Germination of tropical forage seeds stored for six years in ambient and controlled temperature and humidity conditions in Thailand

Authors

  • Michael D. Hare Faculty of Agriculture, Ubon Ratchathani University, Ubon Ratchathani, Thailand. Ubon Forage Seeds Co. Ltd., Jaeramair, Muang, Ubon Ratchathani, Thailand.
  • Naddakorn Sutin Ubon Forage Seeds Co. Ltd., Jaeramair, Muang, Ubon Ratchathani, Thailand.
  • Supuaphan Phengphet Ubon Forage Seeds Co. Ltd., Jaeramair, Muang, Ubon Ratchathani, Thailand.
  • Theerachai Songsiri Ubon Forage Seeds Co. Ltd., Jaeramair, Muang, Ubon Ratchathani, Thailand.

DOI:

https://doi.org/10.17138/tgft(6)26-33
Abstract Authors How to Cite

Abstract

The germination performances of fresh seed lots were determined for 5 tropical forage species: Mulato II hybrid brachiaria [Urochloa ruziziensis (syn. Brachiaria ruziziensis) x U. decumbens (syn. B. decumbens) x U. brizantha (syn. B. brizantha)], Mombasa guinea [Megathyrsus maximus (syn. Panicum maximum)], Tanzania guinea [M. maximus (syn. P. maximum)], Ubon paspalum (Paspalum atratum) and Ubon stylo (Stylosanthes guianensis), stored under ambient conditions in Thailand (mean monthly temperatures 23‒34 ºC; mean monthly relative humidity 40‒92%) or in a cool room (18‒20 ºC and 50% relative humidity) for up to 6 years. The first paper of this study showed all seeds, except unscarified Ubon stylo seed, were dead after a single year of storage in ambient conditions. This second paper shows that cool-room storage extended seed viability, but performance varied considerably between species. Germination percentage under laboratory conditions declined to below 50%, after 3 years storage for Mombasa guinea seed and Tanzania guinea seed, 4 years for Ubon paspalum seed and 4‒5 years for Mulato II seed. Ubon stylo seed maintained high germination for 5 years, in both cool-room storage (96%) and ambient-room storage (84%). Apparent embryo dormancy in acid-scarified Mulato II seed steadily increased with time in cool-storage and this seed had to be acid-scarified again each year at the time of germination testing to overcome dormancy. Physical dormancy of Mulato II seeds, imposed by the tightly bound lemma and palea in unscarified seed, was not overcome by length of time in cool-storage and these seeds had to be acid-scarified to induce germination. Hardseeded percentage in Ubon stylo seed remained high throughout the study and could be overcome only by acid-scarification. The difficulties of maintaining acceptable seed germination percentages when storing forage seeds in the humid tropics are discussed.

Keywords: Embryo dormancy, hardseededness, humid tropics, seed storage, seed viability.

DOI: 10.17138/TGFT(6)26-33

Author Biography

Michael D. Hare, Faculty of Agriculture, Ubon Ratchathani University, Ubon Ratchathani, Thailand. Ubon Forage Seeds Co. Ltd., Jaeramair, Muang, Ubon Ratchathani, Thailand.

Michael Hare has been involved with seed production of tropical and temperate forage grasses and legumes for almost four decades in Thailand (tropical) and New Zealand (temperate). In Thailand Michael started large scale machine harvesting of Townsville stylo and Verano stylo in the 1970s and later was involved in a village farmer seed programme of various species which continues until this day. From 1984 to 1994 Michael worked as a herbage seed scientist at Grasslands Division, DSIR, Palmerston North, New Zealand, researching seed production problems on a wide range of temperate species. Since 1994, Michael has worked at Ubon Ratchathani University in Thailand, researching seed production of tropical forages and starting a new village seed programme with Tropical Seeds, a subsidiary of a Mexican seed company, Grupo Papalotla. This programme contracts over 1000 village farmers in Thailand and Laos to produce seed of Mulato II and Cayman hybrid brachiarias, Mombasa and Tanzania guinea grasses, Ubon paspalum and Ubon stylo. Seed is currently being exported to countries in Central America, the South Pacific, other parts of Asia and now Africa. Michael conducts research trials on the above species and is involved in final evaluation of new hybrid brachiaria accessions from CIAT for which Grupo Papalotla has the production rights. Michael is a professor in the Faculty of Agriculture, Ubon Ratchathani University and recently became a Fellow of the Tropical Grassland Society of Australia Inc. He has been author or co-author of 130 papers on various aspects of seed and forages in both temperate and tropical pastures.

How to Cite

Hare, M. D., Sutin, N., Phengphet, S., & Songsiri, T. (2018). Germination of tropical forage seeds stored for six years in ambient and controlled temperature and humidity conditions in Thailand. Tropical Grasslands-Forrajes Tropicales, 6(1), 26–33. https://doi.org/10.17138/tgft(6)26-33

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Published

2018-01-31

Issue

Vol. 6 No. 1: January 2018

Section

Research Papers