Having 'cheap' cotton would make some difference, especcially in the south, and might change the economy of soutthern spain. Otoh, i dont think it will be cheap enough for britain to abandon linen, for innstance.
One problem is that growing cotton is extremely hard on soils. Even if Al-Andalus managed to acquire and grow Indian cotton, how much land is available for expansion as the original cotton fields wear out? What are the sources of labor for the labor-intensive jobs of cultivating, picking and processing cotton? Simply importing Indian cotton seeds is only the beginning.
Indeed, but with a good commercial couverture for investment, Al-Andalus lands could have enough with the Algrave's lands (that cover quite the needs of cotton culture with rain between november and March, sunny sky the rest of time.
Don't forget that Al-Andalus is the major region, with Sicilia, of cotton production in Europe.
If Al-Andalus manage to keep the "good lands" for Indian cotton, having a better production together with arabic seeds, it would be a good start.
For information
[URL="http://www.elizabethancostume.net/cibas/ciba64.html" said:
This website[/URL]]As a result of such detailed study, cotton growing in Spain soon began to flourish, and maintained its position for many centuries. As late as the eighteenth century the English traveller Richard Twiss described the cotton fields on either side of the road from Cordova to Ecija with the yellow and red blossoms of the plants, and he wrote with admiration of the rich crop yielded every year by the plantations. These cotton plantations contributed at an early date to the fame of the workshops of Granada. When Abderrahman III (912 to 961) began to restore the prosperity of the country after the ravages of war, and to revive industries which had declined ever since the period of Roman occupation, Arabs and Moors were commissioned to instruct the natives in the various trades. One craft in which they excelled was leather working, another was weaving, which they practised with equal skill in silk, flax, hemp, and cotton. In the fourteenth century cotton cloth was made in Granada which was used as a dress material, and which in the opinion of Ibn Alchabid, who wrote a history of Granada, at that time was superior in softness, purity of material, and in beauty to the fabrics of Syria. The dye used in dyeing this material was madder.
Al-Andalus have the soils, the infrastructure to support indian seeds-based reconversion.
Mrs. MNP actually is a big time fiber arts aficionado, but as she frustratingly points out to me when I ask, her interests lay in the present and not the history of those crafts. I actually am VERY interested in your suggestion of Languedoc being like Flanders. What makes you say that? Does it have the natural resources to make lots of fabric?
For christian side, same site.
In Christian Catalonia, too, cotton weaving must have been established at an early date. Already in the thirteenth century the "fustaneros", the weavers of fustian, were organized in a guild, and old street names show to this day where they carried on their trade. In some towns the weavers were obliged to transfer their activities to the outskirts of the town, as the neighbours complained to the municipal authorities of the annoyance caused to them by the proximity of the workshops. Fourteenth century laws not only inform us that the sale of fustian was under official supervision, we also learn something of the regulations which the dyers of these fabrics had to observe. Records of the activities of the fustaneros take us down to the fifteenth century; for the most part these records are regulations for the sale of pure cotton or mixed fabrics and also penalties for bad work. It would appear that this branch of the Spanish textile crafts did not survive the fifteenth century; it seems to have been replaced by the silk industry which began to prosper greatly about that time.
For Mrs.MNP, it is possible to have an hybrid between indian and arabic cotton, and it is possible to have then a plant with the softness of indian and the more "rustic" needs of the arabic?
For Languedoc (Mmm, if you're interested to, i would better copyright it for EaH sooner than i tought first

), well if Al-Andalus manage to improve its production, there's two option : or export it to Italy by sea with the concurrence of Tunisian and Egyptian cotton, or to export it in Catalonia and Languedoc, improving the pre-industrial manufacturing production here. As the catalan and provencal harbours were quite active in Mediterranean sea (critically with a non-sealed one), it's not imlausible to me that we would have a land arch between Valencia and Marsèlha, wool and silk based and with a better commercial role than OTL, maybe even concurrencing Italy.