text: The effects fl|ay be classlfied in three (a) Restrictions on the acquisition ofof their subsidiaries in third counCries, (b) Acts of biological aggressiont (c) Restrictions on the acquisition of ne!,technology.groups: products of United States companies or and advanced phytosanitary 72. The most lridespread means of contror.ling pests, diseases and weeds is the useof insecticides or pesticides. Before 1961, these products were traditional.ypurchased in the united states froo a side range of companies. A1l this trade wasrestricted by the economic b!,oackade lnrposed on cuba by the united states in 19G2. 73' The effects of aggression rere mrre acutely felt after the second harf of the1960s, \dhen the Revolutionary Government expanded its plans for increasingagricultural production. Farmers vrere unable to use the carbon-baged insecticidesand fungicides or herbicides derived from ureic acials that were producedexclusivery by libr th American firms such as Rohm and llaas, Du pont de Nemours,union carbide and others untir their patents expired anar they could be produced byother European and Japanese firms. 74. only recently, tbe BASF company of the Federal Republic of Germany rdasprevented from delivering a sample of the product ,,Aviso Mn to cuba because itcontained a substance exclusive to Du pont de Nemqurs. 75. rn 1971. at a time ehen rnajor efforts uere being ''Ede to i-ncrease lheproduction of pork and pork products, African swine fever was diagnosed r.n cuba,for the first time on the American cont.inent. rnvest.igarions i.nto the origin ofthis epidemic led to the concrusion that it had been introduced through thecriminal activities of tbe Uni.ted States Central Intelligence Agency. 76' More than 470'000 pigs had to be srauqhtered because of the disease, affectingconsumption on the domestic market and eventually halting pork exports because ofLhe fear of other countries that their territories might be conlaminated.
analysis: The text appears to be discussing the economic and environmental impacts of biological aggression and trade restrictions on Cuba's agricultural sector. It highlights the effects of the US trade embargo on the availability of certain agricultural products and technologies, as well as the introduction of diseases such as African swine fever. The text also mentions the consequences of these events on Cuba's agricultural production and exports.