SeedQuest - Central information website for the global seed industry

News Page

The news
and
beyond the news

Index of news sources

Topics

Species

Archives

News archive 1997-2008

Root rots on pea in Alberta, Canada

A ProMED-mail post <https://url.emailprotection.link/?bczGkw5NaxKViInVN3o8WI7SkfPjCplYcnrvkSnR7vDdzBseB4Z4JgOzMtf4NyhKwZ-87t_ekCqY4X1TR9IACFg~~>

ProMED-mail is a program of the International Society for Infectious Diseases <https://url.emailprotection.link/?bJcYJd1UM9bbZyueyHGqCfuWBsCz6JLr6QpMnBNG04Pz2V8akThtcwE1bjLVZbAR2-PZoubzhx-ALOhYt6Kir6w~~>

Date: Thu 4 Feb 2021

Source: The Western Producer [abridged, summ., edited] <https://url.emailprotection.link/?bw7mBztLZK92IfHSUktl25BAwnDPM_E2IqMkRONpl6kZbGxIO6k0d6AE-jl11KcP8Um_VJzNB7Vm-LopHyHh4sneIY9q-aMlhrlnIp-_ZT-HrbZRvSu9BqhSiCBhy7ML7>

Widespread root rot [was] found in Alberta pea fields. The severity in surveys last year [2020] reached levels at which the disease can become an economic threat. They found root rot in every field visited on an estimated 66% of roots examined.

"Root rots continue to be a real issue in peas," said Alberta Agriculture's Michael Harding. "Mycosphaerella and ascochyta were by far the most commonly observed pathogen. [They] were very, very common on peas in 2020."

Field peas in Alberta were grown on 1.47 million acres last year [2020].

Root rot diseases are characterized by poor emergence, stunted growth, yellowing of plants, and root discolouration, said Alberta Agriculture's Robyne Bowness Davidson. Among the whole root rot complex, fusarium and aphanomyces are of greatest concern. "The problem is that they occur together more often than not and can be very difficult to distinguish from each other," she said. In wetter parts of the province, it was difficult to tell whether sickly looking crops were due to disease or drowning.

There is likely a lot of root rot inoculum in fields, raising the threat of root diseases in 2021, depending on moisture and other conditions. Aphanomyces is aggressive and spreading, and it travels with other pathogens, so it continues to be a concern. Bowness Davidson suggested a pulse rotation of 6-8 years to avoid it.

[Byline: Barb Glen]

Communicated by: ProMED <promed@promedmail.org>

[Root rots of pea (_Pisum sativum_) can be caused by a number of fungi or fungus-like microorganisms, alone or in disease complexes. They may include species of _Fusarium_, _Thielaviopsis_, _Mycosphaerella_, _Phoma_, _Phytophthora_, and _Pythium_. Symptoms may include stunting of plants and leaf yellowing; the taproot may completely rot away.

Disease development is generally favoured by humid conditions.

External stress factors such as temperature, nutritional problems, or herbicide damage can make plants more susceptible to infection.

The pathogens are soil borne and can survive in the soil for years.

They are spread with plant material (including plant debris, volunteer crop plants), mechanical means (including contaminated equipment, human and animal activities), soil, and water. Once the pathogens are present in a field, disease management is difficult but may include long crop rotations to slow down build-up of soil inoculum, field drainage, choosing fields with low fungal soil load, as well as removal of inoculum sources (such as crop debris). Fungicide seed treatments may be effective in some cases but are subject to strict regulations in many countries. Root rot susceptibility of commercial pea cultivars varies, but no resistant varieties are available.

Maps

Canada (with provinces):

<https://url.emailprotection.link/?bcjOBNIswALIRPt9JpYlUyS3FoDcxZNNjAmJRJIs7ygUmK6PjRuADgJNBYKbXMhe--gkUV1ice_KHO9a0O3miCtpToJQgfdFhIT5QPRLfcHZxo-ixYNrRw_CxS-YdX594>

Pictures

Root rot symptoms on pea:

<https://url.emailprotection.link/?bzw3Qv_M6fPSjyW1GUCcyerU2X0F_yvJwlbbMmIgsSe50GtzoPBWhR0Dv2rSEfj4SaoecNAeQFsU1ct0zapKICGRCUbXEBX5LF-YM0YoCMWN98r7wwVl3uXa-MIoZji_qNOsCFsdzsWEGy_34_roMrJ7N3uUCkw0NgtspazJXSBA~>,

<https://url.emailprotection.link/?blZ8kqzliBXCURB6IXLLCW7NXCttc7kSNJDRBhI6e_BqN1oEU5B0QjqxMfoyuowg2Kokp6aPTNbAh4fgZfdzcGeOaq9ISfrzM4yCRUoN782FO6TTyKurGPV1iCC5HlliACCLC9HU60O7cx9PP0BAEEtp0LO5av5lCbMeE2Nahu9o~>,

<https://url.emailprotection.link/?bIbJjyHQAo5UYQkp5l_ws0tUkF7Fsnhe7VItaIsKb4mTLYK-hPd92jTuEgxPwOQqhnpxIk00iESTR9f6ALHyuJRGzGOinCGpp5hcyMMZbSJwxm4k6eA9GuGo5h7KG0AtqXsZPmIHNBs_2fIZx1z276pYMYMb-h69EsfPM2uchoIo~>,

<https://url.emailprotection.link/?bZQwb1mB_S247pEN-QPQBWgQvVEanTyKKD8jvUrhoPCk7g9l_bs0D-zD_oNVjRRPzWJcOpKefhFWrXOO_SMRbb6PsgXUc4ECWQu_znmfmcuCg23xBbjZNhuqu-an5HXvb>

and via

<https://url.emailprotection.link/?bUcuoGl0KFiaqFqwu9EQ0U-bPF_TjvKA7s_TkmUiuXGsuNFrgRznfczOuKN_jmoELCKwE-eHcGcATbq2gaYyqdj3_OHUMcSvjr8oUV9JEoJQ77ELmokl0tMx-UQjcKErb>

Links