MEMO: APRIL 14, 2000

To: Mini-Cassia District Growers

From: Agronomist & Field Staff

Subject: Concerns regarding moisture, seed germination and emergence, and stand establishment.

Here we are with another crop planted and starting to emerge. It's always exciting , yet somewhat nerve racking. Many fields are dry, with the first two inches not having sufficient moisture to germinate and establish the crop. Irrigation has begun in many fields. Some moisture from rainfall is expected but it's usually erratic and we never know how much we'll get. Profile moisture in many fields is marginal.

The usual result of such spring moisture conditions, is that we end up with erratic and delayed germination of much of our seed and hence the staggered and delayed emergence of plants, and poor stands in some parts of fields. This is usually because pockets of dry soil are formed when working ground when dry surface soil is carried into the depressions in the field. If not adequately irrigated or wetted by rainfall then the beets in these dry pockets are of course delayed in germination and development.

To prevent this, consider thoroughly scouting field moisture conditions and then carefully gaging irrigation to at least meet moisture if profile moisture is good, or adequately and completely wet the profile when moisture is poor or marginal. Then, with some moisture in the profile to draw from, it usually is easier to maintain moisture in the seed zone with subsequent wetting from rainfall or light irrigation.

Don't be fooled by light or intermittent showers which only wet the surface. This moisture usually doesn't contribute much to wetting or maintaining profile moisture. The evaporation in-between these showers is usually more than was ever contributed.

Regarding plant stand numbers and determining what is sufficient for economic return, I would refer you to the article in our issue of "The Sugarbeet" Spring 2000 issue, page 13, entitled, "Replanting Thresholds or Assessing the Need to Replant."

Some of the key statements in this of body of information are:

1) Sugar beet germination requires a minimum of 37 degrees F. for germination, and 90 degree days of heat units for emergence. Therefore, 16-17 days if planted around the 1^st week in April, fewer days if planted when warmer. Be aware of the time frame for expected emergence, and if they're not coming up, check for moisture and/or other problems.

2) Moisture levels of at least 50-60 % maintained, are necessary for good germination and emergence and seedling establishment.

3) Having adequate to optimal plant numbers, properly spaced, to intercept light, (hence energy), makes for the most favorable economical outcome.

This equates to 30,000 plants per acre or at least 126 plants/ 100 foot of row on 22" spacing.

In referring to the Klamath Basin study of planting dates and plant populations, the same yields can be achieved with fewer plants or less population when established earlier. Minimally, comparable results can be produced with 88 plants / 100 foot of row or approximately 21,000 plants per acre, if established prior to May 1^st.

There are qualifying facts which must be considered though. Gaps should be no greater than 15-16 inches between plants in the row and you can't have too many of those in 20 feet or you won't count out even 88 plants / 100 ft. of row.

A good way to assess the stand count in a field is to simply start somewhere in the field and mark out 5 rows 20 foot in length in a block and count the beets in them. Then make counts the same way in any parts of the field which are suspect. You should be able to count 25 in each row for a perfect stand of 125-130 plants /100 ft. row; 20 in each for 100 ; 17 -18 in each for the minimum required of 88 plants /100 ft.; 14 for 70 etc. If there are more than 2 out of 5 rows with under 10 plants, the counts get really critical, and the length of gaps, and whether there are beets in the rows across from the gaps in the opposing rows is also critical to evaluate.

The health of emerged beets has to be assessed as well as any potential for additional emergence of yet ungerminated seed, and the reasons for their delayed start.

All this information has to be rendered down to a figure of stand which can be counted on and then use this figure to make the determination of whether replanting is going to be economical to do.

Calling your field man and having him look at the situation often helps by adding perspective to a given situation. These men look at a lot of fields and varying conditions and can often point things out which may have been missed.

The following chart can be used to assess the value of replanting or not basis of where stands are in a field compared to date originally planted vs. replanting at a given date of later time.

KLAMATH BASIN SUGARBEET REPLANT GUIDE

Sugar Yields Expected with Varied Plant Populations and Planting Dates in the Klamath Basin

(Sugar yields are expressed as percentages of maximum sugar yield per acre.)

HOW TO USE CHART TO DETERMINE REPLANT FEASIBILITY

1) IF REPLANTING IS BEING CONSIDERED ON APRIL 28, WITH A STAND OF ONLY APPROX. 75 BEETS PER 100 FT. OF ROW RESULTING FROM AN ORIGINAL PLANTING ON APRIL 4, AND THE HISTORICAL POTENTIAL OF INCREASING THAT STAND TO APPROX. 126 BEETS / 100 FT. OF ROW ARE REALLY GOOD, THEN THE FIGURES ON THE CHART ( 96 % & 95 %) SHOW THAT THE PERCENTAGE OF PRODUCTION COMPARED TO ORIGINAL PRODUCTION IS NOT MUCH DIFFERENT IF I KEEP THE 75 BEETS / 100 FT. ROW OR TRY TO INCREASE TO 126 BEETS /100 FT. ROW BY REPLANTING.

2) IF APRIL 20 WERE THE DATE BEING CONSIDERED TO REPLANT A FIELD PLANTED ORIGINALLY ON APRIL 8, AND THE STAND RESULTING WAS ONLY 50 BEETS / 100 FT. OF ROW, AND THE SAME HISTORICAL POTENTIAL OF INCREASING THAT STAND TO 126 BEETS / 100 FT. OF ROW BY REPLANTING EXISTED, THEN AN 8 % INCREASE IN PRODUCTION COULD BE EXPECTED.

3) THE COMPARATIVE VALUE OF REPLANTING MUST BE RELATED TO THE GAMBLE OF ACHIEVING SIGNIFICANTLY BETTER STANDS BY DOING SO VS. WHAT A SOLID, WELL SPACED, HEALTHY SO. IF THIS CANNOT BE ACHIEVED THEN A HEALTHY, ACHIEVED, THEN A HEALTHY ORIGINAL STAND WHICH IS ALREADY ESTABLISHED AND GROWING MIGHT DO. MIGHT DO AS WELL OR BETTER. HOWEVER, THE LEAST CONSIDERABLE STANDS FOR KEEPING SHOULDN'T FALL BELOW 50 PLANTS PER 100 FOOT OF ROW. THE FIRST COLUMN SHOWING 9000 PLANTS PER ACRE OR 38 PER 100 FT OF ROW, IS ON THE FRINGE OF REALISTIC POTENTIAL OF MOST FIELD CAPABILITIES AND WEATHER CONDITIONS. AS WELL, THE RE-EMERGENCE CAPABILITIES OF EACH INDIVIDUAL FIELD RELEVANT TO CRUSTING, WEED EMERGENCE AND NECESSARY CONTROL UNDER WARMER CONDITIONS AT THE SAME TIME AS REPLANTED BEET EMERGENCE, AND ALL OTHER PERTINENT FACTORS SHOULD BE ASSESSED.

4) THE BLOCKED OUT AREA IN THE UPPER RIGHT SHOWS THAT FORCED REPLANTING, ( COMPLETE LOSS) OF THE CROP WITH IN THE FIRST 2 - 3 WEEKS OF ORIGINAL PLANTING DATE, CAN STILL ACHIEVE ABOUT THE SAME YIELD POTENTIAL IF RE-ESTABLISHMENT AND SUBSEQUENT GROWTH IS GOOD.

5) THE MAY 10 DATE AS A DEMARKATION POINT FOR REPLANT SHOWS THAT AT LEAST 10 + PERCENT OF POTENTIAL HAS BEEN LOST NO MATTER THE STAND INCREASE.

6) THE MAY 22 DATE ( OR APPROX. THERE ABOUT) SHOWS THAT AT LEAST 20 + PERCENT OF THE ORIGINAL YIELD POTENTIAL HAS BEEN LOST NO MATTER THE STAND INCREASE BY RE-PLANTING.

INFORMATION FROM THE ABSTRACT: "EFFECTS OF SUGARBEET PLANTING DATE AND PLANT POPULATION ON SUGAR YIELD IN THE KLAMATH BASIN", BY HARRY L. CARLSON, KENNETH A. RYKBOST, DONALD W. KIRBY & RANDY L. DOVEL, UNIVERSITY OF CALIFORNIA INTERMOUNTAIN RESEARCH & EXTENSION CENTER, AND OREGON STATE UNIVERSITY KLAMATH EXPERIMENT STATION.