Effect of Seed Orientation, Acid Delinting, Moisture Level, and Sample Type on Cottonseed Fracture Resistance

Cottonseed damage during processing is a growing concern for cotton ginners and cottonseed oil processors. A test to evaluate the durability of seed samples would be beneficial to breeders and ginners to help reduce problems associated with seed damage. Toward this goal, cottonseed fracture resistance was studied with a tensile tester fitted with an adapter to apply compressive force. Seeds cracked with more compressive force when oriented vertically in the tester than when oriented horizontally. Seeds had a greater fracture resistance when they were drier. Even differences in environmental relative humidity (35% to 65%) were enough to affect the testing, indicating that cottonseed requires conditioning to obtain consistent results. Treating the seed with sulfuric acid to remove surface linters did not affect the seed’s tendency to fracture, but significant differences were discernible among seed samples with different genetic backgrounds and production histories. Because several individual seeds needed to be tested to achieve representative results, the compressive fracture resistance may not be the most convenient tool for determining the potential for seed damage during processing. A better test might be some form of mechanical damaging device (e.g., a shaker or roller mill) that would allow faster analysis of a representative seed sample. Keywords: Cottonseed, Ginning, Seed damage, Seed fracture resistance.

Insect Pests of Shorea robusta Gaertn. f. : An Update

Shorea robusta Gaertn. f. (Dipterocarpaceae), commonly known as sal, is one of the most important timbers of India both ecologically and economically. It is of Indian origin, widely distributed in central and north India and constitutes an important ecosystem, which provides cool and calm environment rich in biodiversity. This tree species has a highest number of insect fauna among the forest trees. Of about 346 insects recorded on sal, about 155 species of insects belonging to the order Lepidoptera (105), Coleoptera (31), Thysanoptera (9), Hemiptera (4), Orthoptera (4), Ephemeroptera (1) and Isoptera (1) are associated with living tree. The major insect pests of sal are, ‘seed and seedling borer’ Pammene theristis Meyrick (Lepidoptera: Eucosmidae), feeding on seed while they are on the tree; Sitophilus rugicollis Casey (Coleoptera : Curculionidae), damage seed either on the forest floor or during storage; white grubs such as Holotrichia spp. (Coleoptera : Scarabaeidae), which feed on the root system of the plants in nurseries and beetles feed on the foliage; defoliators such as Caviria sericea Moore (Lepidoptera : Lymantriidae), Lymantria mathura Moore (Lepidoptera : Lymantriidae), Paectes subapicalis Walker (Lepidoptera : Noctuidae), Trabala vishnou Lefebvre (Lepidoptera : Lasiocampidae), which feed on the leaves; stem borer such as Hoplocerambyx spinicornis Newman (Coleoptera : Cerambycidae) and sap sucker, such as Drosicha stebbingi Green (Hemiptera : Coccidae). Termites, such as Coptotermes curvignathus Holmgren (Isoptera : Rhinotermitidae) and timber borers, such as Sinoxylon anale and S. crassum (Coleoptera : Bostrychidae), damage sal timber in dying, felled or stored logs in depots.

Effect of frost injury on quality of flax seed

In field and laboratory studies, flax (Linum usitatissimum L.) was frozen when 40–60% of the capsules were still green. Seed visibly frozen at this stage were of lower weight and density, darker in color, and lower in germinabihty than the fraction of the sample that was not visibly frozen. Also, oil color was darker, oil and protein concentrations and stearic and oleic acid levels were lower, and palmitic, linoleic and linolenic acid levels and iodine values were higher in the frozen than the normal seed. Key words: Flax, Linum usitatissimum, frost damage, seed quality, germination

Use of desiccants to reduce frost damage in immature flax

The desiccants diquat, glufosinate-ammonium, dimethipin and glyphosate were applied to flax when 44–84% of the capsules were green to reduce damage from subsequent frost. Beginning 3 d after desiccant application, plant samples were taken at 2–4 d intervals and exposed to a temperature at −20 °C overnight. Diquat application gave the most promising results, reducing the proportion of discolored seed and sometimes reducing loss of germinability, while resulting in a small yield loss compared with freezing of untreated plants. Key words: Flax, Linum usitatissimum L., desiccants, frost damage, seed quality, germination

Conelet abortion in longleaf pine

Conelet abortion in longleaf pine (Pinuspalustris L.) ranged from 85 to 100% in 4 of 5 years in a clonal seed orchard in southeastern North Carolina. Investigation of the cause of the malady was inconclusive, but freeze damage, seed bugs, and inadequate pollen supply were excluded as principal causes. Where combinations of balanced fertilizers and ammonium nitrate had been used in the orchard, abortion was variable by clone, with some clones showing more abortion under higher fertilizer regimes.

SOME EFFECTS OF BARLEY GRASS SEED ON YOUNG SHEEP

Studies were made of the effects of barley grass on young sheep. Up to 8 kg per lamb loss of weight gain during summer has been shown to be due (to barley grass seed damage. Seed in the eyes caused the most rapid growth check but irritation to nostrils, mouth, and skin all contributed. Lambs were affected far more than adult sheep and differences between breeds of sheep were sufficient to consider change of breed where barley grass was troublesome. The beneficial effects and disadvantages of herbicide conmtrol are discussed in relation to density of barley grass infestation.