[2] This epic effort brought to light the main contents of the book, a wealth of botanical information on Malabar that had largely remained inaccessible to English-speaking scholars, because the entire text was in the Latin language.

In January 2020, Manilal was conferred with the Padma Shri award, the fourth-highest civilian honour in India, for his contribution to the field of Science and Engineering.

Manilal's efforts ultimately resulted in an English edition of Hortus Malabaricus, for the first time, 325 years after its original publication from Amsterdam.

[9] Based on this work, initially a concise reference book: An Interpretation of Van Rheede's Hortus Malabaricus, was published (with his collaborators) from Berlin (1988), by the IAPT.

This remains the only book by Indian authors published by them (IAPT) till date and is an essential resource in study on the taxonomy of Southeast Asian plants.

[11] The compilation and publication of Hortus Malabaricus is intimately connected with the history of India, politics of the 17th century Netherlands and the then social conditions of Malabar.

Manilal studied these aspects for over 35 years bringing to light many interesting facts, some of which were included in his book: Botany & History of Hortus Malabaricus, published from Rotterdam and Delhi (1980).

In the research paper published in the journal Global Histories, entitled "Plants, Power and Knowledge: An Exploration of the Imperial Networks and the Circuits of Botanical Knowledge and Medical Systems on the Western Coast of India Against the Backdrop of European Expansionism", Malavika Binny states that Kerala had medical traditions that existed even prior to Ayurvedic tradition.

Manilal pioneered taxonomic research and biodiversity studies in Kerala by training a genre of young taxonomists and identifying and cataloguing local plants in biodiversity-rich South India.

These studies have, besides seeing the flower as the most significant part of the plant, with biological, commercial, aesthetic, evolutionary and taxonomic importance, also promoted success in hybridisation and breeding experiments, to create new high-yielding varieties.

As the beaches in southern Kerala and Tamil Nadu (particularly in the Districts of Kollam and Nagarcoil) have natural deposits of radioactive minerals causing genetic damage to flora and fauna, Manilal undertook studies to familiarise with the techniques of research in the field of radiation ecology.

It was found that these species could absorb and adsorb as much as 40 times their body weight of the radioactive Thorium compounds from surrounding seawater, and continue to live normally.

About ten years later, some British scientists did a similar work and their results were published in the prestigious U.K. journal Nature, and wide publicity in the press as a biotechnological break-through.

Manilal, as founder President, established IAAT in the year 1990 with its headquarters located at the Department of Botany, University of Calicut, Kozhikode, India.

During the years 1972–1998, he and his students discovered over 240 new species of flowering plants and several new records for India from Kerala, and published many research papers in Taxonomy in national and international journals.

The Centre does research and field experiments to establish the (taxonomic) identification of fast-growing fuel-wood trees suitable for various agro-climatic zones of Kerala.

[16] This assignment of rights was a gesture by Manilal in good faith and in response to a specific appeal from the then Vice-Chancellor of the University of Kerala, that the university wanted to generate funds from this publication for utilisation of such royalty incomes toward re-publication of old Malayalam classical works, which are out of print, and not forecasted to generate a viable level of income due to limited sale of such classical works.

In a recorded interview with Manilal in August 2008, he expressed his regret and frustration at the manner in which the publishers subjected him to digression from the publication project soon after he legally assigned his rights as author.