1Swift Current Research Centre, AAFC, 2 Montana State University
3 Wheatland Conservation Inc. Swift Current, SK.
The semiarid prairie represents a significant expansion opportunity for the pulse industry in western Canada, and it is the target area for chickpea production. However, agronomic guidelines for chickpea production suitable to this region have not been developed. Questions have been raised by producers regarding optimal management practices to obtain profitable seed yield and quality. Three field experiments were conducted at Swift Current Research Centre, in cooperation with Wheatland Conservation Area Inc. in 1998 and 1999, to determine the optimal agronomic management practices for establishing chickpeas in the semiarid prairie. In the first experiment, kabuli-type chickpea (Sanford and B-90) and desi-type chickpea (Myles) were used, to determine how the two types of chickpeas respond to phosphorous fertilizer in this drier region and the impacts of seeding depth and seeding date on seed yield and marketing quality. Seed size is a key factor in commercial kabuli chickpea markets with seed size greater than 8.6 mm commanding market premiums. Thus, in the second experiment, we determined how climatic and agronomic factors affected seed size fractions. Also, we screened out two seed size fractions (large vs small seeds) from the same seedlot and compared the yield differences between plants grown from the large seed and plants from the small seed. Seed cost of growing chickpea is quite high, as compared to other crops, while chickpea seedling emergence is usually low in the semiarid environment. Therefore, in the third experiment, we determined optimal seeding rate for both kabuli and desi chickpeas by assessing plant density per square area, days to flowering and maturity, and final seed yield and quality (e.g., seed weight and seed size fractions).
Responses of chickpea to fertilizer-P application were inconsistent between the two years. In 1998, the chickpea seed yield increased 7 to 11% with fertilizer-P at the rate of 17 to 34 lb actual P per acre, as compared to the non-P treatment. In 1999, however, no yield differences were found between the fertilizer-P treatments, although the fertilizer-P slightly increased dry matter production before flowering. Overall chickpea seed yield in 1998 was less than 1000 lb/ac, while in 1999 average yield was near 2000 lb/ac. Great soil moisture in 1999 favored rhizobial activities and symbiotical N-fixation, and reduced plant-to-plant competition for growth resources, which might have masked the possible effect from fertilizer-P as shown in 1998. Kabuli chickpea was planted at two depths (5-cm vs 10-cm). On average, plants emerging from the 5-cm depth produced a higher (5 to 10%) amount of dry matter at flowering than plants that emerged from the 10-cm depth. Consequently, the shallow seeding resulted in 2 to 6% higher seed yield than the deep seeding. Mean seed weight was higher for seeds harvested from the shallow-seeded plants than those of deep-seeded plants. Two seeding dates were used in each year with the early seeding date being between April 30 to May 5 and the late seeding date between May 16 to May 20. Averaged for the two years, the early-seeded kabuli produced 10 to 16% more yield for B-90 and 4 to 12% for Sanford. We observed that the early-seeded plants had a longer period of time between flowering and plant maturity, resulting for great seed set. In either year, the size of seeds planted did not have any impact on final grain yield. Climatic factors and the agronomic practices were shown to affect the seed weight and the seed-size fraction.