QUIZ – This Week in Agronomy

We have three quiz questions on agronomy topics that came up in conversation this week. One on stand establishment issue, one on spray water quality and one with a bit of both.


Many things can cause canola seedlings to go missing. In the article How to count canola plants and explain low numbers, what cause is associated with this description: “Results in notched, wilted, dead or cut-off plants. Plants may be gone entirely“ ?


A scenario: A farmer used a pre-seed burnoff containing florasulam, the common Group-2 herbicide used for pre-seed burnoff in fields planned for cereals. Canola is not going on that field. However, this was the farmer's last pre-seed burnoff spray of the year and the next scheduled spray is an early application of Liberty on canola. Liberty herbicide is very good at scrubbing Group-2 herbicides out of sprayer systems and releasing them into the spray solution. This contamination can damage canola crops. To prevent this, the farmer will want to give the sprayer a very good cleaning before starting on in-crop applications.

The guides to crop protection describe three basic methods for spray tank clean out:

  • Method A – Drain contents of tank – 1 to 2 x Water Rinse – 2 x Ammonia Rinse – 2 x Water Rinse (one just prior to the next spraying event)
  • Method B – Drain contents of tank – 2 x Water Rinse – 2 x Detergent Rinse – 2 x Water Rinse
  • Method C – Drain contents of tank – Several repetitions of the Water Rinse with nozzles and screens removed and checked for debris.

What is the basic spray tank clean out method for florasulam?


Hard water – water with high concentrations of calcium and magnesium – will reduce the effectiveness of glyphosate. With hard water, use the maximum recommended rate of glyphosate and add which of the following?