Sorkel Kadir

Fruit Quality at Harvest of “Jonathan” Apple Treated with Foliarly-Applied Calcium Chloride

Abstract The response of “Jonathan” apple trees (Malus domestica, Borkh.) grafted on EMLA 111 to frequent application of calcium chloride (CaCl2) was studied at Topeka, Emporia, and Conway Springs, Kansas, orchards in 2002. Trees were sprayed one to eight times with foliar applications of calcium chloride at the rate of 8.971 kg ha−1. First spray was made when fruits were 1.4, 0.9, and 1.6 cm diameter at Topeka, Emporia, and Conway Springs, respectively. More than six applications of CaCl2 improved fruit quality at harvest. Improvement included an increase in fruit weight, size, appearance, skin redness, and reduction of scald incidents. Although CaCl2 applications had no effect on percent of soluble solids, the ratio of soluble solid content to titratable acidity was increased by frequent CaCl2 application. Fruit skin redness was the most improved quality of “Jonathan” apple as the result of CaCl2 applications. No symptoms of fruit russetting or leaf scalding resulting from frequent CaCl2 application were observed. Increase in fruit quality was attributed to a linear increase in Ca concentrations in fruit and leaf tissues. Increase in Ca concentrations in fruit and leaf tissues of treated trees coincided with increases in potassium (K), magnesium (Mg), phosphorus (P), and nitrogen (N) concentrations compared with untreated control trees. Potassium, Mg, P, and N were correlated with fruit quality as much as, or in some cases more than, Ca. This information suggests that changes in mineral balance with CaCl2 applications contributed to improvement of fruit quality and is evidence that frequent Ca application improved “Jonathan” apple quality in Kansas.

Growth of Vitis vinifera L. and Vitis aestivalis Michx. as Affected by Temperature

Abstract Four European (Vitis vinifera L.) winegrape cvs., ‘Semillon’, ‘Pinot Noir,’ ‘Chardonnay’, and ‘Cabernet Sauvignon’, and one American (Vitis aestivalis Michx.) winegrape cv. ‘Cynthiana’, were subjected to three temperature regimes in growth chambers set at 20/15°C, 30/ 25°C, or 40/35°C, for 16/8 hr day/night to determine the influence of temperatures on vine growth and development. In general, the best temperature for shoot and root growth 28 days after temperature treatments was 20/15°C for ‘Semillon’, ‘Cabernet Sauvignon’, and ‘Cynthiana’, and 30/25°C for ‘Pinot Noir’ and ‘Chardonnay’. Although 40/35°C reduced number of leaves, shoots, tendrils, and internodes, total leaf area (LA), and total shoot biomass of all the cultivars, the reduction was more pronounced in ‘Cynthiana’ than in the European cultivars. The average reduction in number of leaves at 40/35°C for the European cultivars was 47%, compared with 92% for ‘Cynthiana’. The two types of grapes adapted differently to high temperature. Shoot growth in the European cultivars continued under high temperature, whereas growth ceased in ‘Cynthiana’. Roots of ‘Cynthiana’, however, were less susceptible to the adverse effect of high temperatures than were the shoots. This study shows that the European cultivars were relatively more tolerant to high temperature than the American cultivar and they have a potential for production of wine in the climate of south central Kansas.

Weed Control in Grape After Fall and Spring Application of Selected Herbicides1

Soil-residual herbicides can be applied to the soil under grapevines during fall or spring before weed emergence. But, early spring moisture and warm weather conditions may enhance weed emergence before spring herbicide applications. Therefore, fall application of herbicide can be useful if the herbicides provide adequate weed control the following spring and summer. Fall and spring applications of oryzalin or norflurazon, applied alone or in combination with diuron, simazine, or oxyfluorfen, were evaluated for weed control in grape at Oskaloosa and Eudora in northeast Kansas in the 2002 to 2003 and 2003 to 2004 growing seasons. Weeds were not controlled adequately with oryzalin or norflurazon applied alone. At the end of the growing season, weed control was 10 to 20% greater when herbicides were applied in the spring than when applied in the fall. In addition, weed control with norflurazon was slightly greater than with oryzalin. In general, norflurazon or oryzalin applied in combination with simazine, diuron, or oxyfluorfen gave greater weed control than norflurazon or oryzalin applied alone. The greatest control was with norflurazon or oryzalin applied with oxyfluorfen. In general, all herbicide combinations provided similar weed control 4 mo after spring treatment in 2003 and 3 mo after spring treatment in 2004. This study showed that acceptable weed control can be achieved when norflurazon or oryzalin is applied with oxyfluorfen or diuron in the fall. Nomenclature: Diuron; norflurazon; oryzalin; oxyfluorfen; simazine; grape, Vitis labrusca #3 VITLA. Additional index words: Grape injury, common ragweed, horseweed, prickly sida, prickly lettuce, tumble windmillgrass, yellow sweetclover. Abbreviations: MAST, month after spring treatment.

Influence of preharvest calcium application on storage quality of ‘Jonathan’ apples in Kansas

Abstract ‘Jonathan’ apple (Malus × domestica Borkh.) trees at three commercial orchards were sprayed one to eight times with calcium chloride (CaCl2) solution containing 3.2 g/L, starting when apple sizes were between 0.9 and 1.6 cm average diameters. Apples were stored for two and four months in regular atmosphere storage at 2°C (36°F). Fruit firmness, ratio of soluble solid concentrations to titratable acidity (SSC/TA), and fruit red skin color during the two storage periods and fruit weight after four-month storage were determined. Apples stored for two months had better quality than those stored for four months. Depending on the location, five to eight CaCl2 applications and two to seven applications were necessary to retain an average of 26% of fruit firmness and an average of 35% of the SSC/TA, respectively, in the two-month storage. At least seven applications were required to retain an average of 29% of fruit firmness of apples stored for four months. Six to seven applications of CaCl2 retained fruit weight by 22 to 33% more than the non-treated control apple. Fewer CaCl2 applications were required to sustain fruit skin color during storage than to maintain fruit firmness or fruit weight after two months of storage. Two-month stored apples from Topeka, Conway Springs, and Emporia that were treated with two applications of CaCl2 were 33, 27, and 17% redder than the control, respectively. In general, CaCl2 was beneficial for storage quality of ‘Jonathan’ apples in Kansas. Between six to seven preharvest applications of CaCl2 were necessary to retain quality of ‘Jonathan’ for a short-term regular storage, whereas, more than eight applications should be considered for long-term storage.

Changes in fruit quality parameters of ‘Jonathan Rasa’ and ‘Delicious Flanagan’ apples in response to elevated temperatures

Abstract Attached apples on trees of ‘Jonathan Rasa’ and ‘Delicious Flanagan’ (Malus x domestica Borkh.) were enclosed in polyethylene bags or left unbagged for 5 d in 2002 and 2004 to determine the effect of elevated temperatures just before harvest on fruit quality parameters measured immediately thereafter. Mean maximum daily air temperatures within the bags were 5 to 9°C warmer than those of the air, recorded in full sun. Mean maximum daily fruit surface and flesh temperatures of bagged apples were 5 to 12°C warmer than those of unbagged fruit. Maximum daily fruit surface and flesh temperatures of bagged apples were similar. Peel color (L*, chroma, hue) of both cultivars was altered by the bagging treatment, but not flesh firmness. Bagged fruit generally had a lower soluble solids concentration (SSC) and starch index rating than those of unbagged apples. Titratable acidity of bagged apples was generally lower than that of unbagged fruit. Respiration rate of bagged apples more than doubled with a 3 to 4°C increase in air temperature. Thus, several fruit quality parameters were adversely affected by elevated temperatures over a 5 day period.

Growth, Yield, Fruit Composition of 24 Wine and Table Grape Cultivars and Selections

ABSTRACT Eight American (Vitis labrusca L.); eight European (Vitis vinifera L.), including four Eastern European selections; four hybrids; and four table grape cultivars planted in 2002 were evaluated for yield components, berry composition, berry split, and frost damage from 2004 to 2006 in south-central Kansas. Over the three years, harvest started in July, although summer of 2006 was the warmest year, which accelerated maturity, reduced titratable acidity (TA), and increased soluble solids concentration (SSC). Earliest-and latest-ripening grapes, respectively, were ‘Valiant’ and ‘Catawba’ (American), ‘Nero’ and ‘Bromariu’ (European), ‘LaCrescent’ and ‘Traminette’ (hybrids), and ‘Reliance’ and ‘Marquis’ (table grapes). In 2005, hybrids were the most productive grapes, with highest crop load, whereas American grapes were the least productive, with the lowest crop load. Table grapes produced the largest clusters (160 g). ‘LaCrescent’ was the least productive hybrid, with the smallest cluster (65 g). ‘Toldi’, produced the largest berry (4 g), whereas ‘Cabernet Sauvignon’ produced the smallest berry (1.2 g). The highest mean SSC was recorded for the hybrids at 21.7°Brix, followed by European grapes at 20.3°Brix. Titratable acidity was reduced for most of the grapes in 2006 by more than 20%. Hybrid berries, especially ‘Swanson Red’, were the most susceptible to hail damage, whereas American and table grapes were the least susceptible. Frost damage was greatest on European grapes and least on American grapes. ‘Cabernet Franc’ was the most sensitive cultivar, whereas ‘Valiant’ was the least sensitive American cultivar to frost.

A 3-Year Adaptation Study of Three Distinct Grapevine Cultivars under Midwestern Field Conditions

ABSTRACT Simultaneous responses of American (Concord), European (Pinot Noir), and American-European hybrid (Traminette) cultivars to seasonal and diurnal variation in field environmental conditions were assessed to propose suitable cultivars for potential use for selection and breeding in grapevines in dry areas. ‘Pinot Noir’ had higher gas exchange parameters, higher water potential, and chlorophyll fluorescence, while ‘Concord’ had the lowest values in all three seasons and experienced moderate stress by the end of each season. The dry conditions in 2005 caused water potential to decline sharply compared to values recorded in 2004 and 2006. ‘Pinot Noir’ and ‘Traminette’ exhibited a mild stress, while ‘Concord’ exhibited a moderate stress in 2006. Photosynthetic rate decreased slightly during the summer with a slight recovery at the beginning of September, and did not differ across the seasons among cultivars. Stomatal conductance followed the same pattern. However, in both 2004 and 2005, stomatal conductance dropped sharply late in the season because of frequently occurring high temperatures that were greater than 32 °C. Maximum morning values of Fv/Fm were within the optimal range. The study suggests the presence of marginal photoinhibition during mid-summer in Concord cultivars, because no full recovery of photochemical efficiency early in the evening was observed. The European cultivar (Pinot Noir) and the American-European hybrid (Traminette) are more adapted to field conditions in Kansas than Concord cultivars. However, high cold-mortality of Pinot Noir due to high sensitivity to cold winter temperature makes the hybrid cultivars the most suitable cultivar for Midwest regions with relatively cold winters.