Chapter 7.pdf

Chapter 7 Barley Prof. Nezar Samarah  Origin and History of Culture Hordeum vulgare originated in the Near East. Barley is major source of cereal production in semiarid region where wheat is less adapted. Planting is common in Middle East and north Africa. Others la...

Chapter 7 Barley Prof. Nezar Samarah  Origin and History of Culture Hordeum vulgare originated in the Near East. Barley is major source of cereal production in semiarid region where wheat is less adapted. Planting is common in Middle East and north Africa. Others large producers of barley are: South Korea, Iran, India, Turkey, Ethiopia, Canada. Uses: Feed Malting Chapter 7: Barley 2  Botanical Description Inflorescence: Spike. Two types of barley: 1) Two-row barley (Hordeum distichum): Has one developed spikelet per node on each side of the rachis. Each spikelet has one floret. 2) Six-row barley (Hordeum vulgare): Has three spikeletes per node on both sides of the rachis. Each spikelet has one floret. Chapter 7: Barley 3  Glumes of both types of barley spikeletes are reduced and hair-like. Nearly all barley cultivars have awn on the lemma of each floret: – Smooth – Rough Hulls (lemma and palea) adheres to caryopsis. Hulless: Naked barely (the lemma and palea are not attached to the caryopsis). Chapter 7: Barley 4  Auricles: Large clasping auricles (larger than wheat). Small ligules. Waxes coating on leaves. Life cycle: Spring or Winter annual. Flower type: Incomplete and perfect. Leaf: Narrow, alternate, parallel venation. Stem type: Culm. Root system: Fibrous roots, reach depth 1-1.5 m. Chapter 7: Barley 5  Growth Stages 1) Germination. 2) Seedling establishment. 3) Tillering stage. 4) Stem elongation. 5) Boot stage. 6) Heading. 7) Ripening. Chapter 7: Barley 6 Growth Stages Chapter 7: Barley 7  Environmental Requirements Cool season crop. Grown in semiarid region where water is limiting factor for crop growth. Tolerant to adverse conditions: 1) Drought. 2) High temperature: 32o C under dry condition. Less tolerant under humid condition. 3) Frost tolerant. 4) Salt tolerant. Chapter 7: Barley 8  Best suited for heavier soil with PH 7-8. Although barley is more tolerant to adverse environmental conditions than other crops, its growth is responded negatively to less than optimum conditions. Barley response to drought is similar to wheat response (drought reduces seed number and yield). Chapter 7: Barley 9  Temperature: Grown in temperature range (3-38oC). Optimum Temperature during: Germination: 4-30oC. Vegetative growth: 24oC. Flowering: 30oC. A cool with short day conditions is required for tiller formation. Maturation is favored under warm, dry condition. Chapter 7: Barley 10  Winter barley: – Planted in Fall and harvested in early summer. – Dormant during cold period. Spring barley: – Planted in spring in area where winter is too severe to plant winter barley. – Planted in Fall in area where winter is not too severe. In general, barley is not winter hardy as wheat. Chapter 7: Barley 11  Production Practices Tillage: – In general, barley requires tillage operation and seedbed preparation similar to wheat. Seeding methods: 1) Broadcast. 2) Grain drill. Seeding Depth: – In Jordan: 8-10 cm showed significant increase in barley yield over shallow sowing (2-4 cm). Chapter 7: Barley 12  Seeding Date: – November-December [Early planting (December) resulted in higher yield than late planting (February)]. Seeding Rate: – 100 kg/ ha. – Excess planting rate result in tall, weak-stem plants, and easily lodged. Chapter 7: Barley 13  Fertilizer: In Jordan: – In region of 200-300 mm rainfall, it is not necessary to apply N to barley at sowing. – If rainfall above averaged, 30 kg N /ha may be applied as top dressing at tillering stage. – 40-80 kg P2O4 /ha at seeding. Chapter 7: Barley 14  Harvesting: – Self-propelled grain combine. – Harvested at moisture content 15% or less. – In area where shattering is a problem, plants are windrowed and left to dry in the field. – Harvesting barley at high moisture content reduces grain loss due to shattering. However, harvesting seeds at high moisture can result in spoilage of seeds and heating during storage. Chapter 7: Barley 15  Crop rotation: – Barley-barley. – Barley-Fallow. Chapter 7: Barley 16  Diseases 1) Smut: kernels are replaced with spore mass. Fungal disease. Spores are carried on surface of the kernels. Control: – Resistance cultivars. – Mercury compounds. – Hexachlorobenzene. Chapter 7: Barley 17 2) Nuda loose smut: Fungal disease. Entire flower is replaced with spore mass. Transferred by wind and rain. Control: – Resistance cultivars. – Chemical treatments are ineffective. – Hot water. Chapter 7: Barley 18 3) Stem rust, leaf rust, stripe rust: Fungal diseases. Common in humid areas. Control: – Resistance cultivars. 4) Powdery mildew: Control: Sulfur dust. Chapter 7: Barley 19 5) Ergot: Hard, horny spore mass (sclerotia) replaced grain. Control: – Resistance cultivars. Germinating Ergot Fruiting Structure Chapter 7: Barley 20  Weeds Weeds include: Pigweed, lambsquarters, thistle, wild oat. Control: – Mechanized: during seedbed preparation. – Herbicides: Pre-emergence herbicides. Pos-emergence herbicides Chapter 7: Barley 21  Insects 1) Aphids. Control: genetic resistance. 2) Grasshoppers: Control: Chlorinated hydrocarbon insecticides. Chapter 7: Barley 22