A study on the effectiveness of organic mulch to inhibit or control

kalunay (Amaranthus spinosus L.) in tomato (Lycopersicon

esculentum) field

II. Introduction

Farmers all over the world choose to produce high-yielding tomatoes

(Lycopersicon esculentum), but this is not an easy task because pests can
significantly reduce yields while increasing production expenses. Growing
tomatoes profitably involves both expert labor and regular access to current
information on all aspects of the crop, including irrigation, soil fertility,
harvesting, and, most significantly, pest control such as weeds
(Cherlinka,2023).

One of the weeds that interfere tomato fields is Kalunay the interference of
Kalunay in tomato fields can result to yield reduction due to Kalunay
growing taller than the tomato and Kalunay also take the nutrients and water
that was meant for the tomato (Garvey et Al.,2013)

Kalunay is usually a dry-season annual weed, so it can germinate in hot

conditions and tolerate hot weather. The rapid growth, prolific seeding and
long growing season characteristic of amaranth makes these species capable
of Spreading quickly in vegetable cropping systems, reducing Yield and
quality by crowding out crop plants and competing For resources (Coleman
et Al.,2021).

To address these tomato growing issue, a study was conducted to determine

the effectiveness of organic mulch in inhibiting or controlling kalunay
(Amaranthus spinosus L.) in tomato fields. Because the researchers know
that organic mulches suppress annual weeds by blocking seed germination
stimuli, physically impeding weed emergence, and releasing natural
substances that inhibit seedling growth (Schonbeck,2012).

III. Review of Related Literature (RRL)

Tomato industry in the Philippines and it’s importance

Tomatoes (Lycopersicon esculentum), also known as tomatoes, are widely

farmed in the Philippines and around the world. It is commonly used in
Filipino cuisine. Tomatoes can be eaten raw in salads or prepared as pastes
or sauces. These include carotene and lycopene. Both antioxidants help to
prevent cancer. It also contains high levels of vitamin C. Tomatoes are grown
in the lowlands of Luzon between October and March, when the weather is
cool and dry. Planting takes place in high-altitude areas such as Laguna and
Quezon from January to February. Some places in Laguna, Quezon, Batangas,
Nueva Ecija, Bukidnon, and Misamis Oriental plant tomatoes during the rainy
season to take advantage of the shortage.(Tataba,2023).

Studies exploring methods to enhance tomato production during hot and

humid months have revealed that tomato grafting, particularly when coupled
with flood and disease resistant rootstocks, can effectively address both
abiotic and biotic challenges. The findings underscore the significant role of
tomato cultivation in the country. The abstracts from these studies
consistently emphasize the high demand for tomatoes in the Philippines due
to their substantial economic benefits, rich nutritional profile, and remarkable
adaptability to various growing conditions. This robust demand underscores
the importance of advancing production techniques to ensure a stable supply
of fresh, high-quality tomatoes that meet the needs of both local consumers
and broader market demands, cementing the crop’s pivotal position within
the agricultural landscape of the country(Solis et Al. 2022)

Effects of weeds in crops specially on tomato

Weeds, classified as undesirable plants, fiercely compete with crop plants for
vital resources such as nutrients, water, and sunlight, thereby impeding the
proper growth of the crops. By vying for these essential elements in the soil,
weeds not only deplete the resources needed by the main crop but also
create an imbalance that hampers the crop’s overall development.
Regardless of the availability of resources, the presence of weeds
significantly diminishes the crop yield, highlighting the critical importance of
effective weed control measures and strategic resource management. This
impact on crop yield is particularly evident during the crucial growth stages
when weed interference disrupts the normal developmental pathways of the
crops, ultimately leading to decreased productivity and suboptimal harvest
outcomes. (Horvath et Al.,2023).

Tomato (Solanum lycopersicum), a widely cultivated vegetable worldwide,

demands meticulous attention during its growth to avert yield loss, chiefly
because weeds pose a significant threat to its productivity. Among the
troublesome weed species in tomato production across the southeastern
United States are yellow and purple nutsedge, large crabgrass, and Palmer
amaranth. The detrimental impact of weeds on tomato yield stems from the
fierce competition they engage in with the crop for essential resources,
including water, nutrients, sunlight, soil, and space. This competition, known
as weed competition, significantly hampers tomato plants’ ability to thrive,
ultimately leading to diminished yields. Weeding is, therefore, a vital practice
in tomato farming to control the growth of these troublesome competitors
and safeguard the crop’s productivity. By implementing effective weed
management strategies, farmers can mitigate the adverse effects of weed
competition, improve tomato yields, and enhance the overall success of their
tomato cultivation endeavors.(De Oliveira et al., 2023)

Kalunay as Weeds

There is a study says that Amaranth’s rapid growth, prolific seeding, and
lengthy growing season allow these species to spread quickly in vegetable
cropping systems, lowering yield and quality by crowding out crop plants and
competing for resources. They are difficult to control in leafy vegetable crops
since there are few licensed herbicide choices. Amaranth’s environmental
tolerance, combined with its fondness for moist soils and the number of seed
plants it can produce, make it ideally suited to the circumstances prevalent
in vegetable production systems. Amaranth species are regarded pests in a
variety of vegetable crops throughout the world, including the northern and
southern hemispheres. Amaranth has been found to have a negative impact
on crops in Australia.In Australia, crops identified as being negatively
Impacted by amaranth include cucurbits, lettuce, tomato, Capsicum and
chili, beans, sweet corn, peas, and brassicas. Amaranth species are also
noted for their capacity to host a variety Of crop pests, diseases and viruses,
including caterpillars, Cucumber mosaic virus, tomato spotted wilt virus,
root-knot Nematodes, thrips, and aphids (Coleman et Al.,2021)

Effects of Organic Mulching Against Weeds

Mulch can be utilized in nearly every garden setting. From a robust vegetable
garden to ornamental landscape beds, preventing seeds from germinating is
the best defense against a weedy garden. Mulch will smother annual weed
seeds and reduce or eliminate cultivation, hand weeding and chemical weed
control while contributing beneficial organic matter (Finneran et Al.,2018)

organic mulches can reduce weed emergence. Positive effect of mulches was
particularly obvious in the period of intensive germination of weeds. Straw,
peat and sawdust had the strongest influence on the decrease of weed
germination and re- growth. Grass mulch quickly decomposed and its effect
on weed density was shorter. Germination of annual weeds was significantly
reduced by all organic mulches applied. Re-growth of perennial weeds was
significantly reduced by straw (up to 4.5 times), peat (up to 3.0 times),
sawdust (up to 3.5 times) and grass (up to 3.9 times) mulches, however,
they had a diverse effect on species composition of perennial weeds.
Declining weed density in mulched plots decreased amount of weed seeds in
the soil. But the amount of weed seeds in the soil may even increase when
organic mulches are used. It is very important to make sure that mulches are
not polluted with weed seeds.Organic mulches have different effects on
agrocenosis, they suppress weeds by different ways, therefore a good
knowledge of the characteristics of mulching materials and their proper
choice are essential (Pupalienė et al.,2015)

IV. Methodology

The researcher conducted the experimental study at the PRMSU San

Marcelino campus on the date of January to May 2024.

Land Preparation
The researcher prepared the land with a hand plow, a hand shovel, a plastic
bottle, and a rake. First, the researchers remove the plastic mulch and the
eggplant (Solanum molongena)that planted there then they clean the debris
left on the plot. Second, the researchers plow the areas to make lines for the
plot and rake the top of the plot to clean the rest of the debris left. Third, the
researchers place the 5 sacks of carabao manure and 2 sacks of decomposed
materials in the middle of the plot. Fourth, the researchers use the plow to
cover the carabao manure and decomposed materials.
 Cultivation Applying organic materials

Mulching and Planting

The researchers applied the control materials, which were rice straw as a
mulch, then watered the plot to moisten the rice straw, soil, and Organic
materials. Then the researchers left it for several days to decompose the
materials applied.After 5 days, the researchers plant tomato seedlings and
moisten the organic mulch and soil to reserve moisture for the crops they
planted.

mulching plating
Fertilizer Application
After two weeks the researchers reapplied compost materials to serve as a
organic fertilizer.

Weed observation
The plot was initially clean and weed-free, but after two days of adding
compost materials, the researchers noticed that the weeds began to sprout,
which they are all same, and they were thorny Kalunay (Amaranthus
spinosus) with only one crab grass (Digitaria sanguinalis) added, but the
researchers only left it to see if the weeds would continue to grow through
the weeks.

Integrated Pest Management

After three weeks of monitoring, the researchers discovered that the kalunay
infestation was serious, so they took cultural and mechanical action to
control the kalunay, such as pulling the kalunay and keeping their garden
neat and clean.

uprooting of Kalunay ( Amaranthus sponusus)

Results and discussion

After two days, after the researchers applied compost materials, the
researcher witnessed that the weeds that have germinated in their plot is
mostly kalunay (Amaranthus spinosus) since the researchers reapplied
compost materials, on this time ,the kalunay (Amaranthus spinosus) is more
invasive compared to the other weeds such as crab grass (Digitaria
sanguinalis) because in first week it has 15 kalunay in the plot and it has
only 1 crab grass, and after 3 weeks the population of kalunay reach the
number of 76 and the crab grass can’t survive just like the tomatoes that
started to wilt and there are some kalunay (Amaranthus spinosus) has
reached maturity and the others are growing

The infestation of kalunay ( Amaranthus

sponusus) After three weeks

The researchers conduct control measures to manage the growth of weeds,

the control that has been used is the applying organic mulch specially rice
straw, to inhibit the growth and control the weeds but this control is not
sufficient to inhibit the growth of kalunay so They concluded that organic
mulching is not sufficient to control the kalunay but it is only for other types
of weeds because the kalunay (Amaranthus spinosus) can sustain and
survive the condition, since the kalunay (Amaranthus spinosus) is deep
rooted and it is basic for kalunay (Amaranthus spinosus) to penetrate.
 A root of a Kalunay

so they applied methods or control just like integrated pest Management that
capable on handling the growth of kalunay and this is by Cultural Practice
that maintaining the field clean and neat to disrupt the habitat and lifecycle
of kalunay and also the Mechanical Control or the Handpicking and removal
of kalunay.The Effectiveness of those Control Methods includes managing
kalunay infestation and promoting plant health. Organic mulching has shown
to be beneficial in mitigating weed infestations in tomato if it is accompanied
by an integrated pest management approach, combining cultural,
mechanical control methods
 tomato field after applying cultural and
mechanical control

Organic mulching is one of the most susceptible tactics to suppress spiney

amarath because the application of organic mulch acts as a physical barrier
for the plant because it causes dampening thermal germination stimuli that
can suppress weed seed germination and reduce seedling growth
(Schonbeck,2012). In vegetable farms, hand weeding is also useful for
removing significant weeds such as amaranth that are growing close to crop
plants or, more broadly, within the crop bed when selective herbicides are
unavailable and prior weed management methods have failed. This is
particularly relevant for weeds that are flowering, fruiting, or setting seed, as
well as plants that were overlooked when other management methods were
applied. Using adequate agricultural hygiene procedures also helps to keep
amaranth seeds from spreading throughout a property and into crop beds
from other locations where the weed is present.(Coleman et Al.,2021)

Summary and Conclusion

This research study focuses on the effectiveness of the organic mulch (Rice
straw) to inhibit or control a weed specifically kalunay (Amaranthus spinosus)
in tomato field, by using rice straw as organic mulch. In order to carry out
this study, the researchers first planted tomatoes ( Lycopersicon
esculentum) and it starts with plowing the land to be planted or land
preparation and after that they planted tomatoes ( Lycopersicon esculentum)
and they put organic mulch after that they observed the growth of weeds
here and they realized that the infestation of weeds in their garden was
invasive or high so organic mulch does not sufficient to handle it, so they did
cultural and mechanical control to eliminate the weeds and this is by
uprooting it and keeping their field neat and clean. as a result, organic
mulching can eliminate weeds like Kalunay (Amaranthus spinosus )as long as
it is supported by integrated pest management, such as eliminating weeds
through hands and keeping the field clean.

As a conclusion organic mulching with the support of integrated pest

management approach, combining cultural, mechanical control methods to
be effective in managing kalunay infestation in the tomato field. By
implementing a holistic pest management strategy, the impact of kalunay on
tomato plants was minimized, leading to improved plant health and yield.

References

- Cherlinka, V. (2024, May 10). Growing Tomatoes: How To Plant,

Maintain, And Harvest. EOS Data Analytics. https://eos.com/blog/how-
to-grow-tomatoes/
- Garvey, P. V., Meyers, S. L., Monks, D. W., & Coble, H. D. (2013, March
1). Influence of Palmer Amaranth (Amaranthus palmeri) on the Critical
Period for Weed Control in Plasticulture-Grown Tomato. Weed
Technology. https://doi.org/10.1614/wt-d-12-00028.1
- Coleman, M. J., Kristiansen, P. E., Sindel, B. M., & Fyfe, C. (2021, April
1). Amaranth (Amaranthus spp.) Weed management guide for
Australian vegetable production. ResearchGate.
https://www.researchgate.net/publication/353945381_Amaranth_Amara
nthus_spp_Weed_management_guide_for_Australian_vegetable_produc
tion
- Schonbeck M.(2012,August 15).Organic Mulching Materials for Weed
Management. eOrganic.https://eorganic.org/node/4871