Description and Adaptation
Chickpea (Cicer arietinum L.) has two major commercial classes or seed types that are grown in Saskatchewan: Desi and Kabuli. Desi type has smaller, angular seeds with thicker colored seed coats and colored flowers. Kabuli types have a larger seed size that is more rounded in shape with a thinner cream-coloured seed coat and white flowers. All seeds have a protruding seed root tip that forms a distinctive “beak”.
Chickpea seed undergoes hypogeal germination where the cotyledons and seed coat remain below ground. The first two nodes produce scale leaves and at least one node will remain below ground during early growth. This offers protection from late spring frosts and the plant may regrow from these nodes if top growth is damaged. The first true leaf is produced at the third node position. On average, a new node is produced every three to four days.
Desi chickpeas and newer Kabuli varieties have leaves about 5 cm long with nine to 15 leaflets, and are described as having a fern-leaf structure. Some older Kabuli varieties, such as CDC Xena, have a single (unifoliate) leaf structure instead of leaflets.
Plants range in height from 30 centimetres (cm) to 70 cm (12 to 28 inches). The plants are erect with natural resistance to lodging. The shatter resistant pods are short and inflated and contain one to two seeds. The bushel weight of chickpeas is 60 pounds.
Chickpeas have an indeterminate growth habit. Plants continue to flower until they encounter some form of stress, such as drought, heat, frost, or nitrogen deficiency. Flowers, which are highly self-pollinating, are produced at the 13 tor 14 node stage (usually 50 to 55 days after seeding) in axillary racemes. In most years the plant would be expected to reach maturity in 110 to 130 days.
Figure 1. Chickpea seedling
Chickpeas are heat tolerant and thrive under good moisture conditions with daytime temperatures between 21°C and 29°C, and nighttime temperatures between 18°C and 21°C. However temperatures of 30°C and higher cause stress during early flowering and pod development. It is relatively drought tolerant as its long taproot (often greater than a meter in depth) can access water from a greater depth than other pulse crops.
Chickpeas grow best on well drained soils with lighter soil texture, neutral pH, and with about 15 to 25 cm (5.9 to 9.8 inches) of growing season rainfall. It is best adapted to the Brown and Dark Brown soil zones in Saskatchewan. Chickpeas are not well adapted to saline soils or to high-moisture areas. They are also not well suited to soils with high clay content or areas where soils are slow to warm in the spring. Chickpeas do not tolerate wet or waterlogged soils.
Two serious production limitations in Saskatchewan are the long growing season requirement for current varieties and the high risk of Ascochyta blight, an extremely aggressive disease. Planting chickpeas outside the areas of best adaptation has proven to be very risky due to delayed maturity, high green seed content, and destructive disease infections.
Chickpeas can be planted on either summerfallow or stubble in the Brown Soil Zone and on stubble in the Dark Brown Soil Zone. Planting on stubble fields tends to reduce vegetative growth and results in moisture stress to hasten maturity. Due to the indeterminate growth habit of chickpeas, plants can regrow late in the season after rain showers or in the absence of a killing frost. In some cases, application of glyphosate may have limited success in halting late season growth.
Desi chickpeas are short and earlier in maturity. They are higher yielding and more resistant to mechanical, frost, and insect damage than Kabuli type chickpeas. Their area of adaptation can extend into the moist Dark Brown soil zone if grown on stubble or on lighter textured soils.
Kabuli chickpea varieties are strongly indeterminate, usually maturing in 110 to 120 days. In a cool, wet season, the maturity of Kabulis can easily extend past 120 days. The Brown soil zone provides the conditions most likely to encourage maturity in a reasonable time. Frost in the fall usually causes more damage to Kabulis and increases the level of green seed.