Testing the Adaptability of Growth of Finger Millet (Eleusine carocana) in Mansfield, Ohio During the 2017 to 2019 Summer Growing Seasions

by Peter Emau

One objective of EMAU FARM's sustainable agriculture program is to establish and preserve grains such as finger millet- that has been used for many generations as stable food in many regions of the world. Birds, including poultry, also love to eat millet.  Specifically, the objective is to test the growth, of different varieties of Finger Millet from India and Africa in Ohio, US. 

The challenge for Ohio is that growth of Finger Millet is affected not only by the climatic conditions, but also by the photoperiodism (.e. Finger millet is a Short-day plant, for which onset of flowering requires long nights of approximately 12 hours ).  Thus, plants will need to be ready to start flowering by August- September (when the day-length decreases from 13 or less hours/night-length increases from 11 or more hours a day).  The ideal variety would be that which requires 10 - 11 hours of darkness to start flowering; which would mean it starts flowering by early August, and thus have enough time for seeds to mature before the onset of frost - which can occur by end of September.

Therefore, we tested the ability of Finger Millet to grow and adapt in Richland County, Ohio located at latitude of 40.7567° N, and longitude of 82.5186° W.  No previous reports exist for growing Finger millet in Ohio.  However, the warm-hot summers from June through September, with adequate rains throughout the summer could provide conditions supportive of Finger Millet cultivation for grains and summer forage.  The challenges are the cold and/or wet soils in April-May (which can hinder the start of planting), the short-day length (i.e., long-night) requirements for induction flowering in finger-millet, and the onset of early frost in the Fall which may cut-short the flowering and maturation of finger-millet. Despite these challenges, we are testing the ability of different finger millet accessions to grow in Ohio climatic conditions and select accessions that show rapid growth from germination to early flowering and maturation of seeds.

Using morning soil temperatures to identify optimum planting for Finger Millet in Ohio

In September 2016, we obtained germplasm of Finger Millet (approximately 200 seeds of Accession number PI 302662, origin, India, Himachal Pradesh, 1964) from the US National Plant Germplasm System (NPGS) and planted them directly into the soil at the end of May 2017 (when soil temperature was at least 15°C (60°F).  We placed 150 seeds directly into soil in the outside garden as a single row at 10 mm depth and 25-30 mm between seeds.  The soil was silt loam with approximately 16% clay, 64% silt and 27% sand. In the second seeding, the seeds from the 2017 harvest were broadcasted directly into soil in outside garden plot and covered with soil at a depth of approximately 10 mm. Second seeding was conducted in the second week of May when soil temperatures were above 12°C. The results of growth (days to first flowering and maturation) of the PI 302662 in Mansfield, Ohio are summarized in the Table below.

Seeds planted	Origin	Date planted	Soil temperature at planting	Days to first flowering	Days to seed maturation  (ready to harvest)
Original seeds received. (Accession: PI 302662)	India, 1964	22 May 2017	16.4°C	91 (20 August 2017)	133 (01 October 2017)
Seeds from 2017 harvest)	Ohio, 2017	08 May 2018	12.9°C	91 (09 August 2018)	133 (22 September 2018)

The observation that the days from planting to first flowering and maturation is the same for the original and seeds from the 2017 harvest; suggests that the duration of growth is maintained from year to year.  In addition, the observation that the date of first flowering was in August (second to third week) of each year, suggests that flowering starts in the descending curve of daylength as the daylength shortens and night length increases.  The observation that PI302662 accession completed this process before the onset of frost- indicates that this accession can be adaptable for growth in Ohio.

 In the year 2019, received and tried to expand additional 20 varieties of Finger millet from the African countries- Zimbabwe, Zaire, Ethiopia, South Africa, Kenya, Uganda, and Zambia. Many of the varieties failed to germinate due to poor viability of the seeds; those reported with viability less than 20% for seeds had less than 2 seedlings and failed to expand.  Those that grew were subjected to selection of 1) must have at least 10 plants by the time of flowering, 2) must have at least 30% of those plants flowering by the end of August, when the  hot summer is coming to an end, and 3) must have adequate mature seeds by the time of first frost in Mansfield, Ohio (i.e. by mid-October).  Thus, the selection criteria was based on rate of germination and growth to mature plants; percent flowering and rate of  seed maturation and finally percent yield - by estimating the number of seeds per finger head of a mature finger millet.  In addition, the size of the seeds and folding structure and numbers of the fingers of each plant head was considered.  Based on these criteria, the different varieties were ranked for each category/criterion and the total points was determined for each variety.  From these, eight varieties were selected for growth/expansion in 2020 growing season.  These varies were from Zambia, Zaire (2), Ethiopia (2), Kenya (2) and South Africa Transvaal.  Overall, the variety from Transvaal was the best in terms of early maturity and yield. One variety from Ethiopia was also fast growing and early maturity abut poor yield because the structure and form of the head looked more like grass than millet, therefore seeds were small.  This variety was stopped from further development.  The varieties from Zaire and Kenya, although promising, had poor germination rate and slow growing so that any seeds obtained in 2019 was lost in 2020- because the warm growing season started later in 2020 than in 2019.

			Percent (%) flowering of different finger millet accessions at approximately weekly intervals during flowering season in 2019.
Accession	Origin	Viability (%)	14 September Day 105	21 September Day 112	29 September Day 120	09 October Day 130
PI225892	Zambia, 1955	55*	30.8	61.5	76.9	100
PI247841	Zaire, 1958	5*	9.1	72.7	81.8	100
PI248523	Zaire, 1958	31*	53.8	73.3	80	92.9
PI251627	Ethiopia, 1958	100	2.6	14.6	31.7	90.2**
PI307693	South Africa, 1965	82*	55.9	93.8	100	100
PI318897	Ethiopia, 1967	32*	87	100	100	100
PI321083	Kenya, 1967	59*	17.6	80	100	100
PI321084	Kenya, 1967	20*	33.3	66.7	66.7	100
PI226270	Zimbabwe, 1955	86	100	100	100	100

 

Planted all accessions on 28 May 2019 directly into soil in outside garden plot. Seeds were planted in rows (single row per accession) at depth of 10 mm and 25-30 mm between seeds within a row. *Some Accessions were replanted on 10 June 2019 due to poor germination (except for PI251627 which had good germination by 10June 2019).  All accessions germinated by 18 June 2019 (19 days after planting).  However, when replanting is considered, germination is considered to have occurred between 11 – 19 days after planting.

The following accessions were also planted on 28 May 2019 but failed to germinate:  PI225569 (0% viability); PI 248524 (1% viability); PI273887 (unknown viability), PI 321086 (0% viability), PI 321114 (7% viability), PI321125 (33% viability), PI 321126 (82% viability); PI321127 (2% viability), PI321129 (6% viability), PI321130 (0% viability), and PI358593 (0% viability).  Based on these observations, poor germination was due to a combination of low seed viability and too much rain and waterlogged soils in May 2019. 

First flowering occurred by 12 August 2019 for accession PI 226270; and between 02 – 13 September 2019 for the rest of the accessions. The flowering head of PI226270 (Eleusine coracana subsp. Africana) was like that of Eleusine indica (Indian goosegrass). It had the most rapid, abundant growth with earliest maturation of seeds.

Except Accession PI251627, other accessions developed mature seeds ready for harvest by 02 November 2019 (i.e., within 160 days from planting despite onset of freezing conditions).   Accession PI251627 had the slowest rate of flowering and failed to develop mature seeds, despite early germination (likely due to high viability of original seeds.

Illustrations below show our suggested optimal growing Season of Finger Millet in Mansfield, Ohio- based on the results of 2017 to 2019 tests relative to soil temperatures and day-length.