Browsing by Author "Gayathri Karthikeyan, P"

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Habitat and utility assessment of Singapore daisy (Sphagneticola trilobata L.)
(Department of Agronomy, College of Agriculture , Padanakkad, 2025-02-10) Soorya Ganesh.; Gayathri Karthikeyan, P
In order to understand the habitat affinity and utilisation potential of Singapore daisy (an invasive weed of Kerala), study was conducted at three different locations which are thickly infested with the weed in the Kasaragod district viz., Kalichampothi, Nileshwaram and Azhithala to assess the habitat conditions, weed seed bank dynamics, allelopathic effect and utility. Correlation analysis between plant and soil samples revealed that plant height and density had a positive correlation with available nitrogen and soil moisture. Available potassium also had a positive correlation with plant height. Plant height, dry weight and leaf area per plant had a negative correlation with soil pH. Weed seed bank analysis revealed that germination of native weed seeds were adversely affected in the soils collected from the invaded sites in all the three seasons. This was confirmed by the fact that there was more than 95 percentage reduction in the light availability at ground level in the invaded sites compared to the uninvaded sites attributing to the reduced density of associated weed flora. Higher concentrations of shoot extracts of Singapore daisy (1:5 w/v of fresh shoot extract) inhibited the root and shoot growth of all the test plants (cowpea, rice and weedy rice) indicating that allelopathic effect of the aqueous extract of Singapore daisy depended on the concentration of the extract and the plant part used for extract preparation. Singapore daisy has the potential to be used in phytoremediation of cadmium, chromium, lead and arsenic in contaminated soil, with an average biomass production of 12.92 tonnes ha-1. The values of proximate principles of Singapore daisy revealed its potential to be used as a fodder crop as the nutritive values were comparable with common fodder crops of Kerala. The K/(Ca+Mg) ratio was 1.19, which is regarded safe for animal feed. However, the presence of antinutritional factors (tannin and saponin) and phytoremediation potential indicate further studies to justify its use as fodder. Singapore daisy has high ecological flexibility as it was able to establish well under different soil nutrient and moisture conditions. Weed seed bank analysis warns the necessity to control the spread of the weed as it has the capacity to reduce the density of native weed flora with its lush growth; allelopathic potential of the aqueous extract to inhibit seedling growth could also be attributed for the reduction of native weed flora. Singapore daisy has the potential to be used as a phytoremediator, fodder, compost and bioherbicide.
Integrated nutrient management of finger millet (Eleusine coracana L.) in red sandy loam soil
(Department of Agronomy, College of Agriculture, Padannakkad, 2023-05-15) Nookala Sai Aparna; Gayathri Karthikeyan, P
An experiment entitled ‘Integrated nutrient management of finger millet (Eleusine corocana L.) in red sandy loam soil’ was conducted at Instructional Farm Ⅱ, Karuvacheri during rabi season (2021-22) with the objective of standardisation of integrated nutrient management practices for finger millet in red sandy loam soils. The design of experiment was factorial Randomized Block Design (RBD) with ten treatments replicated thrice. Factor A consisted of two levels of farmyard manure (FYM) applied @ 5 t ha-1 (A1) and 10 t ha-1 (A2). Factor B consisted of five different levels of nutrients i.e., B1- KAU POP (NPK @ 45:22.5:22.5 kg ha-1 ), B2- NPK @ 60:30:30 kg ha-1 , B3- NPK @ 75:37.5:37.5 kg ha-1 , B4- Soil test based fertilizer recommendation (SBFR) applied @ 41:6:19 kg ha-1 NPK and B5- Control (No NPK). Statistical analysis of the results revealed that the treatments had significant effect on growth parameters, yield attributes and yield, quality parameters, available soil nutrients and nutrient uptake. Among the different nutrient levels, significantly higher values of growth parameters such as plant height (30.57, 75.60 and 96.29 cm), number of tillers hill-1 (2.39, 4.84 and 5.47) and leaf area hill-1 (303.81, 754.04 and 1503.56 cm2 ) at 25, 50 and 75 DAS respectively were recorded by the highest NPK level of 75:37.5:37.5 kg ha-1 (B3). Interaction effect was also found to be significant with respect to the above parameters with the application of higher dose of FYM @ 10 t ha-1 + NPK @ 75:37.5:37.5 kg ha-1 (A2B3) followed by the FYM @ 10 t ha-1 + NPK applied @ 60:30:30 kg ha-1 (A2B2) except for dry matter production (DMP) where these treatments were on par. Higher values with respect to number of fingers panicle-1 (7.06), grain weight panicle-1 (6.30 g) and panicle length (10.35 cm) were recorded with NPK applied at 75:37.5:37.5 kg ha-1 (B3). Application of different nutrient levels resulted in significant difference with respect to grain and straw yield. Grain yield (2.1 t ha-1 ) was significantly higher with NPK applied @ 75:37.5:37.5 kg ha-1 which was on par with the application of SBFR + NPK applied @ 60:30:30 kg ha-1 (1.98 and 2.01 t ha-1 respectively). Significantly higher straw yield (4.0 t ha-1 ) was recorded with the high dose of NPK @ 75:37.5:37.5 kg ha-1 and in case of interaction effect, the higher straw yield was noticed in A2B3 (4.0 t ha-1 ) which 114 was on par with A1B4 (3.99 t ha-1 ), A1B3 (3.99 t ha-1 ) and A2B2 (3.96 t ha-1 ). Among the quality parameters, higher value or protein content was recorded with the application of higher levels of nutrients at 75:37.5:37.5 kg ha-1 and the lowest value was observed in the control plot. Ash content was significantly high with SBFR which was on par with NPK applied @ 75:37.5:37.5 kg ha-1 . Interaction of higher dose of FYM along with highest nutrient dose hasresulted in higher protein content (9.48 %) which was on par with A2B2 (FYM @ 10 t ha-1 + NPK @ 60:30:30 kg ha-1 ) i.e., 9.23%. Among the different nutrient levels, highest value of organic carbon (0.71%) and available NPK (303, 84 and 289 kg ha-1 respectively) was recorded with B3 treatment. High valuesfor available N and P was recorded with higher dose of FYM (10 t ha-1 ) also. Higher values of nitrogen uptake (60 kg ha-1 ) was recorded with NPK applied @ 75:37.5:37.5 kg ha-1 (B3). Higher values of relative growth rate, crop growth rate and leaf area index were recorded with the higher dose of nutrient levels (B3) and also with integrated use of higher levels of both FYM and NPK (A2B3) during different growth stages. The highest value for grain yield and B : C ratio (2.02) was recorded with the application of FYM @ 5 t ha-1 along with fertilizers applied @ 41:6:19 kg NPK ha-1 . The results obtained from the experiment revealed that different levels of FYM, nutrients and their interaction could influence the growth, yield attributes, OC and available nutrients in finger millet. The effect was reflected in grain yield and B: C ratio. Soil test based fertilizer application has reduced the fertilizer use by 8.88%, 73.34%, 15.55% (Urea, Rock phosphate and MOP) respectively over the KAU POP recommendation. The results can be used as a guide for developing soil test based integrated nutrient management practice under different soil conditions.
Integrated weed management in cowpea (Vigna unguiculata L.)
(Department of Agronomy, College of Agriculture,Pdanakkad, 19-04-04) Amaya, C P; Gayathri Karthikeyan, P
Integrated weed management in cowpea (Vigna unguiculata L.)
(Department of Agronomy, College of Agriculture, Padanakkad, 2022) Amaya, C P; Gayathri Karthikeyan, P
An experiment entitled ‘Integrated weed management in cowpea (Vigna unguiculata L.) was conducted at Instructional farm II of College of Agriculture, Padannakkad located at Karuvacheri, from December 2020 to March 2021 with the objectives of evaluating the efficacy of different weed management practices and to find out the economics of weed management in cowpea. The experimental design was Randomized Block Design (RBD) with 11 treatments replicated thrice. The short duration cowpea variety namely PGCP 6 was used for the study. The treatments consisted of T1 (pre-emergence application of pendimethalin @ 0.75 kg ha-1 at 0-3 DAS), T2 (T1 + hand weeding at 20-25 DAS), T3 (T1 + mulching @ 7 t ha-1 ), T4 (postemergence application of imazethapyr @ 75 g ha-1 at 20 DAS), T5 (T5 + hand weeding at 35 DAS), T6 (mulching @ 7 t ha-1 + T5), T7 (mulching @ 7t ha-1 + hand weeding at 20 DAS), T8 (hand weeding alone at 15 and 30 DAS), T9 (mulching alone @ 7 t ha-1 ), T10 (weedy check/control) and T11 (weed free). Weed density, dry matter and weed control efficiency (WCE) was lowest in weed free plots throughout the observation period and weedy check (control) recorded highest density dry matter and WCE among all other treatments. At 15 DAS, pre-emergent herbicide treated plots recorded lowest density of weeds in the order T3 >T1 >T2. At 30 DAS, T2 and T7 recorded lowest density of weeds. At 45 DAS, T5, T3, T8 and T7 were recorded with lowest density of weeds and which were on par to each other. At 60 DAS, T8, T3, T7 and T6 were recorded lowest density of weeds and which were on par to each other. In the case of weed dry weight at 15 DAS, T3 recorded the lowest value for dry weight compared to all other treatments except for T11. At 30 DAS, significantly lower value for dry weight was recorded in T2, which was on par with T7 and T3. At 45 DAS, significantly lower value for weed dry weight was recorded in T8 among all the treatments which were on par with T5 and T7. At 60 DAS, dry weight recorded by the treatment T2 was significantly lower among all the weed control treatments except for T3, T5, T7 and T8 which were on par to each other. Lowest WCE was observed in control plot or weedy check (T10). At 15 DAS, the treatments T3, T2 and T1 recorded the highest WCE. At 30 DAS, T2 was recorded with significantly higher WCE. At 45 DAS, WCE was significantly higher in T8 and was on par to T5, T7 T2 and T3. At harvesting stage (60 DAS), the treatment T2 recorded significantly higher value for WCE which was on par to T3. Significantly lower value for weed index (WI) was recorded in weed free plots and T7. Plant height, number of branches per plant (harvesting stage) and leaf area index was highest in weed free plot compared to that of all other treatments. Number of nodules per plant was recorded significantly superior in T7 at flowering stage and T2 at harvesting stage. Total dry matter production was highest in T7 which was on par with T3 at flowering and harvesting stages. Number of pods per plant, pod yield and seed yield were highest in weed free plots compare to that of all other treatments. Treatment T7 recorded significantly superior results in the case of number of seeds per pod, pod weight per plant and test weight and which was on par with that of pre-emergent application of T3 and T11. Among the available soil nutrients, depletion of available N was highest in T10 and treatment T8 recorded highest soil N content. Gross returns and net returns were highest in weed free plots compare to all other treatments which was followed by T3. Similar trend was shown in the case of net return also. The highest B:C ratio of 2.45 was obtained for T7 and T3 which were on par with T11 (2.42). The overall results indicated that weed infestation significantly affected yield in cowpea and integrated weed management (IWM) especially during the critical period of crop weed competition in cowpea is inevitable for getting an economic yield and could reduce yield loss even upto 67 per cent. Even though the cost of cultivation was highest in the weed free plots, the B:C was on par with that of the best IWM practices owing to the superior yield in these plots. Pre-emergence application of pendimethalin along with mulching; and mulching along with hand weeding could effectively keep the field weed free for the critical period of crop weed competition and this treatment resulted in highest B:C ratio and highest on par yields.
Invasion impact of greater club rush (Scirpus grossus L.f) on wetland rice ecosystem
(Department of Agronomy, College of Agriculture, Vellayani, 2017) Gayathri Karthikeyan, P; Sansamma George
Production protocol for organic bhindi
(Department of Agronomy, College of Agriculture, Vellayani, 2010) Gayathri Karthikeyan, P; Sajitha Rani, T