Al- Maruf
There are usually four (seasons) of silk yarn produced in Rajshahi in a year. But due to rising temperature and humidity, good yarn is no longer produced in two seasons. Generally 21 to 29 degrees Celsius is favorable for silkworms. But in Rajshahi the temperature rises very high in summer and falls very low in winter. Both of these conditions are harmful. Because, silkworms or silkworms do not grow properly, but die.
In such adverse conditions, farmers have to work extra hard to produce silk yarn. It also increases their expenses. According to research, the temperature has increased the most in Rajshahi and Barendra regions in the country due to climate change. The sericulture farmers are suffering from this.
A tradition of thousands of years
Silk cultivation has been going on for thousands of years in Rajshahi and Barendra region. It is for this tradition that Rajshahi Silk is recognized as a GI product. And Rajshahi district has also been branded as ‘Silk Heaven’ or ‘Silk Paradise’. Mulberry leaves have to be cultivated for silk. Because these leaves are fed to silkworms. Later the saliva secreted from their mouth turns into silk thread.
What the research says
A private development organization (NGO) named Bangladesh Resource Center for Indigenous Knowledge (BARSIK) has worked on the impact of climate change on sericulture. The study titled ‘Investigation on Silkworm Rearing and Climate Change’ has highlighted the problems sericulture farmers are facing due to climate change. During Barsik’s research, information has been collected on the basis of specific questionnaires from silk farmers of Chapainawabganj and Rajshahi districts of Barendra region. This study was conducted from March to May this year.
Effect of temperature variation
The data obtained from the research shows that due to the variation in temperature, silkworm cultivation and yarn production is more or less. Due to the increase in temperature in the global atmosphere, the temperature is increasing at an excessive rate in the Barendra region of Bangladesh as a tropical region. The overall average temperature change rate of the region in the last 100 years is 2.8 degrees Celsius, which is higher than the rest of the country. Rajshahi recorded a temperature of 41.2 degrees Celsius in April this year. At the same time, the temperature of Rajshahi drops drastically in winter.
Generally, a temperature of 21 to 29 degrees Celsius and 90 percent air humidity is suitable for rearing insects. If the temperature and humidity are more or less than this, it affects their behavior, development, survival, growth and reproduction. In short, due to climate change, pollutans do not grow naturally, but often die. As a result there is less yarn in the skein.
Four ‘bands’ of silk yarn production
Earlier all the people in the village used to cultivate silk, but now only one or two families do this work. Due to high humidity ‘Jaishtha Bande’ silk production was not good. The insect has perished.
Jaishtha, Bhaduri, Agrahayani and Chaita—these four bands produce silk yarn in Rajshahi. Due to increase in temperature and humidity, production in Jaishta and Bhaduri banks is not good at the farmer level. If the temperature is too high, the farmers hang wet cloths on the windows of the house and put lime inside the house to reduce the humidity. This native method works somewhat.
Trust in the problem and ‘needle’ insects
According to the research, the sericulture in Barendra region is also being negatively affected by climate change. This causes problems in the life cycle of the silkworm.
There is a native silkworm breed called ‘Nistari’. It is more tolerant than other types of insects. Therefore, taking into account the effect of climate change, it is necessary to push ahead in the cultivation of indigenous silkworms, so that the silk industry of Rajshahi can develop.