Calcium foliar fertilization and its effect on quality and shelf life in andean blackberry fruits (Rubus glaucus Benth.)

Calcium is the third most crucial nutrient for andean blackberry; however, its absorption is limited in acid soils, and its low mobility in the plant decreases its effects on fruits. Therefore, the effect of foliar fertilizers with calcium on andean blackberry fruits was estimated. In three locations, experiments were established with five calcium sources (Ca chelate, CaB nitrate, Ca oxide, CaB and CaBZn gluconate) and a control without calcium, applied in three phenological stages and recording: weight, diameters, firmness, color, juice, pulp, pH, soluble solids, acidity, dehydration, and damage. Soil and tissue analysis was performed to identify the relationship between the plant's nutritional conditions and its fertilization response. For the statistical analysis were used mixed models, tests of means, and principal components. Foliar fertilization with chelate, nitrate, and calcium oxide in andean blackberry crops with thorns, in production, with pruning management, and in the phenological stages of flower bud, fruit set, and red fruit, is a viable alternative to improve firmness, weight, and diameter of the fruits. In contrast, the chemical and color parameters in andean blackberry fruits depend on the edaphoclimatic conditions of each zone. This fertilization should be considered as a complement in soils without acidity problems and with balanced cationic saturations.

El calcio es el tercer nutriente más importante para la mora; sin embargo, su absorción se ve limitada en suelos ácidos y su baja movilidad en planta disminuye su efecto en frutos. Por tanto, se estimó el efecto de fertilizantes foliares con calcio en frutos de mora. En tres localidades, se establecieron experimentos con cinco recursos de Ca (quelato de Ca, nitrato de CaB, óxido de Ca, KCaB y gluconato de CaBZn) y un control sin calcio, aplicados en tres etapas fenológicas y registrándose: peso, diámetros, firmeza, color, jugo, pulpa, pH, sólidos solubles, acidez, deshidratación y daños. Se realizó análisis de suelo y tejido, para identificar la relación entre las condiciones nutricionales de la planta y su respuesta a la fertilización. Para el análisis estadístico, se utilizaron modelos mixtos, pruebas de medias y componentes principales. La fertilización foliar con quelato, nitrato y óxido de calcio en cultivos de mora andina con espinas, en producción, con manejo de podas y en las etapas fenológicas de botón floral, cuajado y fruto rojo, es una alternativa viable para mejorar la firmeza, peso y diámetro de los frutos. En contraste, los parámetros químicos y de color en frutos de mora andina dependen de las condiciones edafoclimáticas propias de cada zona. Esta fertilización, se debe considerar como complemento en suelos sin problemas de acidez y con saturaciones catiónicas equilibradas.

Infuence of kaolin application on most important fruit and leaf characteristics of two apple cultivars under sustained defcit irrigation

BACKGROUND: Apple is one of the oldest and most valuable fruits. Water restriction is one of the major problems in the production of this fruit in some planting areas. METHODS: Effects of kaolin spray treatments were studied on two early apple cultivars of Golab and Shafi-Abadi under sustained deficit irrigation (SDI) in Alborz province, Iran during 2017 and 2018. Irrigation treatments were 100%, 85%, and 70% ETc and kaolin application were concentrations of 0, 3 and 6% in 2017 and 0, 1.5 and 3% in 2018. RESULTS: Results showed that 85% ETc treatment compared to other irrigation treatments improved apple tree crown volume in 2017. Deficit irrigation treatments significantly reduced fruit weight in both years. Application with 6% kaolin resulted in 33.3% increase in apple fruit weight compared to non-kaolin treatment at 100% ETc irrigation in the first year. Severe deficit irrigation (70% ETc) significantly reduced apple fruit length in both years, but 6% kaolin increased fruit length in both apple cultivars in 2017. Severe deficit irrigation treatment increased the firmness of apple fruit compared to control and mild deficit irrigation (85% ETc) in the first year of experiment. There was no significant difference between irrigation treatments for apple fruit firmness in the second year of experiment. Kaolin treatments of 1.5% and 3% at full irrigation increased the soluble solids content of apple fruit by 36.6% and 44.1% in 2018, respectively. Deficit irrigation treatments significantly increased leaf proline content compared to control in both years. In the first year, kaolin treatments increased leaf proline but in the second year, leaf proline was not significant. Deficit irrigation treatment of 70% ETc and 6% kaolin had the highest amount of glycine betaine content, malondialdehyde and hydrogen peroxide in apple leaf in the first year of experiment. CONCLUSIONS: Severe deficit irrigation stress (70% ETc) increased the activity of nonenzymatic defense systems of apple trees. Kaolin as a drought stress reducing agent can be recommended in apple orchards of Golab and Shafi-Abadi cultivars as an effective and inexpensive method to improve tolerance to drought stress conditions.

Studies on Hybrid Vigour in F1 And ots Retention in F2 for Fruit Firmness and Related Traits in Tomato.

Tomato varieties having less number of locules, thicker pericarp and good firmness are preferred by the consumers. A set of 28 half diallel crosses were generated by crossing 8 inbred lines of tomato (Lycopersicon esculentum Mill) namely Gujarat Tomato 1 (GT 1), Pusa Ruby, H 24, Ec 490190, Arka Vikas, Ec 163599, Ec 177371 and Ec 398704. Parents, F1 hybrids and F2 populations using randomized complete block design with three replications were evaluated for fruit weight, equatorial and polar diameter, number of locules, pericarp thickness and firmness at Junagadh Agricultural University, Junagadh (Gujarat, India). Significant genetic differences were observed among the parents, their F1 hybrids and F2 populations for fruit firmness related characters except locules fruit-1 under study. The cross Arka Vikas x Ec 398704 followed by GT 1 X Ec 490190 and Pusa Ruby X Ec 163599 exhibited higher heterobeltiosis as well as standard heterosis along with considerable inbreeding depression for fresh fruit firmness hence, is desired for firm fruited tomato plants and would score over yield when tomato are cultivated for distant markets. This cross also involved at least one parent having grater firmness as well pericarp thickness and few locules, hence, can be recommended for breeding improved fruit firmness lines in future.