|Brahim, Kebe - UNIV OF ARIZONA|
|Ray, Dennis - UNIV OF ARIZONA|
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 8, 1998
Publication Date: N/A
Interpretive Summary: It is not known how seed yields and other agronomically important traits of lesquerella, a potential new industrial oilseed crop, are affected by plant population. Plants were grown at five different plant population sizes for two seasons. Seed yields were greatest when populations were grown at 750,000 and 1,000,000 plants per hectare. Many other traits measured were lowest at the highest plant density, including plant height, width, taproot length, number of branches. This study shows that the seeding rates reflecting the 750,000 and 1,000,000 plants per hectares populations are the most desirable for optimum seed yield. This information will serve as guidelines for farmers growing this potential crop.
Technical Abstract: The effects of plant density on growth, yield, and yield components of Lesquerella fendleri were studied in central Arizona at plant populations of 250,000, 500,000, 750,000, 1,000.000; and un-thinned controls of 1,658,000 plants/ha in 1992-93 and 1,500,000 plants/ha in 1993-94. In the 1992-93 tests, increasing density resulted in a significant decrease in plant width, and number of branches, while causing an increase in taproot length in populations up to 750,000 plants/ha. There were no effects on seed size; however, density significantly reduced the number of seeds/silique for the 750,000 and 1,658,000 plants/ha treatments. Seed yield/plant and harvest index/plant were significantly reduced with increasing density, but yield/ha increased with density up to 1,000,000 plants/ha. At 1,658,000 plants/ha, shattering was excessive and resulted in loss of seeds. The greatest seed yields/ha were obtained at 750,000 plants/ha and 1,000,000 plants/ha densities. The oil content did not vary significantly from 500,000 to 1,658,000 plants/ha, but treatments in this range produced seeds with significantly higher oil content than the 250,000 plants/ha treatment. Differences in oil yield/ha reflected differences in seed yield/ha. The 1993-94 harvest did not show significant differences for seed and oil yields among density treatments. Higher temperatures in 1993-94 were believed to increase the oil content and seed yield in the higher plant densities. Plant densities of 750,000 and 1,000,000 plants/ha are recommended for lesquerella growing areas comparable to central Arizona. At these densities, maximum seed yields and plant heights should be obtained even with annual temperature fluctuations, minimizing seed loses during combine harvest.