Browsing by Author "Sadhan Kumar, P G"

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Effect of ethephon on earliness, vegetative characters, fruit characters and fruit yield in cucumis genotypes
(Kerala Agricultural University, 1986) Sadhan Kumar, P G; Peter, K V
In twenty Cucumis genotypes, whole plant sprays with 3 levels of ethephon produced significant reduction in length of main vine, number of nodes to first female flower and first fruit, seed number and flesh thickness. Number of nodes to first male flower and number of primary branches per plant increased significantly. The effect of ethephon was significant for flesh thickness and fruit yield per plant. Ethephon had no significant effect on fruit length, weight and volume.
Effect of plant growth promoting rhizobacteria (PGPR) on growth and yield of bitter gourd (Momordica charantia L)
(Department of Olericulture, College of Horticulture, Vellanikkara, 2007) Naveen Kumar, K S; Sadhan Kumar, P G
Investigation on the effect of plant growth promoting rhizobacteria (PGPR) on growth and yield of bitter gourd was carried out at Department of Olericulture, College of Horticulture, Vellanikkara, during September 2006 to January 2007 under field conditions. High yielding variety Preethi was used for the study. The study revealed that seeds inoculated with Azospirillum (basal @ 5 kg ha-1 + 40 days after sowing (DAS) @ 5 kg ha-1) recorded early germination (6.48 days) which was followed by the two time application of Pseudomonas flourescens (basal @ 2.5 kg ha-1 + 40 DAS @ 2.5 kg ha-1). The maximum vine length (4.42 m) was recorded in both Bacillus subtilis suspension (108 cfu/ml) @ 2 l/plant application (basal) and Pseudomonas flourescens @ 2.5 kg ha-1. Number of primary branches was maximum (4.80) in plants applied with phosphorous solubilising bacteria (PSB) as basal @ 5 kg/ha and 40 DAS @ 5 kg/ha. Tap root length (23.57 cm) and secondary root length (39.88 cm) were highest in the plants supplied with Azospirillum (basal @ 5 kg ha-1 + 40 DAS @ 5 kg ha-1) where as, dry root weight (4.64 g) was more in case of double application of Bacillus subtilis suspension (108 cfu/ml) basal @ 2 l plant -1 + 40 DAS @ 2 l plant -1. Control plants were the earliest to flower and fruit. Plants inoculated with basal dose of Bacillus subtilis suspension (108 cfu/ml) produced the highest number of female flowers plant -1 (17.50 flowers) than other treatments. Among the different treatments, double application of Aishwarya (basal @ 30 g plant-1 + 40 DAS @ 30 g plant-1) recorded the highest number of fruits plant -1 (13.60 fruits) and seeds plant -1 (49.33 seeds) respectively which was followed (12.68 fruits and 45.33 seeds) by the inoculation of Pseudomonas flourescens (basal @ 2.5 kg/ha) and Bacillus subtilis suspension (108 cfu/ml) (basal @ 2 l plant -1 + 40 DAS @ 2 l plant -1) respectively. Plants treated with Bacillus subtilis (suspension (108 cfu/ml) basal + 40 DAS @ 2 l plant -1 recorded maximum fruit weight, length and girth (223.49 g, 26.16 cm and 22.93 cm respectively). Flesh thickness (0.73 cm) was highest in double application (basal @ 2 l plant -1 + 40 DAS @ 2 l plant -1) of the Bacillus subtilis, PSB and Aishwarya (basal @ 30 g plant-1+ 40 DAS @ 30 g plant-1) treatments. There was a highly significant difference between all the treatments under study. Two time application of Bacillus subtilis suspension (108 cfu/ml) basal + 40 DAS @ 2 l plant -1 produced the maximum yield plant -1 and yield plot -1 (2.72 kg and 16.33 kg respectively), which was followed by the single time application of Pseudomonas flourescens as basal @ 2.5 kg ha-1 (2.36 kg ha-1 and 14.19 kg ha-1). Maximum vitamin C content was recorded in the plants subjected to basal application of Aishwarya @ 30 g plant-1 (138.16 mg/100g) followed by single application of Bacillus subtilis as basal dose. Maximum iron content was recorded (1.89 mg/100g) in plants supplied with Pseudomonas flourescens (basal @ 2.5 kg ha-1 + 40 DAS @ 2.5 kg ha-1). Storage time (4 days) was more for the plants treated with one time application of Bacillus subtilis suspension (108 cfu/ml) @ 2 l plant -1 and Pseudomonas flourescens as basal @ 2.5 kg ha-1. It can be inferred that inoculation of bitter gourd with plant growth promoting rhizobactreia (PGPR) enhanced its growth, yield and quality attributes. Among the different PGPR studied, Bacillus subtilis suspension (108 cfu/ml) with two time application first as basal @ 2 l plant -1 and second at 40 DAS @ 2 l plant -1 performed best with respect to yield, flower and biometrical characters. The next best treatments were two time application of Aishwarya, Pseudomonas flourescens, Azospirillum and PSB respectively.
Incorporation of resistance to fruit cracking in a bacterial wilt resistant genetic background in tomato
(Department of Olericulture, College of Horticulture, Vellanikkara, 1995) Sadhan Kumar, P G; Rajan, S
An investigation on “Incorporation of resistance to fruit cracking in a bacterial wilt resistant genetic background in tomato” was undertaken in the Department of Olericulture, College of Horticulture, Vellanikkara during the period from January, 1991 to March, 1994. The findings are succinctly mentioned below. Evaluation for bacterial wilt resistance revealed that Sakthi and LE 79 – 5 are consistently resistant to bacterial wilt. Four addition sources of bacterial wilt resistance were identified viz., LE 214, CAV – 5, LE 415 and LE 382 – 1. Resistances to bacterial wilt in these lines was governed by recessive genes. Screening for resistances to fruit cracking resulted in the identification of fifteen tomato genotypes which were found to be resistant to both radial and concentric cracking. Resistances to concentric fruit cracking in these lines were found to be dominant. All the bacterial wilt resistant genotypes had a higher content of total phenols, O.D. phenol and ascorbic acid than the susceptible line pusa Ruby. The crack resistant varieties had a higher content of insoluble solids and pectin, lower content of acidity, total sugar and reducing sugar in fruits, thick fruit skin and pericarb as compared to susceptible variety. The elasticity of skin was also higher in crack resistant genotypes. Crack resistant varieties had a compact arrangement of parenchymatous cells when compared with crack susceptible variety. The resistant lines had a thicker cuticle also. The F1 S developed by line x tester crossing were susceptible to bacterial wilt. All the same, they were resistant to both radial and concentric fruit cracking indicating dominant gene action for crack resistance. The F2 segregants with combined resistance to both bacterial wilt and fruit cracking were selected for further improvement.
Response of cucumber genotypes to ethephon application
(Department of Olericulture, College of Horticulture, Vellanikkara, 1982) Sadhan Kumar, P G; Peter, K V
Investigations were carried out during two seasons (October-January, 1981-82 and March-May, 1982) to find out the response of 20 Cucumis genotypes to four levels of ethephon (0,100, 200 and 300 ppm) at the Instructional Farm, College of Horticulture, Kerala Agricultural University, Vellanikkara. Ethephon caused significant reduction in length of main vine, nodes to first female flower, nodes to first fruit, seed number and flesh thickness. Nodes to first male flower and primary branches/plant were significantly increased. There was no significant effect of ethephon on fruit length, fruit weight and fruit volume during both the seasons. There was an increase in yield in CS 27 (326.62%) while definite reduction in yield was observed in CS 26 (42.53%), CS 43 (60.47%), CS 38 (60.79%), CS 51 (50.74%) and CS 31 (63.82%) during the first season. During second season there was no significant effect of ethephon on fruit yield. Effect of ethephon sprays on plant to alter vegetative characters is further confirmed in the present study. Despite reduction in seed number due to ethephon application, no appreciable change was observed for fruit weight, fruit volume and fruit length. This is a matter for worth investigation. Reduction is vine length and increase in primary branches could be attributed to effects of ethephon to effect the phenomenon of apical dominance. The study proved that response of Cucumis genotypes to ethephon is governed by genotype, season of cultivation and concentration of ethephon used.