significantly in terms of all the parameters under study, and Poshilo Makai-1 performed better than Rato Makai at all P levels. So, from this result, it can be concluded that Poshilo Makai-1 appeared to be P efficient over Rato Makai at early growth stage. However, it would be necessary to look at the response of crop up to maturity and at wider range of P to have the better insight of their relative performance.

Keywords: Early vegetative growth, phosphorus fertilizer, maize, root shoot ratio

Estimation of heterosis in yield and yield attributing traits in single cross hybrids of maize

Hari Prasad Sharma, Krishna Hari Dhakal, Raju Kharel and Jiban Shrestha

A field experiment was conducted at National Maize Research Program, Rampur, Chitwan, Nepal during winter season from 6^th October, 2015 to 5^th March 2016 to estimate different heterosis on single cross maize hybrids . Thirteen maize hybrids were tested randomized complete block design with three replications. Hybrid namely RML-98/RL-105 gave the highest standard heterosis (57.5%) for grain yield over CP-666 followed by RML-4/NML-2 (32.6%), RML-95/RL-105 (29%) and RML-5/RL-105 (20.6%). The hybrid RML-98/RL-105 produced the highest standard heterosis (75.1%) for grain yield over Rajkumar followed by RML-4/NML-2(50.2%), RML-95/RL-105(46.6%), RML-5/RL-105 and (35.7%). Mid and better parent heterosis were significantly higher for yield and yield attributes viz. ear length, ear diameter, no of kernel row per ear, no of kernel per row and test weight. The highest positive mid-parent heterosis for grain yield was found in RML-98/RL-105 followed by RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2. For the grain yield the better parent heterosis was the highest in RML-98/RL-105, followed by RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2. These results suggested that maize production can be maximized by cultivating hybrids namely RML-98/RL-105, RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2.

Keywords: Maize, single cross hybrid, heterosis, and grain yield.

Differential resistance reaction of maize genotypes to maize stem borer (Chilo partellus Swinhoe) at Chitwan, Nepal

Ghanashyam Bhandari, Buddhi Bahadur Achhami, Saraswati Neupane and Sheela Devi Sharma

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.

Keywords:  Breeding program, Chilo partellus, damage, Host resistance, Maize

Socio-economic analysis of maize seed production in Arghakhanchi district of Nepal

Mahima Bajracharya,  Mahesh Sapkota and Surya Mani Dhungana

The purpose of this study was to assess the socioeconomic condition of maize seed and non-seed producers. A field survey was carried out in sixty households of Khanchikot VDC of Arghakhanchi district during May, 2014. The district was major seed producing district and Khanchikot was found better in seed production than other VDC in district. Simple random sampling technique was used to collect data using pre-tested interview schedule. About 57% were seed producer among the sample. The average family size of household was 5. Dependency ratio was less in seed producing households (0.41) than non-seed producers (0.72). Farmers were involved in the production of certified seed and the major (50%) source of foundation seed was National Maize Research Program, Rampur, Chitwan. The external input like chemical fertilizer was used in fewer amounts in the study area. The seed test was done at regional laboratory, Bhairahawa and sold to DADO, Arghakhanchi. Decision on loan taking, business operation and bank account were taken by males whereas cropping pattern, deficit labor use, religious and social works related decision were taken by females in the household. Major problem in maize production were lack of technical assistance followed by inadequate irrigation facilities. Proper training, extension service and government support on inputs would help in better socio-economic condition and production of maize.

Keywords: Gender, maize, seed and socio-economic