Panama disease include mostly sanitation and quarantine practices to prevent the spread of Panama disease out of infected fields. However, the most effective tool against Panama disease is the development of banana trees resistant to "Fusarium oxysporum f. sp. Cubense". Unfortunately, the clonal reproduction of banana has led to a consequential lack of other varieties. Efforts are being made to produce resistant varieties, but with bananas being triploids which do not produce seeds, this is not an easy task. Creating clones from tissue cultures, rather than suckers, has proven somewhat successful in breeding resistant varieties, however, these tend to have decreased success
Crop circle alleged 'cattle mutilation' sites." (in reference to cattle mutilation). A study by Eltjo Haselhoff reported that the pulvini of wheat in 95% of the crop circles investigated were elongated in a pattern falling off with distance from the centre and that seeds from the bent-over plants grew much more slowly under controlled conditions. Furthermore, traces of crop circle patterns are sometimes found in the crop the following year, "suggesting long-term damage to the crop field consistent with Levengood's observations of stunted seed growth." In 2000, Colin Andrews, who had researched crop circles for 17 years, stated that while he believed