Assam Agricultural University Research Articles

Prevalence of Plant-Parasitic Nematodes in Horticultural Fields of Assam Agricultural University: Jorhat Campus, India

A random survey of the horticultural crops was conducted to assess the nematode community structure in the Experimental field of Department of Horticulture, AAU, Jorhat during Rabi and Kharif season, 2022-2023. Soil and root samples, representing 200 locations were examined. Analysis of 200 soil and root samples collected from the root rhizosphere of different vegetable, fruit and ornamental crops showed the presence of root-knot nematode(Meloidogyne incognita), reniform nematode (Rotylenchulus reniformis), root-lesion nematode (Pratylenchus spp.), lance nematode (Hoplolaimus spp.), spiral nematode (Helicotylenchus spp.), stunt nematode (Tylenchorhynchus spp.) along with Criconema spp., Xiphinema spp, Longidorus spp., free-living nematodes, mycophagous nematodes and predatory nematodes. Among all the isolated plant-parasitic nematodes, root-knot nematode (Meloidogyne incognita) was found to be more abundant with prominence value of 136.7, 81.3 and 76.3 in vegetable crops, fruit crops and ornamental crops, followed by Helicotylenchus spp. and Rotylenchulus reniformis. The prominence value of reniform nematode (Rotylenchulus reniformis) was found to be 90.5, 54.1 and 54.1 in vegetable crops, fruit crops and ornamental plants respectively.

Demographic Characteristics of Members of Farmer Producer Organisations (FPOs) in Effectiveness of Group Dynamics and their Perceived Constraints in Lower Brahmaputra Valley Zone of Assam, India

The present study to investigate demographic profile of FPOs members in the effectiveness of group dynamics and their perceived constraints was conducted in Lower Brahmaputra Valley Zone (LBVZ) of Assam comprising six districts viz., Kamrup, Bongaigaon, Nalbari, Chirang, Barpeta and Goalpara. In doing so, it utilized the descriptive research design following an ex-post-facto approach to fulfil the objectives of the study. A total of eight FPOs promoted by Assam Agricultural University through CBBO-AAU and World Bank supported APART project were selected purposively. From each FPO, 15 active members were approached for data collection through personal interview method during 2022, which made 120 as final size of sample. The analysis of profile characteristics of the respondents revealed that majority of the respondents (FPOs members) in study areas were middle aged (66.67%) between 29 to 50 years with education level from high school to graduate/ above (80.83%), 64.17 percent were from small family size upto 4 members, 90.83 percent of the respondents had medium level of annual income (i.e. Rs 33190-379866.6), 46.67 percent had medium level of socio- political participation and 38.33 percent low and 35.83 percent high levels of  material possession. The study also found that lack of co-ordination for different group activities, ineffective linkage and ineffective monitoring, lack of professional management, non-availability of timely credit and inadequate access to credit, weak financial position, absence of adequate market  linkage, lack of storage facilities, distance from existing markets, lack of market information, lack of marketing knowledge and skills and difficulty in getting skilled labour were the perceived problems faced by FPO members in effective functioning of FPOs. 

Genetic Variability and Correlation Studies for Yield and Yield Attributing Traits in Mungbean [Vigna radiata (L.) Wilczek]

Background: Mungbean is one important short duration pulse mostly grown in South and Southeast Asia. The level of variability available in the germplasm influences how well a breeding programme would be productive. Understanding the nature and extent of genetic diversity in breeding material is greatly helped by estimates of genetic variability parameters and character associations. The current study aimed to study genetic variability and character associations in mungbean for yield and its attributes, pre-requisite for formulating an effective breeding programme. Methods: The present experiments were carried out with 107 mungbean genotypes collected from NBPGR (New Delhi) and AAU-Zonal research station, Shillongani. The genotypes were evaluated in randomized complete block design over two replications for yield and yield attributing traits at the experimental farm Assam Agricultural University, Jorhat during 2020-2021. Result: The traits like yield per plant, number of branches per plant, clusters per plant, pods per plant, plant height, 100 seeds weight and peduncle length exhibited a high to medium magnitude of genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV). Additionally, these traits showed high heritability and high genetic advance. The correlation studies revealed significant positive relationships between yield and all the assessed traits, with the exception of shelling percentage. The results of the path analysis indicated that a few traits, such as the number of pods per plant and the weight of 100 seeds, had a significant positive impact on seed yield. This suggests that when selecting for seed yield in mungbean, it would be advantageous to take into account these traits.

Effect of Organic Nutrient Management Practices on Growth, Yield and Pests Incidence of Scented Rice (Oryza sativa L.) in Rainfed Situation of Assam

The field experiment was conducted in organic block on experimental farm of AAU-Assam Rice Research Institute, Assam Agricultural University, Titabar, Assam during kharif season of 2019 and 2020 to study the effect of organic nutrient management practices on growth, yield and pests incidence of scented rice (Oryza sativa L.) in rainfed situation of Assam. Eight treatment combinations of organic inputs were laid out in Randomized Block Design with three replications including one control where no organic nutrients were added. The study revealed that combined application of different proportion of green manure, enriched compost, azolla, vermicompost, neem cake with bio fertilizer consortium and rock phosphate as different treatment significantly improved the growth behavior, yield and also reduced pests incidence of scented rice. Among the organic nutrient management treatments, combination of Green manure (2.5 t/ha)+ Vermicompost (2.5 t/ha)+ Biofertilizer consortium (4 kg/ha seedling) as root dip +Rock phosphate (17 kg/ha)+Azolla (20 kg/ha) recorded the highest yield (3.80 t/ha) by improving yield attributing parameters, viz., Panicles (276.3 /m2), Spikelet /panicle (25.50 number) and Panicle weight (3.37g). The organic treatments also significantly enhanced the growth physiology viz., leaf area index (4.32), and specific leaf weight (8.56 mg/cm2) at panicle initiation stage (90 DAT). In organic management treatments, pests and disease incidence significantly reduced compared to control plot. Highest reduction of dead heart (DH%) and white ear head (WEH%) infestation due to stem borer, gall midge (silver shoot) and leaf folder damage was noticed in the treatment combination of Green manure (2.5 t/ha) + Vermicompost ( 2.5 t/ha)+ Biofertilizer consortium (4 kg/ha seedling) as root dip+Rock phosphate (17 kg/ha)+Azolla (20 kg/ha).

Mineral and Labile Organic Nitrogen Fractions in Soil Profile and Their Response to FYM and Inorganic Fertilization in Different Growth Stages of Rice Crop

Nitrogen is the key element among the major nutrients in crop production. The mineralizable soil organic nitrogen is the main contributors of soil N supply. A better understanding of soil organic nitrogen dynamics in agro-ecosystems is needed to improve N management. The present investigation was conducted in Regional Agricultural Research Station (RARS), Assam Agricultural University, Titabar, Jorhat during 2017-18. In this study, the impact of Farmyard Manure (FYM) and inorganic fertilization on soil mineral nitrogen (NO3−-N and NH4+-N) dynamics and labile organic nitrogen fractions viz. microbial biomass N (MBN), particulate organic N (PON) and water-extractable organic N (WEON) at three growth stages of rice viz. active tillering, flowering and physiological maturity stages and nitrogen stock were assessed. Six treatments viz. control (no fertilization), 100% NPK, 100% NPK + FYM 5 t ha-1, 50% NPK, 50% NPK + 50% N through FYM and FYM 10 t ha-1 were tested in randomized block design with four replications. The results showed that NO3−-N and NH4+-N were found to be significantly higher in 100% NPK+FYM 5 t ha-1 at the three growth stages of rice. The labile organic nitrogen fractions were significantly higher in FYM 10 t ha-1. All these variables were decreased with increase in crop growth stages. Integrated use of inorganic fertilizer and FYM recorded the highest nitrogen stock. Stepwise regression analysis indicated that NH4+-N was the main contributor to nitrogen stocks at the three growth stages of rice of the studied soils.

Effects of organic nutrient management on aromatic rice (Oryza sativa)-linseed (Linum usitatissimum) sequence

The experiment was conducted during 2019 and 2020 at the Instructional-cum Research (ICR) Farm, Assam Agricultural University, Jorhat, Assam to study the impact of different combinations of organic nutrient sources on aromatic rice (Oryza sativa L.) (rainy-kharif) and their residual effect on linseed (Linum usitatissimum L.) (winter- rabi) crop for developing a double cropping sequence for rice growers of Assam with organic management. The experiment comprised three aromatic rice cultivars, viz. Kola joha, Keteki joha and Chakhao poireiton and five combinations of organic nutrient sources. Out of the organic nutrient sources, application of N @30 kg/ha through vermicompost along with pre-season green manuring of Sesbania bispinosa and root dip treatment of rice seedlings with Azospirillium and phosphorus solubilising bacteria @3.5 kg/ha each (N3) resulted the highest number of panicles/ m2 (216.72 in 2019 and 223.96 in 2020), highest yield of rice (30.26 q/ha in 2019, 32.58 q/ha in 2020 grain yield and 65.99 q/ha in 2019, 68.98 q/ha in 2020 straw yield). The highest seed yield (394.52 kg/ha in 2019, 416.97 kg/ha in 2020) and stover yield (890.09 kg/ha in 2019, 896.63 kg/ha in 2020) of succeeding relay sown linseed were recorded with the N3 treatment. The highest available N (250.10 kg/ha), P2O5 (20.40 kg/ha) and K2O (140.06 kg/ha), organic C (0.65%), soil organic carbon (SOC) stock (13.29 t/ha), soil microbial biomass carbon (SMBC) (183.43 µg/g of soil) in soil were recorded with the N3 treatment after harvest of linseed in 2020. The study affirmed the suitability of rice-linseed cropping sequence for efficient utilization and conservation of resources.

Genotypic variations of phenological and growth parameters in rapeseed (Brassica rapa, var. Toria)

Rapeseed is a short duration, self-pollinated and long day crop. It is an important and widely used oil seed crops among the people of Assam and North-East India. However, there is still lack of sufficient rapeseed genotypes for the local farmers. Only a few improved genotypes are recommended in the region. To increase the production and productivity, more numbers of improved genotypes have to be identified. Therefore, a field experiment was conducted at the Instructional-cum-Research (ICR) Farm, Assam Agricultural University, Jorhat, Assam, during rabi 2021-22 and 2022-23 to study the genotypic variations of phenological and growth parameters in rapeseed genotypes. The experiment was laid out in randomized block design with three replications comprising of 22 different genotypes of rapeseed including TS-38 (Check), TS-46, TS-67, TS-36, TS-29, TS-75-1, TS-75-1TL, TS-75-2ME, TS-75-2-MM, TS-76-1, TS-76-2, JT-90-1, Panchali, Bhawani, CG Toria-4, TKM-20-1, TKM-20-2, JT-14-5, PT-2018-09, CG Toria-3, Tapeshwari and PT-303. The crops were grown following the recommended package of practice. All the phenological and growth parameters were taken following the standard methodologies. The result of the experiment indicated significant difference in reaching phenological and growth parameters among the genotypes. The genotype JT-14-5 and TKM-20-2 took the longest duration for 50% flowering and siliqua initiation. However, JT-14-5 and JT-90-1 took the longest duration for physiological maturity. On the other hand, TS-67 and TS-75-1TL took the shortest duration for physiological maturity. The genotype TS-75-2ME showed highest dry weight followed by the genotype TS-38 at harvest. There was gradual increase in Absolute Growth Rate and Crop Growth Rate with the advancement of growth. However, in case of Relative Growth Rate, a decline was noticed in the values from 30-60 DAS to 60 DAS-harvest. The genotype TS-75-2ME and TS-38 were recorded highest yield and highest Crop Growth Rate during 30-60 DAS indicating that the parameter at that particular stage of growth, has positive impact on seed yield.

Agronomic efficiency and productivity of transplanted kharif rice (Oryza sativa) as influenced by fertilizer briquettes

An experiment was conducted during rainy (kharif) season of 2022 at the research farm of Assam Agricultural University, Jorhat, Assam to evaluate the effect of fertilizer briquettes on growth and productivity of transplanted rice. The field experiment was laid out in RBD comprising of 13 treatments, replicated thrice. Growth of rice, panicles/m2 and yield were subjected to significant variation under different fertilizer management practices. Higher plant height, tillers/ m2, panicles/m2, yield and agronomic efficiency were recorded under FDP, 120% RDN + 100% P and K + ZnSO4 @10 kg/ha + biofertilizer (T12). This might be owing to reduced losses  of nutrients and efficient uptake by plants compared to broadcasted method of fertilizer application where most of the applied fertilizers were susceptible to various losses availing lesser amount of nutrients for crop uptake.

Attitude of young employees towards financial matters: A study in Assam Agricultural University, Jorhat

Attitude of young employees towards financial matters: A study in Assam Agricultural University, Jorhat

Assessment of Clinico-physiological and Haemato-biochemical Profiles in Hampshire Crossed Pigs

This study investigated clinico-physiological and haemato-biochemical parameters in 18 healthy Hampshire-crossed pigs, classified into three age groups: Group-I (grower), Group-II (finisher), and Group-III (pregnant). Carried out at the 30 Sow Teaching Unit, the Departments of Livestock Production and Management and Veterinary Biochemistry, College of Veterinary Science, Assam Agricultural University, Khanapara, the study aimed to discern age-related variations in pig health. Clinico-physiological assessments encompassed body temperature, heart rate, pulse rate, respiration rate, mucous membrane appearance, feeding behavior, and pen-mate behavior. Group-I exhibited higher clinico-physiological values, with significant variations in the respiration rate (p<0.05) and highly significant variations in heart rate and pulse rate (p<0.01) compared to Groups II and III. The haematological parameters, including hemoglobin, PCV, TLC, and TEC, were evaluated. Group-II exhibited higher hemoglobin and total erythrocyte count, while Group-I had a higher packed cell volume. Total leucocyte count variation was non-significant, but packed cell volume significantly varied (p<0.05), and hemoglobin and total erythrocyte count highly significantly varied (p<0.01). Biochemically, Group-I demonstrated elevated markers; Group-II had higher ALT; and Group-III exhibited increased total protein, BUN, and creatinine levels. While blood glucose, total protein, and AST showed non-significant variations, ALT, creatinine, and cortisol exhibited significant differences (p<0.05), and ALP, LDH, and BUN displayed highly significant variations (p<0.01). This study provides comprehensive insights into age-associated physiological, haematological and biochemical variations in pigs, contributing valuable information for effective pig health management practices.

Comparative Evaluation of Nano Urea Versus Conventional Urea for Nitrogen Management in Rainfed Sunflower (Helianthus annuus L.) Cultivation in Acid Sandy Loam Soils of Assam.

A field experiment was conducted during rabi, 2021-22 at the experimental plot of the Department of Agronomy, Biswanath College of Agriculture (BNCA), Assam Agricultural University (AAU), Biswanath Chariali, Assam having geographic coordinates 26°43'30'' N and 93°08'08'' E to assess nitrogen management in Sunflower (Helianthus annuus L.) with conventional and nano urea under rainfed farming situations in the North Bank Plain Zone of Assam. The experiment confined to 10 treatments in Randomized Block Design (RBD) viz., T1: Control (No Nitrogen), T2: Soil application of 50% N, T3: Soil application of 100% N (RD), T4: 3 foliar applications of 0.6% nano urea, T5: Soil application of 50% N + 2 foliar application of 1% conventional urea, T6: Soil application of 50% N + 2 foliar application of 2% conventional urea, T7: Soil application of 50% N + 2 foliar application of 3% conventional urea, T8: Soil application of 50% N + 2 foliar application of 0.2% nano urea, T9: Soil application of 50% N + 2 foliar application of 0.4% nano urea, T10: Soil application of 50% N + 2 foliar application of 0.6% nano urea. Results revealed that there was no significant effect on the seedling emergence percentage due to different nitrogen management treatments. The highest plant height (84 cm) and maximum number of leaves (33) were found in T10. T9 showed the maximum values of Relative Leaf Water Content (RLWC) (71%), leaf area index (LAI) (3.2 and 4.2 at 60 and 90 DAS), chlorophyll content index (30 DAS) and head diameter (16.70 cm). For most of the growth and phenological parameters, T9 and T10 were at par with each other. T1 (no nitrogen) was the earliest to complete its life cycle which is reflected in 50% heading (65 days) and days to maturity (97 days). Dry matter accumulation varied at different time intervals, initially, it was highest in T3 but later T9 and T10 showed the maximum values. In terms of seed yield, test weight and chaffy grain percentage (%), T9 showed the best results: (1505 kg/ha), (54 g/1000 seeds) and (20%) respectively, followed by T10. Whereas the highest stover yield was recorded in T10. The highest Benefit to Cost ratio (B:C ratio of 1.60) was obtained in the T9.

Evaluation of Promising Lines of Vegetable Amaranth (Amaranthus viridis L.) Suitable for Cultivation in North Eastern India

Sixteen accessions of vegetable amaranth (Amaranthus viridis L.) were collected from different locations of the state of Assam and North East. The accessions were tested for leaf and plant yield and component characters under different breeding trials. They were evaluated consecutively for three years in the Deptt. of Horticulture, AAU, Jorhat in station trials. The accessions viz., Am-1, Am-2, Am-3, Am-4, Am-5, Am-6, Am-7, Am-8, Am-9, Am-10, Am-11, Am-12, Am-13 (Boga Morisa), Am-14 (Ranga Morisa), Am-15 and Am-16 were tested in zonal trials covering UBVZ (Upper Brahmaputra valley zone), NBPZ (North Bank Plains zone) and LBVZ(Lower Brahmaputra valley zone) also. In these trials, among all genotypes JorAm-1(Shyamali) and JorAm-2 (Rodali) were found to be the best for leaf and plant yield and other component characters.The AICRP(VC) trials conducted throughout the country exhibited average plant yield of 137q/ha inJorAm-1 and 133.18 q/ha in JorAm-2 with 25 – 30% yield increase over the best check variety. Shyamaliwas a green leaf variety whereas Rodali was a purplish variety. The edible leaves were getting ready for plucking at 30 – 35 days after sowing. Both of them were found to be tolerant with 5% infection to leaf spot and aphids. They have been recommended in the Zonal Research Committee Meeting (ZREAC)andAnnual Technical Committee Meeting (ATCM) held at Assam Agricultural University (AAU), Jorhatfor release in the state of Assam. In view of the consumer preference and taste, the varieties are spreading very fast and getting popularity throughout entire NE states.Considering yield performance and other desirable characteristics, extensive cultivation of these varieties may be done in better performing states also.

Enhancing the performance of chilli (Capsicum annuum) through twin role of plant growth promotion and disease suppressionvia Bacillus subtilis-based bioformulation

Considering the majority of studies confined in vitro evaluation of microbial bioagents against diseases, a study was carried out during 2018–21 at Assam Agricultural University, Jorhat, Assam, (in vivo and field studies) to assess bio-efficacy of B. subtilis (strain LB22)-based liquid bioformulation against bacterial wilt (Ralstonia solanacearum) and anthracnose (Colletotrichum gloeosporioides) diseases of chilli (Capsicum annuum L.). In vivo efficacy of B. subtilis formulation (inclusive treatment involving seed treatment, seedling dip, soil treatment and foliar spray) showed significant suppressiveness against both the diseases coupled with enhanced growth and yield attributes. Subsequently, the field evaluation of Bacillus subtilis formulation comparing standard chemicals also edged over the latter by 15.45% in terms of yield gains in 2-years of study. A significant reduction was found in disease severity during field evaluation of Bacillus subtilis formulation on account of induced resistance via upregulated synthesis of plant defense-enzymes (Polyphenol oxidase, peroxidase, phenylalanine ammonia-lyase, and β-1,3-glucanase) by 2.3–11.0 folds with their peaks mostly expressed within 24–72 h. These results put forward a conceptual framework for delivery mechanism of a microbial bioagent in a formulation mode, having the potential to be effective against a number of other diseases as well.

Effect of Pruning on Morpho-physiological Characters and Yield of Pumpkin (Cucurbita moschata)

The present study was carried out at the Instructional cum Research Farm, Department of Horticulture, Biswanath College of Agriculture, Assam Agricultural University, Biswanath Chariali with an aim to study the morpho-physiological characters and yield as influenced by pruning in pumpkin. Pumpkin is an important commercial vegetable crop of Assam which is cultivated mainly during rabi season.The treatments were: T1(Trimming of growing tip of the primary vine at 8th node stage), T2(Trimming of growing tip of the primary vine at 10th node stage), T3(Trimming of growing tip of the primary vine at 12th node stage), T4(Trimming of growing tip of the secondary vine at 6th node stage), T5(Trimming of growing tip of the secondary vine at 8th node stage), T6(Removal of all tertiary vines), T7(Retention of two tertiary vines) and T8(control without pruning). The study revealed that among the treatments, T4 recorded the highest primary vine length and inter-nodal length of primary vine at 60, 90 DAS and at 1st harvest. Number of primary vine was found to be highest under T5 whileT3 recorded maximum number of secondary vines, inter-nodal length of secondary vines, the highest total leaf chlorophyll content, relative leaf water content, leaf area index and maximum fruit yield. Therefore, trimming of growing tip of the primary vine at 12th node stage can be suggested for pumpkin to get maximum yield.

Importance of PAR interception and radiation use efficiency on growth and yield of Potatoes under different microclimates in the upper Brahmaputra valley zone of Assam

A field experiment was conducted at Assam Agricultural University, Jorhat, Assam during rabi 2018-19 for assessing the PAR interception and radiation use efficiency in potato variety Kufri Jyoti under different microclimates, which was planted in split plot design with 4 dates of plantings and three mulching treatments with water hyacinth, black polythene and without mulching. The incident, reflected and transmitted PAR were measured periodically over the crop with line quantum sensor and daily incident radiation were calculated from incident PAR and bright sunshine hours. The interception of PAR (iPAR) varied considerably among different treatments, while highest iPAR was recorded under first date of planting and mulching treatment with water hyacinth. The leaf area index (LAI) and biomass production was highest in crop planted in first date planting and grown under water hyacinth mulch. The RUE for tuber yield was highest under water hyacinth (2.35 g MJ-1) followed by black polythene (2.03 g MJ-1) and non-mulched (1.67 g MJ-1) condition, while among planting dates it was highest in case of first date of planting. The  LAI, biomass production and yield of potato were found to be significantly correlated with iPAR and RUE. The predictive models were developed by using stepwise regression method to predict tuber yield from iPAR and REU, which have R2 value of 0.96 and 0.99, respectively. 
  

Assessment of Cold Tolerance in Boro Rice (Oryza sativa L.) Genotypes During Germination for Enhanced Adaptability to Low Temperature Stress

An experiment was conducted to evaluate the cold tolerance ability of ten boro rice genotypes in the laboratory conditions for suitability of growing under low temperature stress. The experiment was laid out in Factorial CRD and the low temperature regimes was provided under controlled environment (Walk-in cold chamber by Saveer Biotech Limited) for germination studies that could maintain the specific low temperature. The experiment was conducted in the Department of Crop Physiology and Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, India. The germination tests were conducted under four different temperature regimes where seed germination under ambient (T4=28 ± 0.2oC) was considered as control. Low-temperature treatments were provided by the growth chamber at three different levels of low temperature viz. (T3=10-12°C), (T2=7-9oC) and (T1=5-6°C). Per cent germination, germination index, shoot length, length of longest root and seed vigour index were considered for the study. The germination percent, germination index, shoot length, length of longest root and seed vigour index was recorded highest under ambient condition (T4) irrespective of all the genotypes. Seeds grown under T3 showed considerable germination values only after 28 days of germination studies, whereas T1 and T2 showed no germination. The study revealed that amongst all the ten genotypes, Kanaklata and Sona Mahsuri revealed superior performance in germination percentage, germination index, shoot length, length of the longest root and seed vigour index. In the correlation studies, germination % was significantly correlated with germination index, shoot length, length of the longest and SVI at 5% probability level. GI was also positively and significantly correlated with Shoot length (SL), Length of longest root (LLR) and Seed Vigour Index (SVI). The present study revealed that Sona Mahsuri and Kanaklata was found to be the ideal genotypes for germination under low temperature (10-12oC). Therefore, Farmers growing boro rice under low temperature regimes could take the opportunity of selecting the varieties viz. Kanaklata and Sona Mahsuri for higher yield.

Influence of Integrated Weed and Nutrient Management on Productivity and Profitability of Summer Maize (Zea mays) Under Rainfed Condition of Assam, India

A field experiment was conducted at the Instructional-cum-Research (ICR) Farm, Assam Agricultural University, Jorhat during the summer season of the year 2020 to evaluate the effects of integrated weed and nutrient management on weed growth, yield attributes and yield of summer maize. The experiment was laid out in factorial randomized block design and replicated thrice. The treatment consisted of three nutrient management practice viz., 100% RDF (N1); N1+ 25 kg ZnSO4/ha (N2) and  75 % RDN and 100 % P2O5 and K2O through chemical fertilizer (CF) + 25 % N through vermicompost + 25 kg ZnSO4/ha (N3) and four weed management practices viz., weedy check (WM1), live mulching with cowpea (WM2), WM2 + hand weeding at 25 and 45 DAS (WM3) and Atrazine 500g+Pendimethalin 500g/ha followed by hand weeding at 45 DAS (WM4). Experimental findings revealed that the different INM practices significantly affected the growth parameters, yield and yield attributes of summer maize. The maximum values of growth parameters were recorded in the treatment involving application of 75 % RDN and 100 % P2O5 and K2O through chemical fertilizer + 25 % N through vermicompost + 25 kg ZnSO4/ha (N3). Similarly, yield and yield attributing characters viz., weight of cob with and without husk, length of cob without husk, number of rows per cobs, grain per row, grain per cob, 1000 grain weight, shelling percentage, grain (23.76 q/ha) and stover (74.55 q/ha) yield. The growth, yield and yield attributing parameters of maize were significantly affected by the different weed management practices. Pre emergence application of Atrazine 500g+Pendimethalin 500g/ha followed by hand weeding at 45 DAS (WM4) resulted the highest value of yield. The highest grain (21.77 q/ha) and stover (71.12 q/ha) yield were recorded in the treatment WM4.The interaction effects of different nutrient and weed management practices were found not significant. The economic study revealed that the highest gross return (₹.1, 03816.00/ha), net return (₹.67, 956.00) and B: C (1.90) were recorded from the treatment combination N3WM4.

An Analysis of the Challenges Faced by Small Scale Backyard Chicken Farmers of Dhemaji District of Assam

Aims: The present study was conducted to know the challenges faced by the small scale backyard chicken farmers of Dhemaji district of Assam.
 Study Design: The data obtained on various challenges faced by the farmers under the study were tabulated and analyzed statistically by using Garrett’s Ranking Technique.
 Place and Duration of Study: The study was conducted at Krishi Vigyan Kendra, Dhemaji, Assam Agricultural University, Simen Chapori, Dhemaji, Assam during the year, 2020-21.
 Methodology: For the purpose, a questionnaire was prepared for surveying and data were collected about various challenges in backyard chicken rearing faced by the farmers of the district. The farmers were asked to identify the challenges he or she and the fellow farmers of their villages faced with respect to rearing of local chickens in their locality and to rank the challenges from 1 to 20 according to the seriousness of the challenges faced by them.
 Results: Lack of suitable germplasm was found to be the major challenge of poultry farmers with mean score of 74.89 and ranked first among the constraints in backyard chicken rearing. Higher incidence of diseases (68.95), unavailability of feed and feed ingredients (66.55) and mortality of young chicks (63.00) were ranked second, third and fourth major challenges, respectively. On the other hand, non availability of vaccine, higher cost of feeds and feed ingredients, lack of extension training or service, high cost of farm equipments were ranked fifth, sixth, seventh and eighth, respectively, as challenges in backyard chicken rearing. Lack of organized marketing facilities, lack of knowledge on scientific poultry farming, high cost of chicks, presence of middle man, higher mortality during brooding period, inability to diagnose sick birds, inadequate veterinary facilities, seasonal price fluctuations, high cost of medicaments, lack of credit facilities, social problems like damaging of the standing crops by the birds and complaint by neighbours, loss of birds due to predators or thieves were some other constraints of lower importance as indicated by the respondents for the backyard chicken farmers surveyed during the study.
 Conclusion: From the study, it can be concluded that the small scale backyard poultry farmers of Dhemaji district of Assam have a lot many challenges in chicken rearing in village conditions, the major being the lack of suitable germplasm and higher incidence of diseases. To address such problems there should be proper initiatives from government level as well as in farmers’ collaborative approach to introduce some newly developed improved chicken breeds and awareness about proper disease prevention and bio-security measures and creation of other facilities.

Influence of weather parameters on Anthracnose in black pepper (Piper nigrum L.) in the upper Brahmaputra valley zone of Assam

Black pepper (Piper nigrum L.) production faces several challenges due to various diseases, with anthracnose being the most significant. It is caused by Colletotrichum gloeosporioides (Penz.) Penz. and Sacc., a fungal plant pathogen that leads to severe infections in black pepper plants, both in nurseries and in the field. The occurrence of anthracnose disease is highly influenced by weather conditions. Epidemiological studies were conducted at Assam Agricultural University, Jorhat, Assam from 2019 to 2021 to determine the impact of weather factors such as temperature, rainfall, rainy days, and relative humidity on anthracnose incidence in seven different black pepper varieties. Upon analyzing the recorded data, it was found that rainfall, minimum temperature, rainy days, and morning relative humidity are the most significant contributors to disease occurrence. However, the role of maximum temperature, evening relative humidity, and bright sunshine hours was statistically non-significant. Data from 2019 and 2020 were further analyzed using stepwise multiple regression to estimate anthracnose incidence in individual black pepper varieties. These regression models were subsequently validated using data of 2021. The root mean square error values varied between 0.0001 and 0.0011, indicating that the models are acceptable. 

Studies of Genetic Variability and Inter-Relationship among Some Pumpkin (Cucurbita moschata L.) Landrace of Assam, India

Thirty diverse landraces of pumpkin comprising from eight districts of Assam viz., four landraces from each district, Sivasager, Dibrugarh, Karbi Anglong, Haflong, Jorhat & Majuli and three landraces from each Lakhimpur and Kokrajhar. The landraces were subjected to analyses of variance and covariance for estimation of genetic variability parameters and correlation coefficients among the 19 characters. The experiment was carried out during the rabi season of 2017-18 at the Instruction Cum and Research (ICR) Farm of Assam Agricultural University in a Randomized Block Design with three replications. From the analysis of variance, it was recorded that the presence of variation among thirty pumpkin landraces for all characters. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) was recorded for single fruit weight with 51.47 per cent and 54.88 per cent, indicating presence of greater variability for the trait. The heritability in the broad sense was recorded highest for the petiole length. The GA calculated as per cent of the mean was recorded for single fruit weight (99.44%), followed by yield per plant. In character association five traits were positively correlated with fruit yield per plant out of 18 characters.