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Nick E. Christians and Dianna L. Liu

It has previously been reported that a byproduct of the corn (Zea mays L.) wet-milling process, corn gluten meal, has potential as a natural preemergence herbicide for use in turf and certain horticultural crops. In 1993, two additional patents were issued on the technology. The first is on the use of hydrolyzed proteins from corn and other grains that were shown to have higher levels of herbicidal activity than the corn gluten meal. These materials are water soluble and can be sprayed on the soils surface. The second patent was on 5 dipeptides extracted from the hydrolyzed corn gluten meal. These dipeptides were shown to have the same type of biological activity observed when the corn gluten meal and the hydrolyzed meal are applied to the soil. The possible use of the hydrolyzed grains and the dipeptides as natural preemergence herbicides in horticultural crops will be discussed.

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A.O. Olufolaji and Lanre A. Denton

The pale yellow-seeded Amaranth is virtually a new crop in Nigerian agriculture. Under the sponsorship of the National Agricultural Research Project (NARP), 12 accessions were evaluated for agronomic characters and yield attributes in three agro-ecological zones of the country. The results showed significant variation in the agronomic characters of the accessions. Top accessions recorded average grain yields of 4.5, 3.5, and 2.6 t·ha–1 in Sudan savanna, derived savanna, and guinea savanna zones of the country, respectively. Response of the accessions to qualitative and quantitative characters in the zones are discussed.

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Yi-Lun Liao, Wen-Shin Lin, and Shu-Yun Chen

of focus in breeding programs, for example, greater grain yield, larger grains, stronger lodging resistance, effective pest and disease resistance, and easier for mechanical harvest ( Tseng and Chen, 2007 ; Tseng et al., 2009 ; Tseng and Kao, 1995

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D. J. Makus

Twenty-one day old seedlings of a vegetable amaranth (RCC 241, Amaranthus tricolor) and a grain amaranth (K343, A. hybridus × A. hvpocondriacus) were transplanted on July 28, 1989. Equal applications of NH4N O3 were made on July 28 and August 25 to give total N rates of 0, 60, 120 and 240 kg/ha. Accessions were harvested on Oct. 18 and 14, respectively. Increasing N, induced a quadratic response in plant dry wt, seed wt/plant and seed size fractions in both amaranth types. Seed size fractions as a percent of the total seed, plant height and seed to plant dry weight ratio were not affected by increased N. Seed protein increased linearly whereas seed nitrate increased quadratically with increasing N application. Higher N rates increased residual soil NO3, NR4 and electrolytes and decreased pH. Decreasing soil pH appeared to reduce soil K and Cu but increase Fe and Mn availability. The effect of N rate on seed germination was inconclusive, but the larger seed size was higher in germination. There were differences among species in most responses tested. These data suggest that N applications be tailored to the season growing length required by the respective species/cultivar.

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D. J. Makus

Twenty-one day old seedlings of a vegetable amaranth (RCC 241, Amaranthus tricolor) and a grain amaranth (K343, A. hybridus × A. hvpocondriacus) were transplanted on July 28, 1989. Equal applications of NH4N O3 were made on July 28 and August 25 to give total N rates of 0, 60, 120 and 240 kg/ha. Accessions were harvested on Oct. 18 and 14, respectively. Increasing N, induced a quadratic response in plant dry wt, seed wt/plant and seed size fractions in both amaranth types. Seed size fractions as a percent of the total seed, plant height and seed to plant dry weight ratio were not affected by increased N. Seed protein increased linearly whereas seed nitrate increased quadratically with increasing N application. Higher N rates increased residual soil NO3, NR4 and electrolytes and decreased pH. Decreasing soil pH appeared to reduce soil K and Cu but increase Fe and Mn availability. The effect of N rate on seed germination was inconclusive, but the larger seed size was higher in germination. There were differences among species in most responses tested. These data suggest that N applications be tailored to the season growing length required by the respective species/cultivar.

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Mike Stanghellini and Jonathan R. Schultheis*

In 1999 and 2000, a total of 28 diploid watermelon cultigens (released cultivars and advanced breeding lines) were evaluated for staminate flower and pollen grain production to assess their potential to serve as pollenizers (pollen source plants) in triploid watermelon production systems. Male reproductive output (staminate flower and pollen production) was quantified during the peak flowering and fruit setting phase of the cultigens under field conditions. The number of staminate flowers produced per plant per day, number of pollen grains produced per flower, and total number of pollen grains produced per plant per day (staminate flowers per plant x pollen grains produced per flower) differed greatly between cultigens (for all tests, P < 0.01). Staminate flower production by cultigens differed by year (P < 0.0003) and days-within-years (P = 0.0094), but pollen production between years by cultigens was stable (P = 0.3845). Total male reproductive output ranged from 134,206 pollen grains per plant per day for `Jamboree' to 321,905 pollen grains per plant per day for `Summer Flavor 500'. These studies demonstrate the genotypic variability in watermelon male reproductive output potential, and may assist growers in selecting an optimal diploid pollenizer for triploid watermelon production.

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A. Talaie, B. Goleyn, A. Vezvaei, and Y. Ebrahimi

`Page' mandarin is a complex hybrid between `Minneola' tangelo and `Clementine' mandarin. Because of self-incompatibility, this cultivar severely needs pollinizers and, if a suitable pollinizer does not exist, it will produce few and small fruit. In this study, the effects of pollen grains of nine cultivars of citrus ['Sour' orange, `Duncan' grapefruit, `Sweet' lemon, `Salustiana' orange, `Local' mandarin, `Hamlin' orange, `Siavaraz III Locan' orange, `Marrs' orange, and `Shell' mahaleh (natural hybrid)] on the quantitative and qualitative characteristics of fruit (weight, diameter, length, volume, peel thickness, juice content, developed seeds, undeveloped seeds, total soluble solids, acidity, pH, vitamin C, and percentage of final fruit set) were investigated and evaluated. After artificial pollination and during fruit growth and development, seven times abscission and fruit color and diameter were recorded. Fruit were harvested 29 weeks after pollination and were analyzed. The results showed that this cultivar, in addition to the complete self-incompatibility, has the ability of week parthenocarpy, which results in small and low-quality fruit and also parthenocarpy is induced. `Page' mandarin is cross-compatible with some cultivars, such as `Marrs' orange. There is a positive and significant correlation between developed seed number and fruit weight. The pollen of `Siavaraz III Local' orange has the most effects on percentage of final fruit set. The pollen of `Shell' mahaleh (natural hybrid) has the most effect of the quantitative characteristics, and the pollen of `Marrs' orange has the most effects on qualitative characteristics. It was concluded that `Hamlin' orange is the best pollinizer for `Page' mandarin in northern Iran. The results of this study were analyzed with the use of a randomized complete-block design.

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Wol-Soo Kim* and Sang-Hyun Lee

In order to investigate the cause of differences of mature pollen in Asian pear (Pyrus phyfolia) that are collected from various sources for the artificial pollination, various factors were measured as below: the composition of nonstructural carbohydrate in bud at 30 days after full bloom, the contents of crude protein in skin, cytosol and membrane, and the affinity for lectin (CON-A: Concanavalin, type III A) of glycoprotein in cytosol of pollen were measured. Contents of sucrose and glucose in buds influenced pollen germination rate and pollen tube growth, respectively. Therefore, soluble types of carbohydrates stored in bud were regarded as influencing on pollen germination rate and pollen tube growth. Pollen, which showed low activity, had low affinity on CON-A, lectin of glycoprotein, because it had fragile membrane, proteins in cells were denatured to pollen surface and certain enzymes concerned in pollen germination lost stability and activity. Pollens that showed high activity contained 92 kDa protein while others not. This was assumed as influencing on control of pollen viability.

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Cevriye Mert

sativa Mill.) ( Mert and Soylu, 2007 ). Pollen grains are the male gametophytes and take part in the reproductive biology. Fruit set is also dependent mainly on the fertilization process in the cornelian cherry cultivars. For this reason, the viability

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Lihong Hao, Hui Ma, Jaime A. Teixeira da Silva, and XiaoNan Yu

level of detail in pollen grain surface sculpture that is discernable. The detail that is available from SEM is often required for taxonomic studies ( Kodela, 2006 ). In this study, the pollen morphology, including shape, size, and surface sculpture, of