P. M. Lombard

Cooking quality of the potato as measured by specific gravity

ConclusionsThe highly significant interaction between seasons and mealiness indicates that a single season/rss test is not a sufficiently adequate basis for rating the mealiness of a variety.The two methods of measuring specific gravity employed in these tests gave approximately the same results. Since the salt solution method is more rapid, it is preferable to the more laborious method of weighing in air and water.The use of salt solutions of known densities was found to be a practical method for making a preliminary selection for mealiness. The study of large populations can be greatly facilitated by employing this method, since much less time is required than by the usual cooking method. Furthermore, the material tested may be used later for planting.

Relation of length of day to flower and seed production in potato varieties

Summary1.Under greenhouse condition at Belsville, Md., the length of day is an important factor in the production of mature flowers and seed balls by various varieties of potatoes.2.Differences exist between certain varieties in mean weight of seed ball and weight of seed for each fruit.3.Varieties differ somewhat in their light requirements for the production of flowers and seed balls.4.A greater number of flowers is produced with the longer photoperiods. This accounts for the increase in number of seed balls.5.In general it appears that satisfactory conditions for both flowering and fruiting at Beltsville are provided by a day length of approximately 16 hours.

Flower bud formation in the potato plant as influenced by variety, size of seed piece, and light

SummaryThe number of young buds that develop in the first inflorescence of the potato is influenced by variety, size of seed piece, and light treatment. Fewer buds were initiated in plants from 5-gram seed pieces than from 25- and 45-gram pieces, and from plants grown in total darkness than in plants exposed to natural daylight.No increase in the number of buds differentiated was obtained by lengthening the natural photoperiod with Mazda light of low intensity. An increase significant to the I-per cent level was obtained from two collections made in dull, cloudy weather by lengthening the natural photoperiod with fluorescent light of higher intensity.

The effect of a mild strain of latent mosaic virus X on yield of some of the new potato varieties in Maine.

SummaryThe reduction in yield from potato seed infected with virus X reported by several investigators varies from a very small amount to as high as 30 per cent. The reduction varies with the potato variety and the strain of virus X.In an experiment with the varieties Chippewa, Sequoia, Sebago, and Teton, seed stock carrying a mild strain of virus X and stock free from virus X were compared with commercial stock for each variety. Both mild-X and commercial seed gave reduced yields in comparison with yields from stock free from virus X. The reduction in yield varied with the variety. Percentage reductions in yield for mild X were: Chippewa, 6.1 per cent, Sequoia, 2.1; Sebago, 4.2; and Teton, 9.5. Percentage reductions in yield for commercial stock were: Chippewa, 6.8 per cent; Sequoia, 0.2; Sebago, 9.8; and Teton, 5.1. In only two cases did the reduction in yield reach or closely approach significance viz., Teton mild-X and Sebago commercial stock. The yield trend for all varieties favored X-free stock.

Seed-setting in potatoes as affected by spraying with a-naphthaleneacetamide and by light

SummarySpraying potato plants with dilute concentrations of a-naphthal-eneacetamide was not effective in increasing flower or seed ball production in the greenhouse at Beltsville Maryland, or Greeley, Colorado. Higher concentrations reduced flower production at Presque Isle, Maine.Sebago and Irish Cobbler produced more seed balls at Greeley than at Beltsville. Less cloudy weather at Greeley during the winter months is probably the chief factor responsible for this result.S 245–25, when self-pollinated, produced as many seed balls at Beltsville as at Greeley. It appears that this variety flowers and sets seed more readily under fairly unfavorable light conditions than either Sebago or Irish Cobbler.

Effect of different storage temparature on the vitality of seeds potatoes

tion, in fact, where late varieties of potatoes are concerned, we believe they should be held at point of production until jus t in advance of the shipping season. Under conditions, however, which demand that they be held for an indefinite period in transit, we do not believe that our type of storage can be improved upon. We have used cold storage facilities from time to time, sometimes shipping two cars from the same lot of seed at the time and placing one of them in cold storage and one in our own storage. We find that cold storage often carries too high a percentage of humidity and does not allow sufficient ventilation to prevent mold developing in the seed. Resacking of seed stock is something we do not attempt to avoid by our method of storage. The customer is entitled to freshly graded stock without shrinkage and for this reason his seed should be packed as carefully as possible jus t before it is shipped to him. Nevertheless, we are convinced that the forced ventilation type of seed storage is the best thing of its kind we have yet developed.