Annual yields per tree for `Starkspur Supreme Delicious' apple (Malus domestica Borkh.) trees on nine size-controlling rootstock were related linearly to number of fruit per tree at harvest each year, independent of rootstock. Mean fruit weight was inversely and less closely related to number of fruit per tree when adjusted for tree size (fruit load). Annual yield-fruit count data for 9 years analyzed together showed that the number of fruit per tree was the principal factor determining yield, regardless of rootstock or tree age. A curvilinear relationship between yield and fruit count per tree during 9 years suggests that the sink strength of an apple crop is nearly, but not precisely, proportional to the number of fruit per tree.
D.C. Elfving and I. Schechter
Samuel Mendlinger and Dov Pasternak
Twenty melon (Cucumis melo L.) cultigens (cultivars and breeding lines) were tested for salt tolerance. All cultigens were grown in the field using drip irrigation at three salt salinity levels: electrical conductivity (ECw = 1.2, 7.5, or 14.0 dS·m-1. Nineteen of the 20 cultigens proved to be salt-sensitive, as measured by reduction in fruit weight, but not necessarily to the same degree (i.e., some cultigens were tolerant at ECw = 7.5, whereas others were not). One line, `Evan Key', was salt-tolerant at ECw= 14.0. Increasing salinity levels did not affect the number of fruits produced in most cultigens. Overall, increasing salinity reduced netting quality but increased the total soluble solids content and shortened mean time to harvest in seven cultigens.
Michel Génard and Claude Bruchou
An approach to studying fruit growth is presented for peach fruit (Prunus persica L. Batsch). It combines a functional description of growth curves, multivariate exploratory data analysis, and graphical displays. This approach is useful for comparing growth curves fitted to a parametric model, and analysis is made easier by the choice of the model whose parameters have a meaning for the biologist. Growth curves were compared using principal component analysis (PCA) adapted to the table of estimated parameters. Growth curves of 120 fruits were fitted to a model that assumes two growth phases. The first one described the pit growth and the first part of the flesh growth. The second described the second part of the flesh growth. From PCA, firstly it was seen that fruit growth varied according to cumulated growth during both growth phases and to date of maximal absolute growth. Secondly, fruit growth varied according to cumulated growth and relative growth rates during each phase. Further examples are presented where growth curves were compared for varying fruit number per shoot and leaf: fruit ratio, and for different sources of variation (tree, shoot, and fruit). Growth of individual fruit was not related to fruit number per shoot or to leaf: fruit ratio. Growth variability was especially high between fruit within shoots.
Rakesh Kumar and Todd C. Wehner
, there are few quantitative genetic studies, especially for important traits such as fruit yield and size. Fruit yield was reported to be correlated with component traits such as fruit count and fruit size ( Kumar and Wehner, 2011b ). Heterosis for
Suzanne P. Stone, George E. Boyhan and W. Carroll Johnson III
according to species within two random 0.25-m 2 quadrants per plot. Weed density, watermelon yield, fruit count, and weeding cost per treatment were recorded and analyzed using an analysis of variance and Fisher’s protected least significant difference test
Teryl R. Roper and John S. Klueh
The sources of photosynthate for fruit growth in cranberry (Vaccinium macrocarpon Ait.) can be spatially partitioned as new growth, old leaves and woody stems, or adjoining uprights. New growth, l-year-old leaves, or both were removed at the time of fruit set and following fruit set. Removing new growth at the time of fruit set reduced fruit set, fruit count, and yield. Removing old leaves at fruit set generally did not reduce fruit set, fruit count, or yield. Removing both often had an additional effect. Removing new leaves after fruit set did not affect fruit set or count, but did reduce fruit size. Removing old leaves after fruit set did not reduce fruit set, fruit count, or size. These data suggest that new growth is an important source of photosynthate for fruit set.
James R. Schupp, H. Edwin Winzeler, Thomas M. Kon, Richard P. Marini, Tara A. Baugher, Lynn F. Kime and Melanie A. Schupp
with increasing pruning severity, whereas fruit number per tree, yield efficiency, and yield decreased with increasing number of limbs removed ( Tables 1 – 4 ). Cumulative fruit count per tree for the 2 years of cropping data in the study was strongly
T.E. Baumann, G.W. Eaton and D. Spaner
Eight day-neutral and seven short-day strawberry (Fragaria ×ananassa, Duch.) varieties were evaluated on raised beds during 1990 and 1991 in the Fraser River valley, B.C. Among day-neutral varieties in 1990, total variation in marketable yield originated in fruit count (26%), total yield (18%), average leaf size (22%), and runner count (19%) per plant. In 1991, total variation in marketable yield originated in fruit count (38%), runner count (23%), crown count (13%), and total yield (16%) per plant. `Selva' was one of the most productive day-neutral varieties and had the heaviest fruit and the fewest culls during both years of the study. The short-day varieties had uniformly low yields of marketable fruit during the establishment year, 1990. Variation in marketable yield in 1991 originated in runner count (34%), total yield (18%), and fruit count (16%) per plant. Of the short-day varieties in 1991, `Shuswap' had the highest marketable yield and, along with `Pajaro' and `Sequoia', had the fewest culls. `Shuswap' was a prolific producer of runners, while `Sumas' and `Redcrest' yielded well without prolific runner production.
William D. Goff
Triphenyltin hydroxide fungicide sprays were applied at 114, 455, or 910 g·ha-1 either 0, 1, 3, 5, or 10 times during pollination of `Success' pecans [Carya illinoensis (Wangenh.) K. Koch]. Pretreatment flower counts were compared to post-treatment fruit counts 7 and 9 weeks after pollination to determine if chemical rate or application frequency affected fruit set. There were no significant differences among rates, application frequency, or combinations in fruit drop (P > 0.35 in all cases). indicating that spraying this chemical did triphenyltin hydroxide (fentin hydroxide).
Charles S. Vavrina, Stephen M. Olson, Phyllis R. Gilreath and Mary L. Lamberts
`Agriset', `All Star', and `Colonial' tomato (Lycopersicon esculentum Mill.) transplants set to a depth of the first true leaf and `Cobia' transplants set to a depth of the cotyledon leaves yielded more fruit at first harvest than plants set to the top of the rootball (root–shoot interface). The increase in fruit count was predominantly in the extra-large category. More red fruit at first harvest suggested that deeper planting hastens tomato maturity. The impact of planting depth diminished with successive harvests, indicating the response to be primarily a first-harvest phenomenon in tomato.