The effects of seed depth on growing point location of wild-proso millet, effects of alachlor placement, and chemical control of wild-proso millet were studied in field and greenhouse experiments. In 1986, 55 to 88% of the seedlings originating in the top 6 cm of soil had their growing point above the soil surface. The respective figures were 11 to 36% in 1987. Shoot exposure to alachlor resulted in significantly greater phytotoxicity than root exposure. Only EPTC or vernolate with a protectant, preplant incorporated, or pendimethalin preemergence, followed by atrazine plus tridiphane postemergence controlled wild-proso millet more than 85% all season.

As water for crop production becomes limited and costs of water increase there is a need for more accurate irrigation scheduling. Irrigation scheduling can be improved with reliable and rapid estimates of crop evapotranspiration (ET). The use of three climatebased equations and the soil‐water‐balance equation for estimating sweet corn (Zea mays L. ‘Jubilee’) ET for irrigation scheduling were compared in a 2‐yr field study on a mixed, mesic Cumulic Ultic Hapoxeroll soil. The three climate‐data‐based equations used were the Food and Agriculture Organization of the United Nations (FAO) modified Penman and the FAO and Soil Conservation Service (SCS) Blaney‐Criddle equations. Five irrigation levels ranging from 0 to 100%, with the 100% level intended to refill the root zone to field capacity, were all proportionately irrigated when approximately 50% of the available water was depleted in the 100% level as measured with a neutron meter. A sixth treatment in this randomized complete block experiment was irrigated with the amount of water equivalent to the crop ET estimated by the FAO modified Penman (M PEN) equation, when the crop ET had accumulated to 50% of the available soil water. The crop ET estimated by the soil‐water‐balance equation in 1984 was 481 and 447 mm for the 100% level and for plots irrigated according to the M PEN equation, respectively. In 1985 these ET estimates were 506 and 488 mm, respectively. The crop ET in 1984 was 404, 372, and 374 mm as estimated by the M PEN, FAO, and SCS Blaney‐Criddle equations, while in 1985 these equations estimated 450,448, and 379 mm, respectively. Yield differences were not significant between plots irrigated according to the M PEN equation and the irrigation levels of 50% or more in both years. Calculations indicated that the lower estimates of ET by the FAO and SCS Blaney‐Criddle equations, if used to schedule irrigations, would not be expected to cause yield decreases.

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Evapotranspiration (ET) of three perennial ryegrass (Lolium perenne L.) cultivars and one cultivar each of colonial bentgrass (Agrostis tenuis L.) and tall fescue (Festuca arundinacea L.) was measured in the field. Soil water depletion was measured with a neutron probe. Under minimal maintenance (i.e., no irrigation and infrequent mowing), ET was not significantly different for five perennial grasses. All grasses used more water than the bare-ground treatment. Soil water uptake was greatest in the upper soil layer (O to 25 cm) and decreased with depth. Few differences in water uptake were noted among grasses within each soil layer.

The yield and quality response of sweet corn (Zea mays L.) to variable water supply was evaluated in 1984 and 1985. Irrigation depths were established with sprinklers at five intervals from 0% to 100%, with the 100% treatment intended to refill the root zone to field capacity. The other treatments were considered as deficit irrigation. Irrigations were scheduled when 47–57% of the available water was depleted in the root zone of the 100% treatment level plots. Yields were similar when irrigation depths were 50% or greater in 1984 and 1985, although water application depths varied between years. Water balance measurements indicated very little deep percolation. Deficit irrigations of about 50% and 70% saved water and maintained yield. Yield, ear weight, and kernel weight decreased in the nonirrigated treatments or when water application depths were about 25%. Nonirrigated sweet corn tended to be more mature at harvest then irrigated corn.