Processors and Growers Research Organisation

Online Pulse Agronomy Guide

Choice and use of seed

In the UK Seed Certification Scheme, seed is graded as Basic (B), Certified Seed of 1st Generation (C1), and Certified Seed of 2nd Generation (C2). Basic and C1 seed is generally grown for the production of further seed crops and C2 seed is used for commercial crop production. Basic seed is the most expensive and C2 the least expensive. Certified seed is required to meet a minimum germination of 80% and to achieve a standard of purity.

Leaf and pod spot (Ascochyta) caused by Didymella pinodes and Ascochyta
pisi, is a potentially serious seed-borne disease, which can affect both quality and yield. However, growers should note that there are no minimum infection standards specified by the statutory certification scheme for this disease. Seed tests are available from PGRO.

Seed Treatment

With the withdrawal of thiram seed treatment, Wakil XL can be used as a seed treatment to protect plants from pathogens such as downy mildew, Pythium and leaf and pod spot. A date restriction applies and seed treated with Wakil XL must not be planted between 29th September and 1st April in any year. 

Wakil XL contains metalaxyl-M, and following renewal of the active substance in 2020 it is likely that from 1st June 2021 outdoor sowing of seeds treated with metalaxyl-M will not be allowed.

The use of nutritional supplements and biological stimulant treatments may boost the natural strength and resistance of establishing plants.

Seed Size

Seed size is very dependent on growing conditions and variety, hence the 1000 seed weight data shown in the Recommended List should be used only as a guide to the relative seed size of varieties.

Seed rate and plant population

Target populations should be set according to the type of the pea variety being sown. The optimum population depends on seed cost and return of produce per hectare. Adjustments should be made accordingly. The populations given below are an average recommended by PGRO as the most profitable levels for each type. Targets could be lower than these on fertile soils. Higher populations may be beneficial on light, drought prone soils, or where there is a risk of attack from birds.

Typical target plant populations

Type

Varieties

Population (plants/m²)

Marrowfats

Akooma, Sakura, Octavia, Banshee

70

 

Maro, Princess, Kahuna, Kabuki

65-70

Green and yellow

All (apart from Zero4)

80-90

 

Zero 4

110

NB: Late sowings may benefit from slightly reduced target plant population

 

The seed rate can be calculated from the following formula:

table3

 

 

 

Use of the seed rate formula, and adjustment for expected field losses, is necessary to achieve the most profitable populations. Expected field losses are given in the table below and are lower for large-seeded peas. Losses will be higher on heavy, poorly drained soils.

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