Day: August 9, 2022

Tomato and Blossom End Rot

Emily Zobel on

By Jerry Brust, IPM Vegetable Specialist, University of Maryland

This is just a reminder with the usual summer weather we have had lately with stretches of very high temperatures and the occasional very heavy down pour we have had over the last few weeks blossom end rot can become a real problem in tomatoes. Sunny days will suck water through a plant quickly and the downpours will disrupt calcium movement through the plant. The key is to try and maintain consistent soil moisture while the fruit is developing. Easier said than done I know, but soil moisture levels need to be monitored as best as they can. When you see something like figure 1, with all the tomatoes on a cluster with blossom end rot you know the soil moisture fluctuated greatly over a fairly long period of time. Applying some foliar calcium sprays may help, but the applications can’t overcome poor soil moisture management.

Cluster of green tomatoes with blossom end rot ( browning at the base).
Fig. 1 All the tomatoes on this one cluster have blossom end rot—indicating poor soil moisture management. Photo By J. Brust. 

Possible Changes to Atrazine Use

Emily Zobel on

By Kurt M. Vollmer, UME Extension Weed Management Specialist

The EPA is proposing several changes to its interim registration review decision for atrazine. The primary issue is the aquatic ecosystem level of concern (CE-LOC). The EPA had previously set this level at 15 ppb, but this was challenged in the Ninth Circuit Court of Appeals. Currently the EPA is proposing a much lower CE-LOC level of 3.4 ppb. This proposed level will have significant impacts on growers’ ability to use atrazine and other triazine products. Labels will also likely include new language to help mitigate the risk to aquatic plant communities. These include:

  • restricting atrazine applications when soils are saturated,
  • restricting atrazine applications during rain or storm events,
  • prohibiting aerial applications,
  • and reducing the annual atrazine application rate from 2.5 lbs. to 2 lbs. per acre annually.

Additional information can be found here: https://list.mg2.mlgnserv.com/track/click?u=df0ec74ed0bf23e091847f07c1d2c483&id=c31eec13d8967c36&e=d300d03f14fec2b3https://list.mg2.mlgnserv.com/track/click?u=df0ec74ed0bf23e091847f07c1d2c483&id=c31eec13d8967c36&e=d300d03f14fec2b3. The EPA is currently seeking public comments about the proposed decision (https://www.epa.gov/dockets/commenting-epa-dockets).

In addition the USDA Office of Pest Management Policy is conducting a related survey on atrazine usage practices for farmers involved in corn and sorghum production over the last three years (https://usdaopmp.gov1.qualtrics.com/jfe/form/SV_agW8JjsVXqR4jjg).