LIBRO-CONGRESO-CITRUS

S11
horticultural, engineering, and economic. The spread of Huanglongbing (HLB, ex Greening) has reduced the
overall tree health in Florida and has heightened growers’ long-standing concern over the added physiological
stress that comes with mechanical harvesting equipment. Equipment performance, as measured by fruit
recovery percentage, has declined as tree canopy uniformity has deteriorated from effects of various tree
diseases, particularly from HLB. As the performance efficiencies of harvesting equipment eroded, the unit costs
of mechanical harvesting increase. The purpose of this paper is to further explore these factors and discuss
how the objectives of growers and juice processors need to be integrated into future designs of mechanical
harvesting systems. Data on the ownership and operational costs of existing equipment strongly suggests
that the potential for harvest cost savings through mechanical harvesting systems remains significantly high.
S11P01
Study on mushroom dregs application in citrus nursery
Guan B., Chen K.L., He J., and Liu J.J.
Horticulture Research Institute, Sichuan Academy of Agricultural Sciences (HRI, SAAS), Centre of Fruit Research, China.
chen-kl@163.com
Peat is an important substrate widely used in citrus nurseries in China. The commonly used formula is peat:sand/
soil:husk of rice = 4:4:2 or peat:soil = 6:4. Use of peat was restricted during recent years. Furthermore, mushroom
producing houses produced great quantities of mushroom dregs at harvest which were often disposed of as
garbage. The aim of this study is to investigate the feasibility of using mushroom dregs instead of peat in citrus
nurseries with nutritional bags. ‘Ziyang-xiangcheng’ (Citrus junos), an important resistant rootstock to alkaline
soil, and five different mushroom dregs were used in this experiment. The trial proportion of the seedling
substrate was mushroom dregs:soil:peat = 1:2:2, 1:1:1, and 1:1:0. There were 2 controls, control 1 had mushroom
dregs:soil:peat = 0:1:1, and control 2 was only soil. Each treatment had three replicates with 100 seedlings per
replicate. The effects of mushroom dregs on the growth of seedlings in the nutritional bags were evaluated.
The results showed that ‘Ziyang-xiangcheng’ seedlings can survive and grow well in most media. The seedlings
height of 11 mushroom dreg treatments and seedlings diameter of 9 treatments were superior to control 1,
and all mushroom dregs treatments were superior to control 2. Therefore, it is feasible and economical to apply
certain mushroom dregs instead of peat in the substrate of citrus container seedlings.
S11P02
Effect of soil preparation systems, mulching and rootstocks on ‘Pera’ orange (Citrus sinensis)
performance in the northwest of Parana State, Brazil
Auler P.A.M. 1 , Fidalski J. 2 , Gil L.G. 2 , and Pavan M.A. 2
1 Instituto Agronômico do Paraná (IAPAR), Área de Fitotecnia, Brazil; and 2 Instituto Agronômico do Paraná (IAPAR), Área de Solos,
Brazil. aulerpe@iapar.br
The objective of this work was to evaluate the effect of minimum soil preparations and mulch management
on the performance of orange trees in a Typic Haplorthox from Caiua Sandstone soil type with lower chemical
fertility and water storage capacity, and higher susceptibility to erosion. The experiment was established in an
area located in the Ipiranga farm (Cocamar), at Paranavaí municipality, Parana State, Brazil. The experiment was
laid out as a split-split plot design, with 12 treatments and 4 replications. The main plots were used to study the
soil preparations: conventional with tillage in total area, and minimum preparation in strip and direct planting
with partial tillage. In the subplots, the management of the tree rows, with and without mulch was adopted. In
the split-split plots the rootstocks ‘Rangpur’ lime (Citrus limonia) and ‘Cleopatra’ mandarin (C. reshni) were used.
The ‘Pera’ orange trees were planted in 2003 with a spacing of 6.8 m x 3.5 m. The mulch was established in the
rows from mechanically mowing the Brachiaria brizantha weeds that grew between rows. There was no- effect
of soil preparations on fruit production and average fruit weight of the first six year crops. Mulching increased soil
K levels and water holding capacity and reduced the need for weed control. In the trees, mulching kept the fruit
production under ‘Rangpur’ and reduced it under ‘Cleopatra’ rootstocks. The minimum soil preparations evaluated
showed an important management for establishing orange orchards in this region. The ‘Rangpur’ rootstock was
more adapted to the mulch management treatment used in this study than was ‘Cleopatra’ rootstock.
Our thanks to the Fundação Araucária for their financial support.
180 - VALENCIA CONFERENCE CENTER, 18th-23rd NOVEMBER 2012