Temperate Vegetables

SPINACH

Objectives: Spinach or English Spinach or Vilayati Palak is the most important potherb or leafy vegetable grown in winter season. The word spinach actually comes from Spanish word Hispania. The shape of the leaves is quiet different from that of Palak. The edible parts consist of the compact rosette of leaves prior to the elongation of central bud in flower stalk formation. It is purely a cool season plant and is dioecious in nature. It is having two types of varieties viz. prickly seeded and round seeded. The present chapter will make the students understand with its importance, production technology, seed production practices and plant protection measures.

SCIENTIFIC NAME	(Spinacia oleracea L.)
COMMON NAME	Vilayati palak,Angreji Palak
CHROMOSOME NUMBER	2n=2x=12
FAMILY	Chenopodiaceae
CENTRE OF ORIGIN	Iran

NUTRITIVE VALUE (per 100g of edible portion)

Energy (kcal)	26	Riboflavin (mg)	0.2
Moisture (%)	90.7	Niacin (mg)	0.6
Protein (g)	3.2	Ascorbic acid (mg)	51
Fat (g)	0.3	Calcium (mg)	93
Carbohydrate (g}	4.3	Phosphorus (mg)	51
Vitamin-A (IU)	9300	Iron (g)	3.1
Thiamin (mg)	0.1	Oxalic acid	658 mg

USES:

• Traditionally spinach or vilayati palak is classified as a pot herb.
• The edible part of spinach is a compact rosette which is normally consumed as a cooked vegetable.
• Sometimes, it is also used as salad along with lettuce and other vegetables.
• Spinach is highly suitable for hydroponics.
• Spinach is also processed, primarily canned and fried.
• Leaves of spinach are rich in vitamin-A (9300 IU) and contain considerable amount of iron and calcium.
• Spinach produces a seed stalk easily in response to low day and night temperature.
• Spacing and environmental conditions influence leaf number and size.
• The margins are smooth or wavy, surface is also variable ranging from smooth to heavily of savoy.
• The blistered appearance of savoy tissue results from differential growth of parenchyma tissues between the leaf veins.
• Spinach is classified as a dioecious plant, however, rarely some monoecious plants may develop in certain cultivars.

 

There are 4 sex forms in spinach.
Extreme males:

• These produce only staminate flowers with minimum foliage.
• Small with very little vegetative development and tend to bolt quickly.
• This plant type flowers early and die soon after flowering.
• Eliminate the extreme males from commercial strains by selection.

Vegetative males:

• These produce only staminate flowers, more foliage and flower later than extreme males.

Female plants:

• These produce only pistillate flowers and have well developed foliage with very late tendency to flower.
• Gibberellic acid plays an important role in sex expression of spinach.
• Female and vegetative male plants are preferred because they are larger, slower bolting and higher yielding.
• Pollination is mostly by wind.
• Fruits usually an achene, the fertilized ovary form a one seeded fruit called utricle. Parthenocarpic fruits also occur in spinach.

Vegetative males and females are slower to flower and produce considerably more foliage, making them the preferred plants type for commercial cultivation.
Monoecious plant:

• These produce staminate and pistillate flowers, well developed foliage and are slow to flower.

There are two types of seeds:

1. Smooth round seeded types (considered as summer type)
2. Irregularly prickly shape (considered as winter type)