Optimum plant population density for chickpea and dry pea in a semiarid environment

Abstract

. 2003. Optimum plant population density for chickpea and dry pea in a semiarid environment. Can. J. Plant Sci. 83: 1-9. Chickpea (Cicer arietinum L.), an annual grain legume, is being broadly included in cereal-based cropping systems throughout the semiarid Canadian prairies, but information on optimum plant population density (PPD) has not been developed for this region. This study, which was conducted from 1998 to 2000 in southwestern Saskatchewan, determined the effect of PPD on field emergence, seed yield and quality, and harvestability of kabuli and desi chickpea compared with dry pea (Pisum sativum L.). Seed yields of all legumes increased with increasing PPD when the crops were grown on conventional summerfallow. The PPD that produced the highest seed yields ranged from 40 to 45 plants m -2 for kabuli chickpea, from 45 to 50 plants m -2 for desi chickpea, and from 75 to 80 plants m -2 for dry pea. When the legumes were grown on wheat stubble, the PPD that gained optimum seed yield ranged from 35 to 40 plants m -2 for kabuli chickpea, from 40 to 45 plants m -2 for desi chickpea, and from 65 to 70 plants m -2 for dry pea. The proportion of large-sized (>9-mm diameter) seed in the harvested seed was >70% when the kabuli chickpea was grown on summerfallow regardless of PPD, whereas the large-seed proportion decreased with increasing PPD when the crop was grown on wheat stubble. Increases in PPD advanced plant maturity by 1.5 to 3.0 d and increased the height of the lowest pods from the soil surface by 1.4 to 2.0 cm (or 5 to 10%), with desi chickpea receiving the greatest benefits from increased PPD. The percentage of plants established from viable seeds per unit area decreased substantially as PPD increased, with kabuli chickpea emergence decreasing from 90% at PPD = 20 plants m -2 to 72% at PPD = 50 plants m -2 , from 81 to 69% for desi type, and from 83 to 59% for dry pea. The reason for the low field emergence with increased PPD is unknown, but methods which lead to improved field emergence represent a great opportunity to increase seed yield and reduce production costs for both chickpea and dry pea in this semiarid region. Quand on cultive le pois chiche kabuli sur une jachère d'été, la proportion de grosses semences (> 9 mm de diamètre) dépasse 70 %, peu importe la DPO, mais un relèvement de cette dernière diminue la proportion de grosses semences quand la culture pousse sur du chaume de blé. Une hausse de la DPO permet aux plants de parvenir à maturité de 1,5 à 3,0 jours plus tôt et les gousses les plus basses dépassent le sol de 1,4 à 2,0 cm de plus (soit 5 à 10 %). C'est le pois chiche desi qui bénéficie le plus d'un relèvement de la DPO. La proportion de plants issus de semences viables par unité de surface diminue sensiblement avec l'augmentation de la DPO. Ainsi, le pourcentage de levée du pois chiche kabuli tombe de 90 à 72 % quand la DPO passe de 20 à 50 plants au m 2 , alors qu'il tombe de 81 à 69 % pour le pois chiche desi et de 83 à 59 % pour le pois de grande culture. On ignore pourquoi une ...

Interrelationships among yield components of chickpea in semiarid environments

“…The overall effects of PPD on chickpea seed yield have been reported elsewhere (Gan et al 2003). In brief, seed yield increased linearly with increasing PPD when chickpea was grown on CS.…”

“…In a previous study, Gan et al (2003) reported that desi chickpea increased fertile pods m -2 by 28% as plant population density increased from 20 to 50 plants m -2 , whereas this level of PPD changes increased pods m -2 by 10% for a large-seeded kabuli crop. On average, kabuli plants produced 45 to 50% as many pods m -2 as desi plants under normal growing conditions.…”

“…The potential to increase seed weight for kabuli chickpea may be at the expense of reducing the number of pods per plant, but this may impact the seed size distribution in the harvested seedlot. In a previous study, Gan et al (2003) demonstrated that plant population did not affect mean seed weight in kabuli chickpea, but the plants at a lower plant density produced a greater proportion of large-sized (>9-mm-diameter) seed in the harvested seedlot. The kabuli crop grown on CS produced >70% of seeds that were >9-mm in diameter; this proportion of the largesized seed was significantly higher than when the kabuli was grown on NT.…”

“…Gan et al (2003) did not report detailed seed yield components, nor the interrelationships between yield components and seed yield. It is not known how chickpea plants adjust their ontogenetic characteristics to maximize seed yield when grown under different plant population densities.…”

Yield and quality of sugar snap pea in the Ebro Valley: sowing date and seed density

“…The effect of seeding densities on yield was minimal. Sugar snap, like the seed peas mg g -1 , has considerable capacity to adapt, with the ability to reach yield levels that are near-optimal with planting densities as wide-ranging as 75 and 150 plants m -2 (Gan et al, 2003;Tawaha and Turk 2004;Pageau et al, 2007). However, the effect was not the same every year.…”