Club and Common Wheat Yield Component and Spike Development in the Pacific Northwest

The superior end‐use qualities and reputation for emergence in poor seed bed conditions has maintained club wheat ( Triticum compactum Host) as an important, though small class, of wheat in the Pacific Northwest. Our objectives were to determine yield component development in two agronomic zones representative of the fallow/wheat growing region of the Pacific Northwest and to characterize and compare yield component and spike development in two club and two common wheat ( Triticum aestivum L.) genotypes. The experiments were conducted at Moro and Pendleton, OR, in 1988 and 1989, where data were collected on yield components and on spike and kernel characters of identified culms. Yields were significantly higher at Pendleton than Moro. Lower floret fertility at Pendleton resulted in fewer and heavier seeds. Kernel weight was apparently the yield component associated with the yield advantage at Pendleton. Early tiller development at Pendleton also favored the development of spikes with greater capacity for yield component compensation. Differences were identified for yield component development in the cultivars Tres, OR8218, Hill 81, and Stephens; however, total grain yield was not significantly different. Although club spikes were one‐half the length of common spikes, spikelet number was not different between classes. Moreover, the number of fertile spikelets and the percentage of fertile spikelets per spike was significantly greater in club genotypes compared with common genotypes. The club genotypes produced more kernels in 1989 than the common genotypes. Kernel weight was consistently less for club lines. These differences were found in the mainstem and tillers T1 to T4. Kernel weight may play an important role in the early seedling establishment in regions where soil moisture is inadequate at planting.