EFFECT OF SIMILAR APPLICATIONS OF TWO SYSTEMIC NEMATICIDES ON SUGARCANE, VAR. SP 79 1011, AT TWO DIFFERENT ENVIRONMENTS AT NORTHEASTERN BRAZIL. PART 1. OBSERVATIONS ON PLANT CANE

Abstract

Two experiments were installed in two large sugarcane fields at two differentmunicipalities in the state of Pernambuco. The first, with the start in August2004 in Carpina county, had deep-dark to black sandy-loam soil, with highfertility and level of organic matter. The second, in Goiana, with the start inDecember 2004, had white sandy and poor soil fertility and low level oforganic matter. The objectives of these two experiments were to study theeffect of two different systemic nematicide; carbofuran, a carbamate, eterbufos, organophosphate, applied at planting, on sugarcane (Saccharum sp.)var. SP 70 1011, growth and yield, and on Pratylenchus zeae reproduction. Thisorganism is a migratory endoparasite plant nematode, highly virulent tosugarcane. Both fields received the same following up including irrigationtreatments. Both areas had more than ten years of sugarcane cropping andhigh population levels of the nematode at the initial population (Pi). Theexperiments pointed out dissimilar results in the two localities. In Carpina,the nematicide terbufos was the only to increase yield (15,9 % and 22,3 t/ha). In Goiana, the best was carbofuran (9,7 % and 8,7 t/ha). The treatmentseven expressive didn’t differ from checks growth. At month 3 after treatments,in both experiments, the nematicides strongly suppressed nematodereproduction but this effect disappeared at month 12 in Carpina when thepopulation levels became equivalent to the check. This was not true forGoiana with high nematode population control at month 12. In bothexperiments at the harvest time the final populations (Fp) were very close tothe level considered high (P> 1000 specimens/sample).