Performance of Four Inbreds in Single‐Cross Hybrids as Influenced by Plant Density and Spacing Patterns¹

Physiological and morphological responses of corn genotypes to planting date and plant population

“…Moisture has been most often implicated as a causal factor of delayed silk ing as noted by Woolley ^ (1962), Barnes (1966) andTatum (1954), It should be emphasized that the present studies were conducted under irrigated conditions and soil moisture was not considered to be a limiting factor through the silking stage.…”

“…1963, Schwanke 1965, Collins e_k alo 1965. Lang ^ (1956), Woolley ^ (1962), Schwanke (1965) and Zieserl et (1963) at separate times and locations demonstrated the intolerance of the single cross Wf9 x G103 to high plant populations. Lang et (1956) reported Wf9 x G103…”

“…high plant population, detasseling and male sterility; has been attributed to the differential accumulation of dry matter (Sowell ^ 1961, Moss andStinson 1961), rate of silk emergence (Sass and Loeffel 1959), ear primordia growth (Sass and Loeffel 1959, Collins 1963, Prine 1965, length of the interval between tasseling and silking (Woolley ^ 1962, Sass and Loeffel 1959, Moss and Stinson 1961, Kohnke and Miles 1951, Schwanke 1965, nitrate reductrace (Zieserl ^ 1963, Knipmeyer et 1962 and plant sugar concentrations (Van Reen and Singleton 1952, Moss and Stinson 1961, Sowell ^ 1961, and Knipmeyer e± al. 1962)» Total dry matter production per plant decreases with increased plant population was shown by Eisele (1935), Shading experiment by Moss and Stinson (1961) and Earley ^ £l.…”

Morphological and physiological traits associated with barrenness and grain yield in the maize breeding population, Iowa Upright Leaf Synthetic #1

“…Lonnquist and Jugenheimer (1943) and Sass and Loeffel (1959) suggested that the primary cause of barrenness is the lengthening of the anthesis-tosiIking period, i.e., by the time late silks emerge, the pollen is not viable. The interval between anthesis and silking lengthens as plant density is increased (Kiesselbach, 1950;Dungan et al 1958;Shav;and Thorn, 1951 ;Wool ley et al 1962;Cardwell, 1967;Meyer, 1970;Buren, 1970;Fakorede, 1977). Additionally, Kohnke and Miles (1951) reported that silking was delayed approximately one day for every increase of 7,000 -8,000 plants/ha.…”

Physiological and morphological responses of corn genotypes to planting date and plant population

“…Increasing plant population resulted in reduced number of ears per stalk or per 100 stalks (Dungan e^ 1958, Woolley et 1962, Prine and Schroder 1964, Norden 1961, Colville 1962, Hinkle and Garrett 1961 and a corresponding decrease in ear weight or kernel number has generally been observed for corn belt hybrids (Dungan et al 1958, Woolley et a^. 1962, Colville 1962)c Southern workers using prolific hybrids have L found little or no effect on ear size with increasing plant population primarily due to a decrease in ear number rather than ear size per plant (Hinkle and Garrett 1961, Norden 1961, Prine and Schroder 1964, Wofford et al 1956).…”