Answer:
Nowadays, the technology of mechanical harvesting is focused on harvesting plants of large crops (e.g. wheat,
corn) using special mowers of large size and cost. On the other hand, in spite of the great technological advances,
the harvesting of vegetables, fruits and other corps (e.g. saffron) depends primarily on human labour. This affects
mainly the cost of production, the product’s quality, as well as the safety of workers in crops that have been sprayed
with pesticides (e.g. greenhouses). The main reasons for the shortage of automated solutions are the difficulty in
tracking the corps and the difficulty in simultaneously cutting and collecting the corps without damaging them.
Saffron (Crocus sativus L) is one of the most expensive edible flowers of the world. Iran, Spain, Italy and Greece
are producers of dried saffron. A farm of saffron needs daily and manually harvesting because every plant of
saffron produces only three flowers in different height and days. There are 2170 flowers in each Kg of harvested
fresh flower, and processing every 78 Kg of fresh flowers results in one kg of dried saffron-spice [1].
This final product is actually the stigma part of flower. The stigma, as the only economic part of flower has
eatable and medicinal applications. One stigma of saffron weighs about 2 mg, each flower has three stigmas and
150,000 flowers are required to produce 1 kg spice. Harvesting the flowers and separation of stigmas from the
flower is a most difficult operation. It is time consuming, laborious and makes saffron the expensive spice of the
world. Picking of 1000 flowers requires 45–55 min, and another 100–130 min is required for removing the stigmas
for drying. Thus, 370–470 h is required to produce 1 kg of dried saffron. The flowers are picked exactly when they
are fully bloomed and the saffron strand or stigma is at its reddest. The harvesting must begin shortly after dawn. If
left exposed to the sun, saffron quickly loses its colour and flavour and withers under the sun light. The task includes
picking the flowers and separating the stigmas from the petals and stamens (Fig. 1). Flowers are picked at the base
of the segments, and put into basket in thin layers to avoid excess pressure and deformation of flowers organs,
particularly of the stigmas
Found in: https://core.ac.uk/download/pdf/82425226.pdf
