Pearl millet, Pennisetum americanum(L.) Leeke, is often established under stressful environmental conditions. Thus, establishment capability is crucial to success of the crop. Objectives of this study were (i) to verify previous results associating establishment of the crop with density and size of seed, and (ii) to identify other seed and seedling traits of pearl millet that are related to seed density and size. Seed of four populations was divided by gravity table into three density fractions, each of which was then separated, by dockage sieves, into three size fractions. Seed representing each population‐density size fraction was evaluated in a field study at Manhattan, KS in 1981 and in the laboratory. Seedling emergence increased from 40% with small, low‐density seed, to 62% with large, high‐density seed. Days from seeding to anthesis decreased from 70 with small, low‐density seed, to 62 with large, high‐density seed. In both cases, density and size interacted in such a manner that each factor had most effect at low levels of the other. Seed weight, a germination index that emphasized speed of germination, and seed diameter were positively affected by both seed density and size. In addition, germination, seedling height 24 days after seeding, and proportion of vitreous starch in seed endosperm were positively related to seed density. Seedling respiration rate, on a per‐seed basis, was associated positively with seed density and size. With a fixed weight of seed, however, there was little effect. Results indicated that seed density and seed size were effective criteria of field establishment and of seed quality as determined by a number of laboratory tests. In some cases, however, the nature of the density × size interaction implied that the major effects of both factors were effectively integrated in seed weight.

Treatment of seeds with fungicides, insecticides, or a combination of both has been practiced by seedsmen, scientists, and farmers in order to protect seeds and seedlings from different pests. Treating seeds with recommended rates of application is usually safe, but workmen sometimes add more than ~he recommended rate. Treated seeds are also kept in storage for some time before planting. The purpose of the study was to find out the effects of those chemicals and to determine whether the treated seeds could be stored without loss of viability. Seeds of three wheat (Triticum aestivum L.) cultivars, Bolal, Bezostaya, and Kose 220/39, were treated with the fungicides carboxin [5,6-dihydro-2-methyl-I,4-oxathiin-3-carboxanilide) and benlate [methyl I-(butylcarbamoyl)-2-benzimidazolecarbamate) and the insecticides aldrin [I,2,3,4,IO,IO-hexachloro-I,4,4a,5,8,8a-hexahydro-exo-I,4 endo-5,8-dimethanonaphthalene), heptachlor [I,4,5,6, 7,8-heptachloro-3 a.4. 7. 7a-tetrahydro-4, 7-methanoindene ), and carbofuran [2,3-dihydro-2,2-dimethyl-7 -benzo(uranyl methylcarbamate) to determine the effects of these chemicals, alone and in combination, on germination and emergence. All seed lots were treated at the same time and were planted IO, 30, and 50 days after treatment at 30-mm depths in soil (a silty clay loam, typical of Turkey's Anatolian Plateau) at a greenhouse in Ankara, Turkey. After the first day of emergence, seedlings were counted daily for 7 days. Aldrin, heptachlor, and carboxin did not reduce seedling emergence. Benlate reduced emergence I7, I8, and 23% in Bezostaya, Bolal, and Kose 220/39, respectively, when seeds were stored for 50 days and seedlings counted II days after planting. Carbofuran decreased emergence as the storage period increased, especially in Kose 220/39. Carbofuran was the only pesticide that was consistently more phytotoxic when rates were doubled or tripled.Combinations of carboxin with either aldrin or heptachlor did not generally reduce emergence. However, all combinations involving carbofuran reduced emergence more than carbofuran alone. Cultivars varied in susceptibility to fungicides and insecticides. Bolal, a hard red winter wheat from Nebraska, showed the most tolerance. Seedling emergence of Kose 220/39, a Turkish variety, was reduced 13 to I9% more than was Bolal at the 11-day seedling count in all seed treatment storage periods. Seedling emergence of Bezostaya, a Russian variety, was intermediate between Bolal and Kose 220/39. Adverse effects of pesticides that reduced emergence were more evident as storage time increased. Results indicated that benlate and carbofuran, used alone or in combination, reduced seedling emergence. Less phytotoxicity resulted if seeds were planted as soon as possible after treatment.

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