Tundra Winter Bean Husbandry Guide

Winter beans are closely related to spring beans but are more tolerant of winter weather and are slower developing. Winter beans do not have a vernalisation requirement and their seed size is usually larger.

Winter beans can be expected to ripen 7-10 days earlier than a spring bean crop sown in March.

The area sown to winter beans has remained limited in Ireland in recent years as growers have chosen to grow spring beans instead. However, spring beans have demonstrated a relatively unreliable performance. This unreliability is often caused by late sowing in the spring and consequent flower abortion in the crop when it encounters even a short lived drought.

Winter beans are not without their challenges either. In the past, two main challenges occurred when winter beans were grown

  1. Crows causing seed and seedling loss,

  2. High disease pressure from Chocolate Spot and consequently high fungicide costs

The guidelines presented here are partly based on trial work conducted by Goldcrop to negate the above two challenges when growing winter beans in Ireland.

See the Progression of Tundra Form Plant to Harvest

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27th May

16th Sept

Site Selection & Sowing

Beans in general prefer heavier soils which are less drought susceptible. However, beans do not like compaction or overly fine seedbeds. Beans are well able to tolerate relatively cloddy seed beds but too rough a seed bed can result in a reduced effectiveness of residual herbicides and encourage slugs.

Beans (or peas) should not be planted more frequently than 1 year in 5 in a rotation.

Ensure that there are no bean volunteers in close proximity to a new winter bean crop; such volunteers can infect the winter bean crop with Ascochyta, a disease for which there is no effective control.

Winter beans should be sown to a consistent depth of 3-4 inches; this puts the seed too deep for crows. Consistent seed depth is very important as it results in uniform establishment and less chance of crows being attracted to shallow seeds.

Only certain seed drills can place seed to this depth. Strip till drills such as SUMO DTS, Claydon etc are ideal. Conventional cereal drills will struggle to achieve depth. Shallowing ploughing down of the seed is an alternative; however, this can result in uneven seed depth and emergence.

Uniform emergence of the crop will make herbicide timing easier and shorten the time in which crows can attack.

Seed rate must be calculated based on the seed size (TGW), germination rate of the seed and expected field losses. Field losses in the absence of crow damage can be expected to be approx 10-15%.

Target plant population for Tundra beans is 24-28 plants/m2. This is lower than spring beans but winter beans will branch and tiller where space is available.

The target sowing date for Winter beans is from mid-November to early December, dependant on region with the earlier sowing date preferable in more northerly latitudes. Sowing too early will result in higher foliar disease pressure and control costs.


 

Fertiliser & Nutrition

Beans do not have a Nitrogen requirement as they fix Nitrogen from the atmosphere.

Any P required should be placed in the seedbed at sowing time. K can be also be placed or broadcast on afterwards.

Beans respond to Trace elements where they are required. Requirements should be based on soil tests and Leaf tissue analysis.

Beans do not like acidic soil conditions; optimum pH is 6.5 – 7.

Weed Control

Weed control in winter beans must be applied prior to crop emergence. Emergence from a sowing depth of 3-4” can be expected to take 3-4 weeks.

Goldcrop have had excellent results from applying a mix of Glyphosate (3L/Ha) and Nirvana (4L/Ha) just before crop emergence. The Glyphosate kills any existing weeds and the Nirvana prevents any further weed development.

By delaying herbicide application till just before crop emergence, the residual component of the herbicide is less exposed to leaching from winter rains. The herbicide will also be applied onto a surface which has been sealed in the time interval since sowing.

Planting using strip till as opposed to ploughing should also result in a seedbed which is better able to carry the weight of a sprayer.

Disease Control

The two main diseases encountered in winter beans are Chocolate Spot & Downy Mildew. Both are best controlled with preventative action. By avoiding sowing winter beans too early, the onset of disease pressure in the spring is delayed.

Goldcrop have found that a 3 spray program based on Signum for Chocolate Spot & Bean Rust control to be very reliable. The first application (0.75kg/Ha) is applied at the beginning of flowering. Two further applications (0.75kg followed by 0.5kg) are applied at 3 week intervals.

Downy Mildew can be well controlled by applying Basfoliar Activ before symptoms arise or just at the very early onset of symptoms.

5 tips for successful establishment

1. Site selection is important

  • heavier soils best, soil pH must be >6.5
  • no beans in rotation for previous 5 years
  • don’t sow near a crop of volunteer beans / near cover crops containing beans (risk of Ascochyta infection)

2. Don’t sow too early

– after mid-November to mid-December is best

3. Sow TUNDRA at 8-10cm / 3-4 inches depth to avoid crow damage.

Direct drill methods work well, especially into stubble ground / standing
cover crops which can increase surface soil tilth.

4. Sowing rate should be 30 – 35 seeds per sq metre

– check TGW & Germination % of seed being drilled

5. All herbicides should be applied before crop emergence

For more information on growing a successful crop of winter beans, please contact John Dunne