The Effects of Seed Rate, Clover and Applied Nitrogen on Broadcast Seed Crops of Pasture Ryegrass

Abstract

This investigation was carried out with leafy varieties of perennial ryegrass at four centres near Aberystwyth over a period of three years. Nitrogen applied in spring increased lodging, the number of fertile tillers and also seed yield, except where sowing was made without a cereal cover crop. While reasonable yields were obtained from badly laid crops, it is suggested that lodging prior to anthesis has an adverse effect on seed yield. Clover included as a companion species tended to depress the yield of seed and increase the degree of lodging.Seed rate had less infiuence on lodging and seed yield, but the data show that similar yields were obtained from light seed rates of 4 lb. per acre as from the heavier rates. On the other hand, there was a tendency for the low rate of seeding to produce weedy plots, especially when sown in the absence of a cover crop.

Irrigation and Nitrogen Studies in s. 23 Ryegrass Grown for Seed: 1. Growth, Development, Seed Yield Components and Seed Yield

“…Increasing the nitrogen from 80 to 160 kg/ha, significantly decreased seed yield, number of fertile tillers and number of seeds/m 2 (Table 4). Most workers have found that increasing the amount of applied nitrogen increases number of fertile tillers per unit area in perennial ryegrasses (Evans, 1954;Lewis, 1959;Evans, 1959;Wilson, 1959;Roberts, 1966;Ryle, 1966;Spiertz & Ellen, 1972) and a number of them have found increases in number of spikelets per fertile tiller (Ryle, 1966), calculated number of seeds per fertile tiller (Roberts, 1966;Spiertz & Ellen, 1972) and 1000-seed weight (Evans, 1959;Roberts, 1958). However, in 1973, in the second-year seed crop, seed yields and all seed yield Significance of nitrogen effect: * 001 < P < 005; ** 0001 < P < 001; *** P < 0001.…”

“…Seed yield 609 components were not significantly affected by doubling the amount of nitrogen (Table 4). Other workers have also shown that positive seed yield responses can be obtained by application of nitrogen to perennial ryegrass crops grown for seed (Evans, 1954;Evers & Sonneveld, 1954;Lewis, 1959;Roberts, 1966;Spiertz & Ellen, 1972), and that maximum yields in S. 23 crops are obtained at about 120 kg N/ha applied to first year seed crops (Evers & Sonneveld, 1954;Roberts, 1966) and that under certain conditions slightly more nitrogen can be justified in second year stands (Reyntens, 1949). In 1974, no significant differences in seed yield or seed yield components were found between NoNoNa or NjjNaNa treatments (Table 4).…”

Lodging studies inLolium perennegrown for seed: 1. Seed yield and seed yield components

“…However, Hebblethwaite (1976) has shown that ryegrass seed crops receiving recommended amounts of nitrogen (80-100 kg/ha) for optimum seed yield usually begin to lodge at about first ear emergence, and that lodging is severe by anthesis. A number of workers have stated that seed yields in ryegrasses are decreased by lodging (Evans, 1931;Roberts, 1958;Lewis, 1959;Spiertz & Ellen, 1972) but no estimation of actual losses has been carried out in this country. Actual losses must be quantified in order to indicate whether chemical control of lodging by decreasing straw length, as in cereals, is justified (Humphries, 1968).…”

The effect of maleic hydrazide and chlorocholine chloride on the growth, seed yield components and seed yield of S.23 ryegrass

“…In badly lodged crops, restricted pollen dispersal, especially under wet conditions, causing poor seed set (Hubbard, 1954;Lewis, 1959;Anslow, 1963) and development, which is aggravated by attacks by saprophytic fungi on the inflorescences (Griffiths, 1967), and tiller death (P. D. Hebblethwaite & P. Brown, unpublished data) have been cited as the main causes of yield losses. Lodging also restricts light interception, thus reducing efficiency of photosynthesis (de Wit, 1965).…”