Browsing by Author "Ajith Kumar, K"

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Ecophysiology of mango (Mangifera indica L.) under high density planting system in Muthalamada area
(Department of Fruit Science, College of Horticulture, Vellanikkara, 2020) Reshma Ravi, P; Ajith Kumar, K
Evaluation of hybrids and clonal variants in pineapple(Ananas comosus L.)
(Department of Fruit Science, College of Agriculture, Vellanikkara, 2022) Lalit Dhurve; Ajith Kumar, K
The present investigation entitled “Evaluation of hybrids and clonal variants in pineapple (Ananas comosus L.)” was conducted during August 2017 to August 2021 at Department of Fruit Science, College of Agriculture, Thrissur, Kerala. The objectives of the research work were to evaluate the somaclonal variants and hybrids of pineapple for yield and quality for identifying novel genotypes and to generate DNA fingerprints of the genotypes using ISSR markers for varietal identification and assessment of genetic resemblance. The plant material for Experiment-I comprised of 75 somaclonal variants derived from the pineapple cultivar Mauritius. They were field planted and evaluated at FCRS. The material for Experiment-II comprised of 25 numbers of Mauritius x Kew and 10 numbers of Kew x Mauritius hybrids which were selected and evaluated at FCRS, by adopting RBD with two replications during the normal season along with the cultivars Mauritius, Kew, and Amritha. For Experiment-III, molecular characterization of 11 superior somaclones along with the parental source was carried out using fifty ISSR markers. Similarly molecular characterization of 10 promising hybrids and three check varieties namely Mauritius, Kew, and Amritha were carried out using fifteen ISSR markers. All the somaclonal variants of Mauritius and their field evaluated hybrids were scored based on the most desirable and undesirable characters. Statistical analysis was performed by using the different selection criteria for somaclones and hybrids. Somaclones were selected by calculating index scores (Singh and Chaudhary,1985) and hybrids were selected based on selection index (Smith, 1937). With relation to this, the scores of individual genotypes were judged and those genotypes which ranked with the highest index values in the selection indices were carried forward for further study. The statistical analysis was performed by using the selection criteria for somaclones using index scores as suggested by Singh and Chaudhary (1985). It was observed that the sum of index values of somaclones which secured rank with the highest index scores within the eleven were identified. Accordingly, eleven somaclones T-4, T-17, T-71, T-47, T-43, T-25, T-22, T-24, T-75, T-10 and T-69 were selected for further molecular characterization. Among the 50 ISSR markers that were used for PCR amplification, only 30 showed polymorphic amplification. The unique amplicons (1-6) and PIC (0.32-0.94) were recorded from ISSR marker profiles. A UPGMA based dendrogram, minimum (0.58) similarity was showed by the parent genotype Mauritius with the somaclonal variants T71 and T-75, indicating the existence of significant genetic variation among these three variants. The selection index developed by Smith (1937) was used to discriminate the genotypes based on selected characters. As per the selection index of Mauritius x Kew hybrids, it was found that the indices have identified the six hybrids. Accordingly, six numbers of Mauritius x Kew hybrids T-1 (H-17), T-7 (H-43), T-8 (H-66), T-14 (H-70), T15 (H-59), and T-24 (H-35) were selected for further molecular characterization. All the 15 ISSR markers that were used for PCR amplification showed polymorphic amplification. The uniqueness of amplicons (1-7) and PIC (0.43-0.93) were recorded. A UPGMA based dendrogram showed that the hybrids H-17, H-35, and H-43 had the high level of Jaccard’s genetic similarity relationship with parent sources Mauritius and Kew, with a similarity coefficient of 0.72. With the selection index of Kew x Mauritius hybrids, it was found that the indices have identified the four hybrids. Accordingly, four hybrids T-9 (H-121), T-2 (H-118), T-4 (H-101), and T-3 (H-115) were selected for further molecular characterization. All the fifteen ISSR markers used for PCR analysis showed polymorphic amplification. The uniqueness of amplicons (1-6) and PIC (0.41-0.81) were recorded for the ISSR primers. A UPGMA based dendrogram showed that the H-115, H-118, and H-121 have registered a high level of Jaccard’s genetic similarity values with parent source Kew and Mauritius, with a genetic similarity coefficient of 0.66. Thus, this study has analyzed 75 somaclones derived from cv. Mauritius, 25 hybrids of Mauritius x Kew, and 10 hybrids of Kew x Mauritius. Based on the selection indices developed, the superior somaclones and hybrids were identified. The identified lines were characterized using the ISSR molecular marker system which had revealed the genetic relativeness among the selected somaclones and the hybrids.
Evaluation of promising strawberry (Fragaria x ananassa Duch.) varieties for Wayanad
(Department of Fruit Science, College of Horticulture Vellanikkara, 2017) Muhammed Aslam; Ajith Kumar, K
Morpho- physiological characterization of litchi ( Litchi chinensis sonn. ) in Wayanad
(Department Of Pomology And Floriculture, College Of Horticulture, Vellanikkara, 2016) Sanjay D Chavaradar; Ajith Kumar, K
Morpho-physiological characterization of litchi (Litchi chinensis Sonn.) in Wayanad
(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 2016) Sanjay D Chavaradar; Ajith Kumar, K
Morphochemical evaluation of jamun (Syzygium cuminii Skeels) collections
(Department Of Pomology And Floriculture, College Of Horticulture, Vellanikkara, 2016) Deepika, V; Ajith Kumar, K
Jamun possesses commercial importance as a minor fruit in tropical and subtropical conditions. It is a versatile fruit tree of best food and medicinal value. India ranks second in production of jamun in the world. It is an important under-exploited indigenous fruit tree of India. As majority of jamun trees are of seedling origin, they show tremendous variation in their morphology and physicochemical attributes. Assessment of the existing variability is a prerequisite for taking up successful crop improvement. The study on “Morphochemical evaluation of jamun (Syzygium cuminii Skeels) collections” was carried from August 2014 to December 2015 at the KAU main campus, College of Horticulture, Vellanikkara, Thrissur, Kerala. The main objective of the study was to evaluate the morphochemical characters of jamun collections maintained in and around the KAU main campus for identifying the superior types. Fifty nine collections of jamun were maintained in the departmental orchard, in and around the KAU main campus were used for the study. All the collections were studied for morphological, physico-chemical and organoleptic properties. All the collections showed variability in tree characters, inflorescence characters, fruit characters, quality attributes and pest and disease incidence. At the similarity coefficient status of 6 per cent, grouping of collections were done which resulted in 12 non-overlapping clusters. Tree characters viz., age of the tree (20 to 35 years), tree height (12 m to 20 m), trunk girth (0.95 m to 4.1 m), crown shape (pyramidal, broadly pyramidal, spherical, semi-circular and irregular), Leaf length (9.1 cm to 17.5 cm), leaf width (2.3 cm to 6.5 cm), leaf shape (broadly ovate and lanceolate), shoot length (7 cm to 26 cm) and internodal length (7.7 cm to 12.2 cm) were observed. Only 17 trees were flowered during the period of study. Variation in flower characters such as position of inflorescence (axillary), flower composition in the inflorescence (solitary and cluster), flower colour (white), flowering season (December and January), duration of flowering (26 days to 42 days) were recorded. At the similarity coefficient status of 40 per cent, grouping of collections were done based on fruit characters, which resulted in 5 non-overlapping clusters. Variation was observed with respect to fruiting season (March-April and April-May), days from flowering to fruit maturity (62 days to 68 days), fruit set to maturity (58 days to 64 days), fruit clustering habit (solitary and cluster), fruit weight (5.91 g to 12.28 g), fruit volume (5.32 cc to 11.40 cc), number of fruits per cluster (3 to 12), specific gravity (0.91 to 1.23), fruit length (1.61 cm to 3.10 cm), fruit width (1.24 cm to 2.41 cm), fruit shape (oblong), fruit colour (blackish purple), firmness/softness (4.09 kg cm-2 to 9.94 kg cm-2), juice content (14 per cent to 44 per cent), pulp content (77.50 per cent to 90.39 per cent), seed weight (9.60 per cent to 22.49 per cent), pulp/seed ratio (3.24 to 9.41) and yield tree-1 (10 kg plant-1 to 54 kg plant-1). At the similarity coefficient status of 7 per cent, grouping of accessions was done based on quality attributes, which resulted in 12 non-overlapping clusters. The percentage of moisture (65 per cent to 82.50 per cent), acidity (0.18 per cent to 0.58 per cent), TSS (9.20⁰ Brix to 15.50⁰ Brix), anthocyanin (44.64 mg 100 g-1 to 63.35 mg 100 g-1), pH (1.80 to 3.17), reducing sugar (5.89 per cent to 20.16 per cent) and total sugar (12.82 per cent to 22.95 per cent) were estimated. Sensory evaluation viz., colour, sweetness, taste, appearance and texture were recorded based on 9 point hedonic scale. From the sensory evaluation KJ- 45 was found to be promising types with respect to appearance, colour and sweetness. With respect to taste and texture KJ- 39 and 47 were found promising when compared with all collections. Minor incidence of pest (gall midge) and disease (leaf spot and sooty mould) were observed during the study. Among the collection, KJ- 45 has higher yield (54 kg plant-1), TSS (15.6o Brix), fruits per cluster (12), fruit weight (12.28 g), pulp/seed ratio (9.41) and anthocyanin content (64.35 mg 100 g-1). Hence, KJ- 45 is considered as superior tree followed by KJ- 48, KJ- 47 and KJ- 7.
Nutrient management for pineapple (Ananas cosmosus L.)cv. Amritha
(Department of Fruit Science, College of Horticulture, Vellanikkara, 2019) Pooja Shree, S; Ajith Kumar, K
Amritha, is the pineapple hybrid released from the Pineapple Research Centre, Vellanikkara, under KAU. The present study entitled “Nutrient management for pineapple (Ananas comosus L.) cv. Amritha” was conducted for standardizing the optimum nutrient doses for ensuring high productivity. When grown under the existing POP recommendation of KAU the fruit weight was varying from 0.5 - 1 kg per plant. Therefore, there is a need to develop optimum nutrient doses for ensuring higher productivity of pineapple cv. Amritha. Experiment was conducted with six treatments viz., T1 - POP recommendation of KAU (8:4:8 N, P2O5, K2O g plant⁻¹), T2 - Modified based on soil test results (9.39:11.45:11.36 N, P2O5, K2O g plant⁻¹), T3 - 25 per cent higher than the modified POP based on soil test results (11.7:14.31:14.31 N, P2O5, K2O g plant⁻¹), T4 - 50 per cent higher than the modified POP based on soil test results (14.08: 17.17: 17.03 N, P2O5, K2O g plant⁻¹), T5 - 75 per cent higher than the modified POP based on soil test results (16.4:20.03:19.13 N, P2O5, K2O g plant⁻¹), and T6 - adhoc organic POP. Length of ‘D’ leaf showed significant difference among the treatments after eight months of planting. T6 recorded the maximum length of ‘D’ leaf (44.3 cm) and was on par with T1 (41.1 cm) and T5 (40.9 cm). This was continued in ninth, tenth, eleventh and twelfth months after planting. Significant difference was observed in ‘D’ leaf area among the treatments after nine months of planting. T6 recorded the maximum ‘D’ leaf area at tenth (113.77 cm2), eleventh (128.70 cm2) and twelfth (155.20 cm2) months after planting and was significantly superior over other treatments. Application of different levels of nutrients had no significant effect on plant height, number of leaves per plant, breadth of ‘D’ leaf, leaf area index and leaf production rate. Treatments, T5 and T6 took 6 ¹/₂ months after planting to attain physiological maturity whereas, other treatments attained physiological maturity at a period of seven months after planting. Days for initiation of flowering was minimum in T5 (39.2 days) and was significantly different from other treatments. In case of days for 50 per cent flowering, T5 recorded the minimum value (47.2 days) and was on par with T4 (49.4 days). Significant difference was observed among the treatments for fruit weight and was highest in T5 (0.985 kg). The maximum length, girth and breadth of fruit was recorded in T5 (14.15 cm), (30.79 cm) and (30.33 cm) respectively. In case of length/breadth ratio T5 (0.48) recorded the highest value which was on par with T6 (0.46). Higher taper ratio values were recorded by T3 (1.041) and T2 (1.040). With respect to the yield per hectare, maximum value (51.99 t/ha) was recorded by T5 which was significantly superior. T5 recorded the highest peel weight (105.74 g), pulp weight (0.402 kg) and crown weight (118.54 g). The minimum peel/pulp ratio was observed in T5 (0.26). There was no significant difference among treatments for days for fruit maturity, harvest index, root:shoot ratio, crop duration and shelf life. On evaluating the quality parameters of fruits, TSS was found to be highest in T5 (15.30 ˚Brix) and was on par with T4 (14.60 ˚Brix). In case of other parameters like titratable acidity, total sugars, reducing sugars, non reducing sugars, sugar/acid ratio, fibre content and ascorbic acid content, the treatments were found to be non significant. The overall sensory score was found to be highest in T6 (69.18) and was followed by T5 (64.12). The highest B:C ratio was calculated for T5 (4.59). Analysis of soil after the harvest of the crop revealed that the values for soil pH, soil EC, organic carbon, available N, P and K were found to be elevated. N, P and K content in the plant and fruit had no significant difference. In the present study early flowering was observed in T5 (75 per cent higher than the modified POP based on soil test results) which in turn resulted in early fruit set and harvesting in the treatment. Highest fruit weight T5 (0.98 kg) and yield per hectare (51.99 t/ha) was also recorded in T5 (75 per cent higher than the modified POP based on soil test results). On sensory evaluation, Adhoc organic POP (T6) was found to be superior and was followed by T5.
Nutrient management in strawberry (Fragaria x ananassa Duch.)
(Department of Fruit Science, College of Horticulture Vellanikkara, 2017) Arjun Mohan, P; Ajith Kumar, K
The experiment entitled “Nutrient management in strawberry (Fragaria x ananassa Duch.)” was undertaken at Regional Agricultural Research Station, Ambalavayal, Wayanad during the year 2016-17. Performance of strawberry variety Winter Dawn was evaluated under nine treatments and a control in the open field viz., FYM 10 t ha-1 + NPK 50:20:50 kg ha-1 (T1); FYM 10 t ha-1 + NPK 75:30:75 kg ha-1 (T2 ); FYM 10 t ha-1 + NPK 100:40:100 kg ha-1 (T3); FYM 20 t ha-1 + NPK 50:30:100 kg ha-1 (T4); FYM 20 t ha-1 + NPK 75:40:50 kg ha-1 (T5); FYM 20 t ha-1 + NPK 100:20:75 kg ha-1 (T6); FYM 30 t ha-1 + NPK 50:40:75 kg ha-1 (T7); FYM 30 t ha-1 + NPK 75:20:100 kg ha-1 (T8); FYM 30 t ha-1 + NPK 100:30:50 kg ha-1 (T9) and an absolute control (T10), without any nutrient application. All the treatments were on par and superior over the control (T10) in case of plant height. In case of plant spread, T2, T3, T5, T6, T7, T8 and T9 were on par and superior over the control while T1 and T4 were on par with each other but differs with other treatments. All the treatments except T2 were on par and superior over the control with respect to number of leaves per plant. Application of treatments had no significant effect on days to first flowering. In case of number of flowers and clusters per plant, T1, T2, T3, T5, T6, T7, T8 and T9 were on par and superior over the control while T4 was on par with the control (T10). Days to first harvest was minimum in T6, T7, T8 and T9 which were on par while all other treatments were on par with the control (T10).In case of number of fruits and yield per plant, T7 (FYM 30 t ha-1 + NPK 50:40:75 kg ha-1) and T8 (FYM 30 t ha-1 + NPK 75:20:100 kg ha-1) were on par and superior over other treatments including T1, T2, T3, T4, T5, T6 and T9 which were on par and superior over the control. Average fruit weight recorded under T3, T5, T6, T7, T8 and T9 were on par which was followed by T2 on par with T4 and T1. Days to final harvest was not found to be influenced by the application of different treatments. Biochemical characters of fruits viz., TSS, acidity and TSS/acidity ratio were not having any significant effect due to the application of treatments. In case of total sugars, T3, T7, T8 and T9 were having the highest content and were on par which was followed by T5 on par with T1, T2, T4, T6 and T10. The overall sensory score was highest in T7 followed by T8. Application of different treatments had no significant effect on the shelf life of strawberry fruits. N, P, K and Ca content in the plant were not significantly affected by any treatment while Mg content was found to be on par in all treatments and superior over the control. Soil analysis after the harvest of the crop revealed that the values for soil EC, available P, K, Mg and S were found to be elevated while soil pH, organic carbon and available Ca content were found to be at lower levels than the initial values before planting. It was concluded that among different nutrient combinations evaluated, T7 (FYM 30 t ha-1 + NPK 50:40:75 kg ha-1) with a BC ratio of 3.06 can be recommended for further optimization and refinement.
Performance of strawberry (Fragaria c ananassa Duch.) in different growing conditions
(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 2015) Anu Kurian; Ajith Kumar, K
Pollinizers – A cornerstone in fruit crops
(Department of Fruit Science, College of Horticulture, Vellanikkara, 2019) Anju, Jayachandran; Ajith Kumar, K
Production dynamics of ginger (zingiber officinale R.) under varying levels of shade, nutrients and triazole
(Department of Horticulture, College of Agriculture, Vellayani, 1999) Ajith Kumar, K; Jayachandran, B K
The experiments were conducted at the Coconut Research Station, Balaramapuram, during 1996-97 and 1997-98 to study the production dynamics of ginger under varying levels of shade, nutrients and triazole. The specific objectives were to study the production potential of ginger under open and different shade levels, to standardise optimum dose of nutrients and mulch for ginger intercropped in coconut garden and to evaluate the efficacy of triazole in the improvement of yield and other desirable characters. The effect of shade on growth and yield contributing parameters viz., tiller number, leaf number, leaf area, leaf dry weight, root spread, root volume, rhizome spread, rhizome thickness, number of rhizomes, leaf thickness, stomatal frequency, DMP and LAI under 20 and 40 per cent shade levels exhibited significant superiority in pot culture study. In pot culture study: maximum fresh ginger yield of 450.0 and 396.3 g plant" were resulted from plants kept under 20 and 40 per cent shade levels respectively. This was 27.4 and 12.2 per cent higher compared to open- condition. The dry ginger yield of 94.5 and 89.2 g plant" were obtained from plants kept under 20 and 40 per cent shade levels respectively. This was 27.8 and 20.7 per cent higher compared to open condition. However, the dry ginger yield obtained from 60 and 80 per cent shade levels were significantly lower compared to open. The shade levels 20 and 40 per cent gave the highest shoot dry weight of 48.9 and 53.6 g plant" respectively. Volatile oil content showed an increasing trend with increasing levels of shade in pot culture study. Maximum NVEE was recorded under 20 and 40 per cent shade levels. Highest starch content was obtained from 20 per cent shade level. Crude fibre gradually reduced with increase in shade levels. The field trial on nutrient requirement of ginger as intercrop in coconut garden revealed that, NPK application at higher levels increased plant height, tillering, leaf number, leaf area, DMP and chlorophyll content. Physiological parameters like, NAR, CGR and RGR were promoted by higher rates of nitrogen application. The results revealed that, N: P, N : K and P : K ratios of l.5 : 1, l.5 : 1 and 1 : 1 respectively, were ideal to get maximum fresh ginger yield. Application of 150 kg N, 100 kg P20S and 100 kg K20 ha-l gave maximum net profit ofRs. 96605/- and Rs. 99227/- during first and second year respectively. The net profit when the existing recommendation of 75 kg N, 50 kg P20S and 50 kg K20 ha-l was Rs. 54960/- and Rs. 54730/- during first and second year respectively. Hence the study suggests that the existing recommendation (75 kg N, 50 kg P20S and 50 kg K20 ha") has to be doubled (150 kg N, 100 kg P20S and 100 kg K20 ha-l) for increasing the productivity of ginger intercropped in coconut garden. Increased rate of fertilizer application did not influence the quality of the produce. Plant uptake of NPK increased with higher levels of fertilizer application. The field experiment on mulch requirement of ginger intercropped in coconut garden showed that the rhizome yield from plots mulched with 30.0, 22.5 and 1 =r. 0 t ha' were on par. Therefore the mulch requirement of ginger intercropped in coconut garden can be reduced from 30 t ha-l to 15.0 t ha-I Application of triazole did not exhibit any beneficial effect on yield and quality of ginger.
Production dynamics of strawberry (Fragaria x ananassa Duch.) in Kerala
(Department of Fruit Science, College of Agriculture, 2020) Anu Kurian; Ajith Kumar, K
Responses of mango (Mangifera indica L.) to chemical regulators under high density planting system
(Department of fruit science, College of Horticulture, Vellanikkara, 2020) Anju Jayachandran; Ajith Kumar, K
Standardization of postharvest processing of ginger (zingiber officinale roscoe)
(Department of Horticulture, College of Agriculture, Vellayani, 1992) Ajith Kumar, K; Sreekandan Nair, G
Investigation on standardization of post-harvest processing of ginger (Zingiber officinale Roscoe) was carried out at the Department of Horticulture, College of Agriculture, Vellayani during 1988 -90. Ginger rhizomes were processed to study the effect of various methods like scraping, slicing, blanching, boiling, coating and their combinations on the yield and quality of dry ginger, storage life and also on storage pests and diseases adopting CRD. In this study among the various treatments low recovery (31.6 per cent) of dry ginger was obtained for scraped ginger. The sliced rhizomes took only four days for drying. The essential oil content decreased with an increase in time. The treatments slicing and drying (T4), blanching and drying (T5), unpealed and drying (T1) scraping and drying (T3) and spliting and drying (T2) were found to be the best for longer storage. The oleoresin content also decreased with an increase in time and the treatment combinations which include boiling resulted in the maximum reduction in oleoresin content followed in the maximum reduction in oleoresin content followed by combinations of scraping and spliting. The study revealed that compared to single treatment a combination of treatments especially when boiling as a component reduced the crude fibre content. The ginger rhizomes when sliced and dried took the minimum period for drying and it resulted in the production of normal coloured product and also comparable in quality aspects. Hence slicing and drying of ginger rhizomes is an alternate method for processing of ginger.
Wild edible fruit crops- the unexplored gems of Western Ghats
(Department of Fruit Science, College of Horticulture, Vellanikkara, 2020) Reshma Ravi, P; Ajith Kumar, K