Effect of cow dung slurry seed treatments on germination and seedling growth in Melia dubia

Introduction

Melia dubia, often known as Malabar neem, is a member of the Meliaceae family having a chromosome number of 2n=28, a large deciduous dicotyledonous perennial tree that blooms in the spring. Each endocarp has five locules, housing 1-5 seeds per fruit. The seeds are enclosed in a stony endocarp, pointed smooth and black. The seeds have an average size of 1.5 cm x 0.5 cm and 100 seed weight about 150 g. Melia dubia has the unique ability to grow up to 40 feet in two years from planting and may be mechanically harvested Troup (1998) [10] . Seed dormancy evolved differently across plant species by adapting to the prevailing local environment to trigger germination when conditions suit the establishment of a new plant Baskin, J. M. and Baskin, C. C (2004). Dormant seeds require a dormancy breaking treatment to enhance uniform germination. Several methods such as cold water, hot water, mechanical and acid treatment are used for breaking seed dormancy and to improve germination rates in different forest seeds. Some seed treatment methods may also be used to speed up germination in seeds with permeable coats Botsheleng et al., (2014) [5] . Melia dubia seeds are hard and may they take up to 3 months to germinate without pre-treatments. Natural germination through seeds is less than 25 per cent. So, there is a need to find an appropriate pre-sowing treatment to enhance seed germination. Pre-treatment should aim at breaking the physical barrier to water absorption and expansion of the embryo. The physiology of the seed will be affected by pre-sowing seed treatments. The purpose of seed treatment is to ensure that seeds germinate quickly and uniformly. The application of seed treatment improves the germination rate and germination process. The majority of dry tropical species are orthodox in nature, which remain dormant because of their rigid seed coat. Seeds immersed in cow dung slurry for 48 hours found to produce good germination and seedling growth. Soaking seeds in water improves the seed's physiology, which [2] . Various pre-sowing treatments are routinely employed in nurseries to achieve rapid and uniform germination. Hence to improve seed germination, by using suitable wetting and drying days by using cow dung slurry seed treatment was carried out in the present study.

Material and Methods

The experiment was undertaken in the Seed Science and Technology, CCS HAU, College of Agriculture, Bawal during 2023-24. This summarizes the materials being used and methods being followed to conduct the experiment under poly house condition and described in the following sub-headings. The mature and healthy capsules were collected from college of forestry, Ponnampet, Karnataka (Figure 1) and capsules (100 seeds x 4 replications) were subjected to the seven pre-sowing treatments with three replications as detailed below. On different number of days, the capsules were treated with cow dung slurry for different treatments and then dried for different number of days in each treatment. The process was repeated for three times in each treatment. The sowed (10x 15 cm Spacing) with CRD design and germination of capsule was studied and recorded daily from the commencement of germination to a maximum of 60 days. Cow dung is taken from livestock department and cow dung and water was used in 1: 1 ratio.

Results and Discussion

The results of the present investigation revealed that, the data on all the seed quality parameters differed significantly due to pre-sowing treatments. The Melia dubia seeds, soaked in cow dung slurry for 15 days and dried for 4 days and the process repeated for 3 times (T5) recorded maximum field emergence per cent (73.00 %), speed of germination (2.27), root length (8.60 cm), shoot length (17 cm), seedling length (25.60 cm), seedling dry weight (3200 mg) and seedling vigour index I and II (1869 and 23360 respectively) and minimum abnormal seedling per cent (3.0 %), hard seed percent of (21.0 %), days to initial germination ( 20.0), germination energy (29 days) (Figure 2). Seeds soaked in cow dung slurry for 15 days and dried for 4 days and the process repeated for 3 times (T5) and followed by seeds soaked in cow dung slurry for 15 days and dried for 2 days and the process repeated for 3 times (T4) recorded field emergence per cent (61.00 %), speed of germination (2.13), root length (7.40 cm), shoot length (16.63 cm), seedling length (24.03 cm), seedling dry weight (2700 mg) and seedling vigour index I and II (1466 and 16477 respectively) and minimum abnormal seedling per cent (4.0%), hard seed percent of (32. days and the process repeated for 3 times (T5) recorded maximum field emergence per cent (73.00 %), speed of germination (2.27), root length (8.60 cm), shoot seedling dry weight in Melia dubia, when the fruits were treated with cow dung slurry for 7 days. Sumbali, et al., (2012) [9] , Murugesh, (2011) [7] working on Terminalia chebula and silver oak revealed maximum seedling growth and biomass production viz., shoot length, collar diameter, dry shoot weight, dry root weight, and total dry seedling weight when de pulped fruits of the species were treated alternately in cow dung slurry (24 hrs) followed by 8 hrs of drying. Similarly, Anand et al., (2012) [1] , Sanjay Sharma, et al (2008) [8] reported significantly increased maximum dry root weight, shoot weight.

Conclusion

The study could be concluded that the drying and wetting method in cow dung slurry seed treatments viz., seeds soaked in cow dung slurry for 15 days and dried for 4 days and the process repeated for 3 times (T5) and seeds soaked in cow dung slurry for 15 days and dried for 2 days and the process repeated for 3 times (T4) were found to be best seed treatment in maintaining the seed quality and seedling performance. The 15 days soaking and 4 days draying in cow dung slurry seeds have given higher number of healthy seedlings in Melia dubia which shows that, the wetting and drying seed treatment is economically feasible. This finding can be exploited on commercial basis as best alternative to on-farm treatments. Seed can be treated with cow dung slurry well in advance before sowing.

Acknowledgement

AcknowledgementAll listed authors and Institutes have made a significant direct and intellectual input to the work and given their support for it to be published.

References

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