ROOT VEGETABLES
INTRODUCTION
Root vegetables grow underground. They come in many flavours and can be prepared in many ways. They contain many and many kinds of essential nutrients and their consumption has many health benefits. Botanically, not all of them are roots, some of them are bulbs, for example, which store nutrients to feed themselves for the colder months.
For example:
- Onions: Fennel, Onion, Shallot, Garlic
- Tubers: Celery root, Water chestnut
- Rhizomes: Ginger, Turmeric, Knot Root
- Tap roots: Beet, Radishes, Carrot, Parsnips, Parsley, Turnips, Maca
- Tuberous roots, underground shoot changes: Potato, Sweet potatoes, Yams, Yucca, Jerusalem artichoke
They have a lot of fibre, antioxidants, and are low in calories, fat and cholesterol. Their importance in the economy and in human nutrition is important.
In this chapter we focus on the most relevant root crops in the project countries (Czech Republic, Romania, Bulgaria, Hungary, Poland, Greece): onion, carrot, parsley, turnips, and potato.
GROWTH AND DEVELOPMENT
Umbellifer species experience slow and variable seed germination and early growth, with emergence extending over weeks due to staggered flowering behaviour. Seed quality is influenced by maturity stage, seed size, composition, mechanical integrity, and ageing. Primary umbel seeds are larger and heavier, with a larger endosperm ratio. Seed-handling practices and technologies like seed conditioning and growth regulator treatments improve germination rate and percentage, while mulches and plastic film covers improve soil temperature and moisture conditions.
1. Figure: Growth and development
Shoot and storage root growth and development occur together, with taproot elongation achieving significant length in as few as 3 weeks after germination. Stubbing is a term used to identify the termination of storage root length, with good stubbing indicating a well-rounded storage root tip. Early storage root length is faster and finalized by about 50 days after germination, with root weight increase being slower initially. Leaf length and weight reach their full potential at mid-production, while root diameter and weight are approached during the last quarter of crop growth. Growing conditions for most carrot cultivars include warm day and cool night temperatures, and storage roots tend to be longer in drier soils.
Vernalisation, the effect of low temperature causing floral stem initiation, is a crucial stage of growth. Juvenility occurs when carrot plants have initiated 8-12 leaves and storage roots are greater than 4-8 mm in diameter. Vernalization is usually done for temperate-region carrot cultivars by exposure for 2-8 weeks at constant temperatures between 0 and 10°C. Chilling treatments of 11-12 weeks at 5°C result in more rapid and prolific flowering than chilling under longer photoperiods. Long days after vernalisation stimulate flowering. Clear changes in carbohydrate metabolism occur during bolting, as the xylem becomes lignified before the floral stalk elongates, rendering root tissues inedible.
Listo of bacterial:
- BACTERIAL SOFT ROT
- BACTERIAL BROWN ROT
- BACTERIAL RING ROT
Listo of fungi:
- POWDERY MILDEW
- SCLEROTONIA ROT
- BOTRYTIS BLIGHT
- VIOLET ROOT ROT
- BLACK ROT
- CERCOSPORA LEAF BLIGHT
- PYTHIUM LEAF BLIGHT
- CARROT ALTERNARIA LEAF BLIGHT 29
List of insects:
- EUROPEAN MOLE CRICKETS
- CLICK BEETLES, WIREWORMS
- POTATO TUBER MOTH (TUBERWORM)
- TURNIP MOTH
- SPIDER MITES
- THRIPS
- CARROT FLY
- APHIDS