S. K. Jawandha

Influence of Maturity Stage on Fruit Quality during Storage of 'Earli Grande' Peaches

Peach is a perishable fruit and to ensure the highest fruit quality peaches must be harvested at an appropriate stage of maturity. In the present study, effect of maturity stage at harvest and cold storage on the physical and chemical characteristics of peaches ‘Earli Grande’ were determined. The fruits for storage were harvested at three stages i.e. before, during and after predictable optimum harvest stage and kept in cold store at 0-20C and 85-90% relative humidity for a period of 21 days and at ambient conditions (28-300C, 65-70% RH) for 72 h. The fruits were evaluated for quality parameters at harvest and after 7, 14 and 21 days of storage. The post-cold storage ambient shelf-life was studied after 3 days to assess the market behavior of fruits. During investigation period fruit quality parameters changed according to stage of harvest. An increase in the spoilage, physiological loss in weight, TSS: acid ratio, anthocyanins was observed with the advancement of maturity and storage period. In contrast, Vitamin A content followed a linear decline with storage and advancement of maturity stages. There was a gradual decrease in reducing sugars of the fruits picked after optimum maturity with increase in storage period. Fruits harvested at optimum stage retained maximum TSS:Acid ratio and palatability rating during post-storage shelf life of three days at ambient temperature after cold storage of 21 days. Results revealed that peach fruits harvested at optimum stage can be stored for three weeks in cold store with post-storage shelf life of three days at ambient temperature.

Mulching and herbicides in peach: Weed biomass, fruit yield, size, and quality

An experiment was conducted to study the effect of mulches and herbicides on weed population, fruit yield, and quality in peach cv. ‘Earli Grande.’ Covering soil with black polythene mulch (100 μm) resulted in 100% control of weeds at six weeks after treatment (WAT) during both the years of study. However, guinea grass, which had emerged out of the black polythene mulch, reduced the weed control efficiencies (WCE) to 96.3 and 98.5% in 2009 and 2010, respectively, at 12 WAT. Application of straw mulch (8 cm, 15.5 t ha− 1) resulted in higher weed control efficiencies at 6 WAT during 2009 and 2010 (98.4 and 98.2%, respectively). At 12 WAT, this decreased to 90.7 and 93.1% in 2009 and 2010, respectively, due to the emergence of bermuda grass and guinea grass from the mulch. The weed control efficiencies with treatments having diuron as pre-emergence herbicide did not differ significantly from black polythene at 6 WAT. Atrazine and pendimethalin were the next most efficient and did not differ significantly from each other. At 12 WAT, diuron followed by fb glyphosate resulted in higher WCE, and it did not differ significantly from atrazine fb glyphosate. In both years, highest fruit yield (69.3 and 67.9 kg tree− 1, respectively) was recorded with straw mulch (8 cm). Straw mulch (8 cm) also resulted in a 20 and 19% increase in fruit weight (81.9 and 81.4 g during 2009 and 2010, respectively) over manual weeding. Straw mulch (8 cm) did not differ significantly from straw mulch (6 cm), black polythene mulch, and diuron treatments for fruit yield during both years. Conclusively, plastic and straw mulches can be used as an effective chemical-free alternative to manual or chemical weed control in peach.

Effect of edible surface coatings on the storability of pear fruits

Punjab Beauty is leading variety of semi-soft pear and commercially grown in Punjab. Fruits mature in third week of July, when temperature and humidity are very high, which reduces the shelf-life. An experiment was conducted to extend the post-harvest life of pear fruits using surface coatings such as carboxymethyl cellulose (CMC) @ 0.25%, Aloe vera gel (AVG) @ 0.25% and chitosan @ 0.25%. The control fruits were kept uncoated. Coated and control fruits were packed in CFB boxes and kept at 0–1°C and 90–95% relative humidity. Fruits were analysed for various physico-chemical characteristics, viz., PLW, palatability, TSS, acidity, total sugars, total phenolics and pectin methyl esterase activity after 30, 45, 60, 67 and 74 days of storage. Results revealed that all edible coatings had significant effect on quality parameters of fruits during storage period. After 67 days of storage, minimum PLW (5.16%) and highest palatability rating (7.10), total sugars (8.67%), total phenolics (60.3 mg/100 g FW) and PME activity (1.60 ml of 0.02 N NaOH) were recorded in carboxymethyl cellulose (CMC) @ 0.25% coated pear fruits. However, after 74 days of storage, fruits from all the treatments were of unacceptable quality. Carboxymethyl cellulose @ 0.25% was found to be the best coating to extend the post-harvest life of pear fruits up to 67 days under cold storage conditions.

Summer stratification and germination: A viable option for recovery of hybrid seedlings in low chill peach and nectarines

In-vitro embryo rescue; and summer stratification and germination under controlled conditions was tested for recovering hybrid seedlings in crosses involving low chilling peach and nectarines. The embryos from all the cross combinations showed very high in vitro embryo germination (>85%) on basal MS medium, which can be effectively performed at hard mature or full ripe stage. The stratification period of the hybrid seed varied from 36.3 days in Shan-i-Punjab × Florda Prince to 44.7 days in Tropic Beauty × Florda Grand. At the end of four weeks of transfering the cultures to culture room, maximum plant height (33.7 mm) was recorded in Shan-i-Punjab × Tropic Beauty, which did not differ significantly from the cross Florda Crest × Tropic Beauty. The fruit development period of the seed parent varied from 78.3 days in Shan-i-Punjab × Tropic Beauty and Shan-i-Punjab × Florda Prince to 104.7 days in Tropic Beauty × Florda Grand. Stratification media of cocopeat + vermiculite + perlite (2:1:1) resulted in the highest seed germination but, the actual germination percentage varied with cross combinations. Highest germination (81.5%) was recorded in the cross FlordaGlo × Tropic Sweet, which did not differ significantly from Tropic Beauty × Florda Grand. It was followed by seed germination (68.0%) in Florda Grand × Tropic Beauty. Under high density nursery system, the hybrid seedlings of FlordaGlo × Tropic Sweet showed highest growth (160 cm) and branches (13). The germination of hybrid seeds was positively correlated (0.86) with fruit development period of the seed parent (FDP) and negatively correlated (−0.85) with chilling requirement of seed parent. The proportion of rosseted seedlings was negatively correlated with FDP (−0.61) and positively correlated (0.39) with chilling requirement of the seed parent. The cross combinations with higher FDP of seed parent resulted in higher seed germination of hybrid seed. Hence, controlled climate stratification and germination after harvest can be a viable option for recovery of hybrid seedlings and reducing the breeding cycle in crosses involving seed parents with higher FDP.

Influence of Post Harvest Calcium Chloride Treatment and Shrink Film Packaging on Storage Life of Pear Fruits

To enhance the storage life of pear cv. ‘Punjab Beauty ’, fruits were dipped in aqueous solution of calcium chloride (1.5 and 2.5%) for 5 min., packed in corrugated fibre board (CFB) boxes or shrinkfilm trays and stored at 0–1°C with 90–95% RH for 67 days. Untreated fruits were dipped in fresh water only and kept in CFB boxes. The weight loss was appreciably reduced in CaCl2 treated + shrink wrapped fruits. CaCl2 treatment @ 1.5% and shrink film tray packaging proved effective in maintaining the firmness and acid content of fruits. Maximum sensory quality of fruits was recorded after 45 days in fruits treated with CaCl2 @ 2.5% + CFB packing. Soluble solids content in fruit juice was highest after 60 day of storage in all the treatments. Combination of shrink film tray packaging + CaCl2 @ 1.5% treatment was effective in minimizing the physiological loss in weight of fruits and maintaining the fruit quality for 60 days under storage.

Response of baramasi lemon to various post-harvest treatments

Baramasi lemon is an attractive fruit for its unique flavor and acidity. Harvesting period of winter crop of Baramasi lemon coincides with the cooler part of the year and there is low consumption of lemon fruits during winters, which leads to the glut in the market. Baramasi lemons are sensitive to chilling injury and it is difficult to store in the commercial cold stores. So, there is a need to enhance the shelf-life of Baramasi lemon fruits at ambient conditions. Keeping this in view, an experiment was conducted during 2014 to study the effect of chemicals and modified atmosphere packaging on the storage life and quality of Baramasi lemon fruits. Mature green Baramasi lemon fruits of uniform size and colour were harvested and treated with gibberellic acid (25, 50 &75 ppm), boric acid (1, 2 and 3%) and sodium benzoate (2, 3 and 4%) and packed in low density polyethylene (LDPE) bags. Fruit were analyzed for various physico-chemical characteristics after 15, 30, 45 and 60 days of storage. Results revealed that minimum spoilage and total soluble solids (TSS) and maximum physiological weight loss reduction, palatability rating, acidity were recorded in gibberellic acid @ 75 ppm + LDPE packaging during the entire storage period. It can be concluded that gibberellic acid @ 75 ppm along with LDPE packaging was found to be most effective in extending the post-harvest life of Baramasi lemon fruits at ambient conditions for 60 days.