By Abdelrahman Hassan Abdellatif
In Sudan, cotton is indigenous and a number of its wild relatives grow in various parts of the country. It is a way of life, reducing poverty and encouraging settlement in rural areas. The bulk of production, nearly 90% , is exported as raw fiber, while the remaining 10% is locally consumed, making it an important economical cornerstone. Sudan has, however, faced a serious stickiness problem which has affected yields and pricing.
One of the groups working to counter this issue is the Agricultural Research Corporation (ARC). An intensive program that develops new varieties, increases yields, and improves quality to meet consumer demand, ARC has focused its efforts on the stickiness contamination.
Stickiness was first observed in Sudan in the early 1960s, but was sporadic at that time and of little importance. During the 1980s, however, the phenomenon became a worldwide issue that garnered ARC's attention.
The first order of business for the group was to manipulate the morphological and physiological characters of the cotton plant in such a way so as to reduce the whitefly population and allow for easy biological, chemical, and cultural control. This effort resulted in very promising leads such as the identification of the type of sugar responsible for the contamination.
ARC continued its research and, in a very short time, findings were revealed. Evidence showed that the distribution of honeydew in a plant was a major variable . The level of cotton stickiness was higher in lint collected from bottom and middle of the plant compared to the top. It was also found that the medium staple cotton (Acala) showed a higher stickiness level compared to extra-long staple cotton (Barakat).
Furthermore, whiteflies usually prefer humid, warm, and shady conditions, as well as protection from wind. Hirsutum (Acala) varieties are hairy and bushy, making them more susceptible to whitefly infestation.
From 1998 to 2000, The Global Research Program (Sudan-France), financed mainly by the Common Fund for Commodities (CFC), was entrusted with the goal of developing an objective methodology to control stickiness. The Global Research Program began to separate sticky fiber from non-sticky fiber so the unaffected parts could be sold at a fair price. The efforts revealed considerable variability in stickiness levels among the cotton production areas, and considerably lower levels of stickiness were observed in some schemes.
Research continued, and practical knowledge on preventing stickiness was shared across Sudan. Of these new methods, decreases in insecticides use, early picking, and improving cultural practices seemed to yield the best results.
According to the recent International Textiles Manufacturers Federation Survey, a better rate of stickiness in Sudan has been consistently reported since 2000.
