Requirements for Plant Growth Plants require certain environment for ________ growth In greenhouse one must maintain best environment for growth

Plant Media Soil –Sand –_______ –Organic Matter

Water 1. Gravitational Water (held by gravity) –Drains away –Soils with _______ pores lose water fastest

Water 2. Capillary Water –Held against gravity in pores –Held in thin film around particles –Particles have an ______ ______

Planting Media Mixes Advantages to ________ media –1. Mix is uniform –2. ________ –3. Lighter in weight –4. Good moisture __________ and ______

Planting Media Mixes Disadvantages to soil less media –1. Lightweight –2. ____________missing must be added –3. Hard to transplant into soil

Planting Media Mixes Content of mixes –Perlite: volcanic origin Improves aeration Small white pebbles

Media contents –_____________: yellow expanded mineral Increases moisture holding capacity

Media Contents Sphagnum Moss: acid bog plants –_______ __________, very light __________: decomposed vegetation –Holds moisture

Media Contents Tree Bark –Improves aeration

Plant Food Water: most _____ –Plant weight = __% water –__% of water absorbed is used, rest is lost through leaves

Plant Food Water: –_________: Water lost through stems and leaves Natural air conditioning

Plant Food Major Nutrients –__, P, __ –Numbers in fertilizer are those three in order so… = 10% N, 15% P, and 20% K

Plant Food Nitrogen –Makes _____ _____ color –Too much is a problem Lowers disease resistance Weakens stem –“leaching” is a problem

Plant Food Phosphorus –Affects maturity –_____ division –Roots –Insufficient = ______ color on underside of leaves

Plant Food Potassium –Affects __________ –Root System –Insufficient = also purplish color, much more rare than P

Soil Acidity = acidic 14= basic 7 neutral _____ = add lime _____= add sulphur

Other Factors Temperature F Light Short and Long Day Plants Plant Diseases –Biggest scares to greenhouses Insects our biggest problem Gases