Research Report

Effect of Pinching and Growth Retardants on Flowering and Yield of African marigold (Tagetes erecta L.) var. Pusa Narangi Gainda  

Naresh Chandra Pushkar , Singh A.K.
Department of Floriculture and Landscaping, College of Horticulture & Forestry Narendra Deva University of Agriculture & Technology, Faizabad- 224229 (U.P.), India
Author    Correspondence author
International Journal of Horticulture, 2012, Vol. 2, No. 1   doi: 10.5376/ijh.2012.02.0001
Received: 01 Nov., 2012    Accepted: 05 Nov., 2012    Published: 08 Nov., 2012
© 2012 BioPublisher Publishing Platform
Preferred citation for this article:

Naresh C.P., and Singh A.K., 2012, Effect of Pinching and Growth Retardants on Flowering and Yield of African marigold (Tagetes erecta L.) var. Pusa Narangi Gainda, International Journal of Horticulture, 2(1): 1-4 (doi: 10.5376/ijh.2012.02.0001)

Abstract

The effects of different chemicals treatment on postharvest cut flower quality of hybrid lily cultivar ‘Eyeliner’ were investigated. Lily stems were harvested when the first flower bud showed full colour. A whole stem (leaf and bud) sprayed with water (control) and with a growth regulator solutions containing TDZ (1&2ppm), BA (25 ppm), GA3 (25 ppm), BA (50 ppm) , GA3  (50 ppm), BA +GA3 (25ppm +25 ppm), BA+GA3 (50ppm +50 ppm), SAMRAS (2&4mlL-1), Agri-Herbo-99 (1&2ml L-1) and Super Gibbre (1&2ml L-1). After the treatments, each stem was then maintained for postharvest evaluation in an individual 500 ml conical flask with 300 ml of normal tap water.  Within each treatment, the numbers of buds per stem were kept constant as possible for ease of data recording. In general, BA alone or in combination with GA3 treatments significantly delayed the flower bud opening. Leaf yellowing and flower senescence was substantially delayed up to one week when cut flowers were sprayed with a solution containing TDZ (2ppm). Application of BA @ 50 ppm significantly delayed total chlorophyll (a+b) degradation after 6 and 9 days. After 3 days sharp increase in total chlorophyll content was found when cut stems were sprayed with 1 ppm TDZ and slightly declined after 6 and 9 days. In conclusion, TDZ @ 2 ppm not only delayed leaf yellowing but also reduced onset of petal senescence in Lilium cut flowers. BA was able to delay the chlorophyll degradation.

Keywords
Pinching; Growth retardants; African marigold

African marigold (Tagetes erecta L.) is a widely cultivated as bedding plants, loose flower, perfume, natural colure, pigments, carotinoids, insect and nematodes repellents, nutrient supplement for poultry feed. Marigold plant habit of profuse flowering, short duration to produce marketable flowers, wide spectrum of attractive colures, shape and size and good keeping quality, attracted the attention producers and traders mostly. Marigold occupies anthelmintic, analgesic, anti-inflammatory, aromatic, bronchodilatory, digestive, diuretic, emme- nagogue, sedative and stoma tic properties. In case of pinching, the terminal portion of shoots is removed early, emergence of side branches starts earlier and more number of flowers of good quality and uniform size are produced. In recent year, a number of plant growth retardants have been used in the field of agriculture for including more acceptable plant characteristics like compact growth, dwarf- ness, increase number of healthy branches and more number of quality flowers (Messiger and Hijcomb, 1986; Song et al., 1990; Banon et al., 2002) which are the desired traits in modern floriculture industry. Effect of pinching, both manual and chemically; using Cycocel and alar was ascertained for improving the production of compact dwarf African marigold var. Pusa Narangi Gainda. Although a lot of information is available to maximum flowering and yield in commercially important plants yet comparative studies involving the use of growth retardants and pinching scarce. Therefore, an experiment was carried out to compare the effects of two growth retardants (Cycocel and alar) and manual pinching on African marigold var. Pusa Narangi Gainda. The objective of study was to enhance production of best quality loose marigold flowers by applying different pinching and growth retardants approaches.

1 Results and Discussion
1.1 Effect of pinching
The data presented in table 1 revealed that the pinching significantly increased all the floral characters. The bud initiation and first flower visibility was observed delayed with pinching 30 days after transplanting. The maximum duration of flowering was recorded at pinching 30 days after transplanting. The highest length of stalk, duration of flower and number of flowers per plant were recorded with pinching 20 days after transplanting. The maximum fresh weight, yield of flowers per plant and vase life of flowers were observed at pinching 20 days after transplanting. Pinching plants were observed delayed in bud initiation, first flower visibility as compared to unpinch one because the formation of physiologically mature shoot for bearing flowers was delayed due to pinching and also as the speed of growth of axillary shoot is slow. The increase in number of flower, weight of flower and yield of flower per plant under pinching 20 days after transplanting might be due to the fact that it checked apical dominance and diverted extra energy in to the production of more number of branches and flowers similar observations reported by Arora and Khanna (1986) and Sehrawat et al (2003).


Table 1 Influences of pinching and growth retardants on flowering and yield of African marigold 2007-2008


1.2 Effect of growth retardants
The data pertaining to flowering characters are presented in table 2 Cycocel at lower concentration of 500 ppm (37.65 days and 38.32 days during 2007-2008 and 2008-2009 respectively) and Alar at 1 500 ppm 39.82 days and 40.73 days during 2007-2008 and 2008-2009 respectively) were found to be very effective in early visibility of bud and flowering. Early bud initiation and flowering with Cycocel and alar treated plants might be due to the fact such plants have built up sufficient food reserves at initial stages due to reduction in plant height and increase number of branches. This reserve food has been utilized for reproductive purpose with a restriction on vegetative growth and also due to gibberellins action of Cycocel (Ramesh et al., 2001). The maximum duration of flowering (59.26 days, 61.86 days, 58.88 days, and 60.46 days in 2007-2008 and 2008-2009) and vase life of flower (9.83 days, 10.92 days, 9.19 days, and 9.99 days during 2007-2008 and 2008-2009, respectively) were also recorded with higher concentration of Cycocel at 1 000 ppm and Alar at 3 000 ppm. Cycocel and alar increased the flower duration and vase life of flower by maintaining the levels of chlorophyll, protein and RNA content of leaves at a higher level for a longer duration suppressing the senescence (Kar et al., 1989). Application of growth retardants and pinching treatment significantly reduced the size and weight of individual flower. The maximum number of flower/plant (75.22 and 78.06; 72.37 and 75.71 during 20007-2008 and 2008-2009, respectively) and yield of flowers per plant (517.42 g and 615.59 g; 548.31 g and 587.87 g during both the years) were observed with Cycocel 1 000 ppm and alar 3 000 ppm. The increase in number of flowers per plant and yield of flowers per plant might be attributed to the development of large number of auxiliary shoots as a result of cessation of terminal growth (Gowda and Jaynthi, 1991).


Table 2 Influences of pinching and growth retardants on flowering and yield of African marigold 2008-2009


1.3 Effect of interaction
The interaction effect among different treatment combination of pinching and growth retardant was observed significantly on certain floral characters and yield trait under the treatment combination P1R2 (pinching at 20 DAT with Cycocel 1 000 ppm).
2 Materials and Methods
A field experiment was conducted at the Main Experiment Station of Department of Horticulture, Narendra Deva University of Agriculture and Tech- nology, Kumarganj, Faizabad (U.P.), during 2007-2008 and 2008-2009. Seed of African marigold var. Pusa Narangi Gainda were purchased from IARI, New Delhi and sown in nursery in 15 September 2007. The transplanting of healthy seedlings after one month seed sowing in experiment unit of 2 m×2 m, keeping row to row and plant to plant spacing 40 cm×40cm consisting of 25 plants per plot were transplanted in evening. After transplanting light irrigation was given in field. Recommended doses of organic manure 10 kg per plot and NPK @30 g, 20 g, 10 g per meter square and other inputs were applied at appropriate time. There were five chemical treatments i.e. Cycocel @ 0, 500 ppm and 1 000 ppm and Alar 1 500 ppm and  3 000 ppm with three levels of mechanical pinching treatment (hand pinching) i.e. no pinching, pinching at 20 days after transplanting and pinching at 30 days after transplanting. The chemicals were applied exogenously to the African marigold plant as foliar spray after 40days of transplanting, while plants sprayed with distilled water were used as control. The plants were sprayed one in their life span. The experiment was laid out in a randomized block design with thrice replication. Data were observed for days to bud initiation, days to first flowering duration of flowering, stalk length (cm) number of flowers per plant, diameter of flower (cm), fresh weight of flowers (g), yield of flowers per plant (g), vase life in days. Data for all observations were analyzed statistically using Fisher's test (1958).
References
Arora J.S., and Khanna K., 1986, Effect of nitrogen and pinching on growth and flower production of marigold (Tagetes ereeta), Indian J. Hort., 43(3-4): 21-294

Fisher R.A., 1958, Statistical methods for research workers, Oliver and Boyd, Edinburgh

Gowda N.J.V., and R. Jayanthi, 1991, Effect of cycocel and maleic hydrazide on growth and flowering of African marigold (Tagetes erecta L.), Prog. Hort., 23(1-4): 114-118

Ramesh K.M., M. Selvarajan, and N. Chezhiyan, 2001, Effect of certain growth substances and salicylic acid on growth and yield of China aster Cv. Kamini, Orissa J. Hort., 29(2): 14-18

Song J.S., Lee M.S., and Hong Y.P., 1990, Studies on the regulation of growth and flowering of Korean-indigenous bedding plants. 1. The effect of pinching time on growth and flowering of the native bedding plants, Res. Rep. of the rural Dev. Admin. Hort., 32(1): 44-53
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