Frost injury on strawberry flowers (cv. Redchief) was studied in a field over two seasons. During the first season, a light frost during anthesis caused varying degrees of injury to blossoms. Five grades were assigned to the blossoms according to the degree of injury observed. The resulting fruit malformations correlated to the severity of blossom injury, ranging from no development (blossom death) when flower receptacles were completely black, to slight dimpling when only a portion of the receptacle had been discolored. During the second season, a colder frost occurring at the bud stage caused generally greater injury to the blossoms. The range of injury was less variable, therefore only three grades were assigned to the blossoms. The resulting fruit malformation again related to the intensity of blossom injury. Frost has long been understood to kill unprotected strawberry blossoms. This study has shown that nonfatal frost injury to strawberry blossoms can result in a variety of fruit malformations which previously may have been attributed to other causes.
David T. Handley
María Teresa Ariza, Carmen Soria, Juan Jesús Medina-Mínguez, and Elsa Martínez-Ferri
has been reported that fruit malformation is closely related to the low temperatures during flower and fruit development ( Ariza et al., 2011 ), regressions were made with average minimal temperatures on the week of harvesting and from 1 to 9 weeks
J.H.M. Barten, J.W. Scott, N. Kedar, and Y. Elkind
To identify the stage of flower development sensitive to low temperature-induced rough blossom-end scarring (RBS) in tomato (Lycopersicon esculentum Mill.), short-term low-temperature treatments (1, 3, and 5 days continuously at 10C or 6, 9, and 12 days at 18/10C day/night) were applied to young, flowering plants and to plants at the six-leaf stage. Flowers were tagged at anthesis over 4 weeks and the growth stage of the flowers at the beginning of the treatments was determined in days relative to anthesis. The blossom-end scar index (BSI), a measure for blossom-end scar size relative to fruit size, and number of locules were recorded for mature fruits. In three experiments, 5 days at 10C or 6 days at 18/10C, applied during early flower differentiation, induced RBS in mature fruits. For each of the three cultivars tested `Horizon', Waker', and `Solar Set'), flower buds were most sensitive from 26 to 19 days before anthesis. In this experiment, RBS induction was not caused by an increase in the average number of locules per fruit. A short period of sensitivity during very early flower development explains the variation in RBS among seasons and within plants encountered in field situations. This study also presents a standard induction technique for further investigation of physiological and morphological backgrounds of the disorder and possible genotype screening.
Rebecca L. Darnell, Nicacio Cruz-Huerta, and Jeffrey G. Williamson
. Moshkovits, H. Rosenfeld, K. Shaked, R. Cohen, M. Aloni, B. Pressman, E. 1998 Varietal differences in the susceptibility to pointed fruit malformation in tomatoes: Histological studies of the ovaries Sci. Hort. 77 145 154 Van-de-Dijk, S.J. Maris, J.A. 1985
David T. Handley and James E. Pollard
Greenhouse experiments were designed to study conditions affecting strawberry malformation caused by the tarnished plant bug (TPB). Duration of blossom exposure to TPB affected the type of malformation. Exposure at anthesis for 8 hours caused visible deformity. Exposure for 48 hours caused some apical seediness, the malformation most commonly associated with TPB. Continuous exposure to TPB usually caused blossom death. Increased exposure to TPB caused a higher percentage of nonviable achenes per strawberry. Some effects appeared to be cultivar-dependent. Honeoye strawberries were less likely to show apical seediness than Redchief strawberries, but were more likely to experience blossom death. Malformation was also affected by strawberry development stage at the time of TPB feeding. Feeding at prebloom caused blossom death. Feeding at petal fall or achene seperation resulted in fruit malformation, about half of which was apical seediness. Feeding at pink receptacle stage caused little visible damage.
J.L. Garcia-Hernandez, E. Troyo-Dieguez, H. Nolasco, H.G. Jones, and A. Ortega-Rubio
The phytotoxic effects on the physiology of chili (Capsicum annum L. cv. Ancho San Luis) caused by four different insecticides were evaluated. Three commercial mixes (methyl azinfos, methyl parathion CE720, and metamidophos 600 LM), and an active ingredient alone (methamidophos) were assayed; water was used as the control. The main goal was to evaluate the insecticide effects on chili using four different doses; the mean dose, recommended on the label of the product (R), a half one (1/2R), 1.5 times (1.5R) and twice the recommended dose (2R). Three frequencies of application were applied; once a week, twice a week, and once every other week, for 6 weeks from the beginning of flowering. Phytotoxicity was evaluated measuring the response of some physiological traits, Chlorophyll Fluorescence (CF), Leaf Temperature (LT), Transpiration (Tr), and Stomatal Resistance (SR). CF was measured by means of a portable chorophyll fluorscence meter; LT, Tr, and SR were measured using a LI-Cor Porometer. The doses and frequencies used are all common in commercial chili fields in Mexico. Results showed that phytotoxicity caused by insecticides can be an important damage factor to the plants, something that can cause reduction of yields. CF was shown to be the most sensitive variable to evaluate the phytotoxicity caused by insecticides. Fruit malformation was observed in all treatments. Chlorophyll content was reduced up to 25%, on average. The phosphorate insecticides affected the physiological parameters more drastically than the others. Results evidence the irreversible crop damage caused by excessive insecticide applications.
Nicacio Cruz-Huerta, Jeffrey G. Williamson, and Rebecca L. Darnell
night temperature effects on ovary diameter, not FW or length ( Aloni et al., 1999 ; Polowick and Sawhney, 1985 ). Our results suggest that LNT effects on ovary swelling in peppers, and subsequent effects on fruit malformation, may be better predicted
Nihat Guner, Zvezdana Pesic-VanEsbroeck, Luis A. Rivera-Burgos, and Todd C. Wehner
consist of mosaic, the presence of blisters and deformations on leaves, fruit malformation with a change in color, and plant stunting. In the field, PRSV-W outbreaks are quite difficult to control, leaving breeding for disease resistance as the most
Martin Makgose Maboko, Isa Bertling, and Christian Phillipus Du Plooy
Rylski, I. 1979 Effect of temperatures and growth regulators on fruit malformation in tomato Sci. Hort. 10 27 35 Saeed, A. Hayat, K. Khan, A.L. Iqbal, S. 2007 Heat tolerance studies in tomato ( Lycopersicon esculentum Mill.) Intl. J. Agr. Biol. 9 4 649