Water use and Irrigation

Question 1

What are the different types of irrigation systems

Answer 1

furrow, drip, flood, dual drip, micro-sprinkler

Question 2

How does water move in plant

Answer 2

from regions of higher to lower water potential 0-> -1.0

Question 3

Osmotic potential

Answer 3

potential of water molecules to move from a hypotinic solution (more water, less solutes) to a hypertonic solution (less water, more solutes) across semipermeable membrane

Question 4

Drought Stress symptoms

Answer 4

kernels shrivel, nut size reduction, wilting, defoliation, shoot growth inhibition

Question 5

Excess Moisture symptoms

Answer 5

leaching of nitrogen, water logging, fungal diseases, water wastage, energy wastage

Question 6

What determines the rate of infiltration into a soil

Answer 6

volume of air space (porosity) and size of pores

Question 7

True or false there is a direct relationship between texture and pore size?

Answer 7

true

Question 8

which irrigation system is the most efficient?

Answer 8

Drip, 90-95%

Question 9

How do you determine water needs

Answer 9

soil based methods, visual touch method, soil moisture probe, plant-based methods, pressure chamber, weather-based methods

Question 10

TDR

Answer 10

time domain reflectometry, based on travel time of a high frequency electromagnetic pulse through the soil

Question 11

FDR

Answer 11

Frequency Domain reflectometry,

Question 12

tensiometer

Answer 12

principle: directly measure soil matrix potential, porous ceramic cut at base in contact with soil

Question 13

What causes low potential at the leaf stomata

Answer 13

photosynthesis, gas exchange, plant water loss

Question 14

What does a pressure chamber do?

Answer 14

measures plant water tension by applying pressure to a severed leaf and stem enclosed in an airtight chamber

Question 15

Evapotranspiration

Answer 15

the sum of water loss from leaves (transpiration) and water loss from soil (evaporation)

Question 16

Reference evapotranspiration (ETo)

Answer 16

defined as the rate of evapotranspiration from a hypothetical reference crop with an extensive surface of green grass of uniform height, actively growing, well-watered, and completely shading the ground

Question 17

Allowable depletion

Answer 17

safe amount of depletion as a percentage of total available water in the profile prior to growth reductions

Question 18

what are the crop factors of evapotranspiration?

Answer 18

crop, cultivar, phenology stage of development, height, planting design, rooting depth and profile characteristics, ground cover

Question 19

What are the management factors of evapotranspiration?

Answer 19

disease, insects, fertility, salinity, irrigation system, planting design, soil water content, ground cover, windbreaks, mulches

Question 20

Cimis

Answer 20

repository of climatological data collected at more than 125 automated active weather locations throughout California

Question 21

What soil texture has the higher water holding capacity

Answer 21

loamy, silt clay loam

Question 22

What soil texture has the least amount of water holding capacity

Answer 22

very course

Question 23

When can you reduce irrigation in almonds for drought

Answer 23

after mid june, likely result of modestly lower individual kernel weight

Question 24

When should pistachios not be under-irrigated

Answer 24

from bloom to end of shell expansion, nut filling to hull split

Question 25

When can you practice di in pistachios

Answer 25

50% reduction in irrigation during shell hardening, 70-75% reduction in irrigation during the postharvest period