Preliminary studies in 1992, demonstrated high yields, simple production practices and relatively long vase-life for cut pod stems. The objective of this study was to determine the number of cut stems of hyacinth bean pods that could be produced, the seasonal variation in production, the impact of plant density on cut stem production, and the number of pods produced per stem.
Hyacinth bean seeds were planted May 1 of both years into MetroMix 510 in 10 cm pots and grown in a greenhouse (17° night/25°C day) for 4 to 5 weeks. Plants were fertilized once per week with 100 ppm nitrogen from 20-4-16 fertilizer. Plants were transplanted to the field in the first week of June. Plants were irrigated when necessary during the summer and fertilized monthly, through August. Pesticide applications for grasshoppers were necessary in mid summer both years, but no other insect pests were a problem even though many were present in adjacent fields.
Although there was no significant effect of density on stem production per linear meter of row in both years, the highest production was achieved with the denser planting (Table 1). This relationship between plant density and yield was also demonstrated by Singh and Pandita (1980) at higher plant densities.
As plant density increased, cut stem production per plant decreased proportionately (Table 1). Hyacinth bean is a very vigorous vine and individual plants grew to fill the space on the fence. The mean number of commercial quality cut stems harvested per plant was as high as 55 cut stems per plant in 1993. The relatively low plant densities used in this study still did not identify the maximum yield that could occur on a per plant basis. The lowest plant density used by Singh and Pandita (1980) was approximately 1.5 plants/m and had a mean yield of 19 inflorescences per plant.
Cut stem lengths varied from 25 to 90 cm. The percentage of stems in standard cut flower grades were nearly identical in both plant densities in both years (Table 2). In 1993, approximately 60% of the stems were in medium stem length grades (46-55 cm and 56-65 cm) with just over 10% in the long stem length grades. Longer stem length grades were dominant in 1994 because the harvest period was short due to cool Sept. weather. Longer stems were more common in the early harvests than in later harvests in both years so the 1993 harvests included many shorter stems from the later harvest periods.
Over 80% of the total harvest of cut hyacinth bean stems occurred in the first two weeks of harvest in late Aug. in 1993 and 1994 (Table 3). Yields were so high that harvest occurred on 2-3 day intervals for 12-15 days. However, the number of stems harvested dropped quickly after the first two weeks. It was hoped that harvest would occur over 6-8 weeks, but this was not the case.
The number of purple fruit ranged from one to 30 per cut stem. The mean fruit number was nine fruit per stem regardless of plant density within the rows. Singh and Pandita (1980) measured a mean of 13 fruit per stem on supported plants. Approximately 90% of the cut stems had 4 to 12 fruit on each stem (Fig. 2). This number of fruit per stem was appropriate for use as a cut stem in flower arrangements.
|Mean number of commercial|
quality cut stems
|Year||Plant density |
|Per plant||Per m|
|Distribution of cut flowers (%)|
|Year||Plant density (plants/m)||36-45 cm||46-55 cm||56-65 cm||66-75 cm||76-85 cm||86-95 cm||Total yield (60 linear m)|
|Distribution of cut stem harvest (%)|
|Year||Plant density |
|Aug. 20||Aug. 30||Sept. 10||Sept. 17||Sept. 24||Oct. 1||Oct. 7||Oct. 29|
Fig. 1. Contrast in mean daily temperature in 1993 and 1994 during hyacinth bean harvest.
Fig. 2. The distribution of fruit number per stem of all cut hyacinth bean stems in 1993.