Agronomic Attributes of Saffron yields in Iran
Many studies were carried out in order to study effective factors in production of crocus sativus. Continue reading this interesting Saffron Express article in order to learn more about age of saffron farms and bulb size effects on the yields.
A brief history
Crocus sativus is an expensive spice and has been grown for a long time in many parts of the world including Spain, Italy, Greece and Iran. Today more than 95% of saffron in the world is produced in Iran and most of this production is from central and southern Khorasan. Crocus sativus is an important cash crop for the small holding in Khorasan province and more than 85000 farmers are involved in its production. Saffron is a family-based crop and most of farming practices particularly picking flowers are carried out by family members or community cooperation. Not only this crop is a cash crop for the farmers but also it has a strong tie with their social life.
Saffron is used locally and it has traditional medicinal uses. Recent reports on crocus sativus as a cancer curing agent has brought more attention to this crop.
Saffron production does not require much water on the saffron yields but timeliness of irrigation, particularly the first irrigation is very important for flower emergence and length of flowering period. Low temperature in autumn is a crucial factor for flower emergence. There are many factors contributing to the yield of crocus sativus. The most important factors are environmental conditions and farming practices such as age of farm, corm size, method of planting, irrigation application, irrigation interval and recent practice of summer irrigation which is not usual practice for saffron.
Materials and Methods
Crocus sativus producing area of southern Khorasan, in these saffron yields 95% crocus sativus is produced, were investigated in four main counties namely Birjand, Qaen, Gonabad and Torbat–Haydarieh in two growing seasons 2001 and 2002. Data were collected from 160 farms with a very diverse criteria including the size (500 m2 to 2 ha), age of saffron fields (1 to 5 year), farming practice (farmers skill) and farming background. A comprehensive survey was made during two years, associated with farming practices such as date of planting, time of first irrigation, time of first flowering period, the amount of manure used, irrigation frequency (including summer irrigation, if any), size of corm, planting method and yield, by personal reference to the farmers and direct monitoring. Climate data were collected from the nearest climate recording station. Statistical analyses were made on the relationship between yield and yield attributing factors and correlation coefficients were calculated accordingly.
Farming practices and phenological stages of plant particularly first time of flower appearance and length of flowering were correlated to the farming practices such as time of irrigation and corm size for the whole area.
Results and Discussion:
Date of Planting
the most frequent date of planting in the area was 1–10th of September, however in Torbat-Haydarieh this practice was more frequent in 10-20th of August and in Gonabad saffron yields 11- 20th of September. Date of planting varied with different geographical locations. In Spain, bulbs are planted during mid-May to early June and in Kashmir mid-July to late August.
In general, two planting methods of hill and row are in practice. In traditional systems, more tendency is towards hill planting where 1 to 15 corms are located in each hill. In general, 14 % of farms are planted through this method. In row planting, corms are planted in rows which are 20cm apart from each other.
Saffron Farm's age
Yield in the first year was low and the maximum yield was obtained in 5th years, but usually saffron farms are kept up to 10 years. With increasing age of farm from 1 to 5, yield was increased. This trend is most pronounced for Torbat–Haydarieh followed by Birjand. Higher saffron yields in Torbat– Haydarieh and Birjand is associated with more suitable farming practices. Age of farms in Iran, which at present are more than 8 years, has been recommended to be reduced to 4 or 5 years, because yield can be improved by shortening the average age of saffron farms from 8 -10 to 4 or 5 years.
Read also: Reproductive biology of Saffron flower
Saffron Bulb's Size
With increasing size of the corm, yield also increased, and there was a good correlation between these two variables. Big corms cause earlier and vigorous flower emergence and therefore higher saffron yields are obtained. This type of corm produces bigger daughter corms for next seasonal growth.
In Torbat–Haydarieh small size corm was not used and the proportion of small size corm was less than 5 % for other counties. Medium size bulb 7 to 10 g was used more than other types in different counties. There are references, indicating that corms with less than 7 g have a low flowering potential and corms with 9 g are the most frequent with optimum flowering potential and corms with 15 g (not frequently used), yield more flower and a saffron yield of 7 kg ha-1 in first year.
Saffron Express team hope you enjoy getting acquainted with the quality of Iranian saffron. In order to gain more information, please find the full article under the name of “Agronomic Attributes of Saffron Yield at Agroecosystems Scale in Iran”, by A. Koochaki, M.A. Behdani, and M. Nassiri – 2006.