Strong and healthy faba beans

Dr Becky Howard

Benefits in rotation

• N fixing – reduced input with benefit to following crop up to 0.8t/ha

• Recycling N-rich residues• Can improve soil structure and

microbial populations• Disease break in cereals and oilseed

rape• Can spread the workload• Provides a source of on-farm protein

for animal feed• Provides a good opportunity for

pollinating and other beneficial insects

Source: Eurostat 2018

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UK average field bean area, production and yield 2009-2018

Area ('000ha) Production ('000t) Yield (t/ha)

UK field bean end use

LegValue - http://www.legvalue.eu/TRUE - https://www.true-project.eu/Photos courtesy of Pete Iannetta at the James Hutton Institute

Factors affecting production and quality

• Rotation• Soil quality and health• Establishment conditions• Variety choice• Seed quality• Plant nutrition• Weather and soil moisture availability• Pests and diseases• Crop protection and integrated farm management• Harvest timing

Soil quality and health

• Compaction – may halve root development, reducing yield by up to 40%

• When soil moisture deficit is high, restriction of roots to reach subsoil causes severe moisture stress

• Although faba beans are the most tolerant of grain legumes to waterlogging, long-term submergence can cause irreversible damage to roots

• Soil-borne pathogens –Fusarium culmorum, Fusarium solani and Sclerotinia sclerotiorum and trifoliorum –causing root and stem rots in plants

Factors affecting soil-borne pathogen infection

• Soil structure

• Rotation – 1 in 5 at most – short rotations lead to build up of soil-borne pathogens

• Cropping history – a long history of bean production may lead to higher pathogen burden

• Conditions at establishment – it’s better to wait for the right conditions than force beans into difficult seed beds

• Conditions during the season – high levels of plant stress lead to greater disease pressure

• Foot rot diseases – prevention is the only solution

www.pgro.orgPGRO Agronomy App

The PGRO Recommended List is published each year using data

from 11 sites (spring sown beans) and 7 sites (autumn

sown beans)

Seed quality

• 2018 harvest – bean seed quality was comparatively low

• Germination capacity – winter beans average 79.5%, spring bean average 83%

• Bruchid damage and mechanical damage of over-dry seed – at each handling point germination can fall by 5% if over-dry

• Ensure seed is tested for germination, pests and diseases

Sowing date and plant density• Work was carried out at 3 sites in 3 years (total 9 trials)

between 2012 and 2015 to evaluate the effects of sowing date and plant density for autumn sown and spring sown field beans

• Sowing dates for spring beans:

• Period 1 – 25 February to 14 March

• Period 2 – 15 March to 28 March

• Period 3 – after 29 March

• Plant density spring beans:

• 20, 40, 60 and 80 per m²

Mean yield t/ha Economic optimum plant density

Plant density for maximum yield

Period 1 4.10 54 61-64

Period 2 3.89 55 63-64

Period 3 3.53 52 56-64

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Fuego spring bean yield 2012-2014 in England

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Mean yield t/ha Economic optimum plant density

Plant density for maximum yield

Period 1 6.84 45 45-50

Period 2 6.51 51 50-55

Period 3 5.68 52 55

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https://cereals.ahdb.org.uk/monitoring/aphid-news

www.cropmonitor.co.uk

Pest and disease monitoring and forecasting

https://www.syngenta.co.uk/bruchidcast

Pest and disease monitoring and forecasting

Current spray recommendation: Temperature has reached at least 20°C for two consecutive days;First pods are present at the base of the plant;

The forecast also tells you when the temperature threshold has not been reached.

Impact of sowing date on percentage bruchid damage in small plot trial at 3 sites in 2015

• Period 1 was early-March and mean % damage was 35.33%

• Period 2 was late March/ early April and mean % damage was 19.25%

• Period 3 was mid-April and mean % damage was 15.27%

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Sowing timing

• Black bean aphid (Aphis fabae)

• Host plants: Highly polyphagous on summer hosts including species of Allium, asparagus, beet, pepper, Chenopodium, thistle, soya, sunflower, legume but mainly affects sugar beet and legume crops; winter host is the common spindle (eggs) or wild legumes (mobile stages)

• Greater impact from direct feeding than from virus transmission, although it can transmit viruses and spread existing infections from plant to plant

Key aphid species in beans

• Pea aphid (Acyrthosiphon pisum)

• Host plants: Moderate host range including peas, field beans, broad beans, vetch, clover and lucerne

• Considered one of the 14 aphid species of most agricultural importance in the world (Blackman and Eastop, 2007)

• Each adult female produces up to 12 nymphs per day – each nymph develops to adulthood in 7-10 days

• Is a vector for more than 30 viruses worldwide

Key aphid species in beans

Population growth optimal at 16 to 23°CAphid mortality increases above 23°C

Biological control of aphids in field beans

• Adalia bipunctata – two-spotted ladybird

• Aphelinus abdominalis/ Aphidius spp. – predatory wasps

• Organic surfactants and plant extracts

• Use of flowering field margins has been shown to encourage populations of beneficial insects and reduce aphid populations in legumes

• Although UK research on the benefits of intercropping legumes for pest and disease control has been relatively small, research in other areas of Europe indicates positive benefits caused by dilution, barrier and changes in crop microclimate, as well as yield benefits

Crop protection

• Loss of active substances means that development of cultural and biological systems is more urgent

• Crop area may limit effort for crop protection products in pulses

• Resistance – there is increased incidence of resistance to plant protection products in the UK and alternative strategies must be used

• Future effort must be in plant breeding, cultural management, soil health and biological products and systems (Integrated Farm Management)

Thank you

• For further information go to www.pgro.org

• becky@pgro.org

• Or call 0044 1780 782585

• We run an advisory service, plant clinic and seed testing laboratory for diagnosis of crop problems

• All publications and updates are available on the website