Regional Agricultural Research Station Research Articles

Studies on the Efficacy and Management of Seed Borne Diseases and its Economics in Chickpea (Cicer arietinum L.)

Background: Seed borne diseases are regarded as major constraints in chickpea production. Seed diseases are caused by biotic factor like fungi and abiotic especially by drought, resulted in decrease in seed yield and productivity. Hence studies on the efficacy and management of seed borne diseases and its economics of seed production in chickpea was attempted. Methods: The field experiment was carried out in Regional Agricultural Research Station, College of Agriculture, Vijayapur during rabi 2021-2022. The field experiment consisted eight treatments of fungicides and bioagents and combi- product of fungicide and bioagents viz., T1: Carboxin 37% + thiram 37% DS @ 2 g/kg of seeds, T2: Carbendazim 25% + mancozeb 50% WS @ 3.5 g/kg of seed, T3: Thiophanatemethyl 45% + pyraclostrobin 5% FS @ 4 ml /kg of seeds, T4: Seed treatment with Pseudomonas fluorescens @ 10/kg of seed, T5: Seed treatment with Trichoderma harzianum @ 10/kg of seed, T6: Seed treatment with Bacillus thuringenesis @ 10/kg of seed, T7: Seed treatment with Trichoderma harzianum @ 10/kg of seed + carbendazim 25% + mancozeb 50% WS @ 3.5 g/kg of seed T8: Control (without seed treatment) were used to study the efficacy of treatments on growth yield and economics and per cent incidence against R. bataticola in field condition. Result: Among the seed treatments carbendazim 25% + mancozeb 50% WS @ 3.5 g/kg of seed recorded significantly higher growth, seed yield, seed quality parameters and reduced per cent disease incidence and higher economics followed bythiophanatemethy 45% + pyraclostrobin 5% FS @ 4 ml/kg of seeds, as compared to control.

Genetic Analysis of Quantitative Traits, Gall Midge and Brown Spot Tolerance in Rice (Oryza sativa L.) Genotypes under Irrigated Ecosystem

Gall midge and brown spot of rice are a fungal disease that affect both seedlings and mature plants. To investigate resistance of rice to this disease twenty nine rice cultures were evaluated under irrigated ecosystem at Regional Agricultural Research Station, Jagtial during kharif, 2020. High heritable estimates were observed for all the 8 traits studied. High estimates of heritability was recorded for important yield attributes viz., days to 50% flowering (91.4, 11.24), plant height (77.8, 9.53), 1000-grain weight (98.4, 54.5), number of grains per panicle (78.3, 40.18) and grain yield (98.7, 33.87) indicated that these traits were under the control of additive genes. Significantly positive correlations were recorded with plant height, Number of productive tillers per plant and 1000 seed weight at both genotypic and phenotypic levels, the results clearly indicated that long duration genotypes with more height and bolder grains contribute for more grain yield. Among the eight traits studied, 1000 grain weight contributed highest (67.8%) towards total divergence followed by days to 50% flowering (11.5%), number of grains per panicle (6.06) and Galls midge incidence percentage (6.06%). Genotypes, JGL 38957 of cluster II, JGL 38950 of cluster III, JGL 38935 of cluster IV and JGL 38921 of Cluster VII could be the best source to develop brown spot, gall midge resistance and high yielding rice varieties.

Evaluation for Multiple Abiotic Stress Tolerance in Rice (Oryza Sativa) Genotypes

Abiotic stresses are the major constraints that affect the morphological, physiological and biochemical attributes of plants resulting in reduction of yield. Recently, combined occurrence of stresses has become a greater cause of concern in farmers’ fields. Hence, there is a need to identify genotypes that are tolerant to more than one stress. A study on physiological characterization for water and salinity stress was conducted in twenty rice genotypes during kharif 2022 at Regional Agricultural Research Station, Maruteru, Andhra Pradesh, India. Results showed that among all the treatments, root length, shoot length, root and shoot dry weight and chlorophyll content were greater under control followed by 1% mannitol, 2% mannitol and salinity stress. Visual scoring for water stress at seedling stage revealed that under mild water stress (1% M) in genotypes viz., CR4423-8, FL 478 and Pantara recorded 75-90% of survival and under severe water stress (2% M) 40-50% survival. Under salinity stress, the score 3 was recorded in FL 478 and 5 in Naveen, Pantara and CR 4423-75. For combined stresses, FL 478 and Pantara were identified as tolerant and can be suggested as donors.

Nitrogen, Rhizobium and molybdenum for higher soil bacterial population, N uptake and productivity of lentil (Lens culinaris) grown under rice (Oryza sativa)-fallow conditions

A field experiment was conducted during the winter (rabi) seasons of 2014–15, 2015–16 and 2016–17 in loamy soils of the Regional Agricultural Research Station, Assam Agricultural University, Shillongani, Assam, to study the effect of varying doses of nitrogen, Rhizobium and molybdenum on bacterial population in soil, N uptake, yield attributes, grain yield and economics of lentil (Lens culinaris Medikus spp. culinaris) grown after the harvesting of winter rice (Oryza sativa L.) variety ‘Gitesh’. Soil bacterial population increased with the increase in nitrogen doses. The crop grown using seeds inoculated with Rhizobium @ 50 g/kg seed and sodium molybdate @ 1 g/kg seed along with 100% of recommended dose (RD) of N (15 kg/ha) accrued in the highest bacterial population in the soil at harvesting. Seed inoculation with Rhizobium and sodium molybdate led to considerably higher bacterial population build up in soil than seed inoculation with Rhizobium and sodium molybdate separately. Nitrogen uptake by lentil got reduced with decreasing N doses, being 28.54 kg/ha under RD of N and 28.03 kg/ha under 75% of recommended N. The treatment combinations involving RD and 75% of RD of N (11.25 kg/ha) and seed inoculation with Rhizobium and sodium molybdate recorded 35.16 kg/ha and 34.97 kg/ha N uptake respectively. These 2 treatment combinations ultimately accrued in higher values for plant height, pods/plant, seeds/pod and 100-seed weight and significantly higher grain yield (928.90 and 868.89 kg/ha respectively) as compared to all other treatment combinations. Benefit: cost ratios under these 2 treatment combinations were 2.18 and 2.09 respectively. The treatment combinations were tested for maximizing lentil production utilizing rice-fallows and farmers’ acceptability in farmers’ fields during rabi 2017–18 through 3 Krishi Vigyan Kendras (KVK) in Upper Brahmaputra Valley (UBV) in Jorhat district, Central Brahmaputra Valley (CBV) in Nagaon district and Lower Brahmaputra Valley (LBV) in Nalbari district of the state. The RD of N + seed inoculation with Rhizobium and sodium molybdate yielded the highest (5.8–8.2 q/ha) at all the locations closely followed by 75% RD of N + Rhizobium + sodium molybdate (5.93–7.25 q/ha).

Impact of Low Light Stress on Physiological Characters, Yield and Yield Attributes of Rice (Oryza sativa L.)

Background: Keeping in view of low light effect on rice yield and quality, identification of low light tolerant genotypes as donor for plant breeding program is needed. Methods: Field experiments were conducted for low light tolerance during kharif 2021 at Regional Agricultural Research Station, Maruteru with an aim to screen and identify low light tolerant cultivars. The impact of low light was investigated on physiological, yield and yield attributes of eighteen rice genotypes. Result: Low light treatment resulted and increase in mean days to 50% flowering and days to maturity. An increment of both plant height and leaf area was noted under low light stress in all the tested genotypes. Yield and yield attributes such as panicle number, grain number per panicle and test weight were also affected. The reduction in total dry matter and harvest index was recorded on exposure to low light condition. Under low light grain yield was maximum in IET 29032 followed by IET 30408 and Gayatri and these were identified as low light tolerant genotypes. These genotypes had a higher panicle number. Genotype Gayatri showed maximum 1000 grain weight and minimum reduction in harvest index was evident in IET 29032 and IET 30408. The chlorophyll a pigment content reduced under low light while majority of the genotypes showed an increase in chlorophyll b pigment. Gayatri followed by IET 29032 and IET 30408 retained higher chlorophyll content under low light stress. Lesser reduction in chlorophyll content (less than 13%) was evident in IET 30408, Gayatri, Swarnaprabha, IET 29031 and IET 29032.

Character association and path analysis among yield components in castor (Ricinus communis L.)

The analysis of the nature and magnitude of associations among 10 quantitative traits and their contribution towardsseed yield was carried out in 30 genotypes of castor (Ricinus communis L.) during the winterseason of 2009 at Regional Agricultural Research Station, Tirupati. The results revealed that 1200 seed weight, oil yield/plant, effective length of main spike, oil content and number ofspikes/plant had significant positive association with seed yield/plant. Path analysis revealed that oil yield/plant, 100 seed weight, number of capsules on main spike, number of nodes upto main spike, plant height up to main spike and days to 50% flowering are the direct contributors for seed yield in castor.

Studies on Promising Restorer Lines for Yield and Yield Components in Rice (Oryza sativa L.)

The present investigation was carried out at Regional Agricultural Research Station, Maruteru with a set of 30 experimental hybrids developed by crossing three male sterile lines with 10 testers in Line × Tester mating design during kharif, 2022. The resultant 30 hybrids were evaluated in Randomized Block Design with two replications along with the parents and hybrid check, HRI-174 during rabi, 2022-23. Analysis of variance for yield and yield components revealed significant differences among the genotypes, parents, hybrids and parents vs. crosses for most traits, indicating significant differences among parents and hybrids, in addition to significant levels of heterosis for the traits studied. In general, the hybrids had recorded higher grain yield per plant, compared to the lines and were observed to be early and relatively tall with a more number of productive tillers per plant and increased panicle length compared to the parents. The hybrids, APMS 15A×RGL 5613, APMS 15A×MTU 1213, APMS 17A×RGL 5613 and APMS 17A ×MTU 2055had recorded significant and positive relative heterosis, heterobeltiosis and standard heterosis of more than 25 per cent for grain yield per plant and were identified as promising heterotic combinations for further evaluation and commercial exploitation.

Effect of Different Doses and Scheduling Time of Plant Growth Regulators and Defoliants on Growth and Yield of Cotton (Gossypium hirsutum L.) under High Density Planting System

A field trial to determine the effect of different dosages, Scheduling time of plant growth regulators and defoliators on growth and yield of cotton under high density planting system was conducted at Regional Agricultural Research Station, Warangal during kharif-2022. The experiment consisted of eleven treatments laid out in Randomized Block Design with three replications. The treatment details were T1: Application of Mepiquat chloride (M.C) 25 g a.i ha-1 @ 40 & 55 DAE + Ethereal 2000 ppm @ 40 % boll burst, T2: M.C 25 g a.i ha-1 @ 40 & 55 DAE + Ethereal 2000 ppm @ 60 % boll burst, T3: M.C 20, 30 g a.i ha-1 @ 40, 55 DAE respectively + Ethereal 2000 ppm @ 40% boll burst T4: M.C 20, 30 g a.i ha-1 @ 40, 55 DAE respectively + Ethereal 2000 ppm @ 60% boll burst T5: M.C 20 g a.i ha-1 @ 40,55 & 75 DAE+ Ethereal 2000ppm @ 40 % boll burst, T6: M.C 20 g a.i ha-1 @ 40, 55 & 70 DAE + Ethereal 2000 ppm @ 60 % boll burst, T7: M.C 25 g a.i ha-1 @ 40, 55 & 70 DAE + Ethereal 2000 ppm @ 40 % boll burst, T8: M.C 25 g a.i ha-1 @ 40, 55 & 75 DAE+ Ethereal 2000ppm @ 60% boll burst, T9: M.C 20, 25, 30 g a.i ha-1 @ 40, 55 and 70 DAE respectively + Ethereal 2000 ppm @ 40 % boll burst, T10: M.C 20, 25, 30 g a.i ha-1 @ 40, 55 and 70 DAE respectively + Ethereal 2000 ppm @ 60 % boll burst and T11: Control .(Water spray at 40, 55 and 70 DAE). Results revealed that foliar application of M.C @ 20 g a.i ha-1 @ 40, 55 & 70 DAE in conjunction with Ethereal 2000 ppm @ 60% boll burst recorded higher seed cotton yield. Plant growth, dry matter accumulation and stalk yield were recorded highest in control plot and lowest with spraying of M.C 20, 25 and 30 g a.i ha-1 @ 40, 55 and 70 DAE respectively + Ethereal 2000 ppm @ 40 % boll burst. Among similar doses of Mepiquat chloride, all the agronomic traits of cotton crop are positively influenced with application of 2000 ppm Ethereal @ 60% boll burst. The spraying of M.C @ 20 g a.i ha-1 at 40, 55 and 70 DAE + Ethereal 2000 ppm @ 60% boll burst would be economically ideal to the farming community.

Influence of Plant Geometry and Cultivars on Growth, Yield Attributes and Yield of HDPS Cotton under Rainfed Shallow Soils

A field experiment was conducted at Siddapur research farm, Regional Agricultural Research Station, Warangal, Telangana, India during kharif 2022 to investigate the effect of plant geometry and cultivars on growth and yield of cotton under high plant density system. The results revealed that plant height (102.7 cm) and drymatter production (6499 kg ha-1) were significantly higher at ultra narrow spacing of 90 x 15 cm (74,074 plants ha-1) than medium and wider spacings of 90 x 30 and 90 x 60 cm, respectively but, was on par with narrow spacing of 90 x 20 cm (55,555 plants ha-1). Though sympodial branches plant-1 (16.4) and number of bolls plant-1 (24.0) were significantly greater with wider spacing (90 x 60 cm: 18,518 plants ha-1), adoption of high plant density method of 90 x 15 cm spacing (74,074 plants ha-1) (2707 kg ha-1) and 90 x 20 cm (55,555 plants ha-1) (2498 kg ha-1) resulted in significantly higher seed cotton yield. The yield from 90x15 cm was 26.2% and 11.7% higher than that of 90 x 30 cm (2391 kg ha-1) and 90 x 60 cm (1998 kg ha-1), respectively. In case of cultivars, though growth and yield attributes were not significantly influenced, but, the boll weight (5.2) and seed cotton yield (2845 kg ha-1) were significantly higher with NCS 2778 over other cultivars viz., Bt Suraj (2151 kg ha-1), WGCV-79 (2310 kg ha-1) and ADB-39 (2288 kg ha-1).

Evaluation of Safflower (Carthamus tinctorius L.) Cultivars under Different Sowing Dates on Yield and Yield Attributes in Non Traditional Area of Northern Telangana Zone (NTZ)

The field experiment entitled “Evaluation of safflower (Carthamus tinctorius L.) cultivars under different sowing dates on yield and yield attributes in non traditional area of Northern Telangana Zone (NTZ)”, an experiment was conducted at Regional Agricultural Research Station, Polasa, Jagtial during Rabi, 2022. The experiment was laid out in factorial randomized block design with ten treatment combinations by replicating thrice. The treatments includes two factors i.e., factor - 1 having two genotypes G1: ISF-764, G2: TSF-1 and factor -2 having five sowing dates D1: 15th October, D2: 30th October, D3: 15th November, D4: 30th November, D5 : 15th December. Among the genotypes of safflower, TSF-1 recorded higher seed yield (1243 kg ha-1) and yield attributing characters viz.; number of heads plant-1 (26.34), number of seeds head-1 (32.34), seed weight plant-1 (42.01 g), seed index (3.71 g), Stover yield (5386 kg ha-1) and biological yield (6629 kg ha-1) over ISF-764. The result showed that among the different sowings of safflower 30th October sowing was recorded significantly higher Yield and Yield attributing characters viz.; number of heads plant-1 (31.24), number of seeds head-1 (35.16), seed weight plant-1 (47.84 g), seed index (3.77 g), seed yield (1412 kg ha-1), Stover yield (6415 kg ha-1) and biological yield (7827 kg ha-1) as compared to 15th November and 30th November, 15th December sowing date respectively and it is on par with safflower crop sown on 15th October. From the study it can be concluded that the genotype TSF-1 sown on 15th and 30th October performed best among all other treatment combinations.

Crop Weather Pest Relationship and Forewarning Model for Spodoptera frugiperda on Maize and Sorghum

Background: Fall Armyworm, Spodoptera frugiperda is a crop pest with over 80 host species that causes severe damage to maize and sorghum crops. S. frugiperda is native to tropical and subtropical region of America that has spread rapidly throughout the world. Methods: Based on the severity of S. frugiperda in India a field experiment was conducted to study the pest influence in maize and Sorghum crops for two years i.e., 2020 and 2021 during the kharif season at Regional Agricultural Research Station, Tirupati. Using correlation and regression techniques, the data was pooled and statistically analysed with weather parameters. Result: Correlation studies revealed a significant positive relationship between pest damage and minimum temperature showed negative relation with morning and evening relative humidity, while wind velocity and evaporation are positively influenced S. frugiperda damage. Maximum temperature, wind velocity and evaporation together played a role in the occurrence of S. frugiperda. Regression equations were developed using SPSS for predicting the damage caused by S. frugiperda.

Yield Attributes and Yield of Wheat Affected by Irrigation Schedules and Varieties under HAT Zone Conditions of Andhra Pradesh, India

Aims: A field experiment was conducted to assess the impact of various irrigation schedules and wheat varieties on yield characteristics and yield of wheat in Andhra Pradesh's high altitude and tribal area (HAT) zone.
 Study Design: Split-plot design was used to conduct the research experiment.
 Place and Duration of Study: Regional Agricultural Research Station, Chintapalle, Visakhapatnam, ANGRAU, Andhra Pradesh. The study was conducted during Rabi season 2021-22.
 Methodology: Split-plot design was used to conduct the experiment in which as main plots, there were three irrigation schedules—irrigation at CRI, maximum tillering, jointing, flowering, and milking stages (M1); irrigation at CRI, flowering, and milking stages (M2); and irrigation at CRI and milking stages (M3)—and four varieties—DBW-252(V1), HI-1544(V2), HI-8759(V3), and HI-8713(V4)—as subplots. The parameters of Spike length, Spike weight, number of productive tillers m-2, number of grains spike-1, number of filled grains spike-1, 1000 grain weight, grain yield, straw yield, biological yield, and harvest index were found to be superior with five irrigations scheduled at CRI, maximum tillering, jointing, flowering, and milking stages. Among the varieties, HI-8759 recorded the highest values, which were comparable to HI-8713.
 Results: Spike length, spike weight, no. of productive tillers m-2, no. of grains spike-1, no. of filled grains spike-1, 1000 grain weight found superior with five irrigations schedules. The highest values among the variations were achieved by HI-8759 and were comparable to HI-8713.The five irrigation schedule resulted in higher grain and straw yields. Despite the fact that there was a reduced grain yield with two irrigations, the straw yield was statistically equal with three irrigations. With five irrigations, the harvest index (%) was much higher, while with two irrigations, it was significantly lower. However, HI-8759 had a much greater grain and straw production than the other cultivars. The straw yield remained at HI-8713 levels. The HI-8759's harvest index outperformed all other kinds by a wide margin. With HI-1544, the lowest grain and straw yields were noted.
 Conclusion: Wheat yield was dramatically increased by five different irrigation regimens applied at various phenological phases. The maximum yield was recorded by variety HI-8759, which was comparable to variety HI-8713 in terms of biological and straw yields.

First Report of Candidatus Phytoplasma asteris (16SrI-B subgroup) associated with phyllody disease of fenugreek in the world.

Fenugreek (Trigonella foenum-graecum) is a leafy vegetable and spice crop, native to Indian subcontinent and Eastern Mediterranean region. Phytoplasma infection symptoms were observed in fenugreek at ICAR-National Bureau of Plant Genetic Resources Regional Station, Jodhpur and Agricultural Research Station Mandore Jodhpur, Rajasthan, India. The first appearance of phytoplasma suspected symptoms of little leaf was recorded after 50 days of sowing in the months of January 2022. The major symptoms recorded were virescence, phyllody, shoot proliferation, witches-broom, little leaf, yellowing and overall stunted growth in 146 germplasm accessions at NBPGR research farm, Jodhpur and one major commercially cultivated variety RMT 305 at Mandore Jodhpur. Ten samples from symptomatic and five samples from asymptomatic fenugreek plants were collected and processed for total DNA extraction using the Qiagen DNeasy plant mini kit (Germany). The extracted DNA was amplified using nested PCR assays with universal phytoplasma detection primers for 16S rRNA gene (P1/P7 and R16F2n/R16R2) and secA gene specific primers (SecAfor1/SecArev3 and SecAfor2/SecArev3) (Schneider et al. 1995; Gundersen and Lee 1996; Hodgetts et al. 2008). The amplicons of ∼1.25 kb with 16S rRNA and ∼480 bp with secA gene specific primers were amplified in all symptomatic fenugreek samples. In negative control (asymptomatic plants) no amplification was observed with either of gene specific primers in gel electrophoresis. PCR amplified products from the six selected positive samples (FPP-NBPGR-J-01 to FPP-NBPGR-J-04 and FPP-MND-01 to FPP-MND-02) of 16S rRNA and secA gene, were sequenced from both ends. Sequences were deposited in the NCBI GenBank with accession numbers ON756108-ON756113 for 16S rRNA gene sequences and ON745809 to ON745814 for secA gene sequences. BLAST analysis of 16S rRNA and secA sequences revealed 100% sequence identity among themselves and 99.95 to 100% sequence identity with the earlier reported phytoplasma strains of aster yellows group related phytoplasma strains (GenBank Acc. No. MN239504, MN080270) belonging to Ca. P. asteris (16SrI group). Further analyses of the 16S rRNA and secA gene-based phylogenetic tree and the iPhyClassifier-based virtual RFLP analysis of 16S rRNA gene study demonstrated that the phytoplasma associated with fenugreek phyllody belonged to 16Sr group I ('Ca. P. asteris') and subgroup B (GenBank accession AP006628), with similarity coefficient of 1.0. Earlier association of 16Sr-II-D subgroup (Ca. P. australasiae) with fenugreek as host was reported from Pakistan (Malik et al., 2020). To the best of our knowledge, this is the first report of a 'Ca. P. asteris', 16SrI-B subgroup related phytoplasma strain associated with fenugreek phyllody in the world. The 16SrI-B phytoplasma strain is a widely distributed strain associated with several agricultural and horticultural crops of India (Rao 2021). This is not only the first instance of fenugreek phyllody disease found in India, but also the first instance of fenugreek phyllody caused by 16SrI-B subgroup phytoplasma worldwide. This report has epidemiological significance and needs immediate attention, as fenugreek is one of the most common seed spice crop being grown all over India.

Study of Genetic Variability for Yield and Yield Attributes and Bran Oil Content in Maintainer Lines of Rice (Oryza sativa L.)

The present investigation was carried out during kharif, 2016 (June to October) at Regional Agricultural Research Station, Jagtial, Telangana, India to study the phenotypic coefficient of variation and genotypic coefficient of variation, heritability (bs), and genetic advance (GA) for yield contributing characters of 40 maintainer lines of rice. The experiment was designed in RBD replicated twice. Analysis of variance revealed significant differences among rice lines for 15 quantitative traits. The phenotypic coefficient of variation (PCV) value was higher than the genotypic coefficient of variation (GCV), indicating a negligible environmental influence in the phenotypic expression of traits. The PCV and GCV values were highest for the grains panicle-1 and moderate for bran oil percentage, indicating that these two characteristics have a higher variability within and between populations than other characteristics. All of the characters had high heritability. The range of bran oil content in the 40 maintainer lines used to assess the range of bran oil content was from 11.87% in line B11 to 19.35% in line JMS17B.The genetic advancewas greatest for number of grains panicle-1 (87.86%) and modest for bran oil %. The high and moderate estimations of genetic advance show that traits such as the number of tillers plant-1, test weight, L/B ratio, plant height, bran oil percentage, kernal breadth, grain yield plant-1 and kernal length were selected. The genetic advance obtained from the high and moderate estimates indicate that the selection for these characters can be used to improve the yield of the crop.

Identification of Blast Resistant Breeding Lines through Uniform Blast Nursery in Rice (Oryza sativa L.)

Rice blast disease caused by the fungus Magnaporthe oryzae is the most devastating disease of rice causing considerable yield losses. Development of resistant varieties is the most effective and environment friendly strategy to combat losses. RNR 15048 (Telangana sona) (IET23746) is a popular local variety possessing a desirable, short-slender grain type with low glycemic index, good cooking quality and having Pi2 gene for blast. However, it is moderately susceptible to bacterial blight disease and having no durable resistance to blast disease with weak culm. In this context, improvement of RNR 15048 for blast, bacterial leaf blight is important to reduce yield losses. Present study was carried out to screen and identify blast resistant breeding lines in Rice at Regional Agricultural Research station, Polasa, Jagtial, PJTSAU during Rabi, 2022-2023. 18 F3 breeding lines were screened in uniform blast nursery along with parents RNR 15048, MTU 1010 NILs, ISM NILs. TN1 and NLR 34449 were used as the susceptible and resistant checks, respectively for screening blast resistance. Screening was done by following 0-9 Standard Evaluation Scale (SES) for leaf blast. Among the studied 18 F3 breeding lines 12 lines were found resistant with score of 3 and 6 lines were found moderately resistant to screening reaction with score of 5. TN1 showed highly susceptible reaction with score of 9 and NLR 34449 showed highly resistant reaction with score of 1.

First Record of Citrus Leaf Roller <i>Archips machlopis</i> (Meyrick) on Sweet Orange in Bangladesh

The occurrence of Archips machlopis (Meyrick) (Tortricidae: Lepidoptera) for the first time on sweet orange (Citrus sinensis) at the Regional Agricultural Research Station, Burirhat, Rangpur, Bangladesh during 2021-22 is reported herein. Larva bears a brown prothoracic shield and a thin white line which delineates the reddish-brown head capsule. Moths are dark grey, 8-10 cm long, while pupa are dark brown to black with elongate cremaster. DNA barcoding with mtCOI gene confirmed it as A. machlopis. Larvae are observed attacking young leaves, and being voracious cause severe foliage damage. It folds leaf around them and feeds inside the folded leaf. Approximately 21.5% young leaves were infested. More investigations are suggested to assess the pest status, hosts, biology and other aspects.

Screening of recombinant inbred lines for resistance to bacterial leaf blight pathotypes in rice (Oryza sativa L.)

In the present investigation 16 recombinant inbred lines (RIL’s) developed from the intra-specific cross between YH3 and AKDRMS 21-54 through Marker Assisted Pedigree Breeding Method were screened along with their parents and the checks, namely, BPT 5204, TN1 and Improved Samba Mahsuri (ISM) against IxoPt-20 pathotype at the ICAR-Indian Institute of Rice Research, Hyderabad during Rabi 2021-22 and a new pathotype of Xanthomonas oryzae pv. oryzae causing Bacterial Leaf Blight disease in rice at Regional Agricultural Research Station, Maruteru during Kharif 2022 to identify pathotype specific resistant sources. Morpho-Molecular screening was adopted to evaluate the recombinant inbred lines over two locations in the consecutive seasons of Rabi 2021-22 and Kharif 2022. Based on per cent diseased leaf area, the genotypes were scored and categorised as per the Standard Evaluation System (SES) scale provided by International Rice Research Institute (IRRI). The results revealed all 16 RIL’s to be either resistant (10) or moderately resistant (6) to IxoPt-20 pathotype. However, only five RIL’s were found to be resistant, while four RIL’s were moderately resistant for the new virulent pathotype. Seven RIL’s with resistant to moderately resistant reaction for IxoPt-20 pathotype, showed moderately susceptible reaction for the new virulent pathotype. Among the resistant RIL’s identified for each pathotype, BPT-1901-72-10-6, BPT-1901-108-4-1 and BPT-1901-111-3-2 were found to be uniformly resistant, while, BPT-1901-45-8-6 and BPT-1901-163-1-18 were uniformly moderately resistant to both IXoPt-20 and the new virulent pathotype at Hyderabad and Maruteru, respectively, indicating their potential as genetic stocks for development of new cultivars resistant to bacterial leaf blight disease.

Exploitation of Castor Genotypes for Enhanced Eri Silk Production and the Prospects for its Promotion among the Farming Community

The present study was conducted at the research farm of Regional Agricultural Research Station (RARS), Palem, Telangana State, India during rabi (October–January) seasons of 2012–13 and 2013–14 to exploit the high yielding castor genotypes with respect to scientific ericulture and to know the prospects for its rate of adoption. Amid the eight genotypes of castor, highest 10th day larval weight of 0.645 g, 0.651 g and 0.639 and highest mature larval weight of 6.012 g, 5.982 and 5.948 g was recorded in the eri silkworm reared on PCH-111, PCH-222 and GCH-4 respectively. Enhancement in shell weight (0.981 g) was obtained in the eri silkworm fed on PCH-111 followed by GCH-4 (0.778 g). Significantly highest ERR was recorded in the eri silkworm reared on PCH-111 (92.7%) genotype and PCH-222 (92.23%) with no significant difference among them. The mortality rate of the eri silkworms reared on different castor genotypes ranged between 3.3%–12.08%. Significantly the highest survival rate of 96.15% was recorded in the eri silkworms reared on Haritha genotype followed by PCH-222 (94.06%). The study revealed that nearly 61.25% of the eri rearers exhibited medium level of extent of adoption, followed by 21.25% with low level of extent of adoption, while about 17.50% of the rearers exhibited high adoption respectively with respect to scientific method of ericulture practices. The perusal of the data revealed that out of nine dependent variables, six variables viz, age, educational qualification, size of land holding, family annual income, risk bearing of the rearers and knowledge gained through training were positively and significantly related with the extent of adoption.

Genetic Analysis of Rice (Oryza sativa L.) Genotypes Under Wet Direct Seeding Condition

Present investigation was carried out with 35 rice genotypes under wet direct seeding condition at Regional Agricultural Research Station, Jagtial, PJTSAU, Telangana, India during kharif (June to October), 2016. High GCV and PCV values for important yield contributing traits viz., 1000 grain weight (24.41, 24.62) and number of grains panicle-1 (26.17, 29.30) were observed. High heritable and genetic advance values for 1000 grain weight (98.30, 49.86) and number of grains panicle-1 (79.80, 48.16) indicated the role of additive genes and these traits can be improved by simple selections. Effective bearing tillers m-2recorded low values of heritability (25.40) and genetic advance (5.19) suggesting the exploitation of heterosis for improvement of this important yield character. Effective bearing tillers m-2 (0.7097**), plant height (0.5014**) and panicle length (0.3219**) exhibited significant correlations with yield, hence direct selection for these traits could improve the yield. Highest inter cluster distance was observed between clusters IV and VI (27.75) followed by III and VI (24.69), IV and V (22.34) and III and V (22.23) thus high heterotic hybrids can be developed by making crosses between genotypes of the clusters. 1000 grain weight (44.2%) contributed highest towards total divergence followed by days to 50% flowering (40.17%) and plant height (10.76). Genotypes from cluster V and VI can be used as parents in breeding programme for development of extra early varieties. Cluster II and IV recorded lowest means for plant height and hence genotypes from these clusters can be used as parents for development of dwarf varieties desirable for wet direct seeding condition.

Effect of boron and molybdenum on chickpea under rainfed ecosystem

A field experiment was conducted at Regional Agricultural Research Station, Vijayapur, during rabi, season 2021-22, to study the effect of boron and molybdenum on chickpea under rainfed ecosystem. The experiment was laid out inRCBD (factorial concept) with three replications. There were sixteen treatment combinations, consisting of four levels ofboron and four levels of molybdenum. Among the boron levels, soil feeding of boron @ 5 kg ha-1 recorded significantly highergrain and haulm yield (2124 and 2943 kg ha-1 respectively), similarly significantly higher yield attributes were also recordedin above treatment. However, it was on par with soil application of boron @ 2.5 kg ha-1 (2082 kg ha-1 and 2888 kg ha-1respectively). Among the molybdenum treatments, seed treatment with molybdenum @1.5 g kg-1seed recorded significantlyhigher grain yield (2052 kg ha-1) and haulm yield (2831 kg ha-1) as compare to other levels of molybdenum seed treatment.However, it was on par with seed treating with molybdenum @ 1.0 g kg-1 seed. Different combination of treatments hadsignificant influence on chickpea yield. The treatment combination of soil application of boron @ 5 kg ha-1and seedtreatment with molybdenum @ 1.5 g kg-1 seed recorded significantly higher grain yield (2418 kg ha-1) and haulm yield (3206kg ha-1). Soil application of boron @ 5 kg ha-1 and seed treatment with molybdenum @ 1.5 g kg-1 seed recorded significantlyhigher gross returns (`1,08,804 ha-1), net return (`79,806 ha-1) and BC ratio (3.75) than other treatments combination.