Botanical seed invigoration as a sustainable approach to improve growth and yield in blackgram

Introduction

Pulses, "the wizard of the health" play a crucial role in supplying all the dietary proteins and they are considered as the second most important human protein source. Pulses are the rich reservoir of both macro and micro nutrients (Kaur et al., 2024) [2] . Among the pulses, Black gram [Vigna mungo (L.) Hepper]; Fabaceae is one of the most valued pulses having its origin in India. Pre sowing seed treatment helps to accelerate germination, breaking dormancy and also protect against early stage pests and diseases. Botanical seed treatment is derived from natural sources based on botanical ingredient. It is a liquid, natural seed treatment and root growth promoter formulation. It also stimulates indigenous microbes in the root zone. It is proved to be a reliable performer in low and high rainfall areas and in all soil types. It is an affordable and effective way to optimize early growth and yield potential. It is also one of the lowest financial investments through which a grower can make maximize productivity. Among the several botanicals, leaf extract has been pharmacologically proved to contain appreciable amount of antioxidant properties with a high nutrient content (Bukhari et al., 2008) [4] . Therefore, leaf extract can be used as a potential source of natural antioxidants which can be attempted for seed treatments to improve vigour, viability and storability maintenance in their commercial form. Nutrients play a vital role in increasing the growth in pulses. Apart from the genetic makeup, the physiological factors viz., insufficient portioning of assimilates, poor pod setting due to the flower abscission and lack of nutrients during critical stages of crop growth play a major role in declined black gram production. Hence this study was taken that, botanical seed invigoration as a sustainable approach to improve growth and yield in black gram VBN 11.

Materials and Methods

Genetically pure seeds of black gram, VBN11, a base material were brought from National pulses research centre, Vamban, Tamil nadu. The fresh leaves of Pungam, Prosopis, Adathoda, Papaya, Thulasi and Neem were collected separately and shade dried. The shade dried leaves were powdered using pestle and mortar. From this whole powder, 6 g of leaf powder should be exactly weighed using weighing balance. The 6g powder is dissolved in 100 ml of distilled water which was measured already in a beaker to make 6 % leaf extract. The leaf extract was filtered by using muslin cloth to remove unwanted materials and leaf debris. The seeds were soaked in equal volume of 1:1 leaf extract for 4 hours along with water. The soaked seeds were dried back to original moisture content. In Thiruvallur, Polivakkam village the Field trial was conducted at a farmers field. In the PG Laboratory of Department of Genetics and Plant Breeding, Annamalai university, the laboratory experiment was carried out. The technique of random sampling was adopted for recording various characters in black gram. T0: Control (Without treatment) T1: 6% Pungam leaf extract T2: 6% Adathoda leaf extract T3: 6% Prosopis leaf extract T4: 6% Neem leaf extract T5: 6% Thulasi leaf extract T6: 6% Papaya leaf extract

Results and Discussion

The seeds hardened with 6% prosopis leaf extract recorded higher values for initial seed quality parameters viz., germination percentage (94 %), root length (15.18 cm), shoot length (26.35 cm), seedling length (41.53 cm), seedling dry weight (0.47 g), vigour index I (3903.82), vigour index II (44.18), electrical conductivity (0.608) against control (Table 1). Botanical leaf extract i.e., prosopis @ 10% showed positive impact on hiked initial seed quality parameters that might be due to the biochemical changes like activation of enzymes that further involves in the modification of cellwall and gibberellins (Macovei et al., 2010) [10] . When compared to untreated seed, in case of prosopis treated seed, the greater colloidal hydration and greater viscosity of protoplasm occurs and here the cell membrane allows the early entry of moisture that can activates the early phase of hydrolyzing the reserved food. These findings were in conformity with the findings of Hussain et al. (2015) [7] . Increase in germination may be due to the seed hardening which induces the hyper alert to the per-germinative metabolism that imprint in seeds as a "sort of stress memory" (Chen and Arora, 2012) [5] . Higher root length, shoot length, seedling length and seedling dry weight may be due to the effect of released nutrients from prosopis leaf extract that protects tissue decay of storage organ by hydrolysis. These similar results were exactly coincides with the findings of Shehzad et al. (2012) [13] . These biocontents may also synergistically interact with Amino Acids especially in the formation of IAA (Indole acetic acid) in germinating seeds in order to bring the enhancement in seedling growth. Similar results were reported by Kamaraj and Padmavathi (2012) [9] in green gram. Physiologically active substances present in the prosopis leaf extract have activated the embryo and other associated structures that results in absorption of more water due to cell wall elasticity and results in the development of stronger and efficient root system, that leads to the hike in vigour index. (Basra et al., 2006; Farooq et al., 2005) [1,6] . The seeds hardened with prosopis leaf extract showed significantly higher values for the growth and yield parameters viz., field emergence (94%), plant height (40.10 cm), days to 50% flowering (32.60), number of branches/plant (5.21), number of trifoliate leaves/plant (13.48), number of pods/plant (32.87), seed yield/ha (1251.53 kg) and 100 seed weight (6.21)against control (Table 2). Rapid and uniform field emergence is the two main essential pre-requisites to the increase in yield. This uniformity in field emergence was achieved by the prosopis hardened seeds. According to Niranjanamurthy et al. (1991) [11] , uniformity and percentage of seedling emergence was by the prosopis leaf extract which supplies the bio active materials such as gibberellins to the seed that plays an important role in seed emergence. The increase in plant height is due to the gibberellin translocation to the plant aerial parts, which is more enough to increase the hypocotyl size and the subsequent increase in first nodal height hence it is perfect and that shows positiveeffect on plant height (Renugadevi and Vijayageetha, 2006) [12] . The increase in yield parameters would be due to the allelopathy chemicals present in the prosopis leaf extract that helps in triggering the gibberellins synthesis that further improves the germination percentage by quickening all the other further process, so consequently leads to the increase in better crop growth and development. The prosopis leaf extract hardened treatments have improved the plant growth during crop early stage with the increased vigour and strong root system that in turn have favoured the available soil moisture derivation and the nutrients enabling the good growth and further results in the greater yield (Jegathambal, 1996) [8] . Hence it is proved from the present study, in order to obtain the maximum profit pre sowing invigoration is one such technological highlight focused for the betterment of the crop. Here among all the treatments seed hardened with 6% prosopis leaf extract is recommended for the quality seed production and productivity in black gram.

Conclusion

Prosopis leaf extract @ 6% hardened seeds recorded higher seed quality, plant growth and yield parameters in black gram. For better quality seed production in black gram the usage of 6% prosopis leaf extract is confirmed and it can be recommended for quality seed production in black gram.

Acknowledgement

AcknowledgementI wish to extend my heartfelt gratitude for unwavering support and guidance to all individuals who contributed to the successful completion. My special thanks to my chairperson, Dr. S. Padmavathi, Professor, Department of Genetics and Plant breeding for her motivation.

References

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