COMPARISON OF 5 ORGANIC AMENDMENTS FOR TH E CONTROL OF GLOBODERA-PALLIDA IN MICROPLOTS IN PERU

The effect of five manures on the reproduction of Globodera pallida ra ce P5A and the yield of potato cv. Revolucion (Solanum tuberosum ssp. andigena) was studied in microplots. Tubers were planted in washed ste rilized sand amended with cow, horse, sheep, chicken or guinea pig (Ca via porcellus) manures to achieve an organic content of 4% (18.8 T/ha) . None of the manures was phytotoxic. In non inoculated microplots chi cken and horse manure increased tuber yield 128% and 85% respectively. In inoculated microplots all the manure except horse manure increased tuber yield significantly compared to the control. Chicken and horse manure reduced significantly the number of cysts per 100 cm(3) of soil and the multiplication rate (Pf/Pi) of G. pallida by 96% and 35%, res pectively. Chicken manure was the best control alternative overall in terms of tuber yield, decreased nematode reproduction on potato, and e conomic rate of return of the crop.