The Effects of Planting Dates and Lunar Positions On the Yield of Carrots
Walter Goldstein and Bill Barber
In the Thun system, consideration is made of the position of the moon relative to the twelve astronomic zodiacal constellations, each of which is of unequal size. Favourable planting dates are reputed to exist for root, leaf, flower, and seed crops according to groups or trigons of the twelve zodiacal constellations. I For example, 'root' crops (including carrots, beets, potatoes, onions) are thought to produce the best yields when the moon is in conjunction with the 'earth' or 'root' trigon which consists of the constellations of the bull, Virgin, or goat-fish. Leafy vegetables are thought to produce best in the 'water' or 'leaf' trigon (scorpion, fishes, and crab); flower crops in the 'air' or 'flower' trigon (waterman, twins, scales); and seed crops in the 'fire' or 'seed' trigon (archer, ram, lion).
Maria Thun developed her system partly on the basis of her observations in research gardens. However, the connection between zodiacal constellations and the elements of earth, water, air, and fire are based on astrological associations. 1
Many farmers and gardeners believe that they have confirmed her research in their practical work. However, effects of the zodiacal rotation of the moon (sidereal rhythm) on organisms are unprecedented in the scientific literature. An extensive review of the biological rhythms that are associated with lunar rhythms showed that the phases of the moon relative to the sun (synodic rhythm) play an important role in setting biological rhythms (metabolism, sexuality, behaviour). ' This is especially clear for sea-dwelling creatures and insects, but is also true for birds and mammals, including humans. Less is known about lunar effects on higher plants. Sidereal effects were not reported for any organisms but this does not mean they don't exist.
However, Hartmut Spiess did many years of experiments under biodynamic conditions and was unable to verify the validity of the trigon system.3,4,5,6 Crops of rye, carrots, radishes, potatoes, beans, or peas seemed to respond to other lunar rhythms besides the lunar-sidereal rhythm. For example, Spiess grew carrots in three years of trials and found that they produced the best yield and keeping quality if they were sown a few days before the full moon. These findings agreed with remarks from the founder of Biodynamics, Rudolf Steiner, about the influence of the synodic lunar rhythm on crop growth (Steiner, I997).7 They also agree with the research results of Lily Kolisko, who, working with indications from Steiner, found that many crops, including carrots, grew well when planted just before the full moon. 8 Actually, Spiess found that the different crops he tested responded differently to the synodic rhythm (quarter phases), tropical (movement of moon up and down relative to the ecliptic), and the anomalistic lunar rhythm (movement towards and away from the earth). An overview of his findings was published recently in BIODYNAMICS magazine (Spiess, 2000).6 His results partly agree with traditional moon planting suggestions.5,6 Spiess' results call into question the universal validity of the recommendations that are given in calendars such as Stella Natura, that teach the Thun system. They have also caused controversy within circles of biodynamic farmers and gardeners.
In this paper we describe results from a single year of field experiments that were carried out in Wisconsin to test the effects of planting dates and lunar positions on the yield of carrots. We recognise the limited validity of a single year of field trials on small plots. However, we decided it might be useful to report these results anyway in order to contribute to the present discussion.
Materials and Methods:
In the spring of 1997 an experiment was laid out as a randomised, complete block design with three replications. Three raised beds were chosen to be the replicated blocks and seventeen plots were randomly assigned to each block-bed. Sheep manure compost was applied at a rate of z2, t/ha (to T/acre) to the top of the beds and incorporated while aerating the soil to a depth of approximately 30 cm (one foot) with a hand tool called a 'T-bar', followed by hand spading. The beds were 122 cm (four feet) wide, the planting area on top was approximately I02 cm (forty inches) wide and too cm (thirty-nine inches) long for each plot. A few days after incorporation of the compost we began seeding.
On the day of a given seeding the plots were weeded with a hoe, then six rows of carrots were immediately planted by hand at 15 cm (six inch) spacing between rows on top of the beds. After emergence the seedlings were thinned to approximately 2.5 cm (one inch) between carrots. The variety of carrot used was Rodelika, a selection of Rothilde that originated from the biodynamic breeder Dieter Bauer, from Dottenfelderhof, Bad Vilbel, Germany. This variety was chosen because Rothilde was used in Spiess' experiments and because it produces large yields of high quality.
Seventeen planting dates were chosen to measure the effects of the moon as it passed through sequential zodiacal constellations. We referred to the Stella Natura calendar to choose our planting dates, preferring those days when the moon would be in the middle of a specific zodiacal constellation.' Planting started on April 25 and ended on May 31. Bed preparation and planting time took place at approximately 16:00 hours (4:00 PM).
The beds were irrigated twice in July and August with overhead sprinklers placed so as to produce as uniform a watering as possible. Weeding was done by hand. On October 2, all carrots were harvested with shovels. Only the central 91cm (three feet) of each of the six rows was harvested. Carrot tops were removed and roots were weighed to determine yields.
It is difficult to separate the effect of a specific lunar constellation from the general growth of the crop during the season. In order to do this we used a technique developed by Spiess. 3,4,5 Using this method, our data for average yields on different days of planting were used to calculate a polynomial equation. This equation produced a line that described the general trend of effects that were due to planting at different times in the spring. The data for individual plantings were then compared with the trend line for all of the replicates. The percent deviation from the trend line was calculated. These values were then analysed with a two-way analysis of variance using a statistical analysis package (SAS for the personal computer). We utilised statistical contrasts (single degree of freedom) to compare the yields obtained for each specific trigon with the general yield levels for all other trigons. We also used contrasts to test whether specific planting days that were of interest differed significantly from the general yield level. These days of interest included the day before the full moon (May 27) in order to test the results reported by Spiess. 5 They also included the days when planting coincided with a lunar phase transition (the new moon and the moon in third quarter or May 6 and May 29 respectively).
The results of the individual planting dates are summarised in Table 1 (not included yet). Yields were unexpectedly high and tapered strongly as the season progressed. The initial four planting dates produced an average yield Of 97 t/ha (forty three T/acre). The last four planting dates produced an average yield Of 56 t/ha (25 T/acre). The yield data, expressed as deviations from the seasonal trend, showed a lot of variation. These data fit a normal distribution, which allowed us to continue to analyse the data further without any numerical transformation.
The relationship between the day of planting in the course of the season and the yield and seasonal trend is shown in Diagram i. The polynomial equation that described the seasonal trend is:
According to this equation the day of planting accounted for 85.4 percent of the variation of the yield (p< 1 %). The effects of different planting dates can be more easily visualised by standardising the trend line at too percent and showing yields on sequential planting days as percentages of that (Diagram 2 )(not included yet).
Visual inspection of the diagrams suggests that the variations in the yields of carrots were often great at the quarters of the moon according to the synodic rhythm. Relative low yields are noticeable when planting occurred at the new moon and the third quarter. The highest yield relative to the trend-line was achieved when planting occurred just before the full moon.
At question is whether effects of phases or trigons had statistically valid effects on carrot yields. Scientists generally only accept the validity of differences if statistical tests of probability are 95 percent certain (P = 5%). There is some willingness to accept that there may be some level of significance when the probability is go percent certain (P=10%). In general, the lower the level of p the more acceptable the idea that a significant difference might exist.
The variability of the yields for different planting dates was high for some dates and not for others (Table 1, data for standard deviations), which probably indicates some variability of soil within the beds. The analysis of variance of the data showed that overall effects of individual planting dates relative to the trend line differed only at p = 10%. The contrasts showed that planting during the root trigon tended (P = 7%) to lower yields by 7 Percent (5.1 tons/ha or 2.3 T/acre) compared to planting during other trigons. There were no effects due to planting during the other trigons.
On the other hand, planting one day before the full moon had the highest positive effect, by causing an increase of yield by 15 percent (11.55 t/ha or 5.1T/acre). This percent increase was statistically significant at p = 1%. Planting during the new moon seemed to decrease yields by 12 percent (10.9 t/ha or 4.9 T/acre) but the significance level was p = 11%. Planting during third quarter reduced yield by 17 percent (9-7 t/ha or 4.3 T/acre). This contrast was significant at p = 2%.
The results from this trial are of limited value because they describe only a single year of trials on small plots. Furthermore, the overall F test for significance of differences between planting dates was only marginally significant. Nevertheless, the results seem to indicate that planting carrots according to the root trigon did not have a positive effect on yield at our site. The variations in the data also indicate that synodic lunar phases may play a more important role for carrots. The results are in agreement with results obtained by Spiess in that the highest relative yields were achieved when carrots were planted just before the full moon. 5 The variations of yield associated with different plantings and lunar positions may be of economic importance under commercial conditions. However, it is also important to recognise the overwhelming significance of an early planting for the yield of carrots, at least in 1997 on this site.
The issue of bias in attitude is often mentioned by practitioners in relationship to research in biodynamics, especially in regards to a subject as controversial as that of lunar plantings. We do not think that bias was a pertinent issue in our experiment. In this experiment Walter Goldstein set out the experiment, analysed the results, and wrote this paper. The vast majority of the field-work (including weeding, planting, harvesting, and weighing yields), was carried out by Bill Barber. Both researchers strove to maintain an open mind towards the planting calendar and dates chosen for the experiment. In fact, Bill, who did sixteen out of seventeen plantings, knew hardly anything about the controversy with the Thun planting system at the time of the experiment.
Walter Goldstein holds a Ph.D. in agronomy and is Research Director and Education Coordinator at the Michael Fields Agricultural Institute, W2493 County Road, ES, East Troy, Wisconsin, 53120. He is currently involved in a number of research projects and travels throughout the US and abroad to consult with prospective biodynamic farmers. He has a thirty-five acre Demeter certified farm with 150 sheep.
Following excerpt from report by Malcolm Gardner
Dr. Spiess reported the results of this and several other experiments already back in 1990 in the English-language journal, Biological Agriculture and Horticulture, vol. 7, pp. 165-189. Regarding his work with radishes over three years, he wrote (p. 187): "the long-term results found here do not confirm the relationship between trigons and root