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Brampton Farm, Old Harbour:
Conditions Found
• Soil Type
• Insect and Viral Control
• Irrigation Practices
• Seed Bed Improvements
• Fertilization Practices
Observations, Diagnosis & Recommendations Bodles
Research Station
Introduction:
This report was compiled based on notes and observations made while on
assignment in Kingston, Jamaica. While the report was specifically written
for the Jamaican Agricultural Development Foundation (JADF), there are
many hints and suggestions here that the average farmer, as well as the
part-time gardener, might find interesting and helpful. The author appreciates
any feedback that anyone might have confirming or repudiating the observations
and suggestions made in this report.
Brampton Farm
The Brampton Farm was originally in use as a dairy farm, with the rapid
production of grasses for grazing as the primary objective. Over utilization
of the existing well led to an intrusion of salt water and high levels
of salt into the aquifer. Salt build-up ruined the grass production and
the farm was abandoned.
Chile production has been attempted for at least a couple of years now.
Chiles are row seeded into a starter bed, protected by shade until sufficient
growth has been achieved, hardened off by removal of the shade, dug up
en masse, and transplanted into the field after being separated. The fields
consist of raised beds set on approximately 24" centers, with intervening
furrows, planted in triples. Separating the triple rows is an open swale
measuring approximately 25 feet. Current production is set at 2 acres
with a plant density of slightly over 7500 plants to the acre. Future
production is desired to be in the 10 acre range.
Chile production has been attempted at the farm and has
met with little success. There are a number of contributing factors that
have led to the difficulties. These factors include, but are not limited
to: soil type, high saline levels, viral presence, and over-irrigation.
These items will be discussed in order with recommendations for their
cure or control given.
Soil Type:
Even a cursory, non-scientific observation of the soil showed it to be
nearly 100% clay. Clay is a very poor growing medium for many reasons.
Clay retains tremendous amounts of water, compacts to a hardness resembling
concrete, does not readily shed leachates, and does not readily yield
nutrients. Clay does also not allow air movement through the soil. Oxygenation
of soils is the principle purpose of aeration, and is critical for root
development. Chiles need warm, dry feet; that is, it is imperative for
chile plants to have well drained soil that is slightly warm. Soil samples
taken from various areas of the Brampton Farm were easily rolled into
long ropes, indicating very high clay content. The area currently used
for the seedbed appeared to be the highest, with samples taken in the
chile fields only slightly less.
Problems associated with high clay content soils
seen at Brampton included:
Poor root development - Several plants were carefully
uprooted from various locations in the field and were all observed to
have a preponderance of lateral growth. In addition the roots were poorly
developed. Most of the root formations observed consisted of a very short
main tap root with limited amounts lateral branching. In addition, the
main root was often bent at a sharp angle as it encountered difficulties
in penetrating the highly compacted and wet clay soils. The most dramatic
effect noticed by the lack of a good root system was the daily wilting
of the chiles. With a limited root system, the plants have a reduced ability
to uptake the necessary moisture to retain turgidity. In short, the transpiration
rate of the plant exceeds its' ability to draw the necessary water out
of the soil. This problem would not be alleviated were the plant sitting
in a lake. The plant lacks the necessary structure to make use of the
already available water present.
Non-migration of leachate - In normal soils, the
periodic build-up of deposits are flushed through the soils via the normal
cycles of irrigation and rain fall. In a soil with a heavy clay content,
water is unable to penetrate and flush the deposits. The heavy use of
pelletized fertilisers in such a soil leave an accumulation of salts.
These contaminants continue to build-up until plant growth is affected.
Most often this is a visible symptom seen as a discoloured area on the
surface of the soil. Such areas were readily visible at Brampton.
Viral Presence:
As related by the proprietor of the farm, and the JADF, viral problems
exist at Brampton. Briefings by the JADF indicated that the virus was
thought to be a type of geminivirus. Observations in the field revealed
that the viral infection, at least for the moment, was limited to a single
species of capsicum. Affected plants showed pronounced chlorosis (yellowing)
of the leaves. Some mottling was present in some of the plants as well.
Vascular tissues in the plant appeared to be normal, with no discolourations
or abnormal growths noted. Vascular tissue was tender, well hydrated,
and uniform in appearance. Leaves on the infected plants were quick to
prematurely abscise (fall) leaving the plant either partially or totally
defoliated. Some resurgent growth was observed on the defoliated plants.
The proprietor indicated that this was due to the heavy application of
a foliar applied fertiliser in an attempt to regain fruit production from
the plant. Field observations, while not scientific, most likely identify
the culprit as a potyvirus rather than a virus of the gemini complex.
Further investigations revealed the most likely strain to be the Pepper
Veinal Mottle. Independent verification by a testing lab is recommended
before accepting this diagnosis. A lab report later provided by the proprietor
indicated that in at least the previous year, the culprit was indeed a
potyvirus, namely Potato Y.
Unfortunately, there are no known cures for most viral
infections. Treatments are given mostly as measures designed to prevent
or limit the extent of the infection. Immediate destruction of the infected
plants is most often the given recommendation. Additionally, any fallen
plant debris should be removed as well. Control of the likely vector responsible
for the infection is also indicated. Both types of potyvirus found to
exist (or suspected to exist) at Brampton depend upon an insect vector
for transmission. Control of the insect population would appear to be
the key to containing the spread of the virus.
Insect and Viral Control:
Aside from some evidence of leaf miners, it would appear that insect control
at Brampton is sufficient. No large infestations of aphids, thrips, mites,
leafhoppers, or other pests were noted. This does not mean to imply that
they have not been present or might not appear at a time other than the
authors' visit. It is recommended that insect control be expanded slightly
to control the edges of the fields and the inter-row areas as well. Protection
of the plants themselves is usually not enough to prevent infestations.
The use of barrier crops is also suggested by many references. One of
the most effective methods of insect control is to deny the insects a
path to the fields. Another option is to reduce the cover foliage that
they need to breed and live. The large puddles of standing water offer
a perfect breeding place for many insects as well as various diseases.
Standing water should be lightly treated to remove it as a breeding site.
Viral control is best achieved by the prevention of the
spread of virus. This starts with good seedbed practices (addressed elsewhere)
and continues through harvest. Infected plants should be immediately removed
and destroyed at a location remote from the field. Care should be exercised
in removing the plants not allowing plant debris to contact other non-infected
plants. Crop debris found in the area of the infected plants should be
removed, especially any remaining fruits. These make tempting targets
for scavenging insects that can then transmit the virus to other plants.
There is little optimism that once infected, a plant can be sufficiently
recovered to make fruit production worthwhile. The proprietor attempted
to regain the productivity of infected plants by giving them a high dose
of fertiliser. This did cause an explosion of resurgent growth. The resurgent
growth noted on the treated plants however, did not include any fruit
buds. Further, the history of infected plants is to produce smaller, less
economically valuable fruits if and when they ever recover. Additionally,
leaving the infected plants in the fields runs the certain risk of spreading
the virus to surrounding plants.
Irrigation Practices:
It is the authors' belief that severe over watering of the plants at Brampton
is occurring. The irrigation schedule, as relayed by the proprietor, consisted
of two hours of drip irrigation daily. Despite a lack of any applied water
for several days, it was found upon investigation that sufficient soil
moisture levels were still present. The proprietor stated that his irrigation
system had suffered a breakdown the previous week and the chiles had been
without water for several days now. Despite this, large areas of the field
were still seen to be retaining standing water. Digging down past a highly
encrusted upper layer revealed that the soil still had sufficient moisture
to ensure healthy plant growth. That the soil still retained such moisture
levels several days after the cessation of irrigation (including natural
rainfall) would lead one to believe that during normal operations the
soil is likely to be extremely wet indeed. Standing water was noted in
several areas of the field and soil samples at root level revealed the
presence of large amounts of moisture.
Plant irrigation schedules were based upon the fact that
the chiles were observed 'drooping' or 'wilting' in the late afternoon
heat. Plants by and of themselves are a very poor indicator of irrigation
needs. Irrigation practices should be developed according to the indications
given by the soil, not the plant. The Scotch Bonnet plants (similar to
the Habanero) have a very large leaf surface area. As such they transpire
at rates much higher than other plants with less leaf surface area. It
is very important to note that it is both normal and natural for the chile
plants to exhibit wilting in high heat and humidity conditions. They will
regain their turgidity overnight. The application of water, while a natural
reaction to this wilting, is not the solution. The author was guilty of
this reaction as well in earlier days. Planting where there is some afternoon
shade, providing a shade crop, or encouraging better root development
will reduce the amount of wilting. Providing additional water into an
already damp and non-porous soil will only encourage the growth of blights
and fungus. As soil conditions improve, the need for more frequent irrigation
will increase, as porosity and drainage will improve.
It might also be noted that with the poor soil drainage
found at Brampton, combined with the relatively high saline levels in
the irrigation water, historic salt levels of the soils, and the high
use of chemical fertilizers, salt damage was noted. A schedule of irrigating
that uses the soil as an indicator should be immediately implemented.
Seed Bed Improvements:
Noted in the seedbeds at Brampton were several conditions that needed
changing. The use of large amounts of un-decomposed wood bark for walkways
was noted. The presence of wood bark can act as a magnet to a host of
blights, rots, and diseases which thrive upon such materials. These pathogens
have then only a short distance to cover before infecting a large number
of chile seedlings. In using compost in seedbeds, only well composted,
aged materials should be used.
Enclosing the sides of the seedbed with insect netting
is also recommended. Insects are the major vectors by which most common
viruses spread. At no other time are chiles so susceptible to infection,
and so densely packed, as when they are in the seedbed. Virus and diseases
can very quickly spread to encompass many thousands of plants in a very
short time. Preventive practices exercised here will pay great dividends
later in the field.
The best possible soil should be used for the beds. It
should be rich in well-composted organics and extremely friable (loose).
In addition the use of phosphorous banding or a root starter will ensure
that the seedlings establish the root structure needed for a healthy start
after transplanting. The soil should be as friable as possible so as to
decrease damage to the root system when the seedlings are removed and
separated. After sprouting, the transplanting of the seedlings into individual
trays is recommended. This will ease the transplant shock that would normally
accompany transplanted chiles when stripped of their natal soil. The soil
depth of the seedbed should also be at least a foot in depth. This will
give the seedlings plenty of room to set down healthy, vigourous roots.
Fertilization Practices:
It is the author belief that an excessive amount of chemical fertilizer
is being used at Brampton. Poor soil conditions can never adequately be
compensated for by the application of artificial fertilizers. Such applications
lead to the build up of salt damage in the fields and can reduce, rather
than improve, later harvests. It is imperative to note that nothing can
replace good soil. As improvements are made to the soil, fertilizer requirements
should decrease. This can be a significant area of cost reduction. Bramptons'
use of fertilisers measured into the many hundreds of pounds. Simply as
a way of illustrating contrasts, the author makes a single 100-pound application
of 12-12-12 prior to planting and a single dose of root starter at transplant
time. No other application of fertilizer is made at any other time during
the season.
Summary:
The poor soil conditions found at Brampton are curable, given time and
patience. Irrigation and fertilization practices can be amended. Insect
and viral control should be practiced following standard recommended practices.
Specific suggestions for improving the chile pepper production at Brampton
include:
1. Immediate application of gypsum at a rate suggested
to be at least 20 pounds per 100 square feet and rotovated into the
soil. This is to reduce the presence of the heavy clays found in the
soil.
2. Planting or allowing a cover crop to grow and plowing it under before
seed pods form. This is to increase the amount of organics in the soil.
3. Repeating these first two steps as necessary and until significant
soil improvement is noted.
4. Reduction of irrigation water to a level determined by soil conditions.
5. Immediate removal and destruction at a remote location of plants
exhibiting signs of viral infection.
6. Seed bed improvements as noted.
7. Keeping fields and field margins free of weeds, grasses and other
insect harboring areas.
8. The first few early fruits should be pulled off, preferably when
still at the blossom stage. Studies have shown that this will increase
the size and quantity of later fruits.
9. Fallow fields targeted for future chile pepper production should
be covered with clear mulch. This practice will cause the soil temperatures
to dramatically increase and destroy harmful organisms.
Additionally, the proprietor has indicated his desire to use plastic,
light reflective mulch for future plantings. It is recommended that this
be tested on a small scale first. Mulches when used in tropical settings
can cook the plants' root zone resulting in destruction of the plant.
Excessive irrigation when combined with mulching can lead to the rapid
breeding and onset of fungal blights, diseases and rots. Extreme care
must be used not to over water in conjunction with the use of mulch. Without
improvements in soil conditions, mulch will cause even more dramatic wilting
of the plants during periods of heat. The temptation will be to increase
the amount of irrigation as a result, which could have disastrous effects.
It cannot be stressed enough that the use of plastic mulching on overly
wet non-porous soils can rapidly breed many types of fungus and rots.
It is the authors' personal preference that the mulch not be used, or
at least used only on a very small test plot, until the soil can be sufficiently
improved.
It is also suggested that the plant density be at least
doubled. The author uses a pattern consisting of a double row with a plant
set of 18 inches between rows and 18 inches between plants with a 9-inch
offset between rows. The authors' plants typically reach heights of between
2.5 and 3.5 feet by seasons end with some reaching 4 feet or more. The
increased proximity of the plants encourages rapid and vigorous plant
growth through natural competition.
Research has shown this can be achieved through the application
of light specific reflective mulches. Red reflective mulch seems to reflect
light in the same spectrum as would a nearby plant. The plant, believing
that there are other plants nearby, responds with vigourous growth.
Experiments are under way at Brampton to determine the
viability of using a greater plant set depth. It is suggested that plant
depth can be greatly increased. Studies from Florida and the University
of Vincennes suggest that burial of plants even past the dichot leaves
yields a greater root structure and a more vigourous plant. The author
has used this practice successfully for several seasons now and can attest
to its' efficacy.
Recommendations:
All recommendations contained in this report are encouraged to be used
on an experimental basis. Empirical observations beat the best theory.
There are several items needing addressed in order to
ensure the successful production of chile at Brampton Farm. These include
soil improvement, insect and viral control, improved irrigation practices,
seed bed improvements, and improved fertilisation practices. Above all
else, it is recommended that there be patience in awaiting changes.
Soil Improvement:
There are two recommended practices for improving the soil. A
slower method consists of the planting of cover crops which are periodically
plowed under and allowed to decompose. This will increase the amount of
natural organics in the soil and lead to improved friability, porosity,
and nutritive content. Suggested cover crops include, alfalfa, clover,
grasses, and ideally, legumes or other nitrogen fixers. These crops are
to be turned under and then rotovated. After time, biomechanics will lead
to their decomposition and soil improvement achieved. It must be kept
in mind that this is a long, slow process. It cannot be stressed enough
that the poor soil conditions did not arise in a single season and are
not going to be cured in a single season. Patience is as much a prescription
as any other recommendation found in this report.
A second, slightly faster and surer, method of soil improvement
is the application of gypsum. Gypsum works by binding the available sodium
in the clay and converting it to sodium sulfate, which is highly water
soluble and easily leached out. The clay then has better porosity and
friability. This second method is the one used by the author on his own
beds. In the space of three years, it has taken a heavily clay soil that
supported no plant growth and improved it sufficiently to support a wide
variety of plant growth. Application rates of gypsum vary according to
soil type, geographic region, and climate. It might be noted here that
it is extremely difficult to over apply gypsum. There should be little
fear of harming the soil by over application of gypsum.
Recommended application rates vary from 20 pounds (10
kilos) per 1000 square feet, to 50 pounds (22 kilos) per 100 square feet.
On a soil only slightly better than that found at Brampton, the author
applied it successfully at the higher rate.
It is specifically recommended that a combination of these two approaches
be used at Brampton. Cover crops should be turned under and an application
of gypsum be made. Additionally, as cover crops appear they should be
continuously turned under and worked into the soil in order to improve
the amount of organics. In time, significant improvements will be noted
to both the soil and the chile production.
Bodles Research Station
A tour was made of the Bodles Research Station. Several projects are being
undertaken there to ensure the continued availability of desirable Scotch
Bonnet peppers. Projects are underway to cross breed the domestic Scotch
Bonnet with a strain of Peruvian c. chinense that has shown viral resistance.
The F1 generation was a week away from producing fruit. Additionally,
the station is breeding a Scotch Bonnet that is truer to type and commercially
desirable. A desirable Scotch Bonnet was identified as one having a continuous
canopy at mid length on the fruit and having four equal sized lower lobes.
As is common with all peppers, the Jamaican Scotch Bonnet has degenerated
into a myriad of shapes and sizes, only a few of which have commercial
value. The nearly irresistible temptation it seems, among farmers world
wide, is to sell of the most valuable fruits and retain the offal for
seeds. Practiced over a couple of generations, the fruit recedes to any
of a myriad types of 'bird pepper'. Bodles is attempting to produce a
viral resistant, 'true' Scotch Bonnet. The desire is to produce a significant
amount of seed to be used for future harvests that have the desired characteristics.
It is strongly suggested that research here be coordinated,
if possible, with other chile pepper breeding programs such as the one
at New Mexico State University and the Chile Pepper Institute. The sharing
of information and results could provide untold benefits and shorten the
length of time necessary to find viral resistance.
It might also be suggested that the research not be limited
to the Scotch Bonnet. Unknown pathogens can arise that could devastate
the crop.
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