quiz03_review - Weed Science, PLS 4601c Section 7644 and...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Weed Science, PLS 4601c Section 7644 and Grad. – Prin. Of Weed Science AGR 6932 Section 9212 University of Florida - Davie http://grove.ufl.edu/~turf/weedscience/ Philip Busey, turf@ufl.edu 954-579-3932 (cell) May 27, 2009 Material from May 21 for Quiz #3 on May 28 Below are the main things discussed on cultural management of weed with an emphasis on irrigation, and weed identification, and our quadrat survey. Please also review Quiz 1 and Quiz 2. Weed Adaptation and Cultural Management 1. What are four factors that determine evapotranspiration in plants? Radiant energy, wind, dryness in the air, and absolute temperature? 2. Why do South Florida plants often need irrigation? Annual rainfall exceeds evapotranspiration (plant water use), and monthly rainfall exceeds evapotranspiration most months. But March, April, and May are months with a net irrigation deficit, when supplemental irrigation is required to keep shallow rooted plants (those will a small rootzone capacity) supplied with water. There is a clear wet-dry cycle in South Florida. Some plants can survive the wet-dry cycle by defoliation (some native species such as gumbo-limbo) or by having deep roots that can spend water rather than saving water (e.g., some taprooted weeds such as southern sida), while other herbaceous (non-woody) weeds often have a shallow root system and an inadequate soil moisture reserve to survive drought without irrigation. 3. How does microclimate affect radiant energy? Shade directly reduces radiant energy, which directly reduces evapotranspiration, which reduces net irrigation requirement. 4. How does wind vary? Typically wind picks up after sunrise, thus evapotranspiration will rise (this can also determine the best times to spray herbicides). 5. How can an irrigation system vary? Poor precipitation uniformity (the evenness of irrigation) can occur because sprinkler heads are spaced too far apart. During the dry season it may be obvious
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Weed Science–Univ. Florida, Davie–Review for Quiz #3 Page 2 from grayish wilted areas that the irrigation system is inefficient. 6.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/23/2011 for the course PLS 4601c taught by Professor Busey during the Summer '09 term at University of Florida.

Page1 / 5

quiz03_review - Weed Science, PLS 4601c Section 7644 and...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online