Comparação de métodos para determinar a seletividade de herbicidas na cultura da cana-de-açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ratoon sugarcane yield integrated drip-irrigation and nitrogen fertilization

The aim of this study was to compare the use of water and nitrogen on ratoon sugarcane during irrigated and rain-fed conditions, and to assess the production potential of stalks and sugar with different rates of N-fertilizer on the subsurface drip-irrigated management. The experimental design was a randomized block with four replications for each experiment and treatments: (T1) irrigated, 0kg N ha-1; (T2) irrigated, 70kg N ha-1; (T3) irrigated, 140kg N ha-1; (T4) irrigated, 210kg N ha-1; (T5) not irrigated, 0kg N ha-1, and (T6) not irrigated, 140kg N ha-1. Biometric, technological, dry matter and yield variables were analyzed among the treatments. The irrigation system together with the application of N-fertilizer at 140kg ha-1 presented significant differences in dry matter accumulation of shoots, and for the production of stalks and sugar, respectively 94, 105 and 106%, higher when compared to the not irrigated, without N-fertilizer (T5). There was a positive and synergistic effect of irrigation with N-fertilizer on the productivity of stalks and sugar. Ratoon sugarcane irrigated with subsurface dripping had the highest yield (22Mg ha-1 of sugar) with the dosage of 140kg ha-1 N.

Harvest managements and cultural practices in sugarcane

The presence of trash from the mechanical harvest of green cane on sugarcane plantations promotes changes in the agricultural management, for example, in the mechanical cultural practices of ratoon cane in-between the rows and nitrogen (N) fertilization. The goal of this study was to evaluate the performance of sugarcane in different harvest systems, associated to the mechanical cultural practices in interrows and N rates. The study was carried out on a sugarcane plantation in Sales Oliveira, São Paulo, Brazil, with the sugarcane variety SP81-3250, on soil classified as Acrudox, in a randomized block design with split-split plots and four replications. The main treatments consisted of harvest systems (harvesting green cane or burnt cane), the secondary treatment consisted of the mechanical cultural practices in the interrows and the tertiary treatments were N rates (0, 30, 60, 90, 120 and 160 kg ha-1), using ammonium nitrate (33 % N) as N source. The harvest systems did not differ in sugarcane yield (tons of cane per hectare - TCH), but in burnt cane, the pol percent and total sugar recovery (TSR) were higher. This could be explained by the higher quantity of plant impurities in the harvested raw material in the system without burning, which reduces the processing quality. Mechanical cultural practices in the interrows after harvest had no effect on cane yield and sugar quality, indicating that this operation can be omitted in areas with mechanical harvesting. The application of N fertilizer at rates of 88 and 144 kg ha-1 N, respectively, increased stalk height and TCH quadratically to the highest values for these variables. For the sugar yield per hectare (in pol %), N fertilization induced a linear increase.

Effects of traffic control on the soil physical quality and the cultivation of sugarcane

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resistência mecânica à penetração em latossolo vermelho após sucessivos cortes mecanizas de cana-de-açúcar

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Otimização da análise da atividade da redutase do nitrato e sua caracterização em folhas de cana-de-açúcar

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fontes e doses de fósforo na presença e ausência de composto orgânico no estado nutricional e na produtividade da cana-de-açúcar

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Eficácia de óleos minerais aplicados como adjuvantes auxiliando na selitividade de herbicidas na cultura de cana-de-açúcar

Pós-graduação em Agronomia - FEIS

Comportamento de genótipos de cana-deaçúcar com irrigação de salvamento em Goianésia-GO

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae): caracterização macroscópica e determinação de inseticida e época de aplicação para controle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação de falhas na brotação da cana-de-açúcar em função da disponibilidade hídrica

The sugarcane is a crop of annual cycle, where its large water demand is not always full, causing stand gaps in the sprouting of ratoons. Thus, this study aimed to assess the stand gaps in the first and second ratoon sugarcane under seven levels of water deficit. The experiment was conducted in the Center of Agricultural Sciences of the Federal University of Alagoas in the period of 22 February 2010 to 20 February 2012. The stand gaps depending on water depths ranged from 11.2 (25% ETo) to 16.8% (100% ETo) in the first ratoon and from 24.8 (0% ETo) to 32.8% (100% ETo) on second ratoon. The average size of stand gaps ranged from 0.60 to 0.68 m in the first ratoon and from 0.70 to 0.74 m on second ratoon. The average distance to find a stand gap ranged from 16.8 to 29.5 m in the first ratoon and from 6.5 to 10.9 m in the second ratoon. The percentage of gaps and the average size of the gaps in the sprouting of ratoon increase with the age of the sugarcane plantation and the average distance between gaps decreases. The use of irrigation in the culture of sugarcane increase the percentage of gaps, but because these spaces are filled with culms of other sugarcane clumps and were irrigated with larger water depths, the agricultural productivity of the culture increases. The depths of irrigation decreases the average distance between gaps with more intensity in the first than in the second ratoon.

Morfologia do tecido ósseo de tíbias de frangos de corte submetidos à dieta com 25 hidrocolecalciferol

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)