Jane Maria de Carvalho Silveira

Coffea arabica (cv Catuaí) production and bean size under different population arrangements and soil water availability

The purpose of this research was to evaluate the effect of drip irrigation under different population arrangements on the phytometric features, coffee productivity and bean size classification according to sieve retention. The experiment with Coffea arabica L. cv Catuai was carried out in Mococa, Sao Paulo, Brazil. The experimental design was a 6 x 2 factorial scheme in randomized blocks, with four replications. The six densities of plantation were E1 (1.60 x 0.50 m); E2 (1.60 x 0.75 m); E3 (1.60 x 1.00 m); E4 (3.20 x 0.50 m); E5 (3.20 x 0.75 m) and E6 (3.20 x 1.00 m), which were divided according to the availability of water (irrigated - I - or non-irrigated - NI - groups). Data were submitted to analysis of variance and averages compared by Tukey test at 1 and 5% of probability. Descriptive analysis of coffee beans according to sieve classification was performed. Irrigation promoted an increase in plant height, crown diameter and production of processed coffee when compared with the NI group. Interaction between population arrangement and irrigation was observed, with an increase in production and crown diameter as the spacing was decreased. Therefore, irrigation provided significant increase in coffee bean size.

Variação sazonal do potencial da água nas folhas de cafeeiro em Mococa, SP

In order to assess the xylem water potential in Coffea arabica L. plants, a field experiment was carried out in Mococa, Sao Paulo State, Brazil, from August 2005 to July 2006 with the following cultivars: Mundo Novo (MN), Obata (OB) and Ouro-Verde (OV). The OB and OV cultivars were eight years old, and MN plants had been topped five years ago. Spacing among the plants were 3.6 x 1.0 m, 2.5 x 1.0 m and 3.5 x 0.75 m, respectively. Predawn leaf water potential (ψam) was measured each 15 days. Xylem water potential along the day (ψa) was measured at the end of April. Data concerning leaf ψam varied according to the soil water profile as affect by seasonal rainfall. ψam values were -1.29, -1.60 and -1.68 MPa during dry months and -0.06, -0.07 and -0.07 MPa during months of greater precipitations for MN, OB and OV, respectively. These values were important and relevant to Arabic coffee cultivars in order to characterize plant water status along the year, because the period of water stress was coincident with the phase of induction (February at June) and maturation of flowering buds; and the period of greater rainfall with the phase of grain filling and fruit maturation.