Page 49 - Ingeniantes 811 interactivo

Revista Ingeniantes 2021 Año 8 No. 1 Vol. 1
mentary pollination to obtain larger fruits for a higher
yield and more commercially attractive fruits. Different
methods such as the use of manual vibration, wind sha-
king and pollinating insects have been used until now in
low-tech greenhouses.
Greenhouse tomatoes require supplemental pollination
during anthesis and are usually pollinated by manual
vibration, which is a very arduous and expensive task.
In Europe, insect colonies (Bombus terrestris L.) have
been used since 1987 to pollinate greenhouse tomato
plants, replacing manual pollination [5]. Although the use
of bumblebees as greenhouse pollinators was rapidly
disseminated, very little research was carried out re-
garding problems with bumblebees, for example, pesti-
cides such as stressors [6].
Robotics in agriculture is not a new technology, since
its use has a history of more than 30 years. Its worldwi-
de utilization has increased joint with the capacity of Hi-
Tech computers, technology research and automation.
As the world population is expected to increase to nine
billion by 2042, which means that there will be a consi-
derable challenge in the provision of high quality food
for this population. Furthermore, the labor force in agri-
culture is declining and automation technology is emer-
ging to replace some traditional labor [7]. For example,
in the production of special crops, labor is often tedious,
non-ergonomic and performed by unskilled personnel.
Automation technology improves productivity, health
and staff satisfaction. However, there are serious tech-
nical challenges regarding the automation of operations
and the control of dynamic processes. A recent robot,
which is the closest to commercialization, is a strawbe-
rry harvester robot [8], but is still in the exploration phase. respectively. To establish climate, irrigation, fertilization,
According to Vega-González [9], the construction of
a prototype consists of four phases, which are called
bench prototype, concept prototype, laboratory proto-
type and technological product. Just a few robots can
reach the last phase and the most of the cases due to
the great amount of investment necessary for produ-
cing the prototype in industrial scale.
On the other hand it worth to mention that floral anthesis
starts early in the morning around 6 am and the flower
continues opening until 11 am. The peak period of anther
dehiscence is between 8 to 11 am depending upon the
initiation of sunshine, atmospheric temperature and hu-
midity. At temperatures ranging between 18 to 25 °C,
the pollen remains viable for 2 to 5 days, the stigma be-
comes receptive 16 to 18 h before anthesis and retains
the receptivity up to 6 days after anthesis, i.e., shortly
before the flower withers. This long duration of stigma
receptivity from near one day prior to 6 days after an-
thesis, permits controlled pollinations. These are further
facilitated by the long-duration viability of pollen as the
pollen retains its viability for 2 to 5 days at temperature
ranging from 18 to 25 °C [10].
45
Given these concerns, the aim of this study was to
evaluate whether the automatic pollination (AP) could
be useful to pollinate tomato plants under greenhouse
conditions according to the setup parameters.
MATERIAL AND METHODS
Design and construction of the automatic pollinator
The robot (AP) includes a DHT11 sensor (Aosong Elec-
tronics Co., LTD., China) and the vibration system, both
devices were connected to an Arduino board. The AP
is a dynamic open-loop control robot, which was de-
veloped using an embedded system [11], to record and
determine the appropriate stage when the electric mo-
tor must be turn on/off. Furthermore, the robot consists
in one horse power motor (DC motor electric 12 volt
56C 1800 rpm, PTJ Industrial) capable to vibrate in an
eccentric way and a digital recording system that sto-
res the information in a micro SD memory configured
to acquire greenhouse data. The operation of the AP
was evaluated by counting the working hours, recording
variables (temperature and relative humidity), switching
the on/off system and vibration according to the set
point parameters, which were controlled by LabView
2013 (National Instruments).
Study area
This research was carried out from January 1st to July
15th 2016, in the Technological Institute of Tamazu-
la, located in the city of Tamazula de Gordiano, Jalis-
co, Mexico. Tomato plants (Solanum lycopersicum L.)
were planted with a density of 3.2 plants m-2 in a plastic
greenhouse, with a traditional design. The greenhouse
is a 4-connected gutter (numbered 1-4). The pollination
was carried out in the gutter 1 and 4 for the MP and AP,
tutoring and pest control and other cultural labors, the
practices suggested by Jaramillo [2], were followed.
Robot functionality and activation
Two treatments were evaluated as follows: i) flower
pollination through AP, and ii) flower pollination throu-
gh MP. In order to evaluate the effect of the pollination
system, the number of tomatoes and clusters per plant
was quantified. The MP was performed every day by
the same person; simultaneously, the AP was carried
out in its respective section by the robot according on
the activation parameters the set point was established
at 25 ± 0.9°C. The treatments were established in two
different gutters as above mentioned (Figure 1A). Twen-
ty plants were randomly selected and numbered (1-20)
for each section either for the MP or AP.
Data analysis
In order to evaluate the feasibility to automatically po-
llinate tomatoes under greenhouse the AP activity was
compared versus MP. Dataset were analyzed using
the independent samples t- test. To identify significant
difference among treatments and statistical significan-
ce for all comparisons was made at p<0.05. Data are