REMEMBER as we go through this exercise: Science is the art of making simple things complicated!

REMEMBER as we go through this exercise: Science is the art of making simple things complicated!

Fertilization of Hops Ron Godin, Ph.D., Colorado State University Extension

Fertilization of Hops - Care & Feeding - Essential Plant Nutrients - Soil test and needed nutrient levels for good yields - Soil applied fertilizers - Nitrogen, nitrogen, nitrogen - Nutrient sensitivities of hops - Foliar (leaf applied) fertilizer: when? - how often? - how much? - Nutrient translocation at the initiation of flowering - What are good yields? - What grower experience is teaching us

Hop Growing Requirements Hop Care & Feeding Essential Plant Nutrients Essential: A plant can not complete its life cycle without all of these nutrients C - Carbon H - Hydrogen O Oxygen * Cations - Anions Macro N Nitrogen - P Phosphorus - K Potassium* S Sulfur - Ca Calcium* Mg Magnesium* Micro Fe Iron* Mn Manganese* Cu Copper* Zn Zinc* B Boron - Cl - Chloride Mo - Molybdenum

Soil Test Results CaCO3 CaCO3 Don t Guess Soil Test!!!!!!!!!!

Hop Care & Feeding ****Soil test each Spring!!! Avoids train wrecks! Get the best yields possible! Recommended 2nd year fertilization rates: fertilizer placement should be in hop row, not broadcast if possible ***Split Applications are best! spoon feed if possible*** Start fertilizing AFTER training & pruning Nitrogen (N) = 175 lbs/ac (6 8 tons compost/ac @ 1.5% N) Phosphorus (P) = 100 lbs/ac (included in compost) Potassium (K) = 75 lbs/ac (included in compost) Subsequent years based on 8-10 bale yields (1600-2000 lbs/ac) (bale = 200 lbs dry cones) Nitrogen (N) = 200 250 lbs/ac (7-8 tons compost/ac) Phosphorus (P) = 60-100 lbs/ac (included in compost)

Nutrient sensitivities in hops Nitrogen, Zinc, Boron and some times Potassium (typically only on sandier soils in Colorado) Nitrogen: Primarily responsible for vegetative growth - is an essential element of all amino acids - amino acids are the building blocks of proteins - Nitrogen is also a component of nucleic acids, which form the DNA of all living things and holds the genetic code - Nitrogen is a component of chlorophyll, which is the site of carbohydrate (sugar) formation from photosynthesis

Nitrogen deficiency: appears in older leaves because it can be translocated in the plant - Interveinal chlorosis

Foliar sprays: when, where and how Typically, you would do a petiole sample & test the first week in June. This way if there is a deficiency it can be corrected in time before the critical part of cone development begins. Should do at least one foliar spray, to increase yields by 10% If needed you can do up to 4 spray about 5-7 days apart Absolute maximum in a foliar: 3 lbs actual N per acre ½ lb actual Zn per acre 1/8 lb B per acre This should be in at least 100 gallons of water (300 gal/ac)

Hop Petiole Sampling & Testing Need 60-100 petioles per variety Should sample early morning Take samples from height on each plant Usually shoulder height or above Send in for analysis

Zinc: Aids plant growth hormones and enzyme system Necessary for chlorophyll production Necessary for carbohydrate formation Necessary for starch formation Production of Auxins, an essential growth hormone It activates enzymes in protein synthesis, plus is involved in the regulation and consumption of sugars It is necessary for starch formation and proper root development It is necessary for the formation of chlorophyll and carbohydrates The presence of adequate amounts of Zinc in the tissue enables the plant to withstand lower air temperatures.

Zinc deficiencies appear first in younger leaves More prevalent in high ph soils Interveinal chlorosis yellowing Some rosetting In

Zinc deficiencies appear first in younger leaves More prevalent in high ph soils Interveinal chlorosis yellowing Some rosetting In

Potassium: Carbohydrate metabolism and the break down and translocation of starches Increases photosynthesis Increases water-use efficiency Essential to protein synthesis Important in fruit formation Activates enzymes and controls their reaction rates Improves quality of seeds and fruit Improves winter hardiness Increases disease resistance The role of potassium in the plant is indirect, meaning that it does not make up any plant part. Potassium is required for the activation of over 80 enzymes throughout the plant. It's important for a plant's ability to withstand extreme cold and hot temperatures, drought and pests. Potassium increases water use efficiency and transforms sugars to starch in the grain-filling process.

Potassium deficiency in hops appears in older leaves first - appears as chlorosis or necrosis on leaf edges or leaf tips - referred to as scorching or firing of the leaf edges

Boron: used with calcium in cell wall synthesis and is essential for cell division (creating new plant cells). Boron requirements are much higher during reproductive growth. Adequate B supply is required to ensure effective sugar translocation within plants. Deficiencies: Boron deficiency reduces the normal expansion and growth of cell walls, resulting in short and thick cell walls. Root elongation is highly sensitive to low B supply and quickly inhibited when B is deficient. Results: stunted growth, yellowing or whitening of leaves between veins.

Boron deficiency: appears first in young leaves new growth is typically thick and twisted

Hop Soil Nutrient Levels for Western Colorado Hop Soil Test Levels Adequate Levels for Spring for 2+ year old bines Soil samples taken from top foot of soil in and near the bine row Nutrient NO 3 -N P K Ca Mg SO 4 -S Zn Fe Mn Cu B Adequate Levels > 60 ppm* > 25 ppm > 250 ppm > 4000 ppm > 500 ppm > 25 ppm > 5 ppm > 10 ppm > 4 ppm >1 ppm > 1.5 ppm * Nitrogen can be applied in separate applications through the first week of July for western Colorado. ppm x 4 = lbs/ac