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Growing Degree Day, Your Safe-to-spray Number

3/21/2018

The cold winter we’ve experienced in the south has its pros and cons. Winter-kill is a possibility, but for the first time in years I'm comfortable spraying Ronstar (Restricted Use Pesticide) on non-overseeded bermuda. That doesn't mean, however, that timing isn't still of importance.

Patrick McCullough at the University of Georgia has come up with a Growing Degree Day (GDD) model that shows the cutoff to insure safety is 100 GDD or less. Syngenta has an easy to use GDD calculator on their website which can be found here. Unless you’re in the upper part of the transition zone time is quickly running out to spray!

If you choose to use granular Ronstar (Restricted Use Pesticide) this year, be sure to use a mini prill (<200 SGN) and as high a spread as possible for optimum coverage. Dr. Mudge from Bayer has recommendations here.

If you’d like to kill two birds with one stone have your Ronstar (Restricted Use Pesticide) sparged onto a blend containing POLYON controlled-release fertilizer. The example below is a 20-0-20 Mini granular fertilizer with 90% Polyon 41 and a 0.67% Ronstar (Restricted Use Pesticide) sparged onto it. This provides 2lbs of N/M and 2.91lbs AI of Ronstar (Restricted Use Pesticide). It also will provide 21 weeks of greening! That’s enough to keep your turf green through the 4th of July!

Nitrogen Release by Week

20-0-20 Mini granular fertilizer with 90% Polyon 41 and a 0.67% Ronstar (Restricted Use Pesticide) 

Date

Week

Released N

Remaining N

2/27/2018

1

0.20

1.80

3/06/2018

2

0.04

1.76

3/13/2018

3

0.04

1.72

3/20/2018

4

0.05

1.67

3/27/2018

5

0.05

1.62

4/03/2018

6

0.06

1.56

4/10/2018

7

0.06

1.49

4/17/2018

8

0.07

1.42

4/24/2018

9

0.08

1.35

5/01/2018

10

0.08

1.27

5/08/2018

11

0.09

1.18

5/15/2018

12

0.10

1.08

5/22/2018

13

0.11

0.97

5/29/2018

14

0.12

0.86

6/05/2018

15

0.10

0.75

6/12/2018

16

0.11

0.64

6/19/2018

17

0.07

0.57

6/26/2018

18

0.08

0.49

7/03/2018

19

0.08

0.41

7/10/2018

20

0.07

0.34

7/17/2018

21

0.07

0.27

7/24/2018

22

0.05

0.22

 

Effect of Nitrogen Dosage

  


Grado Creciente Día, Su Número de Seguro Para Rociar

El frío invierno que hemos experimentado en el sur tiene sus ventajas y llega la muerte invernal es una posibilidad, pero por primera vez en años me siento cómodo rociando a Ronstar (pesticide de use restringido) con no bermuda. Eso no significa, sin embargo, que el tiempo no sea así.

Todavía importante Patrick McCullough en la Universidad de Georgia ha presentado un modelo de Grado creciente (GDD) que muestra que el corte para asegurar la venta es de 100 GDD o menos. Syngenta tiene una calculadora de GDD fácil de usar en su sitio web que puede ser encontrado aquí (here). A menos que esté en la parte superior de la zona de transición, el tiempo se está agotando rápidamente.

Si decide usar Ronstar (pesticide de use restringido) granular este año, asegúrese de usar una mini pepita (>200 SGN) y la mayor extensión posible para obtener el nivel óptimo cobertura. Dr Mudge de Bayer tiene recomendaciones aquí (here).

Si desea matar dos pájaros de un tiro, haga rociar su Ronstar (pesticide de use restringido) en una mezcla que contenga fertilizante de liberación controlada POLYON. El siguiente ejemplo es un fertilizante mini granular 20-0.20 con un 90% de Bolyon 41 y un Ronstar (pesticide de use restringido) al 0.67% rociado sobre él. Esto proporciona 21 libras de NMM y 291 libras de Al de Bonstar También proporcionará 21 semanas de greening. Eso es suficiente para mantener su césped verde a través del 4 de Julio

Nitrogen Release por semana 20-0-20 Mini fertilizante granular con 90% Polyon 41 y un 0.67% Ronstar (pesticide de use restringido)

Nitrogen Release by Week

20-0-20 Mini granular fertilizer with 90% Polyon 41 and a 0.67% Ronstar (pesticide de use restringido)

 

Date

Week

Released N

Remaining N

2/27/2018

1

0.20

1.80

3/06/2018

2

0.04

1.76

3/13/2018

3

0.04

1.72

3/20/2018

4

0.05

1.67

3/27/2018

5

0.05

1.62

4/03/2018

6

0.06

1.56

4/10/2018

7

0.06

1.49

4/17/2018

8

0.07

1.42

4/24/2018

9

0.08

1.35

5/01/2018

10

0.08

1.27

5/08/2018

11

0.09

1.18

5/15/2018

12

0.10

1.08

5/22/2018

13

0.11

0.97

5/29/2018

14

0.12

0.86

6/05/2018

15

0.10

0.75

6/12/2018

16

0.11

0.64

6/19/2018

17

0.07

0.57

6/26/2018

18

0.08

0.49

7/03/2018

19

0.08

0.41

7/10/2018

20

0.07

0.34

7/17/2018

21

0.07

0.27

7/24/2018

22

0.05

0.22

 

 

 

Efecto de Cantidad de Nitrógeno

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In addition to being the nation’s largest distributor of branded fungicides, herbicides, and insecticides, Harrell’s produces custom-blended fertilizers, specialty liquids, and wetting agents. Additionally, Harrell’s is the exclusive US owner, formulator, and distributor of all POLYON® branded products.

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