Adubação orgânica, nutrição e progresso de cercosporiose e ferrugem-do-cafeeiro

The objective of this work was to evaluate the effect of organic nutrional sources on the progress of brown eye spot and coffee rust in coffee plants, between November 2003 and November 2005. The experimental design adopted was the randomized blocks, with four replications and six treatment plots: coffee fruit peel + swine waste (CP+SW); castor bean presscake + crotalaria (CBP+Cr); coffee fruit peel (CP); bovine manure + crotalaria (BM+Cr); coffee fruit peel + castor bean presscake (CP+CBP); and standard fertilization used in the farm, which combines compost, castor bean presscake, swine waste and crotalaria (control). The higher area under the incidence progress curves of brown eye spot and coffee rust was obtained by CP treatment (respectively 62 and 38% higher to control). The larger progress coincided with the increase in leaf potassium and decrease of calcium content in CP, compared to other nutrient sources, and it resulted in higher leaf drop and lower yield. CP+CBP and CP+SW reduced in 38% the brown eye spot incidence, and in 31 and 21%, respectively, the coffee rust incidence, and increased leaf calcium content during fruit filling, compared to CP. The better nutritional status of plants increased resistance to diseases and reduced the variation between 2004 and 2005 harvests.