Two clones of anthocyanin-deficient (AD) Vaccinium elliottii (2×, homozygous recessive, yy) were used as seed parents in experiments combining normal and AD pollen. AD gives a seedling marker to distinguish the pollen parent. In the first experiment, flowers were pollinated daily for one, two, three or four days. AD and normal V. elliottii pollen were applied on separate days. The last day of each treatment received the opposite genotype from the previous day(s). The first pollination gave as many, or more, seedlings as later applications but the number of seeds per fruit was higher with multiple pollen applications. The second experiment used pollen from normal V. corymbosum (4×) alone or mixed with AD pollen from the 2× clones. Results depended on the seed-parent genotype. There was no difference between treatments in the number of hybrids produced by W81-1, which tends to set fruit even with only one seed per berry. Only mixed pollen yielded hybrids from clone FL83-139, which was never observed to produce berries with only one seed; apparently the mentor AD pollen helps to set the fruit, thereby allowing the rare hybrid seeds to develop.
Timothy F. Wenslaff and Paul M. Lyrene
Richard G. Snyder
A successful greenhouse tomato crop depends on the optimization of several factors; among these factors are water, nutrition, and all facets of environmental control. Good pollination, however, is one of the most important requirements for the production of fruit of high yield and quality. Poor pollination causes fruit that are smaller, angular, or puffy, due to reduced seed numbers and poor gel fill in the locules. In Spring 1993, two 7.3 × 29.3 double plastic-covered greenhouses were used to compare the conventionally used electric pollinator to bumblebees for effective pollination; replicated variety trials were performed within each. In one greenhouse (12 replications, RCBD), `Trust' performed better than `Caruso' in yield and quality, although it was smaller in fruit size. In the other greenhouse (four replications, RCBD), `Match' and `Switch' were better than all others (`Belmondo', `Capello', `Laura', and `Rakata') for most yield and quality variables. Means across varieties were similar for the two pollination techniques, with marketable weights identical. For gutter-connected greenhouse ranges of 0.1 ha or larger, bumblebees are an economically viable option for pollinating hydroponically grown tomatoes.
G. W. Elmstrom and D. N. Maynard
Watermelon, Citrullus lanatus (Thunb.) Matsum. & Nakai, requires insects, most commonly honey bees, for pollination and fruit set. The transfer of an adequate amount of pollen is essential to ensure optimum fruit set, size, and shape. To encourage bee visits and the transfer of pollen, two applications of Bee-Scent*, a bee attractant, at 2.47 liter·ha-1 were made to watermelon on five farms in central and southwest Florida. Honey bee, Apis melifera L., activity was monitored for two days following each application and yield and fruit quality were determined. On only a few occasions was increased honey bee activity noted. Application of bee attractant increased total yield in one field in central Florida and resulted in an increase in early yield at all three locations in southwest Florida. Soluble solids content of mature fruit was not directly affected by treatment. Treatment increased the seed content of fruit from three of five farms.
Ian G. Lane, James Wolfin, Eric Watkins, and Marla Spivak
Pollination is an important ecosystem service valuable to both agriculture ( Losey and Vaughan, 2006 ; Rader et al., 2015 ; Southwick and Southwick, 1992 ) and natural systems ( Grubb, 1977 ; Ollerton et al., 2011 ). One group of pollinators
James W. Borrone, Cecile T. Olano, David N. Kuhn, J. Steven Brown, Raymond J. Schnell, and Helen A. Violi
, 1966 ; Robinson, 1933 ). However, studies using “tented” or “caged” trees with or without pollinators, presumably excluding any pollination events by any external pollen, were equivocal ( Clark and Clark, 1926 ; Degani and Gazit, 1984 ; Robinson
Tori Lee Jackson, Mark G. Hutton, and David T. Handley
). Oils applied to corn can damage the plant tissues if applied in a high enough dose ( Hazzard, 1998 ). The efficacy of oil treatments has been demonstrated in some experiments, but phytotoxicity or damage to the developing ear from reduced pollination
María Engracia Guerra, Ana Wünsch, Margarita López-Corrales, and Javier Rodrigo
considered as a cause of low fruit set in japanese plum, although some male sterile cultivars have been reported ( Herrero and Salvador, 1980 ; Ramming, 1995 ). However, pollination factors have been related to fruit set in different cultivars and situations
Maria Victoria Huitrón, Manuel Diaz, Fernando Diánez, Francisco Camacho, and Antonio Valverde
surface area cultivated under plastic houses in Almeria was 6000 ha. For triploid watermelon production, the female flower should be pollinated by pollen from a diploid (2 n ) cultivar to obtain fruit. Early production of watermelon in plastic houses is
Laura C. Merrick, Frank Drummond, Constance Stubbs, and Rhonda Weber
Managed and feral honey bee (Apis mellifera) colonies have declined dramatically in the past decade due largely to parasitic mites, pesticide contamination, and severe weather. Squash (Cucurbita spp.) is one of many agricultural crops whose production may be negatively effected by decline of these pollinators. A study was conducted on a set of nine farms in Maine to assess the relationship between bee abundance and fruit set of summer and winter squash. The organic and conventional farms targeted in the study included farms with and without the presence of honey bees. With winter squash, fields with more bees tended to exhibit higher fruit set. The average fruit set was slightly higher for farms with honey bees (42%) vs. those without (35%), but both types of farms were similar to that found in controlled hand pollinations (31% on average). In contrast, fruit set for summer squash averaged 95% to 96% for all farms, regardless of the relative abundance of censused bees. Bumble bees (Bombus spp.) were the most abundant wild bees found pollinating squash. Farms with honey bees on average had higher numbers of bees in squash flowers than farms without honey bees, although a difference in preference for floral sex type was detected for bee taxa. Honey bees were much more likely to be found in female flowers, while bumble bees were more abundant in male flowers. Significantly more native bees were found in squash flowers on farms without honey bee hives, although native bees were still present to some extent on farms that were dominated by Apis mellifera.
Ali Lansari and Amy Iezzoni
Self-incompatibility was investigated in sour cherry (Prunus cerasus L.) by examining pollen growth in the pistil by use of ultraviolet fluorescence microscopy following self- and cross-pollination. The sour cherry cultivars Tschernokorka and Crisana exhibit pollen tube inhibition in the style characteristic of gametophytic self-incompatibility. `Meteor' and `Montmorency' appear to be partially self-incompatible, with few self-pollen tubes reaching the ovary. Several hybrid seedlings from crosses between self-compatible cultivars were self-incompatible, suggesting that these self-compatible parental cultivars carry self-incompatibility alleles.