Yields of 16 Arabica-type Coffee Varieties Grown Under Partial Shade and in Full Sunlight

Abstract

The productivity of 16 varieties of Arabica-type coffee, grown under intensive management in full sunlight and beneath shade trees, was determined at the Adjuntas Substation. A combined statistical analysis of five crops, grown under approximately 40-percent shade indicated that the best yielders were R-3, Harrar, Mundo Nuevo, N-50, Red Bourbon, Mibirizi, and S-16. Their average yields were 18.98,18.87,18.31,e 18.14,18.02,16.64, and 16.50 hundredweights of market coffee per acre, respectively, with no significant statistical differences among them. The average production of the other varieties were: Geisha, 15.18; Padang, 15.03; Zegui, 14.94; K.P. 228, 14.14; Red Caturra, 13.72; Puerto Rico Selection, 13.62; Villalobos, 12.74; Barbuck Sudan, 10.17; and Enrea, 9.76 hundredweights of market coffee per acre, respedtively. The combined statistical analysis of four crops of the same varieties grown under complete sun exposure revealed no significant statistical differences between the yields of Mundo Nuevo, R-3, Harrar, Mibirizi, S-16, Red Caturra, Red Bourbon, Zegui, Villalobos, and N-50, with 26.93, 24.58, 24.55, 23.77, 22.74, 21.74, 21.61, 21.52, 21.29, and 21.17 hundredweights of market coffee per acre, respectively, but the differences in production when compared to the remaining varieties were significantly high. The remaining varieties and their production were Puerto Rico Selection, 18.92; Padang, 17.79; Geisha, 15.52; Barbuck Sudan, 12.76; K.P. 228, 11.49, and Enrea 9.53 hundredweights of market coffee per acre, respectively. In general, higher yields were produced by the varieties when grown without shade. Much higher yields than the average production for the Island were obtained at both experimental sites (under and without shade) and most of the varieties produced over 200 pounds of market coffee 18 to 20 months after being transplanted to the experimental sites. Most of the intermediate-growth varieties gave a greater total yield for a period of 5 years than the semi-dwarf ones, which tended to give a higher yield in the first crop but were surpassed by the intermediate-growth varieties when the latter reached mature size.