Onion and Garlic Growing Guide PDF

Onion and Garlic Dr. Waleed Al-Busaidi Onion Allium cepa Alliaceae - Agreement originated in Pakistan & Iran - Consumed fresh green, fleshy leaves, dried onion powder, in salads & salsa and as garnish - Local type more preferred by local farmers - Hi...

Onion and Garlic Dr. Waleed Al-Busaidi Onion Allium cepa Alliaceae - Agreement originated in Pakistan & Iran - Consumed fresh green, fleshy leaves, dried onion powder, in salads & salsa and as garnish - Local type more preferred by local farmers - High in nutritional value - Medicinal value; antibacterial, common cold to heart disease, diabetes - Edible portion in bulb - Pungency ➔ lachrymator compounds) and color allowing enzymes called alliinases Growth and development - Cool season -Biennial crop - Frost tolerant - Optimum temperature 13- 24 oC plant development 20-25 oC (seedling) - High temperature favors bulbing and curing - Bulb concentric enlarged leaf bases - Bulbing is day length related - Stem very small - After vernalization 10 oC ➔ bolting & flowering - Weed aggressive root systems –ve affects onion growth Crop establishment - Very well drained fertile soil non crusting soils - pH 6-6.8 Sowing - Direct seeding - Sets -Transplanting beds 0.9-1 m wide (2-6 rows) Fertilizer NPK with soil preparation ➔ broadcast/band 5 cm below seeds - N 1or 2 side dressing during the season ( fertigation) Irrigation Furrow or overhead ➔ excessive moisture avoided, Weeds - Not good competitor with weeds - Shallow cultivation/ chemical (better) Cultivars - Open pollinated crop ➔ F1 hybrids - Short day 11-13 hr - Intermediate day 13-14 hr - Long day >14hr Diseases Smut, downy mildew, Neck rot, tip and leaf blight (botrytis), smudge, bulb rots Insects maggots, trips, cut worm & wire worm Harvest - Green onion ➔ marketable size - Bulbs ➔ 50-80% top leaves have broken over ( Collapsed) - Curing in filed or forced 30 oC and low - Harvest manual or mechanical - Curing 30 oC & low RH - Storage 0 oC or slightly higher with 60-70 % RH bulbs - Green onion 0 oC and 95% RH - Packing Bulb rest - Near maturity bulb rest for 4-9 weeks - Due to chemical inhibitor synthesized in the leaves and destroyed by time - Sprouting inhibited at 0 oC - Optimum at 10-15 oC - Chemical inhibition sprouting application of Malic hydrazide at 1/3 falling of leaves Garlic Allium sativum Alliaceae - Important crop in Oman - Leaves modified to form bladeless storage structure (Cloves) - Cloves composite ➔ bulb - Do not flower ➔ produce aerial bulbs - More nutritious than onion - Fresh/ dehydrated as garlic powder or garlic paste - Top producer China, US, Korea, Spain Growth and development - Cool season hardy perennial - Cool & moist weather/ Vegetative growth - Dry period/ Bulb maturity - Shallow rooted crop - Long days & warm temp induce bulbing 12 hr ( critical length) - ≤ 20 oC for bulbing Soil: - Thrives best on well drained fertile light soil - Heavy soils ➔ misshapen bulbs & harvesting difficult - Bulb discoloration under poor drained soils Planting methods - Field divided in small manageable plots - Cloves/bulbllis (aerials) dibbed deep in flat row 20-30 cm a part - 8-10 cm between plants - Large scale clove planter Seed rate 25 g or 2.5 cm clove size - Large clove produce greater yields Fertilizers - FYM ➔ Annually - NPK - Excessive N application ➔ thick neck of plants Cloves sprouting before harvesting - Micro nutrient Mn, Zn , B & Cu +ve effect Irrigation - Frequent irrigation @8 d Interval during early growth period - Frequency @ 15 d during maturity and stopped before harvesting when signs of drying - Weed controlled by chemicals Cultivars: ➔ Early & late Varieties Harvesting and curing  Harvest/Post-harvest 4-5 month to mature from planting Harvest when 5-6 leaves are yellow/brown Provide shade to avoid sunscald Dry garlic (1 week-10 days) at a warm (27 C degrees or more) temperature to “cure” it or prepare it for longer storage (similar to sweet potato) Dried foliage is maturity index Delay in harvesting ➔ Splitting and resprouting After harvesting ➔ hanged for drying  Leek ‫ كراث‬Korath Allium ampeloprasum Lower leaf stalks are usually blanched with a covering of soil or mulch to keep a white zone. Long season (120 days or longer) to produce a large, thick leaf base. Note flat leaves. Plant in spring from seed and dig in autumn season (can be dug late into the winter) in a temperate climate Used primarily in soups and stews  Shallots A perennial crop that splits at the base to multiply. Has a mild, onion like flavor Can be used for bulbs or green onions Specialized crop-grown in certain areas. Used in gourmet recipes and foods. Used a lot in Europe.