Fruit Rot Incidence Research Articles

THE EFFECTS OF SUMMER PRUNING ON APPLE TREE CANOPY MICROCLIMATE AND FRUIT QUALITY

Summer pruning effects on apple tree canopy microclimate, fruit quality, and summer disease were studied in a commercial orchard in eastern Arkansas. Eighteen lo-year-old trees of `Golde n Delicious'/M111 were treated as follows: 1) non-pruned control, 2) moderate pruned, thinning cuts in the canopy, and 3) heavy pruned, thinning cuts in the canopy and heading shoots on the canopy periphery. Treatments were applied on 23-June, 1992. All trees were dormant pruned. PPFD and relative evaporation (RE), measured with Livingston atmometers, were measured at time of treatment, on 15-July, and at Harvest, 9-Sept. PPFD and RE were immediately increased by summer pruning but by harvest had returned to levels near the non-pruned control. Fruit firmness, titratable acidity, starch, and color were not significantly affected while soluble solids were inconsistently affected. Weight was decreased insignificantly by moderate pruning and decreased slightly by heavy pruning. Summer fruit rot incidence was similar among all treatments. PPFD and RE were significantly higher in upper positions of the canopy as compared to lower positions.

Shoot Topping and Ethephon Effects on White Riesling Grapes and Grapevines

Canopy modification by shoot topping or ethephon application was examined with <i>pendelbogen</i>-trained White Riesling grapevines in the hot, humid Piedmont region of Virginia. Treatments were: control, two levels of shoot topping (10 <i>vs.</i> 20 leaves per shoot retained) or ethephon application to shoot tips (600 mg/L). Topping shoots to maintain 10 or 20 leaves per shoot reduced annual cane pruning weights by an average of 61% or 24%, respectively, compared with non-topped vines. The application of ethephon produced a vine size comparable to that of vines hedged to 20 leaves per shoot. Canopy insolation was least with control vines (due to shoot tops shading original canopy) and similar among other treatments. Vines topped to 20 leaves per shoot produced more fruit than did vines topped to 10 leaves per shoot. More fruit was harvested from shoot-topped vines than from control vines in two of three years. Neither wood maturity nor dormant bud survival were adversely affected by shoot topping or ethephon application. Greatest fruit soluble solids at harvest were generally observed with vines topped to 20 leaves per shoot. Shoot topping resulted in fruit with lower titratable acidity at harvest than with control vines, but fruit pH was not appreciably affected by any treatment. Fruit rot incidence and the concentrations of rot-associated metabolites (glycerol, ethanol, and acetic acid) were significantly and mutually correlated. Fruit rot and rot metabolites were greatest with control and ethephon-treated vines and were least with vines whose shoots were topped to 10 leaves. Shoot topping to 15 to 20 leaves per shoot appears appropriate with vigorous, low-trained White Riesling to maximize benefits of this remedial canopy management practice in the humid mid-Atlantic United States.

Harvesting and bedding practices in relation to grey mould of strawberries

SUMMARYRelationships of cultural and harvesting practices in strawberries to epidemics of grey mould, caused by Botrytis cinerea, were examined in field plots in 1983 ‐ 84 and 1984 ‐ 85. The strawberries were grown in matted rows or solid beds and harvested by hand or by machine. Foliage cut by the machine was removed by hand‐raking. Potential sporulation of B. cinerea on dead strawberry leaves, the principal inoculum source, was estimated by quantifying sporulation on samples of the leaves incubated in humidity chambers.During May, the incidence and density of sporulation, and total spore production per unit area of strawberry bed, usually were lower in plots harvested by machine in the preceding year than in those harvested by hand. Machine harvesting in the preceding year also suppressed incidence of grey mould on the fruits in June. Potential sporulation on dead leaves was usually less in solid beds than in matted rows in 1984 but not in 1985. Bed type usually did not affect incidence of grey mould fruit rot. No relationship was found between dry weights of dead leaves from sampling quadrats and potential sporulation on the leaves. It was postulated that the long‐term impact of machine harvesting on grey mould epidemics was related to removal of the majority of the foliage and berries from the plots during harvesting operations.

Factors influencing external fruit rot of cucumber caused by Didymella bryoniae

Several factors influencing the incidence of internal fruit rot of cucumber caused byDidymella bryoniae were studied.

Resistance of Strawberry Clones to Botrytis Fruit Rot1

Abstract Pre- and postharvest fruit rot, caused by Botrytis cinerea Pers. ex. Fr., were determined during 2 seasons for 48 strawberry (Fragaria × ananassa Duch.) cultivars and selections. All had as much or more preharvest rot than ‘Totem’ which was used as the resistant standard. Many, including ‘Belrubi’, ‘Hood’, ‘Linn’, ‘Olympus’, ‘Rainier’ and ‘Sivetta’ had a significantly higher incidence of preharvest rot than ‘Totem’. ‘Totem’, ‘Olympus’, ‘Shuksan’ and ‘Rainier’ were very susceptible to postharvest fruit rot, ‘Hood’ and ‘Linn’ showed intermediate susceptibility and ‘Tago’ and several selections showed some resistance. Pre- and postharvest rot were correlated on several dates but correlation coefficients were all less than 0.585. Fruit firmness was negatively associated with both pre- and postharvest incidence of fruit rot although correlation coefficients were all less than 0.645. Many selections showing postharvest rot resistance were derived from the very firm fruited clones, NY 844 and ‘Linn’. This study demonstrates that it is possible to select firm-fruited clones which have resistance to both preharvest and postharvest Botrytis fruit rot. Clones with these three desirable traits were WSU 1522, 1641, 1647, 1675, 1696 and 1698.

Control of fruit rot in muskmelon

Most of the fruits formed on muskmelon go to waste due to premature shedding, insect punctures and rotting. An experiment was conducted to test the value of controlling insect damage, eliminating contact of fruits with the soil, avoiding continuous contact of the same part of fruits with the soil, and prophylactic application of fungicides on and around fruits, in saving the fruits from rotting. Placing of fruits on polyethylene sheets was best in reducing the incidence of fruit rot, increasing the yield, and providing high net income. Spraying Bordeaux mixture (6:3:100) on and around the fruits was next best.

Fruit Rot Resistance in Strawberry Cultivars Adapted to the Pacific Northwest1

Abstract Twenty-five strawberry cultivars and advanced selections were ranked according to their field susceptibility to fruit rot caused primarily by Botrytis cinerea Pers. ex Fr. it was apparent that the resistant cultivars, ‘Shuksan’, ‘WSU 1140’ and ‘WSU 1142% derived their resistance from ‘Columbia’ and ‘Molalla’. Among the most susceptible cultivars were ‘Cheam’, ‘Cambridge Vigour’, ‘Northwest’ and ‘Marshall’. There was no apparent relationship between the incidence of fruit rot and yielding ability although 3 cultivars, ‘Shuksan’, ‘WSU 1140’ and ‘WSU 1142’, combined fruit rot resistance with high yields.

Effect of irrigation methods and mulching on growth and yield parameters of chilli (Capsicum annum L.) in arid condition

The research work was carried out to study the impact of various irrigation methods and mulching on plant growth, production and profitability of chilli cv. R.Ch. 1 at Agricultural Research Station, Mandor, Jodhpur during July, 2016 to February, 2017. The results of surface irrigation were compared with drip irrigation system under no mulch and in conjunction with plastic mulch. The results revealed that the crop was irrigated by drip irrigation on raise bed with 100 micron Linear Low Density Poly Ethylene plastic mulch (T8 treatment) exhibited significantly higher seedling survival at 15 and 30 days after transplanting (95.16% and 91.70%), highest plant height (47.10 cm at 45 DAT and 54.60 cm at harvest), highest number of branches (14.93) plant-1, maximum stem girth (2.32 cm) number of roots plant-1 (138.5), highest fruit set (38.47%), length of fresh fruit (12.56 cm), diameter of fruit (3.52 cm) and fresh weight of fruit-1 (8.42g) was observed. The maximum number of fruits plant-1(125), highest yield plant-1 (1052.5g), yield ha-1 (337.63q) and premier fruit quality score (9.11) with maximum net return (Rs.326407.28) and benefit: cost ratio (3.41) was also reported in same treatment. Comparatively minimum time (15 hours) required for one hectare irrigation was also reported in drip irrigation on raise bed with plastic mulch. This led to lower population of white fly plant-1 (4.53), minimum weed infestation (1.53 weed m-2), leaf curl (5.50%) and fruit rot (5.0%) incidence than other treatment combinations. The minimum growth, yield and profitability were reported in check basin method of irrigation without mulch (T1 treatment).

CONTROL OF POSTHARVEST FRUIT ROT IN APRICOT AND PEACH BY METSCHNIKOWIA PULCHERRIMA

Monilinia spp. is one of the most important pathogens that cause preharvest and postharvest rots of apricot and peach fruit. To manage the fungicide resistance, a reduced-risk biofungicide based on antagonistic yeasts were tested against Monilinia spp. mold on Dacia apricot and peach cultivars. &#x0D; The yeasts Metschnikowia pulcherrima were tested as a postharvest treatment to control rots of apricot and peach fruit. The yeasts were sprayed at concentration of 2 x 106 CFU/ml and 6 x 106 CFU/ml onto apricot and peach fruit. Biological treatment with M. pulcherrima reduced the incidence of fruit rot during postharvest storage at 4°C by 100%.

Título en español.

En febrero 1959, se llevó a cabo un experimento para determinar el efecto y el valor que pueda tener una cubierta de papel negro de polietileno sobre la producción de tomates en Puerto Rico. Se usaron cuatro tratamientos y cinco variedades en un diseño de bloque al azar con cuatro repeticiones. Los tratamientos combinados fueron como sigue: 1. Surcos cubiertos con el plástico negro, sin desyerbar, y dejando que las plantas crecieran sin soportes. 2. Surcos al descubierto, desyerbados a mano, y dejando que las plantas crecieran sin soportes. 3. Surcos al descubierto, sin desyerbar, y dejando que las plantas crecieran sin soportes. 4. Surcos al descubierto, desyerbados a mano, y dejando que las plantas crecieran con soportes. Las variedades incluidas en este estudio fueron Rutgers, Platillo, Plamar y dos líneas desarrolladas en la Estación, P.R. 123 y P.R. 126. Los resultados de esta prueba indican que la cubierta con el plástico negro impidió el crecimiento de todos los yerbajos, excepto el coquí, Cyperus rotundus L., pero el costo por acre cuando se comparó con el desyerbo a mano fue un factor limitativo. En cuanto a la producción, no se observaron diferencias significativas entre los tratamientos, al 1 por ciento del nivel de probabilidad. No obstante, se observó una reducción en la producción cuando se comparó el tratamiento 1 con el 4, al 6 por ciento de probabilidad. Aparentemente, la cubierta plástica no tuvo efecto alguno en reducir el número de frutas dañadas debido al contacto con el suelo. Aunque el experimento se cosechó durante la época lluviosa, el número de frutas dañadas fue muy bajo y uniforme en todos los tratamientos. El hecho de que la interacción entre la variedad y el tratamiento, con relación al peso y número de frutas no fue significativa, indica que ninguna de las variedades usadas en este experimento respondió a tratamiento alguno, en particular. No obstante, se observó que fue la variedad Rutgers la que menos respondió respecto a los dos caracteres mencionados anteriormente. La cubierta de plástico negro aumentó la temperatura del suelo en 1°F., cuando se comparó con la del suelo al descubierto, a una profundidad de 2-4 pulgadas.