Colour Break Stage Research Articles

Growth and flowering response of Chrysanthemum morifolium cultivar Anmol to different growth retardants

An experiment was conducted at the experimental farm of Department of Floriculture and Landscaping, Punjab Agricultural University from 2015 to 2016 with the objective to standardize the optimum concentration of different growth retardants for alteration of plant architecture and improvement of flowering parameters in chrysanthemum (Chrysanthemum morifolium Ramat.) cv. Anmol. The experiment was conducted in completely randomized design (CRD) with three replications comprising ten pots per replication. Cycocel (@ 500, 750, 1000, 1250 and 1500 ppm), Daminozide (@ 500, 750 and 1000 ppm) and Ethephon (@ 250, 500 and 1000 ppm) were sprayed on chrysanthemum cv. Anmol (spray type) after one month of transplanting. The effect of growth retardants in reduction of plant height followed the order daminozide> ethephon> cycocel. Internodal length was much reduced by daminozide @ 1000 ppm. Highest plant spread, diameter of main stem and leaf area was obtained under daminozide @ 1000 ppm. Floral characters like days to bud appearance, days to colour break stage and days to full bloom stage was obtained earlier in daminozide @ 1000 ppm and later in ethephon @ 1000 ppm. Flower diameter was much increased by daminozide @ 500 ppm. Highest number of flowers/plant was obtained under daminozide @ 1000 ppm. Highest duration of flowering was obtained under daminozide @ 1000 ppm and minimum under ethephon @ 1000 ppm.

Evaluation of Lilium Hybrids (Lilium x hybrida) for Growth, Flowering and Bulb Attributes in the Hilly Regions of Uttarakhand

The present study was initiated to elucidate performance of 18 exotic lilium hybrids (Lilium x hybrida) to assess their suitability for commercial cultivation in the hilly regions of Uttarakhand. The investigation was carried out at Jilling Floritech farm during 2014-15 under protected conditions in Randomised Block Design. All the 18 hybrid varieties showed significant variation for vegetative, flowering and bulb attributes. Analysis of data indicated that among the cultivars studied, earliest sprout emergence (4.66 days) was recorded in 'Yellow Diamond'. Earliest flower-bud initiation (30.33 days) was recorded in 'Bach', and flower-bud colour break stage (46.33 days) and flowering (50.00 days) in 'Detroit'. Maximum number of flower buds/plant (8.66) was recorded in 'Pollyana', longest inflorescences (25.23cm) in I'ndian Summerset', maximum flower diameter (17.66cm) in 'Creil' and 'Golden Tycoon', maximum plant height (145.13cm) in 'Bright Dimond', and maximum stem thickness (1.86cm) in 'Novana'. However, maximum number of bulblets (6.66) per plant was recorded in 'Ceb Dazzle'.

Fruit maturity and associated changes in Khasi mandarin (Citrus reticulata) at different altitudes in humid tropical climate

Fruit maturity and associated changes in terms of physicochemical and sensorial qualities of Khasi mandarin (Citrus reticulat Blanco) grown at different altitudes, viz. 500-600 m, 700-800 m, 900-1 000 m and 1 300-1 400 m were studied under humid tropical climate of Meghalaya. Rapid increase in fruit growth was recorded from fruit development to colour break stage, however it was slow thereafter at all the altitudes. At 500-600m and 700-800m, juice yield was recorded highest at fruit maturity stage (46.64% and 49.11%) while, it was highest in advanced fruit maturity stage (50.90% and 51.15%) at 900-1 000 m and 1 300-1 400 m. Diurnal variation in climate stimulated drop in chlorophyll (‘a’, ‘b’ and total) and promoted development of yellowish orange colouration on fruit peel at altitude of 500-600 m and 700-800 m while deep orange colouration at 900-1 000 m and 1 300-1 400 m. Significant rise in TSS and TSS: acid ratio with drop in titratable acidity were recorded during maturation. Ascorbic acid content was recorded maximum at 1 300-1 400 m (44.13 mg/100 g) and 900-1 000 m (41.05 mg/100 g) compared with 700-800 m (37.56 mg/ 100 g) and 500-600 m (35.66 mg/100 g) at advanced maturity stage. Duration of 1 and 1 ½ month (fruit development to colour break stage) represents maturation at 500-600 m and 700-800 m considering TSS (10.23 °B and 10.13 °B), TSS: acid ratio (13.22 and 12.60), sweetness (3.93 and 3.67), flavour (8.00 and 7.93) and appearance (8.07 and 7.87) score. While duration of 2 and 2 ½ months (fruit development to fruit maturity stage) required at 900-1 000 m and 1 300-1 400 m considering TSS (10.07 °B and 10.16 °B), TSS: acid ratio (12.40 and 12.02), sweetness (4.07 and 3.93), flavour (7.87 and 7.93) and appearance (7.93 and 8.00) score.

Effect of harvesting at different nodes on growth and flower yield of carnation (Dianthus caryophyllus Linn) in second season crop

The present study was under taken in a commercial floriculture farm under protected cultivation with three cultivars of carnation during July 2010 to February 2011. The experiment was laid out in Randomized Block Design with factorial concept. Harvesting of carnation flower stalk at 3 rd node from the ground level recorded minimum number of days to sprouting of buds than other harvesting nodes i.e. , 2 nd , 4 th and 5 th nodes. Days to first flower bud appearance, colour break stage and days to harvest was also minimum with harvesting at 3 rd node in cultivars Domingo, Dover and Keiro. And the length of lateral, length of flower stalk and flower, diameter of flower stalk and flower, number of flower stalks per plant, fresh flower weight and vase life was maximum with harvesting at 3 rd node than other harvesting heights in cultivar Domingo.

Fruit development and maturity of mrig bahar Nagpur mandarin fruits

Maturation is the most important stage of fruit development which is most active phase, involving high metabolic activity and cellular changes which lead to changes in colour, aroma, flavour and texture of fruits. The knowledge of these changes may be widely used to evaluate fruit maturity period of Nagpur mandarin. A change in peel colour is one of the indices used for maturity. Considering this, an experiment was carried out during 2010-11 at College of Horticulture; Dr. P.D.K.V., Akola comprising four stages of maturity in Randomized Block Design with five replications. The chlorophyll, carotenoid pigments and physico-chemical analysis of Nagpur mandarin fruits of mrig bahar was done. The significant difference was found in all characters recorded at different stages. The maximum fruit weight, volume and size were recorded in matured deep orange colour stage. Chlorophyll 'a' decreased from 0.0855 mg/ g fruit weight in fully developed green stage to 0.0224 mg/g (fruit weight) in matured deep orange colour stage. The decreasing rate of chlorophyll 'a' content was very rapid in fruit sample between fully developed green stage 0.0855 mg/g to colour break stage 0.0399 mg/g. Similar results were recorded in chlorophyll 'b' and total chlorophyll content in fruits. The progressive increase in carotenoid content was observed during advancement of fruit maturation.

Effect of duration of night interruption on growth and flowering of Chrysanthemum cv. Kikiobiory

The study was conducted to determine the effect of duration of night interruption using incandescent bulbs on sustained quality flower production of potted standard Chrysanthemum cv. Kikiobiory. The different night interruption (NI) treatments i.e. control, <5 sec. flash, 30-, 60-, 90- and 120- min. significantly (p<0.05) affected allthe vegetative and floral parameters. The plant height, number of leaves and root suckers per plant increased with the increase duration of NI treatments with maximum at 120- min. NI (90.42 cm, 34.75 and 12.10, respectively). The days taken to flower bud appearance, colour break stage and full bloom were delayed, whereas flower quality with respect to duration of flowering and flower diameter were deteriorated with increase in duration of NI treatments. The days taken to flower bud appearance, colour break stage and full bloom were highest at 120- min. NI (136.84, 183.22 and 202.25 days, respectively) which delayed the flowering by 63.94 days, where full bloom flower appeared in March. There was reduction in duration of flowering and flower diameter with increased NI duration with lowest at 120 min. NI (7.83 days and 15.69 cm). It was observed that increase (120 min.) in night interruption increased the vegetative growth and delayed the flowering; however, flower quality was deteriorated. Thus, it was concluded that 60 min. NI improved flower quality with sustained flower production in potted Chrysanthemum cv. Kikiobiory.

Enzymatic changes in plum (Prunus salicina Lindl.) subjected to some chemical treatments and cold storage.

The objective of the present work is to see the effect of different chemical treatments on pectin methylesterase (PME) activity and softening of the fruits. Purple plums (cv. Satluj) fruits were harvested at colour break stage and treated for 5- minutes in aqueous solutions of salicylic acid at 138, 276 and 414ppm, Ascorbic acid at 10,000, 20,000 and 30,000ppm, and Gibberelic acid at 20, 40 and 60ppm. For control the fruits were dipped in distilled water. Treated fruits were stored at low temperature conditions for 40days. Physico chemical characteristics and PME activity were determined at 10day interval. The colour of the fruits improved with respect to a* and b* values progressively throughout the storage, whereas, fruit firmness decreased. Total sugars and PME activity increased before showing a declining trend. Pre-storage application of salicylic acid (414ppm) significantly delayed colour development. Fruits treated with salicylic acid (414ppm) retained highest firmness, total sugars and PME activity at the end of storage.

Effect of pre-harvest application of NAA and potassium nitrate on storage quality of winter guava (<i>Psidium guajava</i>)

A study was conducted at Punjab Agricultural University, Ludhiana during 2006–08 in winter crop of guava cv. Sardar to evaluate the influence of pre-harvest foliar application of naphthalene acetic acid (NAA) and potassium nitrate on quality attributes in different interval of cold storage. The plants were sprayed with NAA and potassium nitrate at colour break stage of fruit and harvested at optimum maturity, packed in CFB boxes with newspaper lining and stored at 6- 8oC and 90-95% RH. Fruits treated with NAA (100 ppm) effectively reduced spoilage maintained higher fruit firmness, TSS and ascorbic acid and remain slightly desirable after 30 days of storage. Thus, pre-harvest spray with NAA (100 ppm) seems to be effective method for decreasing post- harvest losses and maintaining quality of guava fruits.

Effect of different packaging films on shelf life and quality of peach under super and ordinary market conditions.

Peach (Prunus persica L. Batsch) fruits of cultivar 'Shan-i-Punjab' were harvested at colour break stage and packed in paper moulded trays followed by wrapping with different packaging films viz. cryovac heat shrinkable RD-106, cling and low density polyethylene (LDPE) film. After packaging, the fruits were stored under two different conditions i.e. super-market conditions (18-20°C; 90-95% RH) and ordinary market conditions (28-30°C; 60-65% RH). The fruits were evaluated for various quality attributes periodically. The shrink film helped in reducing the loss in weight, firmness, decay incidence and maintained the various qualities attributes like total soluble solids, sugars, acidity and ascorbic acid content of the fruits during shelf-life better than unwrapped control fruits. The pectin methyl esterase enzyme activity was also found to be lower in shrink film packed fruits over the unwrapped control fruits. The in-package gaseous composition (O2 and CO2) in shrink film packed fruits was found to be at desired level which resulted in maintenance of pleasant flavour of the fruits. On the other hand LDPE film accumulated very high level of CO2, which led to formation of fermenting odour and decay of fruits in the package. The data revealed that RD-106 film proved quite effective in prolonging the shelf-life and maintaining the quality of peach fruits for 9 and 4days under super market conditions (SMC) and ordinary market conditions (OMC), respectively as against 6 and 2days only in case of unpacked control fruits under both the marketing conditions. The results suggest that shrink film could be used in packaging of peach without negative effects on quality.

Characterization of Capsaicinoids and Antioxidants in Hot Peppers as Influenced by Hybrid and Harvesting Stage

Studies were conducted to investigate the accumulation pattern of capsaicinoids and antioxidants such as carotenoids, ascorbic acid and phenolic compounds in three hot pepper hybrids at five different harvesting stages: immature green, mature green, color break, red ripe and dried fruit. Capsaicin and dihydrocapsaicin contents were maximum at mature green stage in both Sky Red (61.30 and 43.76mg/100g) and Wonder King (43.93 and 26.16mg/100g) hybrids, whereas Maha hybrid reached top values at color break stage (39.13 and 24.20mg/100g). The accumulation of total carotenoids showed an 8-fold increase from red ripe (12mg/100g) to dried fruit stage (96mg/100g), while a noticeable decline by 76% was observed for ascorbic acid at same harvesting stages (150 vs. 36mg/100g, respectively). The three hot pepper hybrids showed great variations in the evolution of total phenolic contents during harvesting stages. Overall, the mature green stage was ideal to acquire maximum pungency due to capsaicinoids, while peppers at red ripe stage were best sources of ascorbic acid and dried fruits contained higher levels of total carotenoids.

Effect of Harvesting at Different Heights on Growth and Flower Yield of Carnation (Dianthus caryophyllus L.) in Second Season Crop

The present study was under taken in a commercial floriculture farm under protected cultivation with three cultivarsof carnation during July 2010 to February 2011. The experiment was laid out in randomized block design with factorialconcept. Harvesting of carnation flower stalk at 10 cm height from the ground level recorded minimum number of days to sprouting of buds than other harvesting heights i.e., 5, 15 and 20 cm height. Days to first flower bud appearance, color break stage and days to harvest was also minimum with harvesting at 10 cm height in cultivars Domingo, Dover and Keiro. And the length of lateral, length of flower stalk and flower, diameter of flower stalk and flower, number of flower stalks per plant, fresh flower weight and vase life was maximum with harvesting 10 cm height than other harvesting heights in cultivar Domingo.

The effect of antifungal hot-water treatments on papaya postharvest quality and activity of pectinmethylesterase and polygalacturonase

The effect of antifungal hot-water treatments (AHWT) at 55°C for 0, 3, 6 and 9min on quality attributes and cell-wall enzymatic activity during storage at 25°C was investigated in papaya fruit. The total soluble solids (TSS), pH, titratable acidity (TA), firmness and fresh weight loss were not affected, whereas color on skin was negatively affected by the treatments of 6- and 9-min. However, the skin color was not different between the 3-min treated fruit and the untreated fruit during the storage. Decay was delayed and reduced by AHWT. We observed that the 3-min treatment of 55°C did not affect softening and quality of papaya cv Maradol when applied as a pesticide-free treatment at color-break stage of papaya. PME (Pectinmethylesterase) and PG (Polygalacturonase) activities were not significantly affected by AHWT. We concluded that the AHWT did not affect the softening process from papaya pulp since the cell-wall enzyme activity (PME and PG) was not altered by treatments.

Influence of 1-methylcyclopropene on pectic enzyme activities, gene expression, and cell wall modification in papaya (Carica papaya cv. ‘Sunrise’) fruit

SUMMARY‘Sunrise’ papaya fruit harvested at two stages of maturity [colour break (< 10% yellow peel colour) and 25% yellow peel colour] were treated with 100 nl l–1 1-methylcyclopropene (1-MCP) to determine its effects on ripening, on the activities and levels of gene expression of polygalacturonase (PG), pectin methyl esterase (PME), and βgalactosidase ( βGal), and on the degradation of cell wall components. 1-MCP delayed ripening and the onset of the climacteric, although the peak in the respiration rate was almost the same as that in untreated control fruit. Colour-break fruit treated with 1-MCP exhibited a continuous increase in ethylene production, but at a lower rate than in control fruit. Consequently, 1-MCP-treated fruit ripened with a concomitant reduction in firmness, which was accompanied by an increase in PG and βGal enzyme activities and gene expression. On the other hand, fruit treated with 1-MCP at the 25% yellow stage exhibited lower levels of ethylene production and developed pulp with a rubbery texture at the ripe stage which was attributed to reduced PG, βGal, and PME enzyme activities and gene expression. This was consistent with the higher level of cell wall polysaccharides measured in 1-MCP-treated fruit. The above results indicated that ‘Sunrise’ papaya fruit can be treated with 1-MCP at the colour break stage since they have a greater capacity to recover from the effects of 1-MCP than fruit treated at the 25% yellow stage.

EFFECTS OF 1-METHYLCYCLOPROPENE ON RIPENING OF TWO PAPAYA (CARICA PAPAYA L.) CULTIVARS

Two separate experiments were conducted to determine the response of 'Solo' and 'Sinta' papaya fruits harvested at color break stage to 1-methylcyclopropene (1-MCP). In the first experiment, 'Solo' papaya fruits were exposed to 0.1 or 0.5 μl L -1 1-MCP for 24 h at 25°C prior to storage at 13°C for 18 days. This was followed by ethephon treatment upon transfer at 25°C for ripening. The second experiment consisted of treating 'Sinta' papayas with the same concentration of 1-MCP but fruits were kept at ambient condition (25-28°C). Regardless of cultivar and storage condition, 1-MCP significantly retarded the ripening of papaya fruits. At 13°C, 1-MCP-treated 'Solo' papayas remained at color break stage for 18 d. In the case of 'Sinta' papayas, ripening was delayed for about 6 days at 25-28°C. Respiration rate and ethylene production of 1-MCP-treated fruits were greatly suppressed and no distinct climacteric peak was observed. Upon treatment with ethephon, only non-MCP-treated fruits softened to table ripe stage. 1-MCP-treated fruit on the other hand, remained hard although the flesh attained the full orange ripe color. Rubbery pulp texture was noted in some fruit treated with 0.5 μl L -1 1-MCP. The onset of stem end rot and anthracnose resulted in reduced shelf life. 1-MCP only reduced the severity of infection but did not delay its onset as well as incidence.

Effect of pre-harvest calcium sprays on post-harvest life of winter guava (Psidium guajava L.).

Influence of pre-harvest foliar application of calcium nitrate on quality attributes of winter guava cv. 'Sardar' during different interval of cold storage and post cold storage shelf-life under ambient conditions was investigated. Plants were sprayed with calcium nitrate solutions (0.5, 1.0 and 1.5%) at colour break stage of fruit and a fruit with no treatment was control. The fruits were harvested at optimum maturity. Bruise and disease free fruits were packed in corrugated fibre board boxes with newspaper lining and stored at 6-8°C and 90-95% RH. The fruits were evaluated after 10, 20, 30 and 40days of storage and during shelf-life at 2 and 4days interval. Physiological loss in weight and spoilage of fruits increased and firmness, ascorbic acid and acidity decreased continuously during storage. Fruits treated with 1% Ca(NO3)2 effectively reduced spoilage, maintained higher firmness, total soluble solid and ascorbic acid up to 2days under ambient conditions after 30days of cold storage and remained moderately acceptable up to the 40days of storage.

Papaya Fruit Softening: Role of Hydrolases

Papaya (Carica papaya L.) cultivars show a wide variation in fruit softening rates, a character that determines fruit quality and shelf life, and thought to be the result of cell wall degradation. The activity of pectin methylesterase, β-galactosidase, endoglucanase, endoxylanase and xylosidase were correlated with normal softening, though no relationship was found between polygalacturonase activity and softening. When softening was modified by 1-MCP treatment, a delay occurred before the normal increase in activities of all cell wall activities except endoxylanase which was completely suppressed. Significant cell wall mass loss occurred in the mesocarp tissue during normal softening, but did not occur to the same extent following 1-MCP treatment. During normal softening, pectin polysaccharides and loosely bound matrix polysaccharides were solubilized and the release of xylosyl and galactosyl residues occurred. Cell wall changes in galactosyl residues after 1-MCP treatment were comparable to those of untreated fruit but 1-MCP treated fruit did not soften completely. The changes in the cell wall fractions containing xylosyl residues in 1-MCP treated fruit showed less solubilization and a higher association of xylosyl residues with the pectic polysaccharides. The results indicated that normal modification of cell wall xylosyl components during ripening did not occur following 1-MCP treatment at the color-break stage, this was associated with the failure of these fruit to fully soften and a selective suppression of endoxylanase activity. The results support a role for endoxylanase in normal papaya fruit softening and its suppression by 1-MCP lead to a failure to fully soften. Normal papaya ripening related softening was dependent upon the expression and activity of endoglucanase, β-galactosidase and endoxylanase.

Effect of Pulsing Treatments for Enhancing Shelf-Life of Cut Asiatic Lilium cv. Elite

Studies were conducted on cut Asiatic Lilium cv. Elite to assess the effectiveness of various floral preservatives as pulsing treatments for delaying senescence and prolonging vase life. Uniform spikes of lilium at bud colour break stage were brought to the laboratory in the morning and placed in 8 different pulsing solutions consisting of sucrose (Suc) 5%, aluminium sulphate (AS) 400 ppm, silver thio-sulphate (STS) 2.0 mM and citric acid (CA) 1000 ppm alone and in combination with sucrose. Distilled water without any chemical served as the control. Among individual treatments, STS 2.0 mM maintained better water relations and flower quality compared to others. STS also showed superiority over other treatments when combined with Suc 5% by providing largest flower size (16.74 cm) with maximum vase life (17.29 days) owing to most-favourable water relations parameters.

Effect of Pre-harvest Treatments on the Cellulase Activity and Quality of Ber Fruit Under Cold Storage Conditions

Studies were carried out to find out the effect of various pre-harvest treatments: CaCl2 (@ 0.5, 1.0 and 2.0%), Ca (NO3)2 (@0.5, 1.0 and 2.0%), GA3 (@ 20, 40 and 60 ppm) and Bavistin (@ 0.1%) on the cellulase activity and quality of 'Umran' ber fruits during cold storage. Marked trees were sprayed at colour break stage with the test chemicals. Fruits were packed in CFB boxes and placed in cold storage (3 - 5°C and 85 - 90% RH) for 30 days. The fruits were evaluated after 10, 20 and 30 days interval for various parameters such as cellulase activity, phenolic content, palatability rating and rotting percentage. Cellulase activity registered a gradual increase up-to 20 days of storage thereafter a decline was noted in all the treatments. The palatability rating increased up to 10 days of storage in all the treatments, except control but subsequently it decreased with longer in storage periods. Among the various preharvest treatments CaCl2 (2%) recorded minimum cellulase activity and rotting percentage and registered high palatability rating and phenolics content during cold storage conditions. Studies showed that pre-harvest application of CaCl2 (2%) maintained very good fruit quality and prolonged shelf-life for 20 days under cold storage conditions.

Effect of Pre-Harvest Application of GA3 and PP333 as Bulb Dip and Foliar Spray on Quality and Vase Life of Cut Tulip cv. Cassini

An experiment on effect of pre-harvest application of GA3 and PP333 as bulb dip and foliar spray on quality and vase life of cut tulip cv. Cassini was carried out. Healthy scapes of uniform size were cut in a slanting manner at bud colour break stage and placed in conical flasks containing distilled water for vase life studies. Bulb dip in GA3 (100 ppm) followed by foliar spray of GA3 (100 ppm) significantly improved overall water uptake, prevented water loss and resulted in maximum water balance. The treatment also exhibited the maximum flower diameter (7.40 cm), scape length (16.26 cm) and vase life (9.33 days). However, the lowest water loss to water uptake ratio was recorded with bulb dip plus foliar spray with 200 ppm GA3. Data indicated that GA3 (100 ppm) as bulb dip plus foliar spray proved instrumental in maintaining the quality and vase life of cut tulip as compared to other treatments.

Direct and indirect effects of seed related characters on number of seed in guava ( Psidium guajava L.) fruits

Dessert quality of guava fruit is considerably reduced by high seed content. Number of seeds in guava is associated with different seed and fruit characters. Influence of different seed characters on number of seeds per fruit (NSPF) was studied by analysing character association and direct and indirect effects on NSPF and seed related traits for 68 genotypes of guava collected from diverse sources and conserved at National Active Germplasm Site, CISH, Lucknow. Seed related characters were studied at the colour break stage of the fruits using image analysis software for counting number of seeds. The data was subjected to path analysis to find out direct and indirect effects of different characters on number of seeds in the fruits. At genotypic and phenotypic levels, NSPF was significantly and positively associated with seed weight per fruit (SWPF), number of seeds 100 g −1 pulp (NSPHP) and fruit weight (FW). The genotypic (0.0029) and phenotypic (0.0563) residual values were fairly very low, which revealed that variables included in this study had significant contribution in determining NSPF. The NSPHP exhibited high positive direct effect on NSPF. The maximum direct response ( P = 0.737, G = 1.004) of this component was attributed to the indirect positive effects of the SWPF and fruit:seed weight proportion (FSWP). SWPF also had a very high positive direct effect ( P = 0.521, G = 0.694) on the NSPF. Correlation and path coefficient analysis revealed that SWPF, NSPHP and 100-seed weight (100SW) were deciding factors for realizing improvement for NSPF. The importance of small seeded genotypes in selection of less seeded varieties was emphasized.