14th Workshop on Spray Application in Fruit Growing
Oral Abstract 3
Pesticide dose in persimmon orchards: Bases for adjustment
P. Chueca, A. Vicent, M. Pérez-Hedo, F. Beitia, A. Urbaneja, C. Garcerá
1
Instituto Valenciano de Investigaciones Agrarias. Ctra. CV-315, km 10,7. 46113. Moncada (Valencia, Spain).
Email address:chueca_pat@gva.es
INTRODUCTION
In Spain, production of persimmon (Diospyros kaki Thunb.) has increased by 80% in the
last decade. New phytosanitary problems emerged, which required foliar spray applications.
Current spray programs in persimmon orchards in Spain consist of applying large amounts of
spray volume. In this work, the bases for the dose adjustment of spray applications to the
singularities of persimmon orchards in Spain are presented.
MATERIALS AND METHODS
The study was carried out in two commercial established orchards with different
framework cultivated with persimmon ‘Rojo Brillante’ located in L’Alcúdia (Valencia, Spain).
Spray distribution assessment was carried out during real pesticide applications. Spray timing
was decided by the crop advisor in each orchard depending on the application target. Pesticide
treatments were based on pest population, risk of disease development, or harvest management
strategy. During applications, the conventional spray volume rate was compared with reductions
of 20% and 40% (Table 1). Treatments were carried out with an axial fan air-blast sprayer with
standard disc and core nozzles. The set up of the sprayer was the same for both orchards except
the nozzle orientation, resulting in the same flow rate (L/min) but different spray volume (L/ha).
Table 1. Application dates, phenological stages (BBCH), pesticides and spray volume rates
evaluated in orchards of persimmon ‘Rojo Brillante’ at L’Alcúdia (Valencia, Spain).
Year
2015
Date
30/0405/05
28/0504/06
18-25/09
23-24/05
16/06
Objective
M. nawae
-
M. nawae +
Mealybug complex*
Harvest advance
M. nawae
-
M. nawae +
Mealybug complex*
2016
02-03/08
Product**
Mealybug
complex*
Score
(25 ml/hl)
Ortiva
(67.5 ml/hl)
Reldan
(350 ml/hl)
Movento Gold
(100ml/hl)
BBCH
Spray volume (L/ha)
Conventional
80%con
Orch. 1 Orch. 2 Orch. 1
Orch. 2
60%con
Orch.1
Orch. 2
790
950
67
73
1300
1500
-
1300
1500
1000
1200
790
950
2500
3000
2000
2300
1500
1800
87
73
75
79
*Mealybug complex= Planococcus citri + Pseudococcus viburni
**Indicated only in treatments were efficacy was evaluated.
Spray distribution in the canopy was estimated through coverage on water sensitive
papers. In parallel, persimmon canopy of the two orchards was characterized each time of
application by estimating canopy volume and foliar density (Fig. 1).
14
SuproFruit 2017
14th Workshop on Spray Application in Fruit Growing
Fig. 1. Characterization of persimmon canopies.
In the season 2016, biological efficacy was assessed: The level of mealybug complex (P.
citri and P. viburni) 14 days after treatment, and the incidence and severity of circular leaf spot,
caused by Mycosphaerella nawae, at harvest.
RESULTS AND DISCUSSION
The reduction of spray volume induced a decrease of the coverage in all applications (Fig.
2A). On the other hand, canopy volume and foliar density increased along the season, and
consequently coverage decreased along the season. Despite the reduction of coverage, reduction
of spray volume did not affect the biological efficacy of pesticide applications against M. nawae
(Fig. 3B) and mealybug complex.
30
180
160
1800 L/ha
140
CONVENTIONAL
80%CV
60%CV
Nº leaves/20 shoots
2300 L/ha
3000 L/ha
1500 L/ha
200
950 L/ha
40
790 L/ha
50
1300 L/ha
60
1000 L/ha
% COVERAGE
70
1200 L/ha
80
1500 L/ha
90
2000 L/ha
2500 L/ha
100
120
Fallen leaves
100
Without infection
<10 spots
80
10‐20 spots/leaf
>20 spots/leaf
60
20
40
10
20
0
0
2016 ‐ 2nd
2016 ‐ 3rd
ORCHARD 1
2016 ‐ 2nd
ORCHARD 2
2016 ‐ 3rd
CONV
60% CV
ORCHARD 1
80% CV
CONV
60% CV
80% CV
ORCHARD 2
Fig. 2. A) Estimated coverage for each application and orchard in the season 2016. B) Incidence of
circular leave spot produced by M. Nawae for each application and orchard in the season 2016.
Sprayer calibration together with the reduction of spray volume improved the efficiency,
and thus resulted in costs savings and environmental pollution decreases, due to the reductions of
pesticide use and drift losses.
SuproFruit 2017
15