Variable Rate Applications

Question 1

6 aspects of VRT

Answer 1

Variable rate technologies
1. Fertilization
2. leaf removal
3. Irrigation
4. Chemical weed control
5. Fungicide application
6. Harvest

Question 2

What is the relative important of soil parameters to block yield variability?

Answer 2

70% of block yield variability was explained by water availability in the soil

Question 3

3 precision fertilization strategies

Answer 3

1. Quantify the crop mineral removal by using yield maps from previous years
2. Use of rapid methods for soil mapping based on different fertility components
3. Monitoring the crop mineral status by remote or proximal sensing (suggested for N)

Question 4

Crop response to fertilizers application graph, what is the important take away

Answer 4

That the optimal dose of fertilizers vary

Question 5

The “On the go approach” Pros and cons

Answer 5

On the Go can be challenging because everything is calculated in real time, while a prescription map allows you to do the calculations for each zone prior. It is best for canopy sprays

Question 6

4 steps for the input calculation and what is Qc

Answer 6

1. Dose
2. Output
3. Loses
4. Exogenous

Qc is the corrective dose to be added or subtracted for compensating unbalanced situations

Question 7

2-points Calibration for Fertilizer dose vs Vegetation Index

Answer 7

There is a positive linear relationship between vigor and fetilizer dose when the biomass cutoff is low and
A Negative linear relationship between vigor and fetilizer dose when the biomass cutoff is high

Question 8

5 aspects of drip irrigation and subsurface drip irrigation

Answer 8

• Maintaining high water availability in the soil (lower than field capacity)
• Frequent low-volume irrigations
• At planting, the system need to be set up with
  specific sectors according to soil texture
• Flow rate and distance between drippers can vary according to soil properties (denser and lower flow in shallow soil)
• Easier management in case of limited within- row variability

Question 9

What is VRDI

Answer 9

VRDI is Variable Rate Drip Irrigation. When used in California for Cab Sauv it increased yield and water use efficiency

Question 10

4 Conclusions of using VRDI

Answer 10

1. Yield was increased by 17%
2. It saved 20% of water
3. It reduced variability in Yield and quality
4. When not used the variability in the vineyard came back

Question 11

3 types of CASA Sprayers

Answer 11

1. CIS (Crop Identification System)
2. CHS (Crop Health Sensor)
3. EDAS (Environmentally Dependent Application System)

Question 12

7 important considerations for Innovative and future applications for grape harvesting

Answer 12

• Maintaining berry integrity, quality
• Limitation of fruit loss
• Minimization of MOG percentage
• Berry selection
• Yield mapping
• Selective harvesting
• Non-destructive monitoring of fruit composition (NIRS)

Question 13

5 considerations for Yield Mapping

Answer 13

• Maintaining berry integrity, quality
• Limitation of fruit loss
• Minimization of MOG percentage
• Berry selection
• Yield mapping
• Selective harvesting
• Non-destructive monitoring of fruit composition (NIRS)

Question 14

What is selective harvesting? Think big blue machine

Answer 14

Split picking of fruit at harvest according to different yield / quality criteria, in order to exploit the observed variation. Think of the big blue machine we got a tour of on the day we almost died in the snow storm