Effect of plant growth regulators (PGRs) and pinching on fresh weight and dry weight of plant and flower in gaillardia

Introduction

Gaillardia (Gaillardia pulchella) is extensively grown annual flower in India. Among the Asteraceae family, Gaillardia is generally grown for its cut flowers. It is commonly called 'blanket flower'. The loose flowers of gaillardia are also utilized for making garlands in religious events and also for decoration in societal functions. Among the commercial flowers, this crop is easy to cultivate. Numerous factors like, environment, genetic behavior, and crop management influence the profitable cultivation of the flower crops. In the development of the sustainable package of practices for attaining high yield and quality of flowers, use of the growth regulators is one of the means (Kadam et al., 2020) [3] . Pinching is the cultural practice which is followed in flower crops to produce side branches in plant which ultimately produces higher yield of flowers with better quality. The influence of such practices viz; uses of plant growth regulator and pinching also influence the biomass of the plant as well as flowers which are also the important factors of plant development and flower quality. Higher fresh and dry weight in a plant generally indicates more biomass, suggesting vigorous growth and potentially more efficient resource utilization. With this outlook, the present experiment was formulated to evaluate the influence of plant growth regulator (PGRs) and pinching on fresh and dry weight of plant and flower in gaillardia crop.

Materials and Methods

The field experiment was taken at Research block of College of Horticulture, Dapoli, Dist. Ratnagiri during Rabi season of the year 2020-21. The trial was formulated in Factorial Randomized Block Design comprising of three replications with seven treatments of plant growth regulator (PGRs) (Factor A) viz; Control (No spray of PGR), Ethephon (500ppm), Ethephon (1000 ppm), GA 3 (100 ppm), GA 3 (200 ppm), CCC (1000 ppm) and CCC (2000 ppm). The second factor was pinching practices as Pinching at 30 days after transplanting second was Control (No Pinching). After following preparatory tillage, the flat beds (1.2 X 1.8 m 2 ) were made and 4 weeks old gaillardia seedlings were transplanted at 30 cm X 30 cm spacing. The intercultural operations were followed unvaryingly in all the treatment combination plots. The Sprays with different PGRs were given as per the treatments three times in growth period of crop i.e. 30, 45 and 60 days after transplanting. The pinching was also done as second factor treatment. The observations of weight (fresh and dry) of whole plant as well as flowers were noted. Statistical analysis of the data was carried out by method given by Panse and Sukhatme (1985) [7] .

Results and Discussion

The data regarding influence of PGRs and pinching on fresh weight and dry weight of plant in gaillardia is presented in Table 1.

The data regarding fresh weight of plant showed significant variation due to plant growth regulators. The highest fresh weight of plant (1370.67 g) was recorded in T 5 (GA 3 200 ppm) and it was closely followed by Control (T 1 ). The fresh weight (533 g) of plant was found lowest in T 3 (Ethephon 1000 ppm). Fresh weight of whole plant was directly associated with branching and leaves number. The increase in plant height, spread, number of branches and leaves enhanced the fresh weight of the plant. The maximum fresh weight of gaillardia was noted with GA 3 treated plant. The results were similar to Narute (2020) [6] in marigold. Significantly highest fresh weight (975.29 g) of plant was recorded P 1 (pinching at 30 DAT) where P 2 (no-pinching) treatment recorded lowest plant weight (936.48 g). The increase in fresh weight of plant in pinching treatment which may be because of enhanced growth of plants with pinching resulting more fresh weight of plant. Similar trend has also been reported by Joshi et al. (2002) [2] and Rathore et al. (2011) [8] in marigold. The interaction effect between plant growth regulators and pinching on fresh weight of plant was found significant. The highest fresh weight (1477.00 g) of plant was recorded in T 5 P 1 (GA 3 @200 ppm +Pinching at 30 DAT) and it was followed by T 1 P 1 and T 1 P 2 . Minimum fresh weight (458.00 g) of plant recorded in T 3 P 2 (Ethephon @ 1000 ppm + no pinching) treatment. In present, investigation maximum fresh weight of plant was observed in interaction between GA 3 @ 200 ppm and pinching. GA 3 treated plants with pinching had more branches, highest plant spread and leaf area which may be cause to increased fresh weight of plant.

The maximum dry weight (258.33 g) of plant was perceived in T 5 (GA 3 @ 200 ppm) and was followed by T 4 (232.17 g) and Control (145.00 g). Minimum plant dry weight (98.88 g) was observed in T 2 (Ethephon @500 ppm) at par with T 6 and T 3 . Similar results were reported by Narute (2020) [6] in marigold. The variation in the dry weight of plant may be attributed with the depletion of moisture from the plant. The PGR exhibited synergetic effect on dry weight. Pinching treatment did not significantly influence the dry weight of plant. Interaction effect between plant growth regulator and pinching on dry weight of plant was also found to be nonsignificant. Numerically maximum dry weight (281.67 g) was recorded in T 5 P 1 (GA 3 @ 200 ppm along with pinching at 30 days after transplanting) and the minimum dry weight of plant (96.10 g) in T 2 P 2 treatment. The dry weight was associated with fresh weight. The data on effect of PGRs and pinching on fresh and dry weight of flower are presented in Table 2. Fresh weight of single flower of gaillardia was significantly influenced due to the different PGRs. The maximum fresh weight of flower (3.83 g) was recorded in Control (T 1 ) which was followed by T 7 , T 6 and T 4 treatments . The minimum flower weight (2.50 g) was recorded in T 2 (Ethephon 500 ppm). Treatment control (T 1 ) recorded maximum fresh weight of flower. the variation among flowers weight might be due to alteration in flower size and number of petals due to PGRs treatments. This difference in weight of flower among various PGRs treatments may be allied to the higher carbohydrate level and moisture content in flowers. Similar results were also noted by Makwana (1999) [5] in gaillardia and Dani et al. (2010) [1] in marigold. Pinching significantly influenced on fresh weight of flower and maximum fresh weight (3.20 g) was recorded in P 1 . Whereas, minimum fresh weight (2.99 g) was observed in control treatment. As the flower size in pinching treatment improved which ultimately complimentary for increase in flower weight. Similar findings are related to Rathore et al. (2011) [8] in marigold and Khobragade et al. (2012) [4] in China aster. The non-significant effect on the fresh flower weight was observed between PGRs and pinching interaction. Dry weight of single flower was significantly influenced by the different PGRs. The maximum weight of dry flower (0.88 g) was recorded in T 1 (Control) which was followed by the treatments T 7 and T 6 (0.80 g and 0.67 g).The minimum flower weight (0.44 g) was observed in T 3 (Ethephon 1000 ppm) treatment. Pinching treatment significantly influenced the dry flower weight. Significantly maximum dry weight (0.71 g) of flower was registered in P 1 . Where un-pinched treatment recorded least dry flower weight (0.63 g). Similar findings were related to Rathore et al. (2011) [8] in marigold. The effect between PGRs and pinching interaction on dry weight of flower was non-significant.

PGRs Treatments

Pinching Treatments 1) T1-Control 2) T2 -Ethephon @ 500 ppm 1) P1 -Pinching @ 30 DAT 3) T3 -Ethephon @ 1000 ppm 4) T4 -GA3 @ 100 ppm 2) P2 -No pinching 5) T5 -GA3 @ 200 ppm 6) T6 -CCC @ 1000 ppm 7) T7 -CCC @ 2000 ppm

PGRs Treatments

Pinching Treatments 1) T1-Control 2) T2 -Ethephon @ 500 ppm 1) P1 -Pinching @ 30 DAT 3) T3 -Ethephon @ 1000 ppm 4) T4 -GA3 @ 100 ppm 2) P2 -No pinching 5) T5 -GA3 @ 200 ppm 6) T6 -CCC @ 1000 ppm 7) T7 -CCC @ 2000 ppm

Conclusion

The present investigation revealed that, plant growth regulators had significant effect on fresh and dry weight of plant as well as flowers of gaillardia (Gaillardia pulchella). GA 3 200 ppm treatment was having profound effect plant and flower weight. The pinching also improved the fresh weight of plant and flowers.

References

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