No abstract

Mango (Mangifera indica L.) cv. TomEJC has utmost potential in export market due to its unique quality. Post-harvest disease of mango such as stem-end rot can cause considerable losses of fruits and could therefore be considered as a great threat to local and export market. This disease is controlled by application of fungicides from the time of flowering in cultivations where this disease is severe. However, the use of fungicides could lead to hazardous effects such as oncogenic risks on the consumers. Therefore, search for alternative measures for the management of stem-end rot disease is essential. In this study, an attempt was made to find out the effect of preharvest application of KCl on controlling stem-end rot disease development of ripe fruit. KCl at concentrations of 1 gl-1 , 2 gl-1 and 4 gl-1 were sprayed on fruit when fruits were immature. All fruits were bagged with paper bags and fruits were harvested at the correct maturity stage. Then all fruits were inoculated with Botryodiplodia theobromae mycelial plug and allowed for natural ripening. A significant difference was observed in fruit length, fruit width and fruit volume in KCl-treated fruits when compared to controls. Highest fruit volume was observed in 1 gl-1 KCl-treated fruits and the lowest amount of total soluble solids was observed in 2 gl-1 KCl-treated fruits. An increase in lightness and yellowness of peel color in KCl-treated fruits when compared to control II (non-inoculated, non-treated) was evident, indicated by increasing L*, b* and chroma values. However, no significant difference in hue values of peel color was observed among treatments. Flesh color showed a different response to treatments and no difference in chroma value was observed among treatments. The highest L* value and hue value was observed in 2 gl-1 KCl-treated fruits. Incidence and severity of stem-end rot was significantly decreased by 2 gl-1 KCl treatment without drastically affecting the physico-chemical properties of fruits. Vast research has shown that potassium and chloride fertility have been effective in reducing crop injury from diseases. Different mechanisms such as nutritional effects, changes of the

Climate change due to temperature increment and fluctuations in rainfall has adverse effects on plants and animals. Due to these factors growth and yield of plants are drastically declined. The present study attempted to determine the impact of temperature stress water stresses that would occur as a result of climate change on rice (Oryza sativa L.), selecting the variety Suwandel AC 579 as the model plant. The growth and yield parameters of Suwandel were measured at harvest to determine the impact of temperature stress and water stress, after exposing the rice plants to four treatments, viz. T1: temperature stress, no water stress, T2: temperature stress, water stress, T3: no temperature stress, no water stress (control), and T4: no temperature stress, water stress. The rice plants exposed to temperature stress showed significantly low values (P<0.05) for the height (T1: 75.7±2.68cm and T2: 69.34±3.5 cm) and chlorophyll content (T1: 32.66±0.97 and T2: 24.32±2.53). The yield parameters such as number of productive tillers per plant, number of grains per plant, number of filled grains per plant and test weight showed a significant decline on exposure to temperature and/or water stress further revealing that the rice variety Suwandel will not grow and yield successfully under the predicted climate change. As rice is the staple food of majority of people in the world, in order to meet the demand, high yielding new varieties which are able to overcome the expected climate changes such as increase in temperature and water scarcity have to be developed through breeding programmes.

Mango (Variety "TomEJC") has the highest potential in the export market due to its quality characteristics: excellent flavor, low fiber content and smooth flesh. However, the variety takes two weeks to ripen to table-ripe stage, after harvest. Due to this slow ripening nature of the variety, development of anthracnose has a high potential which leads to rejection by consumers. This disease can be effectively controlled with chemical treatments or fungicides, which may render the treated fruits less safe for consumption. This research was carried out to find out the effect of pre-harvest KCl application on the control of anthracnose development of ripe fruits. Three KCl concentrations, 1 g l-1 , 2 g l-1 and 4 g l-1 were sprayed separately once on to fruits at immature (one-month after fruit set) at pre-harvest stage. Fruits harvested at the correct maturity were inoculated with Colletotrichum gloeosporioides spore suspension and allowed for natural ripening in a humid chamber. Incidence and severity of anthracnose disease was significantly lower on mangoes treated with 2 g l-1 KCl compared to other treatments and untreated control. Fruit length, fruit width, fruit volume and peel color did not affect by the treatments. Therefore 2 g l-1 KCl could be recommended as a pre-harvest application to mango fruits to minimize post-harvest incidences of anthracnose.

Anthracnose caused by the fungus Colletotrichum musae is a widespread disease found among banana resulting in high postharvest losses in Sri Lanka. The use of essential oils (EO) to control postharvest diseases has become an ecologically friendly alternative to synthetic chemicals due to their antimicrobial properties while fruit coating is an effective method to increase shelf life. This study focused on controlling anthracnose and extending the shelf life of banana by incorporating selected EOs into a fruit coating. The gel matrix was extracted from the cortex of Aloe vera and mixed with a gelatin agent to serve as the fruit coating material. EOs was screened against C. musae which was isolated from banana cultivar Kolikuttu under in vitro bio-assay.