At first are bended to the surface only a small parts, well below one percent, several square meters, the most affected areas. Gradually, day by day, sometime hour by hour or even minute by minute, adds another, until finally, just before harvest maybe lying on the ground sometime around 5%. Sometimes more than 20% of the total area, sometimes, unfortunately, over 90 %.
Mara ya kwanza ni bended kwa uso sehemu ndogo tu, chini ya asilimia moja, kadhaa mita za mraba, maeneo yaliyoathirika zaidi. Hatua kwa hatua, siku kwa siku, wakati mwingine saa kwa saa au hata dakika kwa dakika, anaongeza mwingine, hadi hatimaye, kabla ya mavuno labda uongo juu ya ardhi wakati mwingine kuzunguka 5%.