that may affect crop emergence is seed size. Edamame seed mass is ≈30 g/100-seed compared with 15 to 20 g/100-seed for grain-type soybean ( Bernard, 2005 ; Dong et al., 2014 ; Williams, 2015 ). The literature is inconclusive on how seed size affects
( Cucurbita sp.) ( Robinson and Decker-Walters, 1997 ). Watermelon production is mainly focused on the edible flesh of the fruit, placing a premium on fruit characteristics. Seed size is important because watermelon breeders aim to develop hybrid cultivars
Nine seedling populations involving small-, intermediate-, and large-seeded parental clones of tetraploid blackberries (Rubus sp., subgenus Eubatus) were evaluated for seed-size inheritance. All seedling progenies exhibited a wide range of seed sizes with high frequencies of transgressive segregation especially for small seed size The frequency distribution curves were skewed in the direction of small seed size. The data support a model for quantitative inheritance with partial dominance for small seed size. Calculations of heritabihty show an average maximum estimate of 97%, supporting previous observations of the lack of environmental effects on the expression of seed size in blackberries.
The growing of transplants in plug cell trays is the primary method of producing brassica transplants in many countries. Seed quality is an important aspect to achieve success in transplant production. Seed size may affect seed performance, seedling growth and development of brassica transplants. Seeds of cauliflower (`Vitoria de vero') and cabbage (`Unio') from Embrapa Vegetables were used in this study. During seed conditioning, seeds were classified using round screens generating three (>1.5, 1.5-2.0, and 2.0-2.5 mm) and four (>1.5, 1.5-2.0, 2.0-2.5, and < 2.5 mm) seed size categories, for cauliflower and cabbage, respectively. The original seed lot was used as control. Seed weight increased with seed size. Seed germination (laboratory) and seedling emergence (greenhouse) were not affected by seed size. In both species, root and shoot weight, and leaf area, measured 30 days after seeding, in greenhouse conditions, increased with seed size. Also, transplants from larger seed size resulted in a significantly higher root weight, shoot weight, and leaf area relative to the original (control) seeds. The results indicate that, overall, an adequate seed conditioning improve brassica transplant quality.
Objectives of this study were to determine the effects of lima bean seed size differences and a short chilling period after planting on seedling emergence rate, seedling abnormalities and vigor. Individual seeds of 'Jackson Wonder' lima bean were weighed and placed into one of five size classes: 24-33. 36-41. 44-49, 52-57, and 60-73 g per 100 seed. Seed of each size class were germinated at a constant 23-26C or chilled at 8C for 24 hrs and then moved to 23-26C conditions for the remainder of the study. A 24 hr chilling period after planting had a detrimental effect on subsequent lima bean seedling emergence only from 8 through 11 days after planting. Plant fresh and dry weights were significantly less for the chilled seed treatment. Temperature treatments had no effect on percent normal and abnormal seedlings or primary leaf area. No differences in seedling emergence number or rate were found among seed size classes. Smaller seedclasses had significantly fewer normal and more abnormal seedlings than larger seed size classes. The largest seed class produced seedlings with about two times more fresh and dry weights and leaf area than those from the smallest seed weight class. Plant fresh and dry weights and leaf areas from all seed size classes were significantly different from each other.
Recent USDA plant collecting expeditions to Ecuador; the People's Republic of China, and within North America, have obtained a number of lesser known wild Rubus species. These, and additional species, are preserved as seedlots with some plant representatives, at the USDA-ARS National Clonal Germplasm Repository-Corvallis. In this study, the seed size of 40 Rubus species was measured and contrasted. The average weight of the largest-seeded species of the study group, R. megalococcus Focke, an Ecuadorean blackberry, was 24.2 mg; European blackberry, R. procerus Muller, was 3.0 mg. The average weight of other European and North American blackberry and raspberry seed ranged from 2.7 to 1.3 mg. Asian raspberry species tended to be the smallest, ranging from R. coreanus Miq. at 1.2 mg to R. eustephanus Focke ex Diels at 0.3 mg. Several of the smaller seeded Asian species such as R. formosensis Kuntze, R. minusculus A. Leveille & Vaniot, R. hirsutus Thunb., and R. eustephanus had many drupelets, which may be a heritable trait to benefit yield through breeding for increased fruit size.
Genetic experiments were initiated to assess the potential for combining large seed size from PI 285611, a large-fruited, hullless seeded accession, with small fruit size from a hullless seeded breeding line (NH29-13-5-4). An F2 population and parental line were field-grown during Summer 1993 to determine inheritance and heritability of large seed size and the relation between fruit and seed size. Seed size variables of weight, width, length, and thickness were regressed against fruit weight. There was a moderate, positive correlation between large fruit and seed length (R2 = 0.46). However, seed thickness, a major determinant of seed weight, was not correlated with fruit size. In an F2 population of ≈450 plants, there was a small number of plant selections with fruit under 1.5 kg and seed size approaching that of PI 285611.
Greenhouse and field experiments were conducted in 1988 and 1989 to determine the effect of seed size and cultivar on seedling emergence through crusted soil for several hybrid broccoli cultivars (Brassica oleracea ssp. italica). Seed was separated into four sizes (2.0, 1.8, 1.6, and 1.4 mm in diameter) for the greenhouse investigations, and soil crusting was achieved using a crusting resin. In 1989, field experiments using three seed sizes (small = 1.4 to 1.6 mm, medium = 1.7 to 1.9 mm, and large = 2.0 to 2.2 mm in diameter) were planted at the Long Island Horticultural Research Laboratory in a Riverhead sandy loam that crusted readily following rainfall. Seedling emergence data from the greenhouse and field studies indicate that seed size and cultivar significantly affect emergence and stand establishment. Seedling stand, dry weight, and final yield significantly increased as seed size increased for both cultivars in the field experiments. The emergence of `Mariner' generally was significantly better than that of `Greenlady' for each seed size. Seed of `Greenlady' also weighed significantly less than that of `Mariner' within each seed size tested.
Greenhouse and field experiments were conducted in 1988 and 1989 to determine the effect of seed size and cultivar on seedling emergence through crusted soil for several hybrid broccoli cultivars (Brassica oleracea ssp. italica). Seed was separated into four sizes (2.0, 1.8, 1.6 and 1.4 mm diameter) for the greenhouse investigations and soil crusting was achieved with a chemical resin. In 1989, field experiments using three seed sizes (small=1.4-1.6, medium=1.7-1.9 and large=2.0-2.2 mm diameter) were planted at the Long Island Horticultural Research Laboratory in a Riverhead sandy loam which crusted readily after rainfall. Seedling emergence data from both greenhouse and field studies indicate that both seed size and cultivar significantly affect stand establishment. Seedling stand, dry weight and final yield significantly increased as seed size increased for both cultivars in the field experiments. The emergence of `Mariner' was generally found to be significantly greater than that of `Greenlady' for each seed size. Emergence was also influenced by seed weight.
Pumpkin (Cucurbita moschata Poir. cv. Dickinson Field) seeds were grouped by weight into small (110-130 mg), medium (150-170 mg), and large (190-210 mg), and planted in a Drummer silty clay loam and in a Plainsfield sand. In the Plainsfield sand, large seeds produced higher yields of pumpkin fruit than small or medium seeds, but total fruit weight on the loam soil was about double of that on the sand soil. No differences in yield due to seed size occurred on the loam soil. There was no relationship between seed size at planting and seedling emergence.