Search

Climate change has not only exacerbated abiotic stress, but has also rendered external conditions more feasible for pests to spread and infest citrus fruit. Citrus leafminer (Phyllocnistis citrella) is a potential pest that directly feeds the newly sprouted leaves and twigs of all three spring, summer and autumn flushes. Increasing temperatures in spring and autumn, leafminer accrued more heat units or developmental degree days to accelerate the biological stages of its life-cycle, thereby increasing the pressure of infestation. Present work was conducted at three different environmental conditions in Sargodha, Toba Tek Singh (TTS) and Vehari districts of the Punjab province, Pakistan; all three experimental sites were located in different agro-ecological zones. More infestation was recorded in all three flushes at TTS and Vehari than in Sargodha. Overall, more damage was observed due to higher temperatures in TTS and Vehari than in Sargodha. After May–June heat stress, spontaneous vegetative growth continued from July to November, produced newly spouted tender leaves for feeding the leafminer larvae, and was seen more in TTS and Vehari. Leafminer larva prefers to enter young and tender leaves with a maximum entrance in leaves up to 1 cm2 in size while observing no entrance above 3 cm2 of leaf size. Physiological response of leaves primarily attributed to chlorophyll and carotenoid contents, both of which were recorded lower in the mined leaves, thereby reducing leaf photosynthetic activity. Similarly, lower levels of polyphenols and antioxidant activity were also recorded in the mined leaves. The on-tree age of mined leaves of three vegetative flushes of Kinnow plant was also less counted than non-mined leaves. Climate change has affected vegetative phenology and become feasible for pests due to extemporaneous leaf growth, particularly leafminer, and eventually causes economic loss by supplying low carbohydrates either to hanging fruits or next-season crops. [ABSTRACT FROM AUTHOR]

Waste production is associated with human inhabitation and its rate is increasing over time. Globally, the major proportion of waste is disposed of through landfilling and open dumping, which is environmentally unsafe due to emission of greenhouse gases (GHGs). Thus, in order to avoid emission of GHGs from wastes it is important to use techniques that can convert wastes to energy/nutrients on eco-friendly economical way. Furthermore, quantification of the impacts of these waste management techniques on ecosystem is also needed through the application of tools like modeling, remote sensing, geographical information system (GIS), Unmanned Aerial Vehicles (UAVs) and life cycle assessments (LCA). Thus, this review was conducted by considering focus on potential of nutrient and energy recovery techniques from various types of wastes and approaches to enhance the efficiency of the process. The outcomes depicted that the aerobic and anaerobic digestion is suitable to deal with biodegradable and organic fraction of the waste, but anaerobic digestion seem to be more sustainable waste management techniques. Additionally, the review covers the techniques to drive energy and recover nutrient from non-biodegradable proportion. Different modern analytical tools; such as remote sensing, GIS and simple/dynamic models could be useful tool to help in the decision-making processes for waste managements. These tools can help us to design integrated solid waste management processes. Finally, we suggest that LCA should be considered to determine the environmental load of material/product from its production to final disposal (from cradle to grave). [ABSTRACT FROM AUTHOR]

• Increasing level of biotic and abiotic stress was assessed on Kinnow fruit quality features in different ecological zones. • Comparatively biotic and abiotic stress extent was increased in warm regions under changing climate scenario. • Inferior Kinnow mandarin fruit quality with more production of lower grades fruit were recorded at warm regions. • Better quality with higher level of polyphenols and antioxidant activity were recorded at relatively moderate conditions. • Fruit quality parameters were influenced by fluctuating agrometeorological indices in climate change scenario. The quality of Kinnow fruit was assessed in different ecological zones by selecting three main districts: Sargodha, Toba Tek Singh (TTS) and Vehari; all of them have varying environmental conditions. Abiotic and biotic stress on fruit quality was assessed. More growing degree days, photothermal index, photo and helio thermal units were computed in Vehari, while hydrothermal units and energy use efficiency were recorded in higher values at TTS. Fruit diameter was measured from April to December and recorded with increased width in TTS and Vehari during May and June. In May, more fruit drop was noted in TTS and Vehari compared to Sargodha due to heat stress. Pests such as citrus thrips, mites and fruit fly infected fruits were recorded in higher percentage at Vehari and TTS, while citrus red scale infestation was seen more in Sargodha. In Sargodha, a higher incidence of citrus scab and melanose was noted on Kinnow fruits, while more stem-end rot infected fruits were recorded at TTS and Vehari. In abiotic stress, more wind scares were noted at Sargodha, followed by TTS, whereas stem injury and styler-end deformity were found to be non-significant. Fruit physical parameters such as width, fresh weight and peel thickness were noted more in TTS and Vehari, while more surface smoothness and firmness were observed in Sargodha. Biochemical properties such as pH, total soluble solids, titratable acidity, sugars, ascorbic acid, total dissolved salts and electrical conductivity showed higher levels in Sargodha than TTS and Vehari. More antioxidant and total anthocyanins were found in Sargodha, while higher levels of total phenolic contents were estimated at TTS and total flavonoids in Vehari. Kinnow fruit of Sargodha received more sensory scores in organoleptic evaluation. Higher percentage of A-grade fruits was harvested from Sargodha and B-grade fruits from TTS and Vehari. More numbers of fruits and weight were obtained from TTS, followed by Sargodha. Extreme events such as heat stress and smog were seen more in Vehari and TTS and subsequently their fruit quality was found to be inferior. [ABSTRACT FROM AUTHOR]

• More days were taken in Kinnow fruit during ripening phase at warm conditions as well as more agrometeorological indices were computed in fruit different phenophases. • Prior flowering, fruit-setting and cell division initiated with rapid fruit growth at warm districts of TTS and Vehari as compared to Sargodha. • Fruit peel thickness, size index, volume, diameter and weight were recorded as an increasing level in warm districts whereas fruit specific gravity and firmness were decreased in these districts during ripening process. • Timely color development, more fruit specific gravity and firmness were recorded at Sargodha due low fluctuation in climate variables had yielded exportable superior quality Kinnow fruit. • In climate change scenario, more fluctuating climatic variables were observed at warm conditions which adversely affected Kinnow fruit growth and development and also delayed in color development. Kinnow orchards of uniform age, planting density and vigor were selected in three different ecological zones situated in the districts of Sargodha, Toba Tek Singh (TTS) and Vehari of Pakistan. Climate change has adversely affected plants; particularly perennial fruits cultivated in tropical (banana, mango), subtropical (citrus, olive, grapes) and temperate (apple, apricot, plum) zones owing to their slow adaptability. In this context, the fluctuating effect of agrometeorological indices and energy-use efficiency on Kinnow mandarin's fruit growth and development was evaluated. Each experiment was performed in three biological replicates. Ten fruits were randomly collected at the end of each month (April-December) from a single plant to study fruit growth and development. Similarly, physical fruit parameters were recorded from August to February. More days were passed between fruit-setting till arrival of maturity at Vehari, whereas less number of days was counted in Sargodha. More growing degree days and photothermal index were calculated at Vehari during different phenophases of Kinnow fruit as compared to Sargodha. Hydrothermal units were more recorded in Sargodha than Vehari. More yields were obtained from TTS which had increased energy use efficiency than other two districts. Fruit cell division and cell enlargement stages were commenced afore and had finished earlier in Vehari district, followed by TTS. Fruit diameter, peel and pulp thickness as well as fresh weight were recorded in higher values at TTS and Vehari. Non-significant differences were seen in moisture percentage. More fruit size and shape indices were also recorded in TTS and Vehari. Fruit volume was measured larger at TTS, whereas fruit specific gravity was recorded higher at Sargodha from August to February. More intercellular space was seen in fruit samples collected from Vehari and TTS, which at maturity had reduced fruit firmness. Fruit color was recorded as green in samples from all three districts until the beginning of color-break in October. At the arrival of ripening phase in February, more values of color parameters a, b, C and L were enumerated at Vehari. Hue angle of fruit color was found to be at 1200, depicting green color that was rotated at 600 by portraying deep yellow or orange tinge on Kinnow mandarin. Climate variables have had a substantial effect on fruit growth and development phases as well as physical characteristics. Better physical quality and timely color development of Kinnow fruit was noted at Sargodha due to milder environmental conditions compared to TTS and Vehari. [ABSTRACT FROM AUTHOR]