Viper newsletter week 4, 2010

These news and recommendations is specific made for Viper grown in Canada (south western Ontario).

Topics of this first newsletter:

1. Planting and rooting in to growing media.
2. First setting.
3. Single stem Viper, what is the ‘deal’ ?
4. TMV infections.

Planting and rooting in on groving media:

Many Viper growers have planted by now, and many plants have rooted in very well during December and January. Depending on your growing media you should see the plants nicely anchored into slab in 10-14 days. It is important to keep the block moist during this process in order to keep a good contact between block and slab. First days (up to 5-7 days after planting) it can be needed with 6-8 shoots of water over 24 hours to keep the block moist. Especially during cold nights with higher pipe temperature you might be surprised how fast the water disappears from the small block. Growing media should be charged with Ec around 3, and feed should be around 3,0 up to 3,5 during this process. As soon as the roots are going into growing media, it is recommended to cut off some of the water, but still keep in mind that the small plants still have a large amount of roots in the block, so don’t dry them up too soon. During rooting in day and night temperature normally is kept more or less even, day 20-22 and night 19-20, this indicate vegetative growth for the small plants, and most energy will go to build up a good root system.  If you want to space/move your plants into a V position on single gutter system, this is also the time to do it, before the root system is fully established. This job can start quickly after planting, and it is important to not force the plants too far out in a V. Co² is not required the first week to 10 days after planting, and then small amounts can be applied into greenhouse. Keep levels around 500-600 ppm in daytime, and be careful to turn off co² in good time before sunset, or you might end up with too high levels during evening and night. This can cause issues with flowers and setting. Also make sure start time is when the plants are active, and you will notice a big difference between these times from a sunny day to a cloudy day. CO² should be controlled very carefully in the first months of a pepper crop. Remember, building up a good root system is on of your keys to a successful year.

First Setting

Setting too early can be critical due to very fluctuating light levels in January, but if we receive good light levels we also risk losing production if we remove all fruits up to second internodes. What is most important is to look at your plants balance and conditions, create as even setting of flowers/fruits as possible, and to get this, it sometimes require that all fruits up to second internodes is removed. If you have a lower greenhouse, you might want to let the plant set as much as fast as possible in order to calm down the plant and avoid strong growth. When you set your first flush, keep in mind that high fruit load can create issues with setting 2nd and 3rd flush. During setting you should consider using Prenight, it don’t have to be very low and a dramatic drop at this time of year, often a Prenight on 18 or 19  ̊c for a few hours is enough. Keep your 24 hour average over 21 ̊c in order to keep a good speed in the plant.

An example on climate setting during setting could be

Day:
21 ̊c, reached at sunrise, in afternoon on sunny days go up to 25-26  ̊c, keep up to 23-24 ̊c until prenight.
Prenight:
follow sunset, 18-19 ̊c for 2-4 hours.
Night:
19-20 ̊c

Make sure you start heating up to the day early enough, 1 ̊c pr hour would be needed. Prenight should be allowed to drop fast, but try to avoid venting during this process in the cold winter; cold air dropping into crop can cause issues later on. Let the temperature drop due to lower pipe temperature, you might need a bit more time, but then extend your Prenight in the other end if you find it needed.
It is key to create flowers in a good average size and shape. You want to see the flower bend down already as it starts to open up. Flowers need to be clear white and good pollen helps the pollination greatly for this first setting; you really are depending on a good job from the bumble bees at this time of the season.

Viper double system vs single stem system

The concern for a too low fruit average size is normal for the Canadian growers in south western Ontario. Target market is for most products the US market, and the demand is still XL peppers with a high fruit average weight. Due to this concern, some grower’s trialed areas with single stem Viper crops in 2009, and the end result is impressive with 10-15% higher fruit average weight compared to their double stem Viper crop. So not alone did they gain extra production on the single stem Viper, the extra production came from a needed higher fruit average size.

Single stem Viper comes with a higher cost, more seeds are needed as well as propagation space. Propagation is normally shorten down to 35 days old plant, we have seen 2 two different ways of supporting the plants, one is with 2 stick around each plant, the other system is the regular stick with elastic or clips. In order to fit enough plant pr slabs at planting, it is highly recommended to use a 10 cm *15 cm propagation block in propagation, this type of block is also flexible for propagation and give the propagator/grower other options for spacing during the plant rising time.

Planting takes the same time as if you were planting a regular double stem plant; just remember when ordering slabs with pre-cut holes, that you will need more holes pr slab and size of holes will be different from your normal 10 cm * 10 cm.

We normally see one dripper pr 1 block with 2 plants. This is exactly the same as regular double system, where we also normally have 1 dripper pr 1 block with 1 plant (will becomes to 2 plants shortly after planting). We do know that single stem Viper require more water than a regular double stem Viper, up to 25 % extra water can be required, so this is something to keep in mind in if you consider single stem system, your irrigation setup have to be able to handle the extra demand.

Most growers space out the plants after planting the single stem Viper, in order to use the full amount of light available, as well also try to avoid stretching in the plants. This spacing has to be done shortly after planting while the stem still is very flexible. If spacing is done too late, it can create ‘elephant foot’ later on in the season, in general the pepper plants should not be touch at the stem/stem base 8-10 days after planting to avoid any stress on the root system.

Strings will have to be clips or tied on at the same time as a regular double stem Viper. It is more intense job with single stem Viper, since all heads/plants have to tie on at the same time. Labour cost might end up being the same as a regular double stem, just more intense at one time.
Growing strategy is slightly different; plants are getting more vegetative from the beginning. Due to the extra plants in your greenhouse, you will see how the humidity stays at a higher and better level from first day. This helps greatly to control the plant as well and create good flowers with nice pollen. High Ec is also a key tool to use to keep the plant into the generative mood, in general we see growers using Ec from 3,5 to 3,8 during setting first flowers.

Single stem Vipers did grow up to 30 cm more than regular double stem Viper over a full growing season. Also something to keep in mind, if you have a lower greenhouse facility.
At the end of the season of 2009 we saw significant extra production on single stem Viper. For each greenhouse facility it can be different, therefore it is important that each individual grower takes all concerns into consideration before deciding if single stem is a system for their facility. Discuss sizes with sales and marketer, know your labour cost, know you facility’s water supply and height and then make a decision.