Stevie wrote:
Hi David,

The temperature is certainly a lot cooler than it was a few weeks ago
as we have had nothing but rain for the last 3 weeks and outside
temps of around 14 degrees with the occassional 20 degree day here
and there. It is always warmer than that in the conservatory but not
by a huge margin.

I am watering them when the soil in the pots is dry to touch on top. I
am watering them from the bottom of the pot though as I was under the
impression that this is correct? They are being watered pretty much
every day.

I feed them once a week using tomato feed to the dosage advised on the
bottle.

The plant has been fine up until around 2 weeks ago when the yellowing
started. I have around 10 plants of varying types but there seems to
be one that is being affected the most.

Thanks,

Stevie

There will be no insect pollinators in your conservatory but it isn't clear
if this is important, however it may be a problem with other fruiting plants
that require pollinators.

MacGregor who is usually the expert I go to on pollination is uncertain:

quote
The pollination requirements for maximum production of the different
cultivars of pepper
is not clear. Jones and Rosa (1928*) stated that "Self-pollination takes
place, in general,
but there appears to be a considerable percentage of cross-pollination also,
for many
hybrids have been noticed as a result of growing different varieties near
each other."
Hawthorn and Pollard (1954*) implied the same thing. Cobley (1956*)
concluded that
both self and cross-pollination occurred for which he gave credit to ants.
Dempsey (1961)
found no difference in set of open flowers and those caged in special cone
cages. Cochran
(1936) stated that flowers emasculated and bagged set fruit as well as
open-pollinated
flowers, which without qualifications is difficult to accept. Later,
however, he (1938)
conceded that cross-pollination takes place more frequently than is
generally supposed.
Martin and Crawford (1951), Peterson (1958), and Shifriss and Frankel (1969)
reported
male sterility in peppers, which is accentuated by higher temperatures
(Bashir 1953).
Hirose (1959, 1962) reported that high temperatures 13 to 17 days before
anthesis causes
pollen abortion and the deterioration of pollination efficiency. Odland and
Porter (1941)
found that none of the varieties tested were entirely self- fertilized and
concluded that
there is more cross-pollination than is generally realized.
Erwin (1932) measured the effect of pollination on set of fruit. He found
that only 46
percent of self-pollinated flowers set compared to 71 percent that were left
to open
pollination by bees. Nagarathnam and Rajamani (1963) obtained only 6 to 11
percent set
of the flowers present. Angeli (1957) reported that hybrid pepper ripens
earlier, produces
more, and is more disease resistant than the parents. He also stated that
production of seed
by open pollination was unsatisfactory because of the lack of insect
pollinators.
Cochran (1932) reported that high nitrogen and low soil moisture at
flowering time
increase set, but high nitrogen and high moisture increase production.
The period of receptivity of the stigma has not been too well determined,
but apparently it
functions only the first day the flower opens.
Smith (1932) noted that few tomato flowers with elongated styles develop
normally and
set fruit. As previously mentioned, the pepper style varies in length also.
Quite
conceivably, in the absence of pollinating insects, the long style would
prevent pollen
from the anthers reaching the stigma, and fruit setting would be prevented
or reduced.
Markus (1965) noted that crossing occurred primarily between 7 and 11 a.m.
The evidence indicates that pepper flowers do not always release their
pollen, or if it is
released, it may not come in contact with the stigma. Under such conditions,
the transfer
of pollen between flowers by an outside agency is essential.
Pollinators:
file:///E|/Jason/book/chap6/pepper.html (3 of 6) [1/21/2009 3:46:48 PM]
Chapter 6: Common Vegetables for Seed and Fruit
Boswell (1937) stated that peppers are cross-fertilized to a considerable
extent but did not
state what agencies were responsible. Although ants are frequently mentioned
in relation
to pollination of peppers, their type of activity, the lack of a dense coat
of hairs on their
body, and their limited number in relation to the blossoms present in a
commercial
planting, would indicate that they have received more credit as pollinators
of pepper than
they deserve. Honey bees and other bees visit the flowers of pepper on warm
bright days
(Hawthorn and Pollard 1954*) or during dry periods (Erwin 1931, 1932; Markus
1964;
Odland and Porter 1941; Pammel and King p. 605, 1930*).
Other members of the family Solanaceae are noted for their low
attractiveness to bees, for
example, potatoes, tobacco, eggplants, and petunias, although when other
sources of
nectar or pollen are scarce these plants may be visited. This would appear
to apply to
peppers also. Wind, rain, and other insects appear to be of little or no
value in the
pollination of peppers.
Pollination Recommendations and Practices:
None.
unquote

Make of that what you will, it seems contradictory to me but it leaves open
the possibility that you are getting incomplete pollination.

If your watering via the bottom results in the soil getting damp up to the
top and they are not waterlogged it will be fine. Dig down from the top an
hour after watering and see where the soil is damp, if it isn't damp 3cm
from the top you had better change to top watering. Make sure the pots
drain well.

How many hours a day of sun do they get?

At this point i think that the problem is the temperature. I am assuming
you are using Celsius not Fahrenheit otherwise forget chillis! If you have
a max/min thermometer put it in the conservatory and note the temperatures
daily. I am guessing it gets too cold at night. Peppers like it warm.

David