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20173
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Subject: Crop Physiology × End date: 2017 × Start date: 2017 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Effect of entomopathogenic fungi, Metarhizium anisopliae on growth and yield of french bean
    (AAU, Jorhat, 2017-07) Kurmi, Himanshu; Das, K.
    Experiments were carried out during September, 2016 to March, 2017 in the Department of Crop Physiology, Assam Agricultural University, Jorhat-13, to evaluate the effects of different concentrations of fungal isolate of Metarhizium anisopliae on french bean. In one experiment, fungal isolates of M. anisopliae at 105cfu/ml, 106cfu/ml, 107cfu/ml and 108cfu/ml concentrations were tested to determine their effects on germination and subsequent seedling growth of french bean under laboratory condition. It was observed that germination percentage, germination index, vigour index, shoot and root length, fresh and dry weight of shoot and root were affected by M. anisopliae isolates in a concentration dependent manner. Among the applied concentrations, 106cfu/ml and 107cfu/ml concentrations were found to be more stimulatory compared to control. Another experiment was conducted in field condition with these two concentrations (106cfu/ml and 107cfu/ml concentrations) to evaluate their effects on growth and yield of french bean. Three different modes of application, viz. seed treatment (before sowing), foliar application (15 DAS, 30 DAS and 45 DAS) and combination of seed treatment and foliar application were employed. Recorded data revealed that plant growth of french bean in terms of plant height, leaf number, leaf area, root volume, shoot and root dry weights were increased by M. anisopliae. Physiological parameters such as relative leaf water content, total chlorophyll content and leaf N P K content of french bean were also positively influenced by the fungal isolate. However, no significant alteration was recorded in leaf proline content irrespective to mode of application and concentration of fungal isolate. Among the different treatments, 107cfu/ml concentration was found to be more stimulatory when applied as combination of seed treatment and foliar spray. At this treatment combination, pronounced stimulatory effects were recorded on yield and different yield attributing parameters of french bean. From the results of this investigation, it can be concluded that in addition to its well established protective role against insect pest, M. anisopliae also exhibits stimulatory effects on growth, development and yield of the crop.
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    ThesisItemOpen Access
    EVALUATION OF PHYSIOLOGICAL PERFORMANCE OF LENTIL GENOTYPES IN ORGANIC SITUATION UNDER DEFERRED DATES OF SOWING IN RICE FALLOW LAND
    (AAU, Jorhat, 2017-01) Sarmah, Bhargob; Kalita, Prakash
    An investigation was carried out during November, 2016 to March, 2017 in the Instructional-cum-Research (ICR) farm and Department of Crop Physiology, Assam Agricultural University, Jorhat-13, to evaluate the physiological performance of lentil genotypes in organic situation under deferred dates of sowing in rice fallow land. Five lentil genotypes namely HUL-57, SLC-102, PL-406, KLS-218 and SLC- 101were used for the study. There were three dates of sowing viz. 15th November, 30th November and 15th December. The land used for raising the crop has been maintained for last ten years as organic plot and has been used for raising winter rice crop. The lentil crops raised were supplied with nutrients through organic inputs (well rotten cow dung and enriched compost) and the chemicals used for plant protection were also organic. Significant variations were recorded among the genotypes in terms of various parameters namely total leaf chlorophyll content, relative leaf water content, in- vivo leaf nitrate reductase activity, root: shoot ratio, dry matter partitioning, number of pod per plant, number of seeds per pod, grain yield and harvest index .These parameters exhibited a decreasing trend with delay in the date of sowing from the recommended one. However lipid peroxidase activity was found to increase due to delay in sowing of lentil genotypes. Among the genotypes the HUL-57 performed the best compared to the other genotypes under both the situations when sowing was done at recommended date of sowing and when the sowing was delayed. On the other hand the genotype SLC-101 registered the lowest performance. The genotype HUL-57 exhibited the lowest percent reduction in terms of total leaf chlorophyll content, relative leaf water content, in- vivo leaf nitrate reductase activity, root: shoot ratio, dry matter partitioning, number of pod per plant, number of seeds per pod, grain yield etc. followed by the genotype KLS-218. When the sowing was delayed by 15 days (30th November) on an average biomass and grain yield were decreased by 12.29% and 3.30% respectively, whereas the corresponding decreases were 35.49% and 13.53% when biomass and grain yield from 15th December sowing were compared with that of 15th November sowing. In case of HUL-57 the decrease in biomass and grain yield were only 33.97% and 12.11% respectively when performance under 15th December sowing were compared with that of 15th November sowing. The better performance of HUL-57 could be attributed to better performance of this genotype in terms of the parameters namely total chlorophyll content, relative leaf water content, in- vivo leaf nitrate reductase activity, root: shoot ratio, dry matter partitioning, number of pod per plant, number of seeds per pod etc. As with the delay in sowing resulted in the exposure of the lentil plants to moisture shortage coinciding with the vegetative and early reproductive stages, the genotype HUL-57 can be labeled as moisture shortage tolerant genotype; more over this genotype can be said to have adjusted efficiently under the decreasing length of photo period as encountered when sowing was delayed.
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    ThesisItemOpen Access
    PHYSIOLOGICAL BASIS OF SUBMERGENCE TOLERANCE IN LOWLAND RICE
    (AAU, Jorhat, 2017-07) Talukdar, Krishna; Das, Ranjan
    The experiment was conducted for two years during Kharif season 2016 and 2017. About 200 genotypes from different adaptations were collected and screened for submergence tolerance by SES scoring developed IRRI, Philippines. After screening, five genotypes viz. Tejai longpi, Marjina, Badam bao, Sok langlu and OM5451 were selected based on survival, recovery characteristics and comparing with submergence susceptible line IR-64. Significant variation was observed amongst the genotypes for all the parameters viz. lipid peroxidation, leaf soluble protein content, leaf temperature and Membrane Stability Index, Chlorophyll Stability Index, Nitrate Reductase Activity. However, a significant increase in MDA content, root volume, root: shoot ratio was observed under stress condition. Stress induced reduction in stem elongation and plant height was found highest in Badam bao which could be correlated to an increase in total carbohydrate content in the genotype. Badam bao also recorded the lowest reduction in total chlorophyll content and tiller number under submerged condition. It can be assumed that Badam bao being a tall variety has got an inherent capability to cope submergence stress by reducing stem elongation and increasing tiller number thereby increasing yield. In the present study, under submerged condition, Badam bao could maintain its yield and yield attributes in terms of 1000 grain weight and no. of grain /panicle. This could be correlated with a significant increase in flag leaf area in the genotype. Modern high-yielding rice varieties are highly susceptible to flooding whereas traditional cultivars have acquired moderate tolerance to flooding but they carry the penalty being of inherently lower grain yields. Therefore, in the present investigation, it was found that two traditional genotypes viz. Badam bao and Marjina could be grown successfully under submerged condition with moderately higher yield.