May 7, 2015 No. 2015-11
Dr. Jarrod Hardke
Never more than two weeks away from a drought. That definitely seems true right now. In the last 10 days, most areas of the state have gone from muddy fields, to dry and planting non-stop, to planting into dry soil.
Many now find themselves in a position where flushing fields isn’t just a good idea, it’s very much needed. Some areas are seeing severe crusting that’s preventing good, even stands from emerging. Others have residual herbicides out that have yet to be activated. A flush to prevent having to replant or make additional herbicide applications can make a big difference in the bottom line.
More overall planting progress info in Figure 1. The increase to 64% planted moves us in line with 2014 progress and only behind 2012, 2010, and 2007. That progress number is likely to jump substantially again with Monday’s update, when it’s very possible we will have surpassed the 80% mark.
Figure 1. Rice planting progress, 2007-2015.
The extended forecast shows rain through the weekend and possibly all the way through next week. Daytime and nighttime temperatures will be in the 80s and 60s. However, for fields that have dry seed waiting on a flush or rainfall for germination, a week of consecutive rain events are not what we need. That could make things tough establishing a stand.
Picture 1. Many fields being flushed this week.
Seedling Disease a Serious Issue on Early Planted Rice
Seedling disease causing stand loss has been reported on an increasing amount of acreage this week (Picture 2). Fields planted the first week of April have been the most reported, and the issue has been observed across many different cultivars.
Essentially these early planted emerged fairly quickly, but were then subjected to weeks of extended cool, wet conditions. Seedling disease was able to progress on the plants while they remained static – once favorable conditions returned, the damage became evident.
Picture 2. Seedling disease causing plant death.
Fungicide seed treatments are beneficial for the first couple of weeks after planting, but after that do not provide protection; and under extreme conditions can still be overcome. That seems to be the case this year.
Fields that were planted to increasingly lower seeding rates were more likely to have significant stand loss resulting in replants; however, even some fields with higher seeding rates had stands wiped out.
Some fields remain in doubt as to whether they have a sufficient stand or not. A mixture of plants (Picture 3) at various stages of health makes these determinations difficult. Even some plants that look likely to survive are not guaranteed to do so. A flush or rainfall is needed in many of these fields to improve overall plant health to determine the next course of action – keep the stand or replant.
Picture 3. Healthy (L), questionable (C), and dying (R) plants from a field affected by seedling disease.
By Flush or By Rain, Fields Need Help
Picture 4 shows the result of seeds trapped beneath a hard crust. If these plants aren’t rescued soon by flushing or rainfall, they won’t make it out of the ground. For some it may already be too late. Save the seed that’s already there waiting to make a crop.
Picture 4. Plants struggling to emerge from beneath a hard crust – a flush or rainfall is needed immediately to salvage these plants.
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The authors greatly appreciate the feedback and contributions of all growers, county agents, consultants, and rice industry stakeholders.