Markets for organic barley and wheat are expanding. A major problem growing organic barley and wheat is controlling the weeds. Organic barley and wheat were grown in conventional 6-inch drill spacing but also in 30 inch spacing so weeds could be cultivated in a study at the Larry Hart Farm near Maricopa. The weed pressure was moderate and the weed biomass was about 16 to 26% of the crop biomass near maturity. The primary weed was canarygrass and the secondary weed was malva. Grain yields of the wheat (durum) were similar regardless of row spacing, but the barley grain yields were 4327 lbs/acre in the 6 inch spacing and 3330 lbs/acre in the 30 inch spacing.

Phosphorus fertilizer represents a significant portion of the cost of producing small grains. Some evidence exists that there are differences in the ability of small grain varieties to take phosphorus up from the soil and utilize this nutrient in the grain. The objective of this study is to determine if barley and wheat varieties grown in Arizona differ in their response to phosphorus fertilizer. A study was conducted for the third year at the Maricopa Agricultural Center testing the response of 7 barley and 14 wheat (12 durum wheat and 2 bread wheat) varieties to 2 phosphorus rates (0 and 100 lbs P₂O₅/acre). Averaged over varieties, the grain yield increase due to phosphorus application of 100 lbs P₂O₅/acre was 346 lbs/acre for barley and 516 lbs/acre for wheat, similar to previous years. Despite the wide range of apparent yield response (0 to over 1000 lbs/acre) of the varieties to P fertilizer, these differences were not statistically significant. Furthermore, there was no consistency in the yield response of the varieties between this year and last year. Some of the varieties that responded greatest to P fertilizer last year, responded least this year, and vice versa. Therefore, there appears to be no differences in the response of barley and wheat varieties typically grown in Arizona to phosphorus fertilizer.

Barley is generally thought to require less nitrogen fertilizer than wheat, but how much less has not been clearly documented. The purpose of this study is to compare the nitrogen fertilizer requirements of barley and wheat. A study was conducted at the Maricopa Agricultural Center testing the response of 2 durum wheats (Kronos and Havasu), 2 bread wheats (Yecora Rojo and Joaquin), 2 feed barleys (Baretta and Nebula), and 2 malting barleys (Conrad and Moravian 69) to 7 rates of nitrogen fertilizer (0, 30, 60, 90, 120, 150, and 180 lbs N/acre). The surface soil was relatively high in nitrate at planting (19 ppm NO₃-N) contributing an estimated 76 lbs N/acre. Maximum yield was obtained at 156 (durum), 147 (wheat), 137 (feed barley), and 127 (malting barley) lbs N/acre. However, since the yield of durum and bread wheat was higher than feed and malting barley, the nitrogen fertilizer per 100 pounds of grain yield was similar for these crop types (~2.37 lbs N per 100 lbs of grain). If the 76 lbs N/a of nitrogen estimated to be available from the surface soil were included, then about 3.62 lbs of N would have been required per 100 lbs of grain for both wheat and barley. The N requirement reported in this study does not include the extra N potentially needed for wheat to obtain acceptable protein levels. In conclusion, wheat required more nitrogen fertilizer than barley to obtain maximum yield in our study, but the amount of nitrogen fertilizer required per 100 pounds of grain was similar.

Markets for organic barley and wheat are expanding. A major problem growing organic barley and wheat is controlling the weeds. Organic barley and wheat were grown in conventional 6-inch drill spacing but also in 30 inch spacing so weeds could be cultivated in a study at the Larry Hart Farm near Maricopa. The weed pressure was moderate and the weed biomass was about 1 to 5% of the crop biomass near maturity. The primary weed was Palmer amaranth. Grain yields of the wheat (durum) were similar regardless of row spacing, but the barley grain yields were 3921 lbs/acre in the 6 inch spacing and 2530 lbs/acre in the 30 inch spacing.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.