Saturday 19 September 2015

Hello Everyone:

Much talk about, there has been a lot going on at the farm over the past couple of weeks.

I’m going to start by answering a couple of questions that have been posed to me by a couple of customers over the past few deliveries.

Why are the potatoes so small?”  There are several factors that influence a potato size.  First is the number of generations between the potato plant that bore the seed and the seed tuber sown in the field.  Each generation produces progressively larger tubers.  Typically, elite three or elite four tubers are used for sowing potatoes (four or five generations from the seed bearing plant).  My supplier has started using elite two tubers, as it tends to produce a healthier plant.  As a result, the potatoes harvested this season are a little smaller – the largest could be classified as elite three if used for seed.

Another factor is space between plants.  Suggested plant spacing for potatoes ranges between 8 and 12 inches – less for smaller tubers and more for larger ones.  Last summer, I had too many seed potatoes to fill the last potato bed at the 12 inch spacing, so I planted at 10” spacing.  When this bed was harvested, the tubers were smaller, but the overall yield was almost 30% higher than any previous potato yield.  Because of this, I experimented this year by planting some of my beds at 10 inch spacing to determine if this factor was influencing the higher yield.  I still have to go over my notes, but it appears there is little difference – something else is influencing yield increase.

A third possible factor is the time of sowing (I have to talk to Henry about this to confirm, but I think it is the factor that is most responsible for the small size).

Many roots are influenced greatly by the time of year in which they are growing; the change in day length is a signal to the plant to start storing food in the roots.  For instance, the russets were supposed to be a 90 day potato, producing medium to large tubers.  I wanted these to be available in late September in time for Thanksgiving. 

However, the plants matured at about 70 days (leaving them longer would have allowed the wire-worms and scab producing viruses to mar the surface of the tubers – as it was, I left them in the ground a little too long and we lost a few).

I suspect that if I had sown them a little later, (so that most of their growth occurred after the midsummer solstice), they may have been larger tubers.  We had a very dry season, this probably had an effect as well.

A chat with Henry the next time I am buying seed potatoes next year should help clear this up.
It is commonly said that smaller potatoes are of higher quality for texture and taste.  I’m not sure if this is true or just a hopeful sales pitch.

Why so few cucuzinis?”  All of the squash seedlings spent too much time in the hardening off shelter.  The plants were already stressed from too much time in their pots by the time they were transplanted.  The delay was in part due to the late frosts.

Typically, I place the young transplants under row covers for the first three weeks or so, I took the covers off early and this did not help the plants.  Fortunately, I had planted too many in the first place, so that even as we lost a few, the others were able to make up for the losses – particularly with the winter squash varieties.  The cucumber and zucchini's did not fare so well, and have under performed this season. 

Why is the Celtuce so small?”  This is a new crop for me, grown for customers who eat verry little salad such as lettuce.  Information on this crop has been difficult to obtain (It’s a new crop for the seed house I purchased it from as well), and much of what I have found is contradictory. 

As it is a close relative to lettuce, I assume that plant spacing makes a big difference in the size of the celtuce stalks.  A big lettuce is achieved with 12 inch spacing, so I presume that a thick celtuce stalk is achieved the same way.  However, the culinary use of celtuce is different.  One to two large heads of lettuce is satisfactory for a customer per week, but an equivalent amount of celtuce requires about 5 plants.  In other words:

25 lettuces per week = 25 heads of lettuce at 12” spacing, three rows per 25 foot bed.
Requires about 8 feet feet of bed growing space.

15 celtuces per week = 50 stalks at 12 inches per bed, three rows per 25 bed.
Requires twenty five feet of bed growing space.

My only options are to grow about 30 per cent less celtuce (meaning I have to grow more pac choi – which has its’ own challenges, see below), or grow the celtuce at a smaller spacing.

I assume the very big celtuce stalks available at the store also have the “advantage” of petro-chemical fertiliser.

The big news in the past two weeks is a case of aphids in the field.  I'm not going to go into too many details on these little insects that are literally born able to reproduce (Reminds me of an episode of a famous Sci-Fi television series).

Aphid infestations are rare on organic farms in most conditions.  Usually, they are a sign of too much nitrogen in the soil.  It is possible that the poor water delivery and lack of rainfall contributed to this to some extent as well. 

However, one of my earliest observations seems to point to another factor.  The aphids were originally concentrated in the russian kale, asian cabbage, and one succession of pac choi.  These were all sown in the nursery and transplanted at about the same time, but the kale was planted in a different part of the field.  Some lettuces were sown and transplanted at about the same time as well. 
I first found the aphids near the lettuce in question on a few nearby pig weed plants.  I next found the aphids on the cabbage and pac choi.  When I located aphids on the Kale, none of the crops in between the cabbage, lettuce, and choi had any aphids.  (They have since spread to the last turnips and some of the squashes).

This suggests that the aphids got into the plants either in the nursery, the hardening off shelter, or some other source.  I have kept some cabbage plants in these places as earwig monitors.  These have not produced any aphid activity.  Therefore, their must be another common factor to all of these plants, and my farm journal has provided the answer – a new bag of potting soil.

So I have another task ahead of me, I’ll have to solarize the entire bag which is time and space consuming – essentially setting out the soil in a thin layer in direct sun (but keeping dry) until any aphid eggs are cooked beyond viability.

In the meantime, I have to chase the little critters through the field and remove infected leaves until the crops are harvested (or in the case of the cabbage, sealed in a garbage can until everything is dead).  Not fun!

So the result for this year is likely no more arugula or radish, small cabbages, and possibly no Kale if I missed any infected leaves.

More worrisome is next year.  Now that aphids have established themselves on this farm, I need to take steps to wipe out that first generation when it emerges in the spring.  That means that a few beds may be kept off limits for a couple of months, covered by a plastic mulch.

I have contacted a supplier of beneficial insects and looking into the possibility of releasing some aphid eating insects into the growing field.  Hopefully, pesticide bans will come into effect so that the upper end of the food chain (where the pesticides accumulate) will allow our insect populations to balance out.  Predators are important!

Better news:  After a really tough slog, I managed to get the patch of 'lost beds' into a workable state.  2,880 feet broad forked, cultivated, tilled.  Now I begin raking the area down to drag off as much quack grass root as possible.  The dry weather is really helping me with this!

This will result in 27 new beds.

Well, 26 beds.  The last bed is situated near a main path, and had 6 old barn logs (foot diameter, about ten feet long sitting on it - these used to support the cistern).  We brought in a tractor to move the logs, only to find a colony of bumblebees underneath.  I couldn't take away the last two logs, bees are having too tough a time as it is, and I appreciate the fact that I have bees living in my field infrastructure (last year, a colony of wasps made a nest in the compost...)

Lot's more to talk about, but now it's time to tend the kitchen for some real food.

Bob