Microsoft word - pgro tolerance list - beans 04.doc

PROCESSORS & GROWERS RESEARCH ORGANISATION
The Research Station, Thornhaugh, Peterborough PE8 6HJ
Tel: (01780) 782585 Fax: (01780) 783993 E-mail: [email protected]
INFORMATION SHEET NUMBER 135
THE REACTION OF GREEN BEANS & BROAD & FIELD BEANS TO HERBICIDES
Revised January 2004

Although some indication of sensitive varieties may be given by manufacturers on their product
labels, it is important that those concerned with application of herbicides to Phaseolus (dwarf green)
and Vicia (broad and field) beans should be aware of herbicide effects. Varieties can differ in their
tolerance towards herbicides, and experiments testing their reaction to those in common use are
carried out at Thornhaugh annually. The varieties chosen are those in current commercial use, as
well as promising new varieties from the PGRO evaluation trials which may be used in the future.
The classification of sensitivity is based on data from two seasons at least, since the effect of
herbicide can vary with the weather conditions and soil type.
CLASSIFICATION
The sensitivity of the varieties to the herbicides is classified on a 1 to 5 scale as fol ows:-
1 - Highly tolerant
The variety shows little effect when high dose rates are used and it is unlikely that damage will occur
when healthy crops are treated.
2 - Tolerant
The variety exhibits good tolerance to the material and crop damage is unlikely to occur, provided the
crop is healthy when treated.
3 - Slightly susceptible
The variety usually exhibits good tolerance, but occasionally some adverse effects may occur,
particularly under unfavourable conditions or if the crop is not healthy or vigorous.
4 - Moderately susceptible
The variety exhibits some adverse effects under most conditions.
5 - Highly susceptible
The variety is prone to quite serious damage particularly under unfavourable conditions.
No particular problems should occur with varieties in classifications 1 and 2.
Care should be taken when treating varieties in classification 3. For simazine, used for broad or field
beans, sowing depth should be at least 7cms. For Opogard 500L, Senate and Remtal SC or Reflex T
sowing depth can be 2.5cms (or more). Applications of pre-emergence herbicide to very open, loose
or stony seedbeds should also be avoided.
Treflan can reduce green bean emergence and cause stunting on cold, wet seedbeds. The addition
of Silwet to Flex increases phytotoxicity and brown spotting on leaves may occur. For post-
emergence applications crops should be healthy and at the recommended growth stage. Conditions
for application should be as close as possible to manufacturers recommendations, and the correct
dose used.
Varieties in classifications 4 and 5 should preferably be treated with alternative materials.
DWARF GREEN BEANS (Phaseolus vulgaris)
# the susceptibility of most varieties is increased slightly when oil adjuvant is added to No variety so far has been found to be particularly sensitive to herbicides for grass weeds BROAD BEANS (Vicia faba)
PRE-SOWING PRE-EMERGENCE Varieties Alpha KEY: * variety two years data only, provisional classification
No variety so far has been found to be sensitive to Laser (or Stratos) + oil. Damage effects from
bentazone (Basagran) are related to growth stage and adverse weather conditions rather than
variety, however, Talia is slightly sensitive and should not be treated with Basagran at full dose rate.
FIELD BEANS (Vicia faba)
Spring field beans, including most white flowered varieties tested so far are tolerant to pre-emergence
herbicides Opogard and Batallion, although small seeded varieties such as Maris Bead, Titch and
Diana are occasionally more sensitive. Bullet may occasionally cause distortion of the growing point,
but there is no particular varietal sensitivity. Reflex T and Remtal are very safe to all varieties of field
beans. Simazine can be damaging if sowing depth of beans is too shallow. Damage effects
from Basagran and Basagran SG are generally related to growth stage and adverse weather
conditions rather than variety. Information on varieties tested is available from PGRO.
CHEMICAL NAME
pendimethalin/cyanazine - Bul et
The approval for Arresin, used for dwarf green beans, has been revoked following withdrawal
by the manufacturer. Exisiting stocks may no longer be used (use up date was October 2000).

Source: http://www.mauk.co.uk/docs/PGRO%20tolerance%20list%20-%20beans%2004.pdf