Environmental Factors

Light Quantity

Light Quality

Light-solar and incandescent

When there is not enough light

Light Duration Long Day Plants = short night plants Short Day Plants= Long night plants

Temperature

Temperature affects plant processes Photosynthesis and respiration ( previous slide) Transpiration increases with higher temps Flowering triggered by low temps in some plants Sugar storage increases with low temps Dormancy breaks after a# of hours of cold Cool season crops: Warm season crops:

Minnesota hardiness zones

Water

If your plants are to dry First sign is the plant is less reflective If no water is added then wilting will happen Seedlings most easily killed by lack of water Some wilt happens on very bright days Even when the soil is damp—Tomatoes

Plant cells/wilt

Blossom End Rot

If the soil is too wet No room for air in the soil: plant will wilt Germinating seeds can drown Fungus diseases thrive in cold wet soil Damping off Splitting of fruits and veggies Leaf blights ( don’t disturb wet beans) Clay soil

Damping off

Root Anatomy

Water quality Malfunctioning water softeners Hard water wells Using water from streams Diseases spread by irrigation water City water pH 8-9

Irrigation advantages Can be used on a slope In dry places overhead watering can keep salt from accumulating in the soil Can be used for frost protection Easy and cheep if you are not buying water

Irrigation disadvantages Sprinkling uses a lot of water Can spread foliar diseases Wind interference You need pressurized water

Trickle Irrigation advantages Puts water where you want it Much less water loss to evaporation Few disease problems systems can be automatic Fertilizer or compost tea can be applied through a trickle system ( Fertigation)

Trickle disadvantages Time consuming to put in in spring and out in fall can be expensive Wild water needs to be filtered Voles tend to chew it Its plastic

When to irrigate If the plants are graying Aim for 1 inch/week Look at the soil profile to see if you wave watered enough You may need to water even if it just rained

Drainage Duluth has clay soil If you have to tile, do so before planting Plant a water garden in your low spot

AIR CO2 O2 N Moving air is good for plants

16 Nutrients The bulk of the plant is made of C,H,O Macronutrients N,P,K,S,Mg,Ca Most Fertilizers supply N,P,K Micronutrients: Mo, B, Fe, Cl, Cu, Zn, Mn

Nutrients