Eduardo Augusto Agnellos Barbosa

Cana-de-açúcar fertirrigada com vinhaça e adubos minerais via irrigação por gotejamento subsuperficial: ciclo da cana-planta

This study aimed to evaluate the effect of subsurface drip irrigation and the application of stillage and nutrients in some agronomic parameters, stem yield, technological characteristics of sugarcane and yield of theoretical recoverable sugar. The experiment was carried out in completely randomized block design with four treatments and five replications. The treatments were: mineral fertilizers without irrigation; irrigation and fertigation with NPK using mineral fertilizers; irrigation and fertigation with stillage supplying the K and complementation of N and P with mineral fertilizers; and irrigation and fertigation with stillage supplying the NK and complementation of P with mineral fertilizer. The system of irrigation adopted was the subsurface drip irrigation. The irrigated treatments showed higher number of tillers and leaf area index, when compared to rainfed cultivation. The fertigation with stillage supplying the K promoted higher Brix and stem yield when compared to non-irrigated cultivation. The irrigation and fertigation with stillage supplying the NK promoted higher yield of theoretical recoverable sugar, when compared the cultivation without irrigation.

Cana-de-açúcar fertirrigada com vinhaça via irrigação por gotejamento subsuperficial em três ciclos de cana-soca

The objective of this study was evaluate the effect of irrigation and fertigation with mineral fertilizer and vinasse applied by subsurface drip irrigation, in the number of tiller, stem yield, technological quality of sugarcane and yield of recoverable sugar in first three cycles of ratoon cane. The treatments were: T1NI - cultivation without irrigation with mineral fertilization; T2I - cultivation fertigated with mineral fertilizers; T3Iv - cultivation fertigated with the vinasse supplying K and complementation of NP with mineral fertilizer; T4IV - cultivation fertigated with the vinasse supplying NPK. In the cycle of the first ratoon cane, there was no effect of treatments on the variables, already in the subsequent cycles, the T2I and T3Iv showed higher numbers of tillers, 17.4 and 17.2 tiller m-1, in the second ratoon cane and 16.6 and 16.0 tiller m-1 in the third ratoon cane, respectively. The stem yield was amended with the T4IV obtaining the higher yield, 179.6 Mg ha-1, in the second ratoon cane, and the T2I and T3Iv in the third ratoon cane, 151.5 and 151.0 Mg ha-1, respectively. There was no treatment effect on the technological quality and in the second ratoon cane the T3Iv and T4IV showed higher yield of sugar, 25 and 25.9 Mg ha-1, respectively.

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.